Background The epidemiology of obesity in primary care populations has not been thoroughly explored. This study contributes to filling this gap by investigating the relationship between obesity and different sources of personal stress, mental health, exercise, and demographic characteristics.
Background
The epidemiology of obesity in primary care populations has not been thoroughly explored. This study contributes to filling this gap by investigating the relationship between obesity and different sources of personal stress, mental health, exercise, and demographic characteristics.Methods A cross-sectional survey using a convenience sample. Five hundred women who attended family planning clinics were surveyed and 274 provided completed answers to all of the questions analyzed in this study. Exercise, self-rated mental health, stress, social support, and demographic variables were included in the survey. Multiple logistic regression analysis was performed.
Methods
A cross-sectional survey using a convenience sample. Five hundred women who attended family planning clinics were surveyed and 274 provided completed answers to all of the questions analyzed in this study. Exercise, self-rated mental health, stress, social support, and demographic variables were included in the survey. Multiple logistic regression analysis was performed.Results After adjusting for mental health, exercise, and demographic characteristics of subjects, analysis of the data indicated that that being having a large family and receiving no support from parents were related to obesity in this relatively young low-income primary care sample, but self-reported stress and most types of social support were not significant.
Results
After adjusting for mental health, exercise, and demographic characteristics of subjects, analysis of the data indicated that that being having a large family and receiving no support from parents were related to obesity in this relatively young low-income primary care sample, but self-reported stress and most types of social support were not significant.Conclusion Obesity control programs in primary care centers directed at low-income women should target women who have large families and who are not receiving support from their parents.
Conclusion
Obesity control programs in primary care centers directed at low-income women should target women who have large families and who are not receiving support from their parents.

Background Many variables may influence eating behavior and therefore may also influence obesity, including depression, anxiety, stress, social support, race, ethnicity, education and income [ 1 - 8 ]. While the national media and federal websites emphasize the importance of physical activity in controlling body weight, exercise alone is not effective for this purpose. In fact, some research shows no relationship between exercise and body weight in community samples [ 1 ]. Therefore, the important questions are: what other risk factors in addition to exercise may affect obesity and how can they be changed? Studies of stress as a risk factor for obesity are limited. In fact, few epidemiological studies have been reported in primary care journals. An exception is found in a report by Sammel et al, who included a stress index in their study of weight gain among women in their late reproductive years (ages 35–47) [ 1 ]. Three hundred and thirty-six women were followed for four years. A 14-item Perceived Stress Scale was used to assess the degree to which situations were stressful to the subject. Women who gained more than ten pounds were not different in regard to this stress measure than other subjects. Stress can be measured in different ways. The personal circumstances experienced by individuals might be expected to have a direct effect on depression, anxiety, and general health status. After all, when conflict arises within a family, the psychological consequences can be dramatic. Even though the relevance of various sources of personal stress to obesity has not previously been examined in the community health literature, their potential importance is worthy of investigation. The purpose of the study reported here was to investigate the importance of personal stressors in determining obesity. The sample was drawn from a low-income female population: women using a family planning clinic for primary care. Exercise, social support, mental health and other personal characteristics were measured and held constant in order to determine the independent effect of different sources of personal stress on obesity.
Background
Many variables may influence eating behavior and therefore may also influence obesity, including depression, anxiety, stress, social support, race, ethnicity, education and income [ 1 - 8 ]. While the national media and federal websites emphasize the importance of physical activity in controlling body weight, exercise alone is not effective for this purpose. In fact, some research shows no relationship between exercise and body weight in community samples [ 1 ]. Therefore, the important questions are: what other risk factors in addition to exercise may affect obesity and how can they be changed?Studies of stress as a risk factor for obesity are limited. In fact, few epidemiological studies have been reported in primary care journals. An exception is found in a report by Sammel et al, who included a stress index in their study of weight gain among women in their late reproductive years (ages 35–47) [ 1 ]. Three hundred and thirty-six women were followed for four years. A 14-item Perceived Stress Scale was used to assess the degree to which situations were stressful to the subject. Women who gained more than ten pounds were not different in regard to this stress measure than other subjects.Stress can be measured in different ways. The personal circumstances experienced by individuals might be expected to have a direct effect on depression, anxiety, and general health status. After all, when conflict arises within a family, the psychological consequences can be dramatic. Even though the relevance of various sources of personal stress to obesity has not previously been examined in the community health literature, their potential importance is worthy of investigation.The purpose of the study reported here was to investigate the importance of personal stressors in determining obesity. The sample was drawn from a low-income female population: women using a family planning clinic for primary care. Exercise, social support, mental health and other personal characteristics were measured and held constant in order to determine the independent effect of different sources of personal stress on obesity.Methods A cross-sectional survey of primary care patients (adult non-pregnant women) attending one of five Planned Parenthood clinics in the Panhandle of Texas was conducted. The Amarillo Institutional Review Board granted exempt status to the study because no protected health information was collected. Planned Parenthood provide a valuable and unique sampling frame because it supplies basic primary care to low-income women in this area, including birth control, but not abortions. Eligibility for the study was limited to patients who were over age 18 and not pregnant. Questionnaires were placed on a table in waiting areas, with a poster inviting participation. Clinic staff also handed out survey forms. Subjects placed the completed forms in a sealed box. Sealed boxes containing survey forms were returned to Texas Tech for data entry. Microsoft Access was used for data entry. Five hundred forms were distributed. Twenty surveys were returned by persons ineligible for study participation and were excluded from the sample. The final data set was comprised of 345 subjects. Computing the response rate as completed returns divided by eligibles (345/(500-20) produces a participation rate of .719. Complete cases were available from 274 subjects for the multivariate analysis. Measures The dependent variable was obesity. Body mass index (BMI) was computed as weight in pounds times 703 divided by height in inches squared. BMI greater than 30 was classified as obese, and made up about 20 percent of the sample. Cases with missing heights and weights were dropped. Independent variables were stress, social support, age, race/ethnicity, education, income, number of persons in the home, exercise, marital status, anxiety, and depression. Key instruments are discussed below. Health items were taken from the Duke Health Profile [ 9 ]. Mental health was measured in terms of feeling depressed or sad and nervousness. Possible responses for all of the mental health items were "Yes, describes me exactly", "Somewhat describes me," or "No, doesn't describe me at all." Stress and social support items were taken from the Duke Social Support and Stress Scale (DUSOCS). The DUSOCS contains items addressing personal support from various sources. A person who stresses the respondent is defined as one who causes problems or makes life more difficult [ 10 ]. Respondents were asked how much they were stressed by spouses, parents and children. Possible responses were "None," "Some," "A Lot," and "There is No Such Person". Categories were combined into 'none' versus 'a lot or some.' Exercise was measured in terms of times per week (none, one day, two days, three days, four days, more than four). Age, number of persons in the home, race/ethnicity (non-Hispanic white, Hispanic, other), marital status, and educational level (less than high school, high school or GED, more than high school) were used to control for demographic differences among subjects. The median age was 25. Age was categorized as 18–21, 21–30 or 31 or over. Breaks in the age distribution were made at the first and third quartile. Statistical analysis Chi-square tests were used to test for the relationship between each independent variable and obesity. Variables that were significant at p < .10 in univariate tests were included in a multiple logistic regression analysis. EpiInfo 3.2.2 was used for data analysis.
Methods
A cross-sectional survey of primary care patients (adult non-pregnant women) attending one of five Planned Parenthood clinics in the Panhandle of Texas was conducted. The Amarillo Institutional Review Board granted exempt status to the study because no protected health information was collected. Planned Parenthood provide a valuable and unique sampling frame because it supplies basic primary care to low-income women in this area, including birth control, but not abortions.Eligibility for the study was limited to patients who were over age 18 and not pregnant. Questionnaires were placed on a table in waiting areas, with a poster inviting participation. Clinic staff also handed out survey forms. Subjects placed the completed forms in a sealed box. Sealed boxes containing survey forms were returned to Texas Tech for data entry. Microsoft Access was used for data entry.Five hundred forms were distributed. Twenty surveys were returned by persons ineligible for study participation and were excluded from the sample. The final data set was comprised of 345 subjects. Computing the response rate as completed returns divided by eligibles (345/(500-20) produces a participation rate of .719. Complete cases were available from 274 subjects for the multivariate analysis.Measures The dependent variable was obesity. Body mass index (BMI) was computed as weight in pounds times 703 divided by height in inches squared. BMI greater than 30 was classified as obese, and made up about 20 percent of the sample. Cases with missing heights and weights were dropped. Independent variables were stress, social support, age, race/ethnicity, education, income, number of persons in the home, exercise, marital status, anxiety, and depression. Key instruments are discussed below. Health items were taken from the Duke Health Profile [ 9 ]. Mental health was measured in terms of feeling depressed or sad and nervousness. Possible responses for all of the mental health items were "Yes, describes me exactly", "Somewhat describes me," or "No, doesn't describe me at all." Stress and social support items were taken from the Duke Social Support and Stress Scale (DUSOCS). The DUSOCS contains items addressing personal support from various sources. A person who stresses the respondent is defined as one who causes problems or makes life more difficult [ 10 ]. Respondents were asked how much they were stressed by spouses, parents and children. Possible responses were "None," "Some," "A Lot," and "There is No Such Person". Categories were combined into 'none' versus 'a lot or some.' Exercise was measured in terms of times per week (none, one day, two days, three days, four days, more than four). Age, number of persons in the home, race/ethnicity (non-Hispanic white, Hispanic, other), marital status, and educational level (less than high school, high school or GED, more than high school) were used to control for demographic differences among subjects. The median age was 25. Age was categorized as 18–21, 21–30 or 31 or over. Breaks in the age distribution were made at the first and third quartile.
Measures
The dependent variable was obesity. Body mass index (BMI) was computed as weight in pounds times 703 divided by height in inches squared. BMI greater than 30 was classified as obese, and made up about 20 percent of the sample. Cases with missing heights and weights were dropped.Independent variables were stress, social support, age, race/ethnicity, education, income, number of persons in the home, exercise, marital status, anxiety, and depression. Key instruments are discussed below.Health items were taken from the Duke Health Profile [ 9 ]. Mental health was measured in terms of feeling depressed or sad and nervousness. Possible responses for all of the mental health items were "Yes, describes me exactly", "Somewhat describes me," or "No, doesn't describe me at all."Stress and social support items were taken from the Duke Social Support and Stress Scale (DUSOCS). The DUSOCS contains items addressing personal support from various sources. A person who stresses the respondent is defined as one who causes problems or makes life more difficult [ 10 ]. Respondents were asked how much they were stressed by spouses, parents and children. Possible responses were "None," "Some," "A Lot," and "There is No Such Person". Categories were combined into 'none' versus 'a lot or some.'Exercise was measured in terms of times per week (none, one day, two days, three days, four days, more than four). Age, number of persons in the home, race/ethnicity (non-Hispanic white, Hispanic, other), marital status, and educational level (less than high school, high school or GED, more than high school) were used to control for demographic differences among subjects. The median age was 25. Age was categorized as 18–21, 21–30 or 31 or over. Breaks in the age distribution were made at the first and third quartile.Statistical analysis Chi-square tests were used to test for the relationship between each independent variable and obesity. Variables that were significant at p < .10 in univariate tests were included in a multiple logistic regression analysis. EpiInfo 3.2.2 was used for data analysis.
Statistical analysis
Chi-square tests were used to test for the relationship between each independent variable and obesity. Variables that were significant at p < .10 in univariate tests were included in a multiple logistic regression analysis. EpiInfo 3.2.2 was used for data analysis.Results Nearly half of respondents were classified as being obese (47.8 percent). About half of the respondents reported 'a lot or some' stress from parents or a spouse. 'A lot or some' stress from a child was experienced by about 40 percent. More than three-fourths of respondents said they receive 'a lot or some' support from a spouse or parent. About sixty percent received 'a lot or some' support from a child. Over 90 percent reported 'a lot or some' support from a friend. Table  1  shows the results of the univariate chi-square tests. Of the three stress variables, only parent stress met the selection criterion for inclusion in the logistic regression model (p = .0988). Support from parents was marginally related to obesity (p = .0542) while support from a child was significantly to obesity (p = .0390). Table 1 Psychosocial Risk Factors and Percent Obese in Family Planning Clinics (Chi-square tests) Pct Obese Pct Not Obese p Overall 47.8 52.2 Nervous .6064  None 46.7 53.3  Some 45.2 54.8  A lot 57.1 42.9 Depression .1944  None or some 45.6 54.4  A lot 59.4 40.6 Stress from Parents .0988  None 52.8 47.2  A lot or some 42.7 57.3 Stress from Spouse .8084  None 49.1 50.9  A lot or some 46.8 53.2 Stress from Child .1285  None 44.6 55.4  A lot or some 54.2 45.8 Support from Spouse .1607  None 55.4 44.6  A lot or some 45.6 54.4 Support from Child .0390  None 39.5 60.5  A lot or some 42.2 47.8 Support from Parents .0542  None 61.7 38.3  A lot or some 45.2 54.8 Support from Friend 3472  A lot or some 45.9 54.1  None 57.1 42.9 The sample was comprised of relatively young women, with most being under 30 years of age. Most respondents lived with two or more other people and most had high school degrees. More than one-fourth of respondents were married. Over one-fourth were Hispanic and over half were non-Hispanic White. Most had incomes under $30,000 per year. Over 35 percent got no exercise at all. Table  2  shows the results of univariate chi-square tests for the demographic variables and for exercise. Obesity differed significantly by the number of persons in the home (p = .0047), level of education (.0060), income level (p = .0328), and marital status (p = .0183). Over 58 percent of married respondents were obese, compared to 42.5 percent of unmarried persons. Person who lived alone were much less likely to be obese than persons who lived with four or more people (32.5 percent vs 64.8 percent). Over sixty percent of those lacking high school education were obese, whereas only about 40 percent of those who had more than a high school education were obese. The $10–20,000 income category had the lowest percent obese (36.1). Table 2 Other Risk Factors and Percent Obese in Family Planning Clinics (Chi-square tests) Pct Obese Pct Not Obese p Days of Exercise per Week .3857  None 49.6 50.4  One 57.1 42.9  Two 53.4 46.6  Three 39.6 60.4  Four 31.8 68.2  Five or more 41.7 58.3  Missing 54.5 45.5 Number of persons in home .0047  None 32.5 67.5  One to three 44.7 55.3  Four or more 64.8 35.2 Education .0060  Less than high school 63.6 36.4  High school degree or equivalent 55.3 44.7  More than high school 39.7 60.3 Race/Ethnicity .3747  White, non-hispanic 44.6 55.4  Hispanic 51.1 48.9  Other 54.8 45.2 Income .0328  Less than $10,000 54.2 45.8  $10–20,000 36.1 63.9  $20–30,000 56.4 43.6  Over $30,000 46.3 53.7 Marital Status .0183  Married 58.3 41.7  Other 42.5 57.5 Age .3857  Less than 21 49.2 50.4  21–30 44.6 55.4  over 30 53.7 46.3 'Some' or 'a lot; of nervousness was reported by about one-third of respondents, while over one-third said they were depressed 'some' or 'a lot'. Neither depression nor anxiety was retained for use in the multivariate model, since significance levels were below .10. Variables that were significant at p < .10 were included in the multiple logistic regression model (see Table  3 ). Women who reported no support from parents had greater odds of being obese (adjusted odds ratio (AOR) = 2.17, p = .0420). Stress from parents and support from a child had no independent relationship with obesity. Persons who lived in homes of four or more were more likely to be obese (AOR = 4.05, p = .0089). Being in the $10,000 to $20,000 income category lowered the odds of obesity in comparison to the under $10,000 category (AOR=.4864, p = .0267). Table 3 Unconditional Logistic Regression of Obesity in Family Planning Clinics (N = 274) Variable Odds Ratio (Conf. Interval) P Stress from parents  (none vs a lot or some) 1.2427 (.73–2.13) .4294 Support from child  (none vs a lot or some) .8949 (.51–1.57) .6994 Support from parent  (none vs a lot or some) 2.1710 (1.03–4.58) .0420 Number in home  One to three vs none 1.8413 (.80–4.24) .1518  Four or more vs none 4.0503 (1.42–11.55) .0089 Income  $10–20 vs less than 10 .4864 (.26–.92) .0267  $20–30 vs less than 10 1.1426 (.54–2.40) .7248  over $30 vs less than 10 .4945 (.20–1.19) .1176 Marital status  Other vs married .6095 (.32–1.16) .1340 Education  High school vs less 1.1435 (.43–3.07) .7900  More than HS vs less .7489 (.29–1.91) .5439 Comparisons of cases with missing obesity information to cases with complete obesity information revealed no significant differences in regard to age, marital status, or income. However, ethnicity and education were significantly different for persons who were missing obesity information. Missings were more likely to be Hispanic or other than non-Hispanic white. Missings also were less likely to have a high school degree or higher.
Results
Nearly half of respondents were classified as being obese (47.8 percent). About half of the respondents reported 'a lot or some' stress from parents or a spouse. 'A lot or some' stress from a child was experienced by about 40 percent. More than three-fourths of respondents said they receive 'a lot or some' support from a spouse or parent. About sixty percent received 'a lot or some' support from a child. Over 90 percent reported 'a lot or some' support from a friend.Table  1  shows the results of the univariate chi-square tests. Of the three stress variables, only parent stress met the selection criterion for inclusion in the logistic regression model (p = .0988). Support from parents was marginally related to obesity (p = .0542) while support from a child was significantly to obesity (p = .0390).Psychosocial Risk Factors and Percent Obese in Family Planning Clinics (Chi-square tests)The sample was comprised of relatively young women, with most being under 30 years of age. Most respondents lived with two or more other people and most had high school degrees. More than one-fourth of respondents were married. Over one-fourth were Hispanic and over half were non-Hispanic White. Most had incomes under $30,000 per year. Over 35 percent got no exercise at all.Table  2  shows the results of univariate chi-square tests for the demographic variables and for exercise. Obesity differed significantly by the number of persons in the home (p = .0047), level of education (.0060), income level (p = .0328), and marital status (p = .0183). Over 58 percent of married respondents were obese, compared to 42.5 percent of unmarried persons. Person who lived alone were much less likely to be obese than persons who lived with four or more people (32.5 percent vs 64.8 percent). Over sixty percent of those lacking high school education were obese, whereas only about 40 percent of those who had more than a high school education were obese. The $10–20,000 income category had the lowest percent obese (36.1).Other Risk Factors and Percent Obese in Family Planning Clinics (Chi-square tests)'Some' or 'a lot; of nervousness was reported by about one-third of respondents, while over one-third said they were depressed 'some' or 'a lot'. Neither depression nor anxiety was retained for use in the multivariate model, since significance levels were below .10.Variables that were significant at p < .10 were included in the multiple logistic regression model (see Table  3 ). Women who reported no support from parents had greater odds of being obese (adjusted odds ratio (AOR) = 2.17, p = .0420). Stress from parents and support from a child had no independent relationship with obesity. Persons who lived in homes of four or more were more likely to be obese (AOR = 4.05, p = .0089). Being in the $10,000 to $20,000 income category lowered the odds of obesity in comparison to the under $10,000 category (AOR=.4864, p = .0267).Unconditional Logistic Regression of Obesity in Family Planning Clinics (N = 274)Comparisons of cases with missing obesity information to cases with complete obesity information revealed no significant differences in regard to age, marital status, or income. However, ethnicity and education were significantly different for persons who were missing obesity information. Missings were more likely to be Hispanic or other than non-Hispanic white. Missings also were less likely to have a high school degree or higher.Discussion According to our univariate analysis, the profile of an obese woman in this low-income population is having a large family, less than a high school education, and being married. They also were more likely to fall into income groups above or below the $10,000 to $20,000 range. Variables assessing stress from various sources were not significant at p < .05. Multivariate analysis revealed that receiving no support from parents was independently related to higher rates of obesity, while women in the $10,000 to $20,000 income category were less likely to be obese. The reasons for the income differences are not clear, though varying access to food assistance may offer a partial explanation. Additional investigation of the relationship between diet and income among low-income women is needed. The findings of this study should be treated with caution since it is based on a convenience sample and may not be representative of the population from which it was drawn. In addition, the response rate was not optimal and also a number of cases were dropped from the analysis due to missing information, which reduced statistical power and could have biased our conclusions. However, since the sample was not randomly selected we cannot be sure that dropping cases with missing data made the sample less representative of the low-income female primary care population. An additional limitation of the study was its cross-sectional in design which does not allow for proving causal relationships. Because of these limitations, our results must be considered suggestive rather than definitive. Nevertheless, the findings may be important to primary care physicians, epidemiologists and others who study the determinants of obesity in clinic populations. We could not demonstrate a significant relationship between self-reported stress and obesity in this relatively young, female population after adjustment for other variables. However, personal stress may have indirect effects on obesity, an issue not investigated in this study. Furthermore, the relationship between self-reported (perceived) stress with objective (psychological and physiological) measures of stress in this population group are unknown. Consistent with the findings of our study, Sammel et al did not find stress to be related to obesity in their study of women aged 35–47 [ 1 ]. Exercise was not significantly related to obesity in our data. Interestingly, Sammel et al also found no relationship between exercise and obesity 1]. Kaplan et al reported that physical activity was related to obesity in older Canadians, but their sample was quite large (N = 5,980) thus giving them more statistical power [ 3 ]. Obesity rates increased with age in our univarate analyses. This is consistent with what has been reported by other investigators [ 1 , 3 ]. We found no independent relationship with education or race, which agrees with Sammel but conflicts with other research [ 3 , 4 , 8 ]. This contradiction might be due to the fact that our sample was constrained to include primarily low-income women; obesity may be more strongly related to income than race, ethnicity or educational level. We could not show self-assessed depression to be predictive of obesity. Several other investigators have examined this issue, with some seeing obesity as a consequence of depression and others regarding depression to be a result of obesity. In a large study by Carpenter et al [ 11 ], increased BMI in women was associated with major depressive disorder as diagnosed in a structured interview using DSM-IV criteria. A study of the National Health and Nutrition Examination Survey (NHANES) also found that obesity was related to depression. Furthermore, Sammel et al reported that weight gain was related to baseline depression, providing some support that depression may be a cause rather than a consequence of obesity [ 2 ]. Goodman and Whitaker studied the development and persistence of adolescent obesity and found that depressed mood at baseline was an independent risk factor of persistent obesity [ 4 ]. Obesity may also increase the risk of depression in women due to stigma and social isolation related to obesity, particularly among women in western cultures. Since our depression variable was drawn from a single question, it may have contained too much measurement error to permit it to achieve statistical significance in our data set. The reasons why large families increase the risk of obesity are not entirely clear. One obvious mechanism is that, since women traditionally prepare meals, they may have more frequent opportunities to consume food and households with large families are more likely to have greater volumes of food available.
Discussion
According to our univariate analysis, the profile of an obese woman in this low-income population is having a large family, less than a high school education, and being married. They also were more likely to fall into income groups above or below the $10,000 to $20,000 range. Variables assessing stress from various sources were not significant at p < .05. Multivariate analysis revealed that receiving no support from parents was independently related to higher rates of obesity, while women in the $10,000 to $20,000 income category were less likely to be obese. The reasons for the income differences are not clear, though varying access to food assistance may offer a partial explanation. Additional investigation of the relationship between diet and income among low-income women is needed.The findings of this study should be treated with caution since it is based on a convenience sample and may not be representative of the population from which it was drawn. In addition, the response rate was not optimal and also a number of cases were dropped from the analysis due to missing information, which reduced statistical power and could have biased our conclusions. However, since the sample was not randomly selected we cannot be sure that dropping cases with missing data made the sample less representative of the low-income female primary care population. An additional limitation of the study was its cross-sectional in design which does not allow for proving causal relationships. Because of these limitations, our results must be considered suggestive rather than definitive. Nevertheless, the findings may be important to primary care physicians, epidemiologists and others who study the determinants of obesity in clinic populations.We could not demonstrate a significant relationship between self-reported stress and obesity in this relatively young, female population after adjustment for other variables. However, personal stress may have indirect effects on obesity, an issue not investigated in this study. Furthermore, the relationship between self-reported (perceived) stress with objective (psychological and physiological) measures of stress in this population group are unknown. Consistent with the findings of our study, Sammel et al did not find stress to be related to obesity in their study of women aged 35–47 [ 1 ].Exercise was not significantly related to obesity in our data. Interestingly, Sammel et al also found no relationship between exercise and obesity 1]. Kaplan et al reported that physical activity was related to obesity in older Canadians, but their sample was quite large (N = 5,980) thus giving them more statistical power [ 3 ].Obesity rates increased with age in our univarate analyses. This is consistent with what has been reported by other investigators [ 1 , 3 ]. We found no independent relationship with education or race, which agrees with Sammel but conflicts with other research [ 3 , 4 , 8 ]. This contradiction might be due to the fact that our sample was constrained to include primarily low-income women; obesity may be more strongly related to income than race, ethnicity or educational level.We could not show self-assessed depression to be predictive of obesity. Several other investigators have examined this issue, with some seeing obesity as a consequence of depression and others regarding depression to be a result of obesity. In a large study by Carpenter et al [ 11 ], increased BMI in women was associated with major depressive disorder as diagnosed in a structured interview using DSM-IV criteria. A study of the National Health and Nutrition Examination Survey (NHANES) also found that obesity was related to depression. Furthermore, Sammel et al reported that weight gain was related to baseline depression, providing some support that depression may be a cause rather than a consequence of obesity [ 2 ]. Goodman and Whitaker studied the development and persistence of adolescent obesity and found that depressed mood at baseline was an independent risk factor of persistent obesity [ 4 ]. Obesity may also increase the risk of depression in women due to stigma and social isolation related to obesity, particularly among women in western cultures. Since our depression variable was drawn from a single question, it may have contained too much measurement error to permit it to achieve statistical significance in our data set.The reasons why large families increase the risk of obesity are not entirely clear. One obvious mechanism is that, since women traditionally prepare meals, they may have more frequent opportunities to consume food and households with large families are more likely to have greater volumes of food available.Conclusion The research question for this paper was about the risk factors for obesity in a low-income female population in a single community. Our study differs from some other studies of obesity by its inclusion of several types of personal stress as well as social support and mental health measures. We were able to show that personal stress, as defined and measured in this study, was not an important risk factor for obesity in this population group. A limitation of this study is that it does not address occupational stress. Work-related stress has been shown to be related to the health of employees [ 12 - 14 ]. However, since many of the subjects in this sample were not employed, it was not feasible to test hypotheses regarding the relationship between work stress and obesity. Another limitation of the study is its cross-sectional design, which precludes making firm conclusions regarding causality. Despite these limitations, our findings have significance for public health practice related to weight control. Health promotion programs that seek to educate and encourage healthier eating behaviors in low-income female populations should focus on women who are not receiving support from their parents and have large families of their own. In addition, income and eligibility for food assistance may affect dietary practices in unexpected ways, so primary care providers should explore this issue.
Conclusion
The research question for this paper was about the risk factors for obesity in a low-income female population in a single community. Our study differs from some other studies of obesity by its inclusion of several types of personal stress as well as social support and mental health measures. We were able to show that personal stress, as defined and measured in this study, was not an important risk factor for obesity in this population group.A limitation of this study is that it does not address occupational stress. Work-related stress has been shown to be related to the health of employees [ 12 - 14 ]. However, since many of the subjects in this sample were not employed, it was not feasible to test hypotheses regarding the relationship between work stress and obesity. Another limitation of the study is its cross-sectional design, which precludes making firm conclusions regarding causality.Despite these limitations, our findings have significance for public health practice related to weight control. Health promotion programs that seek to educate and encourage healthier eating behaviors in low-income female populations should focus on women who are not receiving support from their parents and have large families of their own. In addition, income and eligibility for food assistance may affect dietary practices in unexpected ways, so primary care providers should explore this issue.Competing interests None declared.
Competing interests
None declared.Authors' contributions JR planned the study, organized the survey, and wrote the first draft of the results. BR wrote the section addressing mental health and obesity.
Authors' contributions
JR planned the study, organized the survey, and wrote the first draft of the results. BR wrote the section addressing mental health and obesity.Pre-publication history The pre-publication history for this paper can be accessed here:
Pre-publication history
The pre-publication history for this paper can be accessed here:


Background About half of all newly presented episodes of shoulder complaints (SC) in general practice are reported to last for at least six months. Early interventions aimed at the psychological and social determinants of SC are not common in general practice, although such interventions might prevent the development of chronic SC. The Education and Activation Programme (EAP) consists of an educational part and a time-contingent activation part. The aim of the EAP is to provide patients with the proper cognitions by means of education, and to stimulate adequate behaviour through advice on activities of daily living.
Background
About half of all newly presented episodes of shoulder complaints (SC) in general practice are reported to last for at least six months. Early interventions aimed at the psychological and social determinants of SC are not common in general practice, although such interventions might prevent the development of chronic SC.The Education and Activation Programme (EAP) consists of an educational part and a time-contingent activation part. The aim of the EAP is to provide patients with the proper cognitions by means of education, and to stimulate adequate behaviour through advice on activities of daily living.Design The article describes the design of a randomised clinical trial (RCT) to evaluate the effectiveness and cost-effectiveness of an EAP in addition to usual care, compared to usual care only, in the prevention of chronic SC after six months. It also describes the analysis of the cost and effect balance. Patients suffering from SC for less than three months are recruited in general practice and through open recruitment. A trained general practitioner or a trained therapist administers the EAP. Primary outcome measures are patient-perceived recovery, measured by self-assessment on a seven-point scale, and functional limitations in activities of daily living. Questionnaires are used to study baseline measures, prognostic measures, process measures and outcome measures.
Design
The article describes the design of a randomised clinical trial (RCT) to evaluate the effectiveness and cost-effectiveness of an EAP in addition to usual care, compared to usual care only, in the prevention of chronic SC after six months. It also describes the analysis of the cost and effect balance. Patients suffering from SC for less than three months are recruited in general practice and through open recruitment. A trained general practitioner or a trained therapist administers the EAP.Primary outcome measures are patient-perceived recovery, measured by self-assessment on a seven-point scale, and functional limitations in activities of daily living. Questionnaires are used to study baseline measures, prognostic measures, process measures and outcome measures.Discussion The inclusion of patients in the study lasted until December 31 st  2003. Data collection is to end in June 2004.
Discussion
The inclusion of patients in the study lasted until December 31 st  2003. Data collection is to end in June 2004.

Background Shoulder complaints Shoulder complaints (SC) have been defined by Sobel & Winters [ 1 ] as pain localised in the region of the deltoid muscle, the acromioclavicular joint, the superior part of the trapezoid muscle and the scapula. Radiation of the pain to the arm as well as limitation of the motion of the upper arm and/or the shoulder girdle may be present [ 1 ]. SC are characterised by pain in the area between the base of the neck and the elbow, at rest or when elicited by movement of the upper arm (Fig.  1 ). Figure 1 Area between the base of the neck and the elbow Musculoskeletal disorders, of which SC constitute the second largest group after low back disorders, account for the second largest share in healthcare costs and represent the largest group of work-related diseases in the Netherlands [ 2 ]. Shoulder complaints in general practice The point prevalence of SC in the general population in the Netherlands has recently been estimated at 21% [ 3 ]. In a British study a lower point prevalence of 14% has been found [ 4 ]. The annual incidence of SC as seen by general practitioners (GPs) in the Netherlands lies between 15 and 25 patients per 1000 registered general practice patients[ 1 ]. About half of all newly presented episodes in general practice are reported to last for at least six months, while 40 percent of the newly presented episodes result in disability in terms of activities of daily living after one year [ 5 ]. The International Association for the Study of Pain (IASP) regards persistent or recurring pain lasting less than three months as acute pain, whereas more than three months of persistent or recurring pain is considered to be chronic pain [ 6 ]. The study by van der Windt [ 5 ] showed that, according to this cut-off criterion, 51% of patients with a newly presented episode of SC in general practice develop chronic SC, that is, complaints lasting more than three months. The Dutch College of General Practitioners provides clinical guidelines for the treatment of SC [ 7 ]. These guidelines, however, do not include treatment aimed at psychosocial factors such as maladaptive behaviour and inadequate cognitions, known to play a role in the development and persistence of chronic musculoskeletal diseases [ 8 - 10 ]. Treatments addressing such factors are mentioned in the guidelines, but only as a last resort, when the biomedical approach has proved ineffective in reducing the pain. To date, early interventions aimed at the psychological and social determinants of SC are not common in general practice, although such interventions in the early stages of the SC might prevent the development of chronic complaints [ 11 ]. Early intervention in general practice We hypothesised that an intervention concentrating on psychological and social determinants in the early stages of SC would prevent the development of inadequate cognitions and maladaptive behaviour, ensuring that such inadequate cognitions and behaviour do not play a role in the development of chronic SC later on. The term cognitions refers to the way patients think about their pain and what the pain means to them, in terms of thoughts, beliefs, attitudes and self-efficacy expectations [ 12 ], whereas behaviour refers to the patients' observable actions [ 13 ]. Patients' cognitions and behaviour should thus be influenced so as to become adequate cognitions and adaptive behaviour. A relatively brief treatment in the early stages of SC, administered by a trained therapist, may be expected to be effective in preventing the development of chronic SC. The Education and Activation Programme (EAP) that formed the subject of the present study is such an early intervention. Aim of the study This paper describes the design of a study to evaluate the clinical effectiveness of an early EAP aimed at using psychological and behavioural factors to prevent chronic SC. In addition, the study is to evaluate the balance between costs and effects. EAP in patients with acute SC is to be compared with treatment according to the Dutch College of General Practitioners guidelines. The Medical Ethics Committee of the Institute for Rehabilitations Research in association with Rehabilitation Foundation Limburg has approved the design of the study presented here. Funding was obtained from the Netherlands Organisation for Scientific Research. This paper describes also the rationale and content of the EAP. Education and activation programme Previous studies have indicated that cognitive behavioural therapies aimed at bio-psychosocial factors are promising instruments for the prevention of chronic musculoskeletal pain [ 14 ]. The EAP focuses on the same elements as cognitive behavioural therapies, but is applied at an earlier stage than such therapies [ 15 ]. Whereas the latter focus mainly on the elimination of inadequate cognitions and maladaptive behaviour after they have already developed in the course of the SC, the EAP focuses on guiding the patient towards adequate pain behaviour and reinforcing this behaviour at an early stage of the SC. The aim of the EAP is to prevent the development of inadequate cognitions and maladaptive behaviour in patients with acute SC. Education is used to maintain or induce adequate cognitions by providing information that is tailored to questions that patients have about their SC. Health care educators frequently assume that giving information equals comprehension, which should automatically translate into changed behaviours as the knowledge is applied [ 16 ]. According to Hussey, however, simply receiving a message hardly correlates with understanding it [ 17 ]. Effective learning also requires the active participation of the patient[ 18 ]. Since inadequate cognitions and maladaptive behaviours are not yet fully developed in patients with acute SC, the focus of the EAP is not on restructuring inadequate cognitions or modifying maladaptive behaviour, but on maintaining or inducing the proper cognitions by education and on maintaining or inducing adequate behaviour by giving advice on activities of daily living. Adequate behaviour is considered to be behaviour in which the patient remains active. A comprehensive description of the EAP is given in the Design section.
Background
Shoulder complaints Shoulder complaints (SC) have been defined by Sobel & Winters [ 1 ] as pain localised in the region of the deltoid muscle, the acromioclavicular joint, the superior part of the trapezoid muscle and the scapula. Radiation of the pain to the arm as well as limitation of the motion of the upper arm and/or the shoulder girdle may be present [ 1 ]. SC are characterised by pain in the area between the base of the neck and the elbow, at rest or when elicited by movement of the upper arm (Fig.  1 ). Figure 1 Area between the base of the neck and the elbow Musculoskeletal disorders, of which SC constitute the second largest group after low back disorders, account for the second largest share in healthcare costs and represent the largest group of work-related diseases in the Netherlands [ 2 ].
Shoulder complaints
Shoulder complaints (SC) have been defined by Sobel & Winters [ 1 ] as pain localised in the region of the deltoid muscle, the acromioclavicular joint, the superior part of the trapezoid muscle and the scapula. Radiation of the pain to the arm as well as limitation of the motion of the upper arm and/or the shoulder girdle may be present [ 1 ].SC are characterised by pain in the area between the base of the neck and the elbow, at rest or when elicited by movement of the upper arm (Fig.  1 ).Musculoskeletal disorders, of which SC constitute the second largest group after low back disorders, account for the second largest share in healthcare costs and represent the largest group of work-related diseases in the Netherlands [ 2 ].Shoulder complaints in general practice The point prevalence of SC in the general population in the Netherlands has recently been estimated at 21% [ 3 ]. In a British study a lower point prevalence of 14% has been found [ 4 ]. The annual incidence of SC as seen by general practitioners (GPs) in the Netherlands lies between 15 and 25 patients per 1000 registered general practice patients[ 1 ]. About half of all newly presented episodes in general practice are reported to last for at least six months, while 40 percent of the newly presented episodes result in disability in terms of activities of daily living after one year [ 5 ]. The International Association for the Study of Pain (IASP) regards persistent or recurring pain lasting less than three months as acute pain, whereas more than three months of persistent or recurring pain is considered to be chronic pain [ 6 ]. The study by van der Windt [ 5 ] showed that, according to this cut-off criterion, 51% of patients with a newly presented episode of SC in general practice develop chronic SC, that is, complaints lasting more than three months. The Dutch College of General Practitioners provides clinical guidelines for the treatment of SC [ 7 ]. These guidelines, however, do not include treatment aimed at psychosocial factors such as maladaptive behaviour and inadequate cognitions, known to play a role in the development and persistence of chronic musculoskeletal diseases [ 8 - 10 ]. Treatments addressing such factors are mentioned in the guidelines, but only as a last resort, when the biomedical approach has proved ineffective in reducing the pain. To date, early interventions aimed at the psychological and social determinants of SC are not common in general practice, although such interventions in the early stages of the SC might prevent the development of chronic complaints [ 11 ].
Shoulder complaints in general practice
The point prevalence of SC in the general population in the Netherlands has recently been estimated at 21% [ 3 ]. In a British study a lower point prevalence of 14% has been found [ 4 ]. The annual incidence of SC as seen by general practitioners (GPs) in the Netherlands lies between 15 and 25 patients per 1000 registered general practice patients[ 1 ]. About half of all newly presented episodes in general practice are reported to last for at least six months, while 40 percent of the newly presented episodes result in disability in terms of activities of daily living after one year [ 5 ].The International Association for the Study of Pain (IASP) regards persistent or recurring pain lasting less than three months as acute pain, whereas more than three months of persistent or recurring pain is considered to be chronic pain [ 6 ]. The study by van der Windt [ 5 ] showed that, according to this cut-off criterion, 51% of patients with a newly presented episode of SC in general practice develop chronic SC, that is, complaints lasting more than three months.The Dutch College of General Practitioners provides clinical guidelines for the treatment of SC [ 7 ]. These guidelines, however, do not include treatment aimed at psychosocial factors such as maladaptive behaviour and inadequate cognitions, known to play a role in the development and persistence of chronic musculoskeletal diseases [ 8 - 10 ]. Treatments addressing such factors are mentioned in the guidelines, but only as a last resort, when the biomedical approach has proved ineffective in reducing the pain.To date, early interventions aimed at the psychological and social determinants of SC are not common in general practice, although such interventions in the early stages of the SC might prevent the development of chronic complaints [ 11 ].Early intervention in general practice We hypothesised that an intervention concentrating on psychological and social determinants in the early stages of SC would prevent the development of inadequate cognitions and maladaptive behaviour, ensuring that such inadequate cognitions and behaviour do not play a role in the development of chronic SC later on. The term cognitions refers to the way patients think about their pain and what the pain means to them, in terms of thoughts, beliefs, attitudes and self-efficacy expectations [ 12 ], whereas behaviour refers to the patients' observable actions [ 13 ]. Patients' cognitions and behaviour should thus be influenced so as to become adequate cognitions and adaptive behaviour. A relatively brief treatment in the early stages of SC, administered by a trained therapist, may be expected to be effective in preventing the development of chronic SC. The Education and Activation Programme (EAP) that formed the subject of the present study is such an early intervention.
Early intervention in general practice
We hypothesised that an intervention concentrating on psychological and social determinants in the early stages of SC would prevent the development of inadequate cognitions and maladaptive behaviour, ensuring that such inadequate cognitions and behaviour do not play a role in the development of chronic SC later on.The term cognitions refers to the way patients think about their pain and what the pain means to them, in terms of thoughts, beliefs, attitudes and self-efficacy expectations [ 12 ], whereas behaviour refers to the patients' observable actions [ 13 ].Patients' cognitions and behaviour should thus be influenced so as to become adequate cognitions and adaptive behaviour. A relatively brief treatment in the early stages of SC, administered by a trained therapist, may be expected to be effective in preventing the development of chronic SC. The Education and Activation Programme (EAP) that formed the subject of the present study is such an early intervention.Aim of the study This paper describes the design of a study to evaluate the clinical effectiveness of an early EAP aimed at using psychological and behavioural factors to prevent chronic SC. In addition, the study is to evaluate the balance between costs and effects. EAP in patients with acute SC is to be compared with treatment according to the Dutch College of General Practitioners guidelines. The Medical Ethics Committee of the Institute for Rehabilitations Research in association with Rehabilitation Foundation Limburg has approved the design of the study presented here. Funding was obtained from the Netherlands Organisation for Scientific Research. This paper describes also the rationale and content of the EAP.
Aim of the study
This paper describes the design of a study to evaluate the clinical effectiveness of an early EAP aimed at using psychological and behavioural factors to prevent chronic SC. In addition, the study is to evaluate the balance between costs and effects. EAP in patients with acute SC is to be compared with treatment according to the Dutch College of General Practitioners guidelines. The Medical Ethics Committee of the Institute for Rehabilitations Research in association with Rehabilitation Foundation Limburg has approved the design of the study presented here. Funding was obtained from the Netherlands Organisation for Scientific Research.This paper describes also the rationale and content of the EAP.Education and activation programme Previous studies have indicated that cognitive behavioural therapies aimed at bio-psychosocial factors are promising instruments for the prevention of chronic musculoskeletal pain [ 14 ]. The EAP focuses on the same elements as cognitive behavioural therapies, but is applied at an earlier stage than such therapies [ 15 ]. Whereas the latter focus mainly on the elimination of inadequate cognitions and maladaptive behaviour after they have already developed in the course of the SC, the EAP focuses on guiding the patient towards adequate pain behaviour and reinforcing this behaviour at an early stage of the SC. The aim of the EAP is to prevent the development of inadequate cognitions and maladaptive behaviour in patients with acute SC. Education is used to maintain or induce adequate cognitions by providing information that is tailored to questions that patients have about their SC. Health care educators frequently assume that giving information equals comprehension, which should automatically translate into changed behaviours as the knowledge is applied [ 16 ]. According to Hussey, however, simply receiving a message hardly correlates with understanding it [ 17 ]. Effective learning also requires the active participation of the patient[ 18 ]. Since inadequate cognitions and maladaptive behaviours are not yet fully developed in patients with acute SC, the focus of the EAP is not on restructuring inadequate cognitions or modifying maladaptive behaviour, but on maintaining or inducing the proper cognitions by education and on maintaining or inducing adequate behaviour by giving advice on activities of daily living. Adequate behaviour is considered to be behaviour in which the patient remains active. A comprehensive description of the EAP is given in the Design section.
Education and activation programme
Previous studies have indicated that cognitive behavioural therapies aimed at bio-psychosocial factors are promising instruments for the prevention of chronic musculoskeletal pain [ 14 ]. The EAP focuses on the same elements as cognitive behavioural therapies, but is applied at an earlier stage than such therapies [ 15 ]. Whereas the latter focus mainly on the elimination of inadequate cognitions and maladaptive behaviour after they have already developed in the course of the SC, the EAP focuses on guiding the patient towards adequate pain behaviour and reinforcing this behaviour at an early stage of the SC.The aim of the EAP is to prevent the development of inadequate cognitions and maladaptive behaviour in patients with acute SC.Education is used to maintain or induce adequate cognitions by providing information that is tailored to questions that patients have about their SC. Health care educators frequently assume that giving information equals comprehension, which should automatically translate into changed behaviours as the knowledge is applied [ 16 ]. According to Hussey, however, simply receiving a message hardly correlates with understanding it [ 17 ]. Effective learning also requires the active participation of the patient[ 18 ].Since inadequate cognitions and maladaptive behaviours are not yet fully developed in patients with acute SC, the focus of the EAP is not on restructuring inadequate cognitions or modifying maladaptive behaviour, but on maintaining or inducing the proper cognitions by education and on maintaining or inducing adequate behaviour by giving advice on activities of daily living. Adequate behaviour is considered to be behaviour in which the patient remains active. A comprehensive description of the EAP is given in the Design section.Design Patients Patients are recruited by GPs and in the open population by advertising in local newspapers. Patients are eligible for inclusion in the Randomised Clinical Trial (RCT) if they consult their own GP or respond to adverts in a local newspaper with a new episode of SC that has lasted no longer than three months, at rest or when elicited by movement in the shoulder area. Patients are included if they are 18 years or older and living in the south of the Netherlands. Only newly presented episodes of SC are considered, that is, patients who have not consulted their GP and have not been treated for their SC in the preceding three months. Additional exclusion criteria are given in table  1 . Table 1 Exclusion criteria • other episodes of SC in the 12 months preceding the consultation with the GP • prior fractures and/or surgery of the shoulder • (suspected) referred pain from internal organs • SC with a confirmed extrinsic cause • inability to complete a questionnaire independently • presence of dementia or other severe psychiatric abnormalities Randomised Clinical Trial A Randomised Clinical Trial (RCT) with a six-month follow-up is used to evaluate the effectiveness and cost-effectiveness of an EAP to prevent chronicity in patients with acute SC, compared to usual care. A computer-generated random sequence table is used to randomise the patients to EAP or usual care. Neither the patient nor the GP, nor the trained therapist, can be blinded for the allocated treatment. The trained therapist is also the researcher coordinating the RCT and conducting the data analysis, but is blinded for treatment allocation during the data analysis. The allocation code will be revealed only after the data analysis has been completed. Treatments Usual care (UC) is applied according to the Dutch College of General Practitioners guidelines for SC (version 1999)[ 19 ]. Management during the first two weeks consists of a wait-and-see policy with information and advice about shoulder complaints, possibly supplemented with analgesics or nonsteroidal anti-inflammatory drugs. If this approach has little or no effect, up to three corticosteroid injections can be given. Physiotherapy is considered for complaints persisting after six weeks or more. If the SC persist, referral to a hospital-based specialist may be considered. The focus of the EAP is to maintain or induce the proper cognitions by education and to stimulate adequate behaviour by means of advice on activities of daily living. Table  2  shows the components of the EAP. The EAP is administered by specially trained GPs or an ambulant therapist (CDB) trained to provide the EAP. The ambulant therapist administers the EAP when no trained GP is available in the living area of the patient. Table 2 Elements of the education and activation programme Education  • Information on the origin, nature and prognosis of the SC  • Information on possible interventions and their effects (tailored to the patient's questions and needs)  • Information on the effect of cognitions and behaviour on the perpetuation of the SC Activation When no alterations in activities have occurred due to the SC  • Positive reinforcement  • Instruction to be aware of possible changes When alterations in activities have occurred due to the SC  • Identification of up to three altered frequent activities of daily living  • Determination of the desired level of activity and the size of the steps needed to reach this level The EAP consists of a minimum of two sessions and a maximum of six follow-up sessions over a period of six weeks. Each session may last up to 20 minutes. The first and second sessions are organised in the general practice setting by the trained GP, or at the patient's home by the ambulant EAP therapist. The other sessions are provided by telephone. Education The first part of the EAP has an educational purpose, and focuses on information about the origin, nature and prognosis of the SC, possible interventions and their effects, the impact on activities of daily living and its consequences and the patient's own possibility to contribute to recovery. This information is tailored to the patients' questions and needs and is based on the information available in the Dutch College of General Practitioners guidelines for SC. In addition, the effect of cognitions and behaviour on the perpetuation of the SC is clarified to the patient by an example. If possible, this example refers to a condition or circumstance the patient has experienced, such as a broken bone or back pain. The patient is helped by the trained GP or the trained therapist to explore whether his or her thoughts about the SC are justified. Negative patterns of thinking are modified into adequate and accurate thoughts. Activation The second part of the EAP consists of a time contingent activation programme, based on the principles of operant learning. It focuses on gradually increasing activities of daily living, despite the pain. Potential avoidance of activities is countered by reinforcement of continuation or resumption of usual activities. Positive reinforcement is used to stimulate patients with a normal activity pattern, in spite of their SC, to continue their activities. This positive reinforcement may be enough to achieve continuation of the desired activities [ 13 ]. These patients are also instructed to be aware of possible changes in their activities that could lead to undesirable behaviour such as reduced use of the affected shoulder. Patients who have reduced their normal activities are helped to identify up to three frequent activities of daily living that they have reduced as a result of the SC. These activities are stepwise gradually increased to the desired level of activity in a time-contingent manner. The desired level of activity and the magnitude of the increases are determined and agreed upon by the EAP therapist and the patient. The patient and the EAP therapist also plan a progress evaluation, which is used to positively reinforce the patient's behaviour if the gradual increase has been correctly implemented or to adjust the magnitude of the increases if the original objectives prove too optimistic. Measurements The first outcome measure is the perceived recovery of the patient. Patients are considered to be recovered when they report to be much improved or fully recovered, on an 7-point ordinal scale, after six months. The second outcome measure is that of functional limitations in activities of daily living. This variable is assessed by a 16-item questionnaire, the shoulder disability questionnaire (SDQ)[ 20 ], with a scoring range of 0 to 16. A reduction of the score on this questionnaire implies a reduction in functional limitations. The outcome measures are recorded at 6, 12 and 26 weeks after randomisation. The SDQ is also measured at baseline. A cost diary [ 21 ] is used to assess health care utilisation, direct non-medical costs and indirect costs. A complete overview of baseline measures, prognostic measures, process measures and outcome measures is given in table  3 . Table 3 Variables Baseline measures T = 0 Demographic variables  • Age  • Gender  • Employment status Specific disease characteristics  • Affected side  • Possible cause of shoulder complaints  • Duration of complaints  • History of shoulder complaints Co-morbidity Physical activity Workload Treatment credibility and preference Prognostic measures T = 0 Mobility of glenohumeral joint  • HIB (hand in back), HIN (hand in neck), passive exorotation  • Active and passive abduction Mobility of cervicothoracal spine Severity of main complaint Psychosocial variables  • Anxiety 1  • Depression 1  • Somatisation 1  • Distress 1 Job content Outcome measures T = 1,2,3 Perceived recovery of complaints Functional limitations to daily activities 2 Process measures T = 0,1,2,3 Psychosocial variables  • Kinesiophobia 3  • Fear avoidance and beliefs 4  • Catastrophising 5  • Coping with pain 5  • Internal locus of control 5  • External locus of control 5 Global assessment Shoulder pain 6 General health 7 Cost T = 0–26 weeks Health care utilisation 8 Direct non-medical costs Indirect costs 1  four-dimensional complaint list [25] 2  Shoulder Disability Questionnaire [20] 3  Tampa Scale for Kinesiophobia – Dutch version (partly) [26] 4  Fear Avoidance and Beliefs Questionnaire – Dutch version (partly) [27] 5  Pain Coping and Cognition List [28] 6  Shoulder Pain Score [29] 7  Generic Health Related Quality of Life [30] 8  Cost Diary [21] Data analysis The statistical analysis will be carried out according to the 'intention-to-treat' principle. Differences between groups, with 95% confidence intervals, will be calculated for each outcome measure. The study groups will be compared by an independent samples t-test for changes since baseline for continuous outcome variables and the chi-square test for categorical outcome variables. In addition, the corresponding baseline value for each continuous outcome will be used as a covariate. The analysis will be repeated taking any loss-to-follow-up into account by applying a sensitivity analysis in which all patients who are lost to follow-up are first considered to show the largest observed improvement and then the largest observed deterioration in outcome measures. The analyses of the difference in change for the outcomes at three and six months will account for the repeated measures character of the data. Baseline characteristics that are a priori considered to be possible prognostic factors for outcome variables, as well as post-randomisation differences between the groups, will be handled as potential confounders. Their influence will be evaluated by means of multivariable regression analyses. In the case of confounding, adjusted effect estimates will also be reported. Sample size About half of all newly presented episodes of SC in general practice are reported to last for at least six months. A number needed to treat of 4.5 after six months is considered clinically relevant. This implies an absolute reduction of 22% of the proportion of patients with SC after six months. With a two-sided alpha of 0.05 and a statistical power (1-β) of 0.80, 70 patients per treatment group are needed to detect a difference in favour of the EAP compared to usual care after six months. Embedding in the Dutch Shoulder Disability Study This RCT is part of the Dutch Shoulder Disability Study, a comprehensive prognostic cohort study on SC, with randomised controlled interventions in subcohorts. The Dutch Shoulder Disability Study is funded by the Netherlands Organisation for Scientific Research (NWO, grant number 904-65-901).
Design
Patients Patients are recruited by GPs and in the open population by advertising in local newspapers. Patients are eligible for inclusion in the Randomised Clinical Trial (RCT) if they consult their own GP or respond to adverts in a local newspaper with a new episode of SC that has lasted no longer than three months, at rest or when elicited by movement in the shoulder area. Patients are included if they are 18 years or older and living in the south of the Netherlands. Only newly presented episodes of SC are considered, that is, patients who have not consulted their GP and have not been treated for their SC in the preceding three months. Additional exclusion criteria are given in table  1 . Table 1 Exclusion criteria • other episodes of SC in the 12 months preceding the consultation with the GP • prior fractures and/or surgery of the shoulder • (suspected) referred pain from internal organs • SC with a confirmed extrinsic cause • inability to complete a questionnaire independently • presence of dementia or other severe psychiatric abnormalities
Patients
Patients are recruited by GPs and in the open population by advertising in local newspapers.Patients are eligible for inclusion in the Randomised Clinical Trial (RCT) if they consult their own GP or respond to adverts in a local newspaper with a new episode of SC that has lasted no longer than three months, at rest or when elicited by movement in the shoulder area.Patients are included if they are 18 years or older and living in the south of the Netherlands. Only newly presented episodes of SC are considered, that is, patients who have not consulted their GP and have not been treated for their SC in the preceding three months. Additional exclusion criteria are given in table  1 .Exclusion criteriaRandomised Clinical Trial A Randomised Clinical Trial (RCT) with a six-month follow-up is used to evaluate the effectiveness and cost-effectiveness of an EAP to prevent chronicity in patients with acute SC, compared to usual care. A computer-generated random sequence table is used to randomise the patients to EAP or usual care. Neither the patient nor the GP, nor the trained therapist, can be blinded for the allocated treatment. The trained therapist is also the researcher coordinating the RCT and conducting the data analysis, but is blinded for treatment allocation during the data analysis. The allocation code will be revealed only after the data analysis has been completed.
Randomised Clinical Trial
A Randomised Clinical Trial (RCT) with a six-month follow-up is used to evaluate the effectiveness and cost-effectiveness of an EAP to prevent chronicity in patients with acute SC, compared to usual care.A computer-generated random sequence table is used to randomise the patients to EAP or usual care. Neither the patient nor the GP, nor the trained therapist, can be blinded for the allocated treatment. The trained therapist is also the researcher coordinating the RCT and conducting the data analysis, but is blinded for treatment allocation during the data analysis. The allocation code will be revealed only after the data analysis has been completed.Treatments Usual care (UC) is applied according to the Dutch College of General Practitioners guidelines for SC (version 1999)[ 19 ]. Management during the first two weeks consists of a wait-and-see policy with information and advice about shoulder complaints, possibly supplemented with analgesics or nonsteroidal anti-inflammatory drugs. If this approach has little or no effect, up to three corticosteroid injections can be given. Physiotherapy is considered for complaints persisting after six weeks or more. If the SC persist, referral to a hospital-based specialist may be considered. The focus of the EAP is to maintain or induce the proper cognitions by education and to stimulate adequate behaviour by means of advice on activities of daily living. Table  2  shows the components of the EAP. The EAP is administered by specially trained GPs or an ambulant therapist (CDB) trained to provide the EAP. The ambulant therapist administers the EAP when no trained GP is available in the living area of the patient. Table 2 Elements of the education and activation programme Education  • Information on the origin, nature and prognosis of the SC  • Information on possible interventions and their effects (tailored to the patient's questions and needs)  • Information on the effect of cognitions and behaviour on the perpetuation of the SC Activation When no alterations in activities have occurred due to the SC  • Positive reinforcement  • Instruction to be aware of possible changes When alterations in activities have occurred due to the SC  • Identification of up to three altered frequent activities of daily living  • Determination of the desired level of activity and the size of the steps needed to reach this level The EAP consists of a minimum of two sessions and a maximum of six follow-up sessions over a period of six weeks. Each session may last up to 20 minutes. The first and second sessions are organised in the general practice setting by the trained GP, or at the patient's home by the ambulant EAP therapist. The other sessions are provided by telephone. Education The first part of the EAP has an educational purpose, and focuses on information about the origin, nature and prognosis of the SC, possible interventions and their effects, the impact on activities of daily living and its consequences and the patient's own possibility to contribute to recovery. This information is tailored to the patients' questions and needs and is based on the information available in the Dutch College of General Practitioners guidelines for SC. In addition, the effect of cognitions and behaviour on the perpetuation of the SC is clarified to the patient by an example. If possible, this example refers to a condition or circumstance the patient has experienced, such as a broken bone or back pain. The patient is helped by the trained GP or the trained therapist to explore whether his or her thoughts about the SC are justified. Negative patterns of thinking are modified into adequate and accurate thoughts. Activation The second part of the EAP consists of a time contingent activation programme, based on the principles of operant learning. It focuses on gradually increasing activities of daily living, despite the pain. Potential avoidance of activities is countered by reinforcement of continuation or resumption of usual activities. Positive reinforcement is used to stimulate patients with a normal activity pattern, in spite of their SC, to continue their activities. This positive reinforcement may be enough to achieve continuation of the desired activities [ 13 ]. These patients are also instructed to be aware of possible changes in their activities that could lead to undesirable behaviour such as reduced use of the affected shoulder. Patients who have reduced their normal activities are helped to identify up to three frequent activities of daily living that they have reduced as a result of the SC. These activities are stepwise gradually increased to the desired level of activity in a time-contingent manner. The desired level of activity and the magnitude of the increases are determined and agreed upon by the EAP therapist and the patient. The patient and the EAP therapist also plan a progress evaluation, which is used to positively reinforce the patient's behaviour if the gradual increase has been correctly implemented or to adjust the magnitude of the increases if the original objectives prove too optimistic.
Treatments
Usual care (UC) is applied according to the Dutch College of General Practitioners guidelines for SC (version 1999)[ 19 ]. Management during the first two weeks consists of a wait-and-see policy with information and advice about shoulder complaints, possibly supplemented with analgesics or nonsteroidal anti-inflammatory drugs. If this approach has little or no effect, up to three corticosteroid injections can be given. Physiotherapy is considered for complaints persisting after six weeks or more. If the SC persist, referral to a hospital-based specialist may be considered.The focus of the EAP is to maintain or induce the proper cognitions by education and to stimulate adequate behaviour by means of advice on activities of daily living. Table  2  shows the components of the EAP. The EAP is administered by specially trained GPs or an ambulant therapist (CDB) trained to provide the EAP. The ambulant therapist administers the EAP when no trained GP is available in the living area of the patient.Elements of the education and activation programmeEducationActivationThe EAP consists of a minimum of two sessions and a maximum of six follow-up sessions over a period of six weeks. Each session may last up to 20 minutes. The first and second sessions are organised in the general practice setting by the trained GP, or at the patient's home by the ambulant EAP therapist. The other sessions are provided by telephone.Education The first part of the EAP has an educational purpose, and focuses on information about the origin, nature and prognosis of the SC, possible interventions and their effects, the impact on activities of daily living and its consequences and the patient's own possibility to contribute to recovery. This information is tailored to the patients' questions and needs and is based on the information available in the Dutch College of General Practitioners guidelines for SC. In addition, the effect of cognitions and behaviour on the perpetuation of the SC is clarified to the patient by an example. If possible, this example refers to a condition or circumstance the patient has experienced, such as a broken bone or back pain. The patient is helped by the trained GP or the trained therapist to explore whether his or her thoughts about the SC are justified. Negative patterns of thinking are modified into adequate and accurate thoughts.
Education
The first part of the EAP has an educational purpose, and focuses on information about the origin, nature and prognosis of the SC, possible interventions and their effects, the impact on activities of daily living and its consequences and the patient's own possibility to contribute to recovery. This information is tailored to the patients' questions and needs and is based on the information available in the Dutch College of General Practitioners guidelines for SC.In addition, the effect of cognitions and behaviour on the perpetuation of the SC is clarified to the patient by an example. If possible, this example refers to a condition or circumstance the patient has experienced, such as a broken bone or back pain. The patient is helped by the trained GP or the trained therapist to explore whether his or her thoughts about the SC are justified. Negative patterns of thinking are modified into adequate and accurate thoughts.Activation The second part of the EAP consists of a time contingent activation programme, based on the principles of operant learning. It focuses on gradually increasing activities of daily living, despite the pain. Potential avoidance of activities is countered by reinforcement of continuation or resumption of usual activities. Positive reinforcement is used to stimulate patients with a normal activity pattern, in spite of their SC, to continue their activities. This positive reinforcement may be enough to achieve continuation of the desired activities [ 13 ]. These patients are also instructed to be aware of possible changes in their activities that could lead to undesirable behaviour such as reduced use of the affected shoulder. Patients who have reduced their normal activities are helped to identify up to three frequent activities of daily living that they have reduced as a result of the SC. These activities are stepwise gradually increased to the desired level of activity in a time-contingent manner. The desired level of activity and the magnitude of the increases are determined and agreed upon by the EAP therapist and the patient. The patient and the EAP therapist also plan a progress evaluation, which is used to positively reinforce the patient's behaviour if the gradual increase has been correctly implemented or to adjust the magnitude of the increases if the original objectives prove too optimistic.
Activation
The second part of the EAP consists of a time contingent activation programme, based on the principles of operant learning. It focuses on gradually increasing activities of daily living, despite the pain.Potential avoidance of activities is countered by reinforcement of continuation or resumption of usual activities.Positive reinforcement is used to stimulate patients with a normal activity pattern, in spite of their SC, to continue their activities. This positive reinforcement may be enough to achieve continuation of the desired activities [ 13 ]. These patients are also instructed to be aware of possible changes in their activities that could lead to undesirable behaviour such as reduced use of the affected shoulder.Patients who have reduced their normal activities are helped to identify up to three frequent activities of daily living that they have reduced as a result of the SC. These activities are stepwise gradually increased to the desired level of activity in a time-contingent manner. The desired level of activity and the magnitude of the increases are determined and agreed upon by the EAP therapist and the patient.The patient and the EAP therapist also plan a progress evaluation, which is used to positively reinforce the patient's behaviour if the gradual increase has been correctly implemented or to adjust the magnitude of the increases if the original objectives prove too optimistic.Measurements The first outcome measure is the perceived recovery of the patient. Patients are considered to be recovered when they report to be much improved or fully recovered, on an 7-point ordinal scale, after six months. The second outcome measure is that of functional limitations in activities of daily living. This variable is assessed by a 16-item questionnaire, the shoulder disability questionnaire (SDQ)[ 20 ], with a scoring range of 0 to 16. A reduction of the score on this questionnaire implies a reduction in functional limitations. The outcome measures are recorded at 6, 12 and 26 weeks after randomisation. The SDQ is also measured at baseline. A cost diary [ 21 ] is used to assess health care utilisation, direct non-medical costs and indirect costs. A complete overview of baseline measures, prognostic measures, process measures and outcome measures is given in table  3 . Table 3 Variables Baseline measures T = 0 Demographic variables  • Age  • Gender  • Employment status Specific disease characteristics  • Affected side  • Possible cause of shoulder complaints  • Duration of complaints  • History of shoulder complaints Co-morbidity Physical activity Workload Treatment credibility and preference Prognostic measures T = 0 Mobility of glenohumeral joint  • HIB (hand in back), HIN (hand in neck), passive exorotation  • Active and passive abduction Mobility of cervicothoracal spine Severity of main complaint Psychosocial variables  • Anxiety 1  • Depression 1  • Somatisation 1  • Distress 1 Job content Outcome measures T = 1,2,3 Perceived recovery of complaints Functional limitations to daily activities 2 Process measures T = 0,1,2,3 Psychosocial variables  • Kinesiophobia 3  • Fear avoidance and beliefs 4  • Catastrophising 5  • Coping with pain 5  • Internal locus of control 5  • External locus of control 5 Global assessment Shoulder pain 6 General health 7 Cost T = 0–26 weeks Health care utilisation 8 Direct non-medical costs Indirect costs 1  four-dimensional complaint list [25] 2  Shoulder Disability Questionnaire [20] 3  Tampa Scale for Kinesiophobia – Dutch version (partly) [26] 4  Fear Avoidance and Beliefs Questionnaire – Dutch version (partly) [27] 5  Pain Coping and Cognition List [28] 6  Shoulder Pain Score [29] 7  Generic Health Related Quality of Life [30] 8  Cost Diary [21]
Measurements
The first outcome measure is the perceived recovery of the patient. Patients are considered to be recovered when they report to be much improved or fully recovered, on an 7-point ordinal scale, after six months.The second outcome measure is that of functional limitations in activities of daily living. This variable is assessed by a 16-item questionnaire, the shoulder disability questionnaire (SDQ)[ 20 ], with a scoring range of 0 to 16. A reduction of the score on this questionnaire implies a reduction in functional limitations. The outcome measures are recorded at 6, 12 and 26 weeks after randomisation. The SDQ is also measured at baseline. A cost diary [ 21 ] is used to assess health care utilisation, direct non-medical costs and indirect costs. A complete overview of baseline measures, prognostic measures, process measures and outcome measures is given in table  3 .VariablesBaseline measures T = 0Prognostic measures T = 0Outcome measures T = 1,2,3Process measures T = 0,1,2,3Cost T = 0–26 weeks1  four-dimensional complaint list [25]2  Shoulder Disability Questionnaire [20]3  Tampa Scale for Kinesiophobia – Dutch version (partly) [26]4  Fear Avoidance and Beliefs Questionnaire – Dutch version (partly) [27]5  Pain Coping and Cognition List [28]6  Shoulder Pain Score [29]7  Generic Health Related Quality of Life [30]8  Cost Diary [21]Data analysis The statistical analysis will be carried out according to the 'intention-to-treat' principle. Differences between groups, with 95% confidence intervals, will be calculated for each outcome measure. The study groups will be compared by an independent samples t-test for changes since baseline for continuous outcome variables and the chi-square test for categorical outcome variables. In addition, the corresponding baseline value for each continuous outcome will be used as a covariate. The analysis will be repeated taking any loss-to-follow-up into account by applying a sensitivity analysis in which all patients who are lost to follow-up are first considered to show the largest observed improvement and then the largest observed deterioration in outcome measures. The analyses of the difference in change for the outcomes at three and six months will account for the repeated measures character of the data. Baseline characteristics that are a priori considered to be possible prognostic factors for outcome variables, as well as post-randomisation differences between the groups, will be handled as potential confounders. Their influence will be evaluated by means of multivariable regression analyses. In the case of confounding, adjusted effect estimates will also be reported.
Data analysis
The statistical analysis will be carried out according to the 'intention-to-treat' principle. Differences between groups, with 95% confidence intervals, will be calculated for each outcome measure. The study groups will be compared by an independent samples t-test for changes since baseline for continuous outcome variables and the chi-square test for categorical outcome variables. In addition, the corresponding baseline value for each continuous outcome will be used as a covariate.The analysis will be repeated taking any loss-to-follow-up into account by applying a sensitivity analysis in which all patients who are lost to follow-up are first considered to show the largest observed improvement and then the largest observed deterioration in outcome measures.The analyses of the difference in change for the outcomes at three and six months will account for the repeated measures character of the data. Baseline characteristics that are a priori considered to be possible prognostic factors for outcome variables, as well as post-randomisation differences between the groups, will be handled as potential confounders. Their influence will be evaluated by means of multivariable regression analyses. In the case of confounding, adjusted effect estimates will also be reported.Sample size About half of all newly presented episodes of SC in general practice are reported to last for at least six months. A number needed to treat of 4.5 after six months is considered clinically relevant. This implies an absolute reduction of 22% of the proportion of patients with SC after six months. With a two-sided alpha of 0.05 and a statistical power (1-β) of 0.80, 70 patients per treatment group are needed to detect a difference in favour of the EAP compared to usual care after six months.
Sample size
About half of all newly presented episodes of SC in general practice are reported to last for at least six months. A number needed to treat of 4.5 after six months is considered clinically relevant. This implies an absolute reduction of 22% of the proportion of patients with SC after six months. With a two-sided alpha of 0.05 and a statistical power (1-β) of 0.80, 70 patients per treatment group are needed to detect a difference in favour of the EAP compared to usual care after six months.Embedding in the Dutch Shoulder Disability Study This RCT is part of the Dutch Shoulder Disability Study, a comprehensive prognostic cohort study on SC, with randomised controlled interventions in subcohorts. The Dutch Shoulder Disability Study is funded by the Netherlands Organisation for Scientific Research (NWO, grant number 904-65-901).
Embedding in the Dutch Shoulder Disability Study
This RCT is part of the Dutch Shoulder Disability Study, a comprehensive prognostic cohort study on SC, with randomised controlled interventions in subcohorts. The Dutch Shoulder Disability Study is funded by the Netherlands Organisation for Scientific Research (NWO, grant number 904-65-901).Discussion Reasons for publishing a study design There are several reasons to publish a study design before the results are available. The main reason is that it provides an opportunity to counteract publication bias, that is, the phenomenon whereby a study producing positive results is more likely to be published than a study showing no difference between the study groups [ 22 ], [23]. Hence, if the design is published but not the results, the study can still be included in a systematic review because data can be retrieved from the researcher [24]. Another reason is that it gives researchers the opportunity to reflect upon the study design independently of the results. When results run counter to the researchers' expectations, methodological flaws are usually examined. But when the results are in line with expectations, methodological flaws are more likely to be overlooked. [ 22 ] The third reason arises from the tendency among randomised controlled studies to deviate from their original designs, mainly because of practical problems. Such deviations from the study design may affect the study results. Publishing the study design forces researchers to test its implementation and to answer for any deviations from the design. Finally, this article offers us an opportunity to describe the rationale and content of the intervention in greater detail than the methods section of an article reporting the results of the RCT would do [24]. Applicability in general practice The EAP is a brief intervention that can easily be administered by GPs in addition to the usual care according to the guidelines. This might give GPs an instrument to prevent the development of chronic SC in the early stages of the complaints by focusing on psychological and social determinants. Time schedule The inclusion of patients in the study lasted until December 31 st  2003. Data collection will be completed in June 2004. Currently, 108 patients have been included and are being followed up.
Discussion
Reasons for publishing a study design There are several reasons to publish a study design before the results are available. The main reason is that it provides an opportunity to counteract publication bias, that is, the phenomenon whereby a study producing positive results is more likely to be published than a study showing no difference between the study groups [ 22 ], [23]. Hence, if the design is published but not the results, the study can still be included in a systematic review because data can be retrieved from the researcher [24]. Another reason is that it gives researchers the opportunity to reflect upon the study design independently of the results. When results run counter to the researchers' expectations, methodological flaws are usually examined. But when the results are in line with expectations, methodological flaws are more likely to be overlooked. [ 22 ] The third reason arises from the tendency among randomised controlled studies to deviate from their original designs, mainly because of practical problems. Such deviations from the study design may affect the study results. Publishing the study design forces researchers to test its implementation and to answer for any deviations from the design. Finally, this article offers us an opportunity to describe the rationale and content of the intervention in greater detail than the methods section of an article reporting the results of the RCT would do [24].
Reasons for publishing a study design
There are several reasons to publish a study design before the results are available. The main reason is that it provides an opportunity to counteract publication bias, that is, the phenomenon whereby a study producing positive results is more likely to be published than a study showing no difference between the study groups [ 22 ], [23]. Hence, if the design is published but not the results, the study can still be included in a systematic review because data can be retrieved from the researcher [24].Another reason is that it gives researchers the opportunity to reflect upon the study design independently of the results. When results run counter to the researchers' expectations, methodological flaws are usually examined. But when the results are in line with expectations, methodological flaws are more likely to be overlooked. [ 22 ]The third reason arises from the tendency among randomised controlled studies to deviate from their original designs, mainly because of practical problems. Such deviations from the study design may affect the study results. Publishing the study design forces researchers to test its implementation and to answer for any deviations from the design.Finally, this article offers us an opportunity to describe the rationale and content of the intervention in greater detail than the methods section of an article reporting the results of the RCT would do [24].Applicability in general practice The EAP is a brief intervention that can easily be administered by GPs in addition to the usual care according to the guidelines. This might give GPs an instrument to prevent the development of chronic SC in the early stages of the complaints by focusing on psychological and social determinants.
Applicability in general practice
The EAP is a brief intervention that can easily be administered by GPs in addition to the usual care according to the guidelines. This might give GPs an instrument to prevent the development of chronic SC in the early stages of the complaints by focusing on psychological and social determinants.Time schedule The inclusion of patients in the study lasted until December 31 st  2003. Data collection will be completed in June 2004. Currently, 108 patients have been included and are being followed up.
Time schedule
The inclusion of patients in the study lasted until December 31 st  2003. Data collection will be completed in June 2004. Currently, 108 patients have been included and are being followed up.Abbreviations SC: Shoulder Complaints GP: General Practitioner IASP: International Association for the Study of Pain EAP: Education and Activation Programme RCT: Randomised Clinical Trial UC: Usual Care CDB: Camiel De Bruijn SDQ: Shoulder Disability Questionnaire NWO: Netherlands Organisation for Scientific Research
Abbreviations
SC: Shoulder ComplaintsGP: General PractitionerIASP: International Association for the Study of PainEAP: Education and Activation ProgrammeRCT: Randomised Clinical TrialUC: Usual CareCDB: Camiel De BruijnSDQ: Shoulder Disability QuestionnaireNWO: Netherlands Organisation for Scientific ResearchCompeting interests The author(s) declare that they have no competing interests.
Competing interests
The author(s) declare that they have no competing interests.Authors' contributions CDB participated in the design of the study, will provide the EAP as an ambulant therapist, coordinate the data collection, will perform the statistical analysis and publish the results. RDB participated in the design of the study and will participate in the statistical analysis. JG, MG, WVDH and G-JD also participated in the design of the study. AK participated in the development of the education and activation programme and will conduct the training of the general practitioners that will give the education and activation programme. GVDH conceived of the study, and participated in its design. All authors read and approved the final manuscript.
Authors' contributions
CDB participated in the design of the study, will provide the EAP as an ambulant therapist, coordinate the data collection, will perform the statistical analysis and publish the results. RDB participated in the design of the study and will participate in the statistical analysis. JG, MG, WVDH and G-JD also participated in the design of the study. AK participated in the development of the education and activation programme and will conduct the training of the general practitioners that will give the education and activation programme. GVDH conceived of the study, and participated in its design. All authors read and approved the final manuscript.Pre-publication history The pre-publication history for this paper can be accessed here:
Pre-publication history
The pre-publication history for this paper can be accessed here: