Minimally important difference and predictors of change in quality of life in type 2 diabetes: A community-based survey in China.
BACKGROUND
To identify the minimally important difference (MID) of the EQ-5D-3L and determinants of change in quality of life (QoL) as measured by the EQ-5D-3L over 1 year for Chinese type 2 diabetic patients (T2DPs).


METHODS
Clinically diagnosed T2DPs were recruited from 66 community health centres in five Chinese cities using a multistage quota sampling method between December 2010 and October 2011. Demographics, diabetes-related information, and health-related behaviours were collected at baseline. The EQ-5D-3L was administered at baseline and at 12 months. Anchor-based and distribution-based approaches were employed to estimate MIDs. Using the MIDs as cut-points, we identified the change in EQ-5D-3L-measured QoL into "worsening," "no change," and "bettering." Logistic and ordered logistic regressions were conducted for those who reported best possible EQ-5D health state ("best possible HS") and impaired EQ-5D health states ("impaired HS") at baseline, respectively. Explanatory variables included demographics, diabetes-related information, and health-related behaviours.


RESULTS
A total of 1958 patients (54.9% female, mean age 61.2 years, mean diabetes duration 7.9 years) were included in our analysis. MIDs of the EQ-5D-3L for deterioration and improvement were estimated as -0.066 to -0.003, and 0.049 to 0.077, respectively. For the impaired HS group, older age, lower education, and less exercise were significant predictors for worsening in QoL; whereas, those predictors were older age, female gender, and lower income for the best possible HS group.


CONCLUSIONS
Minimally important differences for deterioration and improvement were estimated for the EQ-5D-3L. Age, gender, education, income, and exercise were significant determinants of QoL change for Chinese T2DPs.
['Jin|Xuejing|X|', 'Liu|Gordon G|GG|', 'Gerstein|Hertzel C|HC|', 'Levine|Mitchell A H|MAH|', 'Guan|Haijing|H|', 'Li|Hongchao|H|', 'Xie|Feng|F|0000-0003-3454-6266']
D000368:Aged D002681:China D003924:Diabetes Mellitus, Type 2 D005260:Female D006304:Health Status D006801:Humans D007206:Individuality D008297:Male D008875:Middle Aged D011379:Prognosis D011788:Quality of Life D012307:Risk Factors D012959:Socioeconomic Factors D011795:Surveys and Questionnaires
minimally important difference quality of life type 2 diabetes EQ-5D