The COVID-19 pandemic has been a devastating and enduring mass-bereavement event, with uniquely difficult sets of circumstances experienced by people bereaved at this time. However, little is known about the long-term consequences of these experiences, including the prevalence of Prolonged Grief Disorder (PGD) and other conditions in pandemic-bereaved populations.n = 711), c. 8 (n = 383), 13 (n = 295), and 25 (n = 185) months post-bereavement. Using measures of Prolonged Grief Disorder (PGD) (Traumatic Grief Inventory), grief vulnerability , and social support , this analysis examines how participant characteristics, characteristics of the deceased and pandemic-related circumstances  are associated with grief outcomes, with a focus on symptoms of PGD.A longitudinal survey of people bereaved in the UK between 16 March 2020 and 2 January 2021, with data collected at baseline  of participants were female, with a mean age of 49.5 (SD 12.9). 311 (43.8%) deaths were from confirmed/suspected COVID-19. Sample demographics were relatively stable across time points. 34.6% of participants met the cut-off for indicated PGD at c. 13 months bereaved and 28.6% at final follow-up. Social isolation and loneliness in early bereavement and lack of social support over time strongly contributed to higher levels of prolonged grief symptoms, while feeling well supported by healthcare professionals following the death was associated with reduced levels of prolonged grief symptoms. Characteristics of the deceased most strongly associated with lower levels of prolonged grief symptoms, were a more distant relationship , an expected death and death occurring in a care-home. Participant characteristics associated with higher levels of prolonged grief symptoms included low level of formal education and existence of medical conditions.Results suggest higher than expected levels of PGD compared with pre-pandemic times, with important implications for bereavement policy, provision and practice now  and in preparedness for future pandemics and mass-bereavement events . However, little is currently known about the longer-term consequences of pandemic bereavement, including which groups of people are most at risk of adverse outcomes over time and whether initial predictions of increased levels of Prolonged Grief Disorder (PGD) are substantiated –4. AlthoMost evidence to date on the grief and mental health consequences of pandemic bereavement is from studies conducted in China , 13, NorOf particular interest early on in the pandemic was whether COVID-19 deaths would be associated with worse grief experiences than other types of death. Higher levels of grief and other psychological conditions have been identified among those bereaved by COVID-19 than would be expected in non-pandemic populations –14, 17, However, to date no longitudinal results that we know of have been published on grief outcomes during the pandemic, and most of the above mentioned studies included pandemic-bereaved populations who were on average bereaved less than 6 months before e.g., , 20, 23], 2320, 22.2.1.A longitudinal survey of people bereaved during the pandemic in the UK. The web-based survey was conducted as part of a larger mixed methods study, which aimed to investigate the grief experiences, support needs and use of bereavement support by people bereaved during the pandemic –26. The The Checklist for Reporting Results of Internet E-Surveys  was foll2.2.An open web survey was designed by the research team, which includes a public representative (KS), with input from the study advisory group. Each survey was piloted, refined with public representatives with experience of bereavement, and tested by the study advisory group and colleagues. Non-randomized open and closed questions covered end of life experiences, grief experiences, and perceived needs for, access to and experiences of formal and informal bereavement support , 22.2.3.Prolonged Grief Disorder was assessed at surveys T2-T4 using the Traumatic Grief Inventory Self-Report version (TGI-SR) ((TGI-SR) , 40. Thi(TGI-SR) . The TGI(TGI-SR) , 40.Vulnerability in Grief was assessed in all survey time points using the validated 9-item Adult Attitude to Grief (AAG) scale (G) scale , with ouG) scale , 23. TheG) scale , which iG) scale ]. AlthouSocial support was assessed using the Inventory of Social Support (ISS) (rt (ISS) . The ISS2.4.We assessed whether participant characteristics and characteristics of the deceased, experiences of end-of-life care and pandemic-related problems independently predicted levels of PGD symptoms and grief vulnerability and whether perceived social support mediated the relationships of these variables and symptoms of PGD. Factors included in the analysis are recognized risk factors for poor bereavement outcomes  , 44–46 oSix items at baseline assessed pandemic-related challenges prior to and after the death, e.g., being unable to visit the person who died prior to their death, restricted funeral arrangements, social isolation and loneliness. All items were answered yes/no. Respondents were asked to tick all experiences that applied to them.See 2.5.The baseline survey was administered via JISCInclusion criteria for study enrolment: aged 18+; family member or close friend bereaved since social-distancing requirements were introduced in the UK (16/03/2020); death occurred in the UK; ability to consent. The initial section of the survey requested informed consent and details data protection.2.6.All analysis was performed using R (version 4.1.1), implemented in R-StudioIndependent variables were classified into three categories: characteristics of the participant/bereaved, characteristics of the deceased, and characteristics of the experience of bereavement. The latter included the six items assessing the pandemic-related challenges prior to and after the death as well as whether participants felt well supported by healthcare professionals immediately after the death. For the analysis of levels of PGD symptoms, ISS was also included in this category.Independent variables with more than 5% missing data at any of the four time points were not considered for analysis. A summary analysis of missing data was carried out for the remaining variables to check if there were any obvious patterns of missingness and none were identified. In order to maximize the sample, results presented are from analysis carried on all data available for each variable or combination of variables used in each analysis, but all the analyses were also carried out using complete cases  as a control to ensure that the missing data were not causing a great influence in the results.Days since bereavement was scaled into z-scores due to the wide range of values. This variable was initially tested both as a linear and as a quadratic term, but the latter showed very small effects and did not improve the fit of the statistical models significantly and hence the scaled linear effect was used instead. Other genders besides male or female were not included in the analysis due to the very small sample sizes. For relationship with the deceased, the categories “other family member” and “colleague or friend” were merged into one category in the analysis. Likewise, for place of death, the categories “other” and “do not know” were also merged. The existence of any medical conditions, whether the bereaved respondent was unemployed during the pandemic and whether they had suffered any further bereavements throughout the study were considered cumulatively, i.e., if a participant had reported a medical condition, becoming unemployed or suffering a further bereavement in one round of the survey, that was carried through even though they might not have reported it again in a subsequent round.The first step of the analysis consisted of fitting Linear Mixed Models (LMMs) to assess the single effects of each independent variable on each of the outcome variables . The second step consisted of fitting LMMs for each group of variables in combination to assess which group of variables  were better at explaining each of the outcome variables.The third step consisted of fitting LMMs that included all groups of variables in combination to assess the effect of the experience of bereavement in each of the outcome variables, while controlling for the characteristics of the participant/bereaved and the characteristics of the deceased. These models failed to converge and, hence, a Principal Component Analysis (PCA) was carried out on the six items assessing the pandemic-related challenges prior to and after the death, to assess if these could be reduced to a smaller number of factors. The models were initially run with the factors from the PCA, instead of the six different items. Variables with negligible effect sizes were then removed and the factors were replaced by the six items in the reduced model. The final models were used to compute and plot predictions showing the change of IoV, ISS, and TGI scores across time for the different levels of the independent variables that showed medium or strong effect sizes. For the TGI (symptoms of PGD), two different models were fit, one with ISS as predictor and one without, to assess the role of ISS as a potential mediator of other predictors.p < 0.05) found in the single models were also tested in the final models. Model estimates and standardized effect sizes were used to evaluate the effect of each variable independently on IoV, ISS, and TGI scores; Cohen’s d were used for categorical predictors: d = 0.3: small effect, d = 0.5: medium effect, d = 0.8: large effect, d = 1.2: very large; and partial R for continuous predictors: <0.10: trivial effect, 0.1–0.3: small to medium effect, 0.3–0.5: medium to large effect, >0.50: large to very large effect  and conducted in accordance with the Declaration of Helsinki. All respondents provided informed consent.3.A total of 711 participants answered the survey at baseline (T1), 383 answered it in the second round (T2) and 295 answered it in the third round (T3), including 35 who had not completed T2. A total of 185 answered it on the fourth round (T4), two of whom had only completed T1 (but not T2 or T3) and 19 who had completed either T2 or T3. A total of 165 participants completed the survey at all time points.3.1.3.2.3.3.3.4.TGI: Mean TGI (PGD) score at T2 was 51.5. This decreased steadily across survey time points, dropping to 48.5 at T3 and 44.7 at T4. At T2 43.7% met the threshold for indicated PGD (≥54), dropping to 34.6% at T3 (c.13 months post-bereavement) and 28.6% at final follow up, c. 25 months post-bereavement.AAG: Mean IoV (grief vulnerability) score at baseline was 20.4, decreasing slightly but steadily to 18.7 at T3 and 18.3 at 24. At baseline 48.4% exhibited low levels of vulnerability ; 23.4% exhibited high levels , and 28.2% exhibited severe levels . By T4 67% exhibited low levels of vulnerability, 18.9% exhibited high levels and 13.5% demonstrated severe levels.ISS: Social support scores were stable and did not change across survey time points. Mean ISS score at T2,T3,T4 was 3.3 see . This co3.5.2 values for the models containing each set of variables. Across all the analyses, characteristics of the deceased were generally and consistently the best predictors of all three indices: TGI (PGD symptoms), ISS and IoV. For TGI and IoV, relationship with deceased, followed by place of death, showed the largest effect sizes across all variables, while for ISS, the largest effects were from feeling supported by health care professionals following the death and ethnicity, only then followed by place of death and relationship with deceased. Ethnicity also showed a large effect on TGI, with white respondents showing worse grief outcomes compared to minoritized ethnic respondents, but not on IoV. Qualifications showed large effects for TGI and IoV, with those from lower education levels showing worse grief outcomes, but not for ISS. All items related to contact prior to death showed small effects for all three indices, while items for social isolation showed large and very large effects for TGI and IoV; specifically sense of isolation and loneliness had a very large effect on TGI and a large effect on IoV, while restricted funeral arrangements had a large effect on TGI but a medium effect on IoV. Days since death had a larger effect on TGI than IoV or ISS; although the effect of the slope is not very large even for TGI, it represents a considerable change in TGI scores over an extended period of time .3.6.These were general patterns averaged across participants, but it was noticeable that for all indices of bereavement different participants would show different patterns, with some improving through time, some worsening through time, some showing oscillations but no real trend and some showing no change .3.7.The results from the full models examining the effects of the experiences of bereavement while controlling for characteristics of the participant and the bereaved, showed that sense of isolation and feeling supported by healthcare professionals were the most important experiences in predicting TGI and IoV scores, while only the latter was an important predictor of ISS. Those who felt very well supported by healthcare professionals showed better grief and support outcomes compared to all other groups. ISS score was also an important predictor of TGI; in the same model but without ISS, feeling supported by healthcare professionals showed a much larger effect on TGI than when ISS was included, which suggests that ISS has a mediating effect between feeling supported and TGI levels, while sense of isolation has both a direct and indirect effect on TGI. These patterns are depicted in Despite representing a relatively modest effect, being unable to visit a loved one prior to death had an increased effect on TGI once all other factors were accounted for . Restricted funeral arrangements showed a much smaller effect for IoV when other variables were controlled for than in the single model. Number of negative experiences during bereavement showed very low effect sizes across all three indices, once other variables were accounted for.3.8.Place of death and relationship with the deceased remained the strongest predictors of grief and support outcomes, although the effect of relationship with the deceased was generally smaller when other factors were accounted for, most noticeably for IoV. Specifically, the estimated differences in IoV between losing a partner or a parent or grandparent were much smaller than when the variable was considered in the single model. Those bereaved of a partner showed higher TGI scores and slightly higher IoV scores compared to other groups. Losing a child showed small differences in TGI and IoV scores compared to losing a partner when looked at in isolation, but when other factors were accounted for, those bereaved of a child showed smaller TGI and IoV scores than all other groups. However, confidence intervals for these differences are wide  and thesThere were generally worse outcomes for those who had a loved one dying in a hospice and best for those who had a loved one dying in a care home, with TGI scores also high for those on the “other” category. ISS scores were lowest for deaths in hospices and highest for the “other” category.An unexpected death had a negative effect on both TGI and IoV, while cause of death only had a meaningful influence on IoV—those who lost someone to COVID-19 had slightly worse outcomes, while age of deceased only had a meaningful influence on TGI, with worse outcomes for bereavements of younger people. Although only the linear trend was fitted for simplicity, visual analysis of the relationship between age of deceased and TGI showed a sharper decrease from the age of 70 years . These patterns are shown in Qualifications also showed important effects for TGI and IoV, with those with higher education levels showing better outcomes. Having medical conditions showed a negative effect for TGI. Ethnicity showed an estimated average difference of around 5 scale points in TGI level (with higher TGI scores for white group), but due to the small sample size and large variability in the minoritized ethnic group and potentially its relatively high association with ISS, this variable has an overall small effect size on TGI when controlling for other variables. These patterns are shown in Age of participant, further bereavements during the study, and whether people were unemployed during the pandemic showed the lowest effect sizes across all three indices, once other variables were accounted for.4.This analysis represents the only published longitudinal examination of COVID-19 pandemic grief outcomes that we are aware of, with a focus on symptoms of PGD as our primary outcome. In a sample of people bereaved during the first 9 months of the COVID-19 pandemic in the UK, we found decreasing but relatively high levels of indicated PGD at c. 8 (44%), 13 (35%), and 25 (29%) months post-bereavement. Factors most strongly associated with levels of PGD symptoms were those relating to the person who died, in terms of their relationship to the participant, where they died and whether the death was expected. Large effects relating to support were also observed, specifically isolation and loneliness around the time of bereavement and perceived social support over time, with support from healthcare professionals immediately following the death also a factor. Level of education and existence of medical conditions were the main participant characteristics found to have an effect. These findings have important implications for bereavement policy, provision and practice in the current COVID-recovery and post-pandemic period  and in preparedness for future pandemics and mass bereavement events .4.1.We found relatively high levels of indicated PGD and grief vulnerability (IoV) overall, and across time. As in other studies, time since death was negatively associated with overall levels of PGD symptoms , 34, andWe now summarize the factors associated with poorer grief outcomes and consider which of these factors might explain the apparently higher levels of indicated PGD that we observed in this pandemic-bereaved cohort.4.2.We found that, over time, relationship to the deceased continued to be strongly associated with symptoms of PGD and grief vulnerability, as in our baseline analysis . People Age of the deceased had a small but significant effect on symptoms of PGD , with y4.3.While worse outcomes have been identified for people bereaved by COVID-19 compared with pre- pandemic general bereaved populations –14, 17, As in our baseline analysis , place o4.4.There are a number of factors relating to the circumstances of the death that might be expected to have impacted upon grief levels. In previous quantitative and qualitative publications we identified experiences of sub-optimal end-of-life care, as healthcare systems and settings navigated the incredible strain and restrictions placed upon them , 24. As We found only small effects on PGD symptoms and grief vulnerability for factors relating to restricted contact at the end of life , although being able to visit the patient at the end of life increased in importance once other factors were controlled in the PGD model, suggesting the “real” impact of this experience may be somewhat masked by other factors. These relatively small effects are nonetheless surprising given the devastating impacts of these experiences that were described in our qualitative data, including lasting feelings of guilt, anger, regret , and the4.5.We found that loneliness and social isolation in early bereavement was strongly predictive of worse levels of PGD symptoms and grief vulnerability, as in our baseline analysis . Lower l4.6.Several demographic or participant factors were found to have an effect on support and grief outcomes. Existence of medical conditions was associated with higher levels of PGD symptoms (but not grief vulnerability), and a small negative (but non-significant) effect on perceived social support. This points toward the detrimental impact of poorer health status on a person’s ability to cope and adjust, in particular at a time where clinically vulnerable populations were required to “shield,” and opportunities for usual social and recreational activities and access to services were heavily restricted , 64. ThiAs in previous research, and our baseline analysis , lower lDespite the disproportionate impacts of the pandemic on minoritized ethnic communities, in terms of death-rates, and disruption to grieving practices and community networks , 78, thi4.7.This analysis has identified several pandemic-related factors which, in influencing grief outcomes, might at least partially explain the apparently higher levels of indicated PGD that we observed, compared with similar non-pandemic studies . When coWithin our qualitative findings, as in other studies , the sig4.8.This longitudinal study benefits from a large initial sample-size, with quantitative and qualitative data collected across four time points up to approximately 2 years post-bereavement. Although participant numbers decreased over this time-period, we retained sufficient numbers to enable robust analysis, albeit with reducing proportions of younger and older participants, and people from minoritized ethnic backgrounds or with lowest qualifications levels. The sample was reasonably well represented across geographical areas, education and deprivation, but was self-selecting and biased toward female and white respondents, despite targeting men and people from minoritized ethnic communities in our recruitment approaches. Due to missing data on religious/spiritual beliefs and sexual orientation we were also unable to consider the effects of these other aspects of participant identity and subjectivity that may have influenced their coping and grief experiences , 79, 80.4.9.Through subsequent qualitative interviews, we have explored in depth the experiences of people with characteristics less well represented in the survey, including men, people identifying with a sexual or ethnic minority background, with publication forthcoming. However, further research is required exploring the needs of bereaved people from minoritized ethnic and socially disadvantaged backgrounds, same-sex couples, men, children and young people, and people with pre-existing mental health conditions, as we navigate the COVID-recovery phase and beyond. Research exploring the impact of religious and spiritual beliefs would also help to address current gaps in the evidence . Given t5.We found relatively high-levels of indicated PGD at c. 8, 13, and 25 months post-bereavement when compared with similar non-pandemic studies of bereaved populations . SeveraHowever, effect sizes for many of these factors were in absolute terms “small,” and our qualitative insights paint a much fuller and more intricate picture than we could capture in our quantitative measures and analyses. Taken together, our mixed-methods findings suggest that is likely the combined and compounding effects of the many different challenging experiences of people bereaved during the pandemic that contributed to higher-levels of complex and prolonged grief.Based on these findings we make the following recommendations to inform bereavement support and policy at the present time and in future pandemics, many of which resonate with the recent report by the UK Commission on Bereavement .Implications for the current COVID-recovery phase and beyond:In view of the higher proportions of people experiencing or at risk of PGD following the pandemic, bereavement support services require increased investment to ensure adequate levels of specialist provision which can effectively cater for those with more complex needs, as well as robust methods of identifying and reaching people most in need of more intensive support. Bereaved people more likely to require such support include those grieving children, partners and siblings and following unexpected deaths, as well as people who are isolated and have limited social support, health conditions and low levels of formal education.Opportunities for informal emotional and social support should be strengthened through provision of peer-support groups, as well as compassionate community initiatives and educational programs which seek to improve grief literacy and the support available to people within existing social and community networks . CommuniPolicies and training should be implemented to ensure compassionate and supportive communication and behaviors from healthcare professionals at the end of life, especially in acute and care-home settings. “Follow-up” contact should be consistently delivered by care providers following the death and enable meaningful discussion and reflection on difficult and troubling experiences, with signposting to locally and nationally available bereavement support services.To ensure preparedness for future pandemics and other mass-bereavement events, best practice-guidance and related policies should be developed for:4. Health-care settings, with specific regard to managing and balancing infection-risk with the need to facilitate patient-family contact, including use of Personal Protective Equipment and remote communication-methods, and ensuring effective and compassionate communication with family members during times of crises.5. Funeral-providers and crematoria, including identifying different options for meaningful and alternative funeral and mourning practices when restrictions are needed. The role of funeral directors in providing compassionate and supportive responses should be recognized, including their roles in sign-posting to further support-services , 62.6. Managing social contact, recognizing the need to restrict social interaction in times of high-infection rates, while making allowances for those living alone and with particular vulnerabilities, including the recently bereaved. Greater understanding of permissible levels of “safe” contact relative to infection levels, and the best means of enabling this  would also be helpful.7. Rapid mobilization of locally and nationally coordinated bereavement support provision, including existing providers and other community organizations. Any such responses should involve proactive sign-posting to and advertising of such support, mechanisms for identifying those requiring more intensive specialist support, and crisis-specific training and practice- sharing to ensure that the support offered is crisis- as well as culturally-competent , 85.https://reshare.ukdataservice.ac.uk/855751.The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found at: UK Data Service via The studies involving humans were approved by the Cardiff University School of Medicine Research Ethics Committee. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.EH and LS designed the study, led the application for funding, and were co-principal investigators. EH drafted the manuscript. RM conducted the statistical analyses, with data management assistance from SG. RM wrote the statistical analysis and results sections of the manuscript. SG, ML, AB, DF, LM, KS, AP, and SS were members of the research team or the study advisory group and contributed to the design of the study and survey. All authors contributed to drafting the manuscript and read and approved the final manuscript.This study was funded by the UKRI/ESRC (Grant No. ES/V012053/1), with the final fourth survey round funded by a Marie Curie Small Grant (MCSGS-21-701). This project was also supported by the Marie Curie core grant funding to the Marie Curie Research Centre, Cardiff University (grant no. MCCC-FCO-11-C). EH, AB, SS, and LM were supported by the Marie Curie core grant funding (grant no. MCCC-FCO-11-C). The funder was not involved in the study design, implementation, analysis or interpretation of results and has not contributed to this manuscript.AP declared a potential financial interest relating to lobbying by the Childhood Bereavement Network and National Bereavement Alliance for additional financial support for the bereavement sector.The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


To assess risk factors associated with motor development delay at three months of age. Cross-sectional study with mothers and their three-month-old babies in Southern Brazil. The Bayley-III Scale of Infant and Toddler Development (BSID-III) and the Alberta Infant Motor Scale (AIMS) were used to assess motor development. We evaluated 756 mothers and their three-month-old babies. The overall mean motor development assessed by the BSID-III and the AIMS was 104.7 (SD 13.5) and 55.4 (SD 25.4), respectively. When assessed by the BSID-III, the lowest motor development scores were among babies born by cesarean delivery (p = 0.002), prematurely (p < 0.001), and with low birth weight (p < 0.001). When assessed by the AIMS, babies born prematurely (p = 0.002) and with low birth weight (p=0.004) had the lowest motor development means. After a cluster analysis, we found that babies born by cesarean delivery, with low birth weight, and prematurely had more impaired motor development compared with children born without any risk factors. Identifying risk factors allows the implementation of early interventions to prevent motor development delay and, therefore, reduce the probability of other future problems. During the first years of life, motor skills increases greatly. Regarding motor development, the evolution occurs in a craniocaudal manner, with the acquisition of cervical tone at around three months of age, followed by the ability to seat at six months, and the ability to stand at around 12 months of age. In early life, movement variation serves for exploration, followed by trial an error2.Child development is a process that begins during pregnancy and involves several factors, such as physical growth, neurological maturation, and the building of skills related to behavior and the cognitive, social, and affective spheres3, and environmental characteristics, such as lower maternal age, lower maternal schooling, and substance abuse  during pregnancy9. On the other hand, studies point to some protective factors that contribute to a better motor development of the baby, such as breastfeeding and vaginal delivery12.Current literature considers motor development a non-linear process with transition phases, which are affected by many risk factors. These factors include child and birth-related characteristics, such as being born prematurely and/or with low birth weight, being a boy, and having fewer siblings16. Most research on child development that focus on motor skills comes from developed countries and uses samples with children at older ages. Therefore, assessing early motor development in developing countries is also essential, so that appropriate interventions can be adopted when necessary, ensuring that children have a better development throughout their life and preventing further damage.Delays in child development in different age groups are strongly associated with premature birth and, consequently, with low birth weight17. A better understanding of these changes is extremely important, since premature babies may have negative effects in psychomotor skills and impaired learning when they reach school age. Early diagnosis of these alterations is essential so that interventions on child development begin as early as possible18.From this perspective, technological advances in the care of premature newborns have contributed to the reduction of mortality levels in this population. However, the number of premature babies with alterations in neuromotor function, hearing, language, and cognitive development has increased19. Moreover, alcohol and tobacco use during pregnancy21, cardiovascular, respiratory, neurological disorders, neonatal infections, malnutrition, low socioeconomic conditions, and poor parental schooling are the main causes for motor development delay23.Besides prematurity, low birth weight (LBW) is a factor that may be related to impaired child development. The World Health Organization (WHO) defines LBW as a birth weight below 2,500 grams, regardless of the gestational period. LBW is a determinant factor of malnutrition, influencing child growth and development, and, in the long term, may affect health conditions in adulthoodIdentifying risk factors for delayed motor development in early childhood is essential for planning interventions, counseling parents, and updating and specifying information for professionals about children at early ages. Therefore, this study aimed to assess risk factors, such as sociodemographic, maternal, behavioral, gestational, perinatal, and child-related variables, for motor development delay in the first three months of a child’s life.Instituto Brasileiro de Geografia e Estatística (Brazilian Institute of Statistics - IBGE) as primary sampling units. For more details, see Pinheiro et al.24. From May 2016 to August 2018, the research team invited women up to 24 weeks pregnant to participate in the study. After this step and 90 days after delivery, these women and their children were assessed. This assessment took place at the institution where the study was conducted, in a structured, standardized, and stimulus-neutral room, so that the babies could be assessed by trained psychologists and physical therapists. The duration of the motor development assessment was about 30 minutes. During the baby’s assessment, the mother was in the same room, answering the study interview and available to attend to the baby’s needs, such as breastfeeding and sleeping.This population-based cross-sectional study was performed with pregnant women in the urban area of the city of Pelotas, Rio Grande do Sul, Brazil. The sampling process included multiple stages, with the census sectors delimited by the 26.In order to assess motor development at three months of age, the motor subscale of the Bayley-III Scale of Infant and Toddler Development (BSID-III) was applied. This is considered the “gold standard” tool for the assessment of child development. The BSID-III is individually administered and assesses motor development by the observation of changes in the child’s posture and behavior in response to standardized stimuli. The BSID-III has no validated cut-off point for the Brazilian population. Thus, for the analysis in this study, the composite score was used, which is calculated by the weighted score according to the child’s age corrected for prematurity. Higher scores show better motor development27, was also used. The AIMS is an observational scale for the assessment of broad motor development and includes 58 items that analyzes children’s spontaneous movement in four subscales (or postures): prone positioning (21 items), supine positioning (nine items), sitting (12 items), and standing (16 items). The raw score is obtained by summing the points from the four subscales. Based on this score, and considering the corrected age of the child, the gross motor performance percentile is identified28.Since the BSID-III has no validated cut-off point for the Brazilian population, the Alberta Infant Motor Scale (AIMS), which is validated for this populationAssociação Brasileira de Empresas de Pesquisa (Brazilian Association of Research Companies - ABEP), which is based on the accumulation of material goods, the schooling level of the head of household, and whether the residence has piped water and paved street. This classification divides the participants into five levels , based on the scores achieved. The letter “A” refers to the highest socioeconomic level and the letter “E” to the lowest29. For this study, the levels were combined: high (A+B), medium (C), and low (D+E).The socioeconomic classification used the criteria of the Moreover, the following maternal variables were assessed: age , schooling , living with a partner (no/yes), psychiatric drug use during pregnancy (no/yes), and alcohol and tobacco use during pregnancy (no/yes). The following gestational and baby variables were also considered: first pregnancy (no/yes), gestational hypertension (no/yes), gestational diabetes (no/yes), type of delivery , baby’s sex (boy/girl), prematurity (up to 36 weeks and six days), low birth weight , and siblings (no/yes). The variable “psychological and/or drug treatment” was included for adjustment purposes as a confounding factor, considering its possible effect on motor development.After encoding the tools, data were double entered into EpiData 3.1 to test their consistency. For data analysis, SPSS software version 24.0 was used. In univariate analysis, simple and relative frequency, mean, and standard deviation were used to describe the characteristics of the sample. In order to compare the means between motor development and exposure variables, the analysis of variance (ANOVA) test was used. For the adjusted analysis, all variables with p < 0.20 were included in a linear regression. A cluster analysis was performed for the BSID-III (the gold standard for assessing motor development), using ANOVA and Tukey’s test. Thus, the following categories were created: 1) none of the perinatal risk factors; 2) cesarean delivery as the only risk factor; 3) cesarean delivery and low birth weight as risk factors; 4) cesarean delivery and prematurity as risk factors; and 5) three risk factors .To verify multicollinearity in the regression analyses between the variables that remained in the regression model, the variance inflation factor (VIF) and tolerance were estimated. A VIF above 4 or a tolerance below 0.25 points the existence of multicollinearity between the variables. All participants signed an informed consent form, allowing them and their babies to participate. The research team advised the mothers on activities to stimulate the baby’s development.We evaluated 756 mothers and their three-months-old babies. The lowest means for motor development at three months of age were among children of older and multiparous mothers, who were born by cesarean delivery, prematurely, with low birth weight, and had siblings, regardless of the tool used (p < 0.05). We included other variables in the multivariate analysis, since they showed p < 0.20 in the bivariate analysis: socioeconomic status (both tools), maternal age, and living with a partner (AIMS).After the adjusted analysis, the lowest means for motor development at three months of age assessed by the BSID-III remained associated with cesarean delivery (p = 0.002), prematurity (p < 0.001), and low birth weight (p < 0.001). Children born by cesarean delivery scored 3.1 points (95%CI: −5.0 to −1.1) lower in the mean of the BSID-III compared with babies born by vaginal delivery. Premature babies scored 8.8 points (95%CI: −12.4 to −5.3) lower in the mean of the BSID-III compared with term children. Babies born with low birth weight scored 7.1 points (95%CI: −11.0 to −3.2) lower in the mean of the BSID-III compared with newborns with normal birth weight. Having siblings showed a tendency to impair motor development (p = 0.051). Babies with siblings scored 2.6 points lower in the mean of the BSID-III compared with only children .We also performed a multivariate linear regression analysis considering the variables with p < 0.20 in the bivariate analysis  and the cluster variable. After the adjustment, the cluster variable was the only one still associated with motor development with β −0.07 . All VIF values were below 4 and tolerance was above 0.25, which ensures that multicollinearity is not a problem.Our results showed that the means for motor development in three-month-old children were lower among babies born by cesarean delivery, prematurely, and with low birth weight, and who had siblings. We also found that children with three risk factors  had a difference of almost 20 points less in mean motor development (BSID-III) compared with babies without any risk factors.30, babies born by cesarean delivery had a greater risk of delayed fine and gross motor skills at six months of age than babies born by vaginal delivery. Similarly, Zaigham et al.31 showed that children born by cesarean delivery had lower fine and gross motor skills at four and 12 months of age. In this same study, the authors showed that babies born by vaginal delivery had better neurodevelopmental scores at four months compared with babies born by cesarean delivery. They also observed these differences for gross motor skills at 12 months of age. According to Cavaggioni et al.32, cesarean delivery provides evidence of psychological risks in fine motor skills, language expressions, and the manifestation of adaptive behavior. However, Rodrigues and Silva33 state that even though the motor skills of children born by cesarean delivery are inferior compared with babies born by vaginal delivery, they would still be in accordance with the typical parameters for their age. On the other hand, manipulative skills, visual language, speech skills, and personal autonomy are significantly reduced in children born by cesarean delivery33.Regarding the type of delivery, other studies also show an association between cesarean delivery and poorer motor development. In a study conducted by Sun et al.34. Other studies also found the same association at 12 months36 and the same results when using AIMS. According to Lefebvre et al.37 in their study with extremely premature children (28 weeks or less) at four, 10, and 12 months of age, motor development delay was higher at four months. In an Australian study with children born at 30 weeks or less, 53% had poor motor development at an adjusted age of 12 months38.Regarding the relationship between prematurity and motor development, we can assume that a premature child is more susceptible to changes in motor development, especially in the first years of life. A study conducted in Chicago, USA, with 106 premature babies, found an association between low motor development and prematurity, both in motor development results measured by the Test of Infant Motor Performance (TIMP) at three months, and in motor development measured by the BSID-III at two years of adjusted age39 found that premature children with low birth weight had poorer motor development compared with term children on the AIMS subscales. Premature and low birth weight babies had delayed motor development from one to 19 months of adjusted age compared with children born at term39. Similarly, Zhang et al.40 found that babies with low birth weight had a higher risk of being diagnosed with motor development delay from one to six months of age compared with babies born with normal weight.Similarly, low birth weight was associated with motor development delay. Syrengelas et al.In the cluster analysis, we also found that the more risk factors, the lower the motor development mean. However, even considering cesarean delivery as the only risk factor, the groups showed a difference in their motor development means. Therefore, we reinforce that a cesarean section is a procedure that should be performed only if necessary, in cases where the life of the mother or the baby is at risk.41. Therefore, since cesarean delivery is a risk factor for delayed motor development, investing in awareness policies for both pregnant women and health professionals is necessary.The occurrence of elective cesarean sections in Brazil has increased greatly since the late 1980s. In general, in the Brazilian public health system, different professionals provide care to pregnant women during the prenatal period, and cesarean delivery is indicated upon diagnosis of complications in pregnancy or childbirth. On the other hand, private health services allow the scheduling of a cesarean delivery by the indication of the obstetrician or by choice of the pregnant woman. One of the reasons that leads pregnant women to opt for cesarean delivery is the fear of vaginal delivery, especially due to the pain they may feel, which is more intense in primiparous women. In a study conducted in Brazil, more than half of the pregnant women evaluated underwent a cesarean delivery, and almost 90% of them used private health servicesOur study has limitations. We collected data about the alcohol and tobacco use during pregnancy in the second stage of the study (after delivery), thus, we can assume a memory bias. Moreover, these data may be underreported: women may understand that alcohol and tobacco use is harmful to the baby’s health and may omit their use at the time of the interview.On the other hand, this population-based study included two scales considered the gold standard for motor development. Early assessment of motor development in babies is scarce in the literature, especially in Brazil. Adopting adequate measures for early detection of development delays in children may improve their development at subsequent ages.This study sought to identify the risk factors associated with poor motor development at three months of age. Our results showed an association between lower motor development and cesarean delivery, prematurity, and low birth weight. The identification of risk factors for delayed motor development may allow early interventions related to factors that can be avoided in some cases, such as those observed in this study. Thus, this study helps expand knowledge about the determinants of poor early motor development in Brazil.


This study aimed to examine depressive symptoms associated with interpersonal sensitivity, sleep quality, and psychological capital among postgraduate students during static campus management after the COVID-19 pandemic in China.t-test and ANOVA. The PROCESS macro was used to determine the relationship between interpersonal sensitivity and depression, together with the independent and serial mediating role of psychological capital and sleep quality.Research data were obtained during static campus management (10–19 April 2022) after the reappearance of COVID-19 in cities in eastern China. We collected data through an online questionnaire, and the anonymous self-reported questionnaire included the Patient Health Questionnaire, the interpersonal sensitivity subscale of Symptom Checklist-90, the Psychological Capital Questionnaire, and the Pittsburgh Sleep Quality Index. analysis of variance was performed using p < 0.001). Between interpersonal sensitivity and depressive symptoms, psychological capital and sleep quality played a single mediating role  and a chain mediating role together .A total of 2,554 postgraduate students were included in this study. The prevalence of mild, moderate, and severe depressive symptoms was 30.97, 6.58, and 1.45%, respectively. Interpersonal sensitivity was significantly associated with depressive symptoms (direct effect = 0.183, Interpersonal sensitivity has a significant influence on depression among Chinese graduate students. Psychological capital and sleep quality may not only independently mediate the relationship between interpersonal sensitivity and depression, but also co-play a chain-mediating role in the pathway from interpersonal sensitivity to depression. Positive psychological interventions and sleep guidance may be beneficial in alleviating depressive symptoms. To control the rapid spread of COVID-19, the World Health Organization (WHO) has recommended a series of measures. One of those measures, lockdown, has proven effective in controlling the spread of the disease . The proLocking down university campuses is a static management method used in China. In order to protect students from the COVID-19 pandemic, all college students are not allowed to enter and leave the campus gates at will during static management, but they are allowed to carry out activities on campus according to their actual needs, such as walking, eating, and shopping for daily necessities. It was found that the mental health of college students had been affected by campus lockdown , more soIn addition to depression, sleep was also affected during the lockdown . Sleep qInterpersonal sensitivity itself is a prominent mental health problem faced by contemporary college students , reflectPsychological capital (PsyCap) has been defined as the positive psychological state that individuals show in the process of their own growth and development, including four components: self-efficacy, optimism, hope, and resilience . PreviouIn conclusion, this study examines interpersonal sensitivity, psychological capital, sleep quality, and depression to investigate the mental health of graduate students in the context of COVID-19 and campus lockdown, providing guidance for university mental health departments to deal with depression caused by COVID-19 and other pandemic diseases. Thus, our study further explores the mediating role of psychological capital and sleep quality on the pathway from interpersonal sensitivity to depressive symptoms, which are listed below along with a multiple mediation model :Hypothesis 1: interpersonal sensitivity has a significant impact on depression among Chinese postgraduate students;Hypothesis 2: PsyCap and sleep quality can independently mediate the relationship between interpersonal sensitivity and depression;Hypothesis 3: PsyCap and sleep quality co-play a cascading mediating role in the pathway from interpersonal sensitivity to depression.The research sample data were collected from the Student Mental Health Center at a university in eastern China, 2 weeks into its campus static management (10–19 April 2022) after the reappearance of COVID-19 in the city in 2022. All participants completed the questionnaire by scanning a QR code and then filling it out. Inclusion criteria: postgraduate students enrolled in the target university; postgraduate students who volunteered to participate in the survey after reading the instructions.Exclusion criteria: in principle, there are no exclusion criteria since the online questionnaire platform used for this research sets the restriction that the questionnaire cannot be submitted until the questions are answered. During data screening, researchers excluded the questionnaires that: (1) had obvious logical errors; (2) had a clear pattern of responses.This study was approved by the Ethics Committee of Xuzhou Medical University. All procedures were carried out in accordance with relevant ethical guidelines and regulations.via the questionnaire, including gender, age, grade, region, whether being an only child, whether living with parents during childhood, and whether having concerns about COVID-19, eating breakfast, and exercising or not. Second, the survey included four scales as the assessment tools (see below for details):The survey consisted of two sections. First, the social, demographic, and other relevant characteristics of the postgraduate students were recorded The 9-item Patient Health Questionnaire Depression Scale (PHQ-9) was used to measure the severity of depressive symptoms. The PHQ-9 is the most widely used depression measure in the world and has shown good reliability and validity in the context of the pandemic . The scaThe interpersonal sensitivity subscale of Symptom Checklist 90 (SCL-90) was used , which hThe psychological capital of college students was measured by the Psychological Capital Questionnaire (PCQ-24), which was developed by Luthans et al. , and theThe Pittsburgh Sleep Quality Index (PSQI) was adopted to measure the sleep quality of individuals. The scale was developed by Buysse et al.  and inclt-test and one-way analysis of variance (ANOVA) were employed to describe the distribution of the four variables. The PROCESS v 3.4 macro was used to test the serial multiple mediation model, and models 4 and 6 were selected . Independent samples selected . All of post-hoc analysis in G*Power was used to calculate the achieved power (1-β) of the sample size of our study. Since the process macro was based on the multiple regression model, the fixed model of linear multiple regression was set as the statistical test. The calculated parameters were as follows: the effect size f2 was entered as 0.15, α was 0.05, the total sample was 2554, and the number of final predictors was 12 (the number of tested predictors was 3). The result showed that the statistical power of the regression model was 100%, indicating that 2554 postgraduate students reached the necessary sample size.We adopted G*Power 3.1.9.2 to calculate the sample size. A year = 25.85, standard deviation = 2.63), with 36.53% of male participants and 63.47% of female participants , were concerned about COVID-19 (p < 0.001), ate breakfast (p < 0.001), and exercised (p < 0.001). Specifically, the postgraduate students who did not live with parents when they were between 0 and 6 years old, were not concerned about COVID-19, did not eat breakfast, and did not exercise had higher scores on interpersonal sensitivity, sleep quality, and depression, and lower scores on PsyCap.In our study, the mean score of the PHQ-9 was 4.51, and the prevalence of mild, moderate, and severe depressive symptoms was 30.97, 6.58, and 1.45%, respectively. According to the PSQI threshold, the proportion of participants with poor sleep quality was 35.40%. The average score of interpersonal sensitivity and PsyCap were 1.91 and 104.92, respectively. Interestingly, there was a significant difference in the four variables among all postgraduate students who lived with parents during childhood  and negatively related to PsyCap . Interpersonal sensitivity was also positively related to sleep quality . In addition, a negative correlation was identified between PsyCap and sleep quality .Correlations for all variables are presented in a = −0.547, p < 0.001). With the statistically significant effect of PsyCap on depression , it appears that interpersonal sensitivity had a positive direct effect , and further had an indirect effect on depression via partially mediating the role of PsyCap   .c’ = 0.290, p < 0.001) and sleep quality . In addition, sleep quality was also positively associated with interpersonal sensitivity . A significant indirect effect of interpersonal sensitivity on depression via sleep quality was observed   . H1 and p < 0.001). In addition, interpersonal sensitivity had a significant effect on PsyCap and sleep quality . Depression was impacted by PsyCap and sleep quality . As the basis of the serial model, a significant regression result was observed between PsyCap and sleep quality .After the single mediation model was tested, we conducted the serial multiple mediation model to verify H3. As shown in via PsyCap and sleep quality . In the pathway via PsyCap only, the indirect effect was 0.136 (95% bootstrap CI: 0.108–0.166); and in the pathway via sleep quality only, the indirect effect was 0.100 (95% bootstrap CI: 0.080–0.122). In support of H3, the specific indirect effect of interpersonal sensitivity on depression through both mediators in the serial pathway  is also significant . Based on the above results, our three hypotheses are all supported.status quo of depression and the mediating role of PsyCap and sleep quality on the relationship between interpersonal sensitivity and depression among Chinese postgraduate students. We found a high self-reported prevalence of depression among postgraduate students using the validated self-report questionnaire during the lockdown period, which was generally higher than the result (33.87%) reported by Liang  had the same differential changes as depression in these students with different choices about having lived with parents in childhood, who were concerned about information on COVID-19, having breakfast and exercising. In general, postgraduate students who did not live with their parents in childhood, were not concerned about the epidemic, did not have breakfast, or did not exercise had the poorest mental health. Postgraduate students should pay attention to these aspects and make changes in these aspects to ease psychological symptoms.Central to our research findings is the examination of PsyCap and sleep quality are postulated as jointly mediating variables in a model of the relationship between interpersonal sensitivity and depression. Our findings demonstrated that the serial multiple mediation effect of PsyCap and sleep quality in sequence and the separate mediation effect of them were both significant. The results also provided new insights into the differences in the strength of the indirect effect of PsyCap and sleep quality on this association. Specifically, it was found that the serial indirect effect of interpersonal sensitivity on depression through PsyCap was found to be stronger than the other two indirect effect pathways.Our research found that interpersonal sensitivity has a significant impact on depression among Chinese postgraduate students. Some of the manifestations of interpersonal sensitivity are highly consistent with depression, especially characteristics such as sensitivity and suspiciousness, and low self-esteem . People Furthermore, sleep quality also independently played a mediating role in the relationship, which was consistent with previous research . StudiesOur findings also revealed the serial multiple mediating roles of PsyCap and sleep quality in the pathway from interpersonal sensitivity to depression in Chinese postgraduate students. Sleep quality was negatively affected by PsyCap in our study, which was consistent with previous research in different populations , 43. TheSeveral limitations of our research should be acknowledged. First, due to the nature of the cross-sectional study, the causal relationship of the mediation model was not sufficiently effective. A longitudinal study method should be adopted to test the causal relationship. Second, our study only included postgraduate students from only one university, which limited the generalizability of our findings. The scope of the study should be expanded. Third, because the main aim of this study was to investigate an intervention mechanism, the effect of covariates on depression was not examined, which may have led to biased results.This study provided empirical evidence on the pathways linking interpersonal sensitivity and depression among Chinese postgraduate students. The results showed that interpersonal sensitivity was significantly associated with depressive symptoms. Psychological capital and sleep quality played independent and cumulative mediating roles in the relationship between interpersonal sensitivity and depression. In addition, the single mediation model indicated that psychological capital had a greater impact than sleep quality on the relationship between interpersonal sensitivity and depression. The finding has important implications for the importance of positive psychological factors concerning the mental health of postgraduate students during the lockdown. Positive psychological interventions and sleep guidance should be considered to alleviate depressive symptoms in postgraduate students.The original contributions presented in this study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.This studies was involving human participants were reviewed and approved by the Xuzhou Medical University Ethics Committee. The patients/participants provided their written informed consent to participate in this study.All authors listed have made a substantial, direct, and intellectual contribution to the work, and approved it for publication.


This study aimed to examine the associations between workload and satisfaction with working conditions and mental health  of healthcare workers collecting test samples during the local outbreaks of COVID-19, and explore satisfaction with working conditions as a moderator of these relationships.A total of 1,349 participants were obtained via an online survey in Zhengzhou, Henan Province, China. Multivariate regression was used to assess the associations between workload and satisfaction with working conditions and anxiety disorder, depression, and somatization. The simple slope analysis and Johnson-Neyman technique were used to assess the effect value and change trend of the moderator.The prevalence of anxiety disorder, depression, and somatization were 8.6, 6.9, and 19.2% of healthcare workers collecting test samples, respectively. High levels of workload were associated with an increased risk of an anxiety disorder , depression , and somatization , while high satisfaction of working conditions was associated with a reduction in the risk of these outcomes, and ORs (95%CI) were 0.35 (0.20–0.64), 0.27 (0.13–0.56), and 0.32 (0.21–0.48), respectively. The findings also indicated that a weaker association between workload and anxiety disorder, as well as depression and somatization, has been reported in those with a high level of satisfaction with working conditions.Workload significantly increased the risk of healthcare workers suffering from psychological problems, while satisfaction with working conditions alleviated these negative effects, and effective resource support was crucial for healthcare workers. The COVID-19 pandemic has presented an unprecedented challenge to healthcare workers (HCWs) . StudiesIn the post-pandemic era, local outbreaks and distributions of COVID-19 have become a new pandemic pattern. When positive patients appeared in a region or city, nucleic acid testing of close contacts or indirect possible contacts was an important strategy for the early detection of positive patients. Notably, the incubation period of the virus or errors in the test may lead to a misleading result in a single test and an increased risk of epidemic spread. Therefore, repeated nucleic acid sampling and testing have become the primary strategy for the identification of positive cases. In addition, the increased rate of transmission of mutated viruses in the population means that nucleic acid sample collectors need to complete the testing of millions of people in a short period to identify infected individuals in a timely manner, which was undoubtedly a huge challenge for healthcare workers.The Job Demand—Control Model (JD-C) believed that work stress comes from the joint influence of characteristics that the job demands and job control . Job demThe present study aimed to examine workload and satisfaction with working conditions and mental health  and explore satisfaction with working conditions as a moderator of these relationships.www.wjx.cn. First, a questionnaire introduction and explanation document were provided to indicate the purpose and object of this survey. Then, participants who met the inclusion criteria and were willing to participate in the survey could complete and submit the questionnaire through the link in the attachment. To ensure the quality of the questionnaire, we filled out and estimated the time to complete the questionnaire in advance, and then the time spent by participants filling out the questionnaire was used to evaluate the quality of the questionnaire. Those participants who completed the questionnaire in <180 s were excluded, and a total of 1,349 valid questionnaires were obtained for analysis (88.2% were women).The data of the present study were obtained from an online survey conducted in Zhengzhou, Henan Province of China, from 1 September 2021 to 7 September 2021 when a wave of local epidemics had just been confined in Henan Province. The participants of this study were healthcare workers who participated in nucleic acid detection when a local epidemic occurred. The questionnaire was distributed via an online platform, called This study was following the ethical standards of the responsible committee on human experimentation, and all participants read the instructions and informed consent before filling in the questionnaire. Participants could stop answering and quit at any time if they were unwilling to continue answering.The 20-item Self-rating Anxiety Scale (SAS) was used to assess anxiety disorder over the previous 2 weeks  in termsThe 9-item Patient Health Questionnaire (PHQ-9) was used to assess depression . The scaThe 15-item Patient Health Questionnaire (PHQ-15) was employed to assess the severity of somatization . The scaPearson correlation coefficient of the two items was 0.122 (p < 0.05). In addition, we further divided the workload into a binary variable, if any variable reported as “severe” or “long” of the number of participating waves and shift time, then it was divided into high workload (coded as 1), and others were divided into low workload (coded as 0).In this study, the workload of healthcare workers was measured by the number of tasks and continuous working time , which wp > 0.05, CFI = 1.00, TLI = 1.00, RMSEA = 0.001, SRMR = 0.002. Satisfaction with working condition latent factor was used for subsequent analyses. Satisfaction with working conditions was measured by the total score of the seven items. Cronbach's alpha in the present study was 0.938. The last 27th percentile of the total score was further divided into a high group and defined as high satisfaction (coded as 1), and others were divided into low satisfaction (coded as 0).Satisfaction with the working condition was accessed via seven items , and cooperation level of collected objects). Healthcare workers reported their satisfaction with these conditions during their work. Responses were given on a 5-point scale, and scores ranged from 1 (very dissatisfied) to 5 (very satisfied). A confirmatory factor analysis using SPSS AMOS 25.0  revealed that four of the seven items loaded significantly onto one factor . Model fVariables including age, gender , occupation (physician vs. nurse), marriage status, self-rated health, and prior participation in the first-line anti-epidemic were considered in the study. Self-rated health was assessed by an item: “How do you evaluate your health?”. Available options ranged from 1 (poor) to 4 (great). We assessed whether health workers participated in the first wave outbreak in early 2020, and the responses were divided into two categories (yes or no).M ± SD). First, binary logistic regression analysis was used to evaluate the associations between workload and satisfaction and outcomes . Two models were constructed to explore these effects: Model 1 was the crude model and no variables were adjusted, and Model 2 was an adjusted model of controlling for age, gender, marriage status, self-rated health, and prior participation in the first-line anti-epidemic. Next, multiple linear regression was used to assess the relationships between workload and satisfaction with working conditions with outcomes  after adjusting for a series of covariates, and moderation of the relationship between workload and mental health outcomes  by satisfaction with working conditions was assessed using regression models with an interaction term (workload x satisfaction with working conditions). Finally, a simple slope analysis was used to assess the associations between workload and psychological outcomes, respectively for low and high SWCs . Furthermore, the Johnson-Neyman method was used to assess trends in the effects of workload on mental outcomes at different values of moderating variables , and continuity variables  were described using mean ± standard deviation , and PROCESS v3.3  was usedAmong the 1,349 participants, 88.2% were women and more than half were between 20 and 40 years old. More than half of the participants (78.0%) were nurses, and 54.0% of the participants had participated in the first-line anti-epidemic . The resThe results showed that a high level of workload significantly increased the risk of an anxiety disorder , depression , and somatization , while high level of satisfaction reduced these risks, and OR and 95% CI were 0.35 (0.20–0.64), 0.27 (0.13–0.56), and 0.32 (0.21–0.48) after adjusting for gender, age, occupation, participating in the first-line anti-epidemic, education level, married status, and self-rated health .The results also suggested that women reported a higher risk of somatization than men . Healthcare workers aged 26–30 years old  and 31–35 years old  reported a higher risk of anxiety disorder. The results also suggested that participants who participated in the first-line anti-epidemic before reported a higher risk of somatization . Compared with the education level of college, those with the education level of bachelor's degree and master's degree or above reported lower odds of anxiety disorder, depression, and somatization, but for anxiety disorders and depression, the statistical significance only was observed in the education level of bachelor's degree, and OR (95%CI) were 0.39 (0.24–0.63) and 0.47 (0.28–0.79). In addition, participants with moderate and good self-reported health were more likely to report a lower risk of anxiety disorder, depression, and somatization than those who had poor health.b = 0.73, p < 0.001), depression , and somatization  in healthcare workers, even after adjusting a series of covariates, while satisfaction with working conditions was negatively associated with anxiety disorder, depression, and somatization , depression , and somatization .Similar to logistic regression analysis, multiple-line regression results showed that workload positively predicted anxiety disorder  . Similarly, for healthcare workers with low SWC, high workload was associated with depression . However, for healthcare workers with high SWC, high workload was not significantly associated with depression   and high SWC  (< 0.001) . However= 0.124) . Healthc< 0.001) .Furthermore, the results in the Johnson-Neyman method showed that the cut-off value for SWC moderating the association between workload and anxiety disorder was 0.79 , which wThis study examined the association between workload and the mental (including depression and anxiety disorder) and physical health of healthcare workers during a local outbreak of COVID-19 and explored whether satisfaction with working conditions moderated this association. The results of the study showed that workload was positively related to anxiety disorder, depression, and somatization among healthcare workers collecting test samples, and this effect was moderated by healthcare workers' satisfaction with their working conditions. Understanding the associations among these factors had a heuristic value for public planning and interventions aiming to reduce the negative psychological and physical outcomes of healthcare workers.In addition, the results also suggested that women reported higher levels of anxiety disorders, depression, and anxiety disorders compared to men but only reached significant levels of somatization.The findings suggested that women were more likely to report somatization as compared to men, and that the risk of anxiety and depression was comparable in men and women, which could be explained by the fact that the overall physical fitness of women and the body's ability to bear the load was weaker than that of men . It was The results also showed that healthcare workers aged 26–35 years reported a higher risk of higher anxiety disorder. The possible reasons for this were that healthcare workers in this age group had just entered the workforce and were on the rise in their careers, thus health concerns and career confusion might have increased their anxiety levels. Compared with college, healthcare workers with undergraduate and graduate education or above have a lower risk of depressive symptoms, as well as somatic symptoms, but a significant difference was only observed in undergraduate education. Studies indicated a U-shaped association between depression and education level, the perceived subjective wellbeing from a graduate degree was much lower compared to getting a college degree . In addiThe findings of the present study indicated that workload was a significant predictor of anxiety disorder, depression, and somatization of healthcare workers collecting test samples. This was consistent with previous studies in which excessive workload during a new coronary pneumonia outbreak was strongly associated with the mental health of medical staff, such as anxiety disorder, depression, insomnia, and somatization , 31, 32.This study found that a higher level of satisfaction with working conditions negatively predicted the mental problems of healthcare workers. Not only that, but satisfaction with working conditions also mitigated the negative effects of workload on the poor mental health of healthcare workers. The results of this study confirmed the theoretical hypothesis of the J-R model. On the one hand, more resources positively impacted the level of psychological health and reduced emotional exhaustion and negative idleness in healthcare workers, thus improving psychological health. On the other hand, such resources also alleviated the negative effects of work characteristics on psychological symptoms. As Bakker et al.  pointed There are several limitations to this study. First, this study was a cross-sectional investigation, and this kind of study limited the ability of causal inference. Further longitudinal studies are needed to replicate and reproduce these findings. Second, data were collected based on a web-based questionnaire, which could not guarantee the response rate. Finally, the measurement of workload in this study was limited only in terms of shift duration and the number of nucleic acid tests participated in; therefore, future studies should be conducted using more refined instruments to evaluate these associations.Overall, this study highlighted the negative impact of workload on the psychological health of sampled healthcare workers in the post-epidemic era, which could be moderated by satisfaction with working conditions. Healthcare workers still faced beyond-neglect psychological challenges, and proactive health service measures should be considered to alleviate these challenges.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by Zhengzhou University. The patients/participants provided their written informed consent to participate in this study.KW: conceptualization, data analysis, writing—original draft, and visualization. BY: methodology, data curation, writing—review, and editing. LZ: investigation, data curation, writing—review, and editing. CW: conceptualization, resources, formal analysis, supervision, and project administration. All authors read and approved the final manuscript.


The indoor–outdoor difference is only significant  when considering studies performed exclusively on Asian athletes . When performing the analyses within each season, no significant differences are observed between indoor and outdoor athletes. To control for multiple cofounders  simultaneously, we constructed a multivariate meta-regression model, which estimated a serum vitamin D concentration lower by 4.446 ng/mL in indoor athletes. While a multivariate model suggests that outdoor training is associated with slightly higher vitamin D concentrations when controlling for the season, latitude, and Asian/Caucasian race, the type of training has a numerically and clinically small impact. This suggests that vitamin D levels and the need for supplementation should not be decided based on training type alone.Vitamin D, its importance in different processes taking place in the human body, the effects of abnormal levels of this hormone, either too low or too high, and the need for supplementation have been extensively researched thus far. Variances in exposure to sunlight can cause vitamin D levels to fluctuate. Indoor activity can be a factor for these fluctuations and can lead to a decrease in vitamin D levels. We conducted a systematic review and meta-analysis aiming to identify whether indoor compared to outdoor training has a significant influence on vitamin D levels; we also performed subgroup analyses and multivariate meta-regression. The type of training has an impact on vitamin D levels that is influenced by multiple cofounders. In a subgroup analysis not considering cofounders, the mean serum vitamin D was 3.73 ng/mL higher in outdoor athletes, a difference which barely fails to achieve significance ( For the human body, vitamin D is an essential fat-soluble hormone with multiple functions, the main one being the regulation of calcium and phosphate levels . This anThe synthesis of vitamin D is influenced by the amount of sunlight  on exposed skin. Before it can begin its activity, it must be metabolically activated by hydroxylation, a process that takes place in the liver and subsequently in the kidneys and is modulated by multiple factors, such as 1,25(OH)2D, the phosphate and calcium levels in the blood, and the parathyroid hormone . The amoOptimal levels, with increasing requirements due to aging, are situated at 50–100 nmol/L, with low values linked to osteomalacia in adults and rickets in children but also increased risk of death caused by cancer, cardiovascular disease . FurtherDue to its many functions, especially those engaged in maintaining bone, muscle, and immune health, vitamin D plays a very important role in an athlete’s performance . CurrentConsidering the aforementioned importance of vitamin D for an athlete’s quality of life and performance and that its level is closely linked to sun exposure, we designed a study aimed at identifying if practicing indoor sports as opposed to outdoor sports can significantly impact vitamin D levels. Due to the fact that vitamin D levels are significantly influenced by factors other than training type, we also investigated the impact of the season, self-reported race, latitude, and gender, and whether the type of training remains an independent predictor of serum vitamin D when accounting for these variables.We conducted a systematic review aiming to identify whether there were any differences in vitamin D levels among athletes practicing indoors or outdoors. This study was performed in accordance with Preferred Reported Items for Systematic Reviews and Meta-Analysis (PRISMA) ,25,26. WAs very few studies investigated the difference between vitamin D levels in indoor and outdoor athletes directly compared to the relative abundance of studies of vitamin D levels in athletes practicing a specific sport, we proceeded with a meta-analysis of means, rather than mean differences, on which we then performed subgroup analyses.We included articles and dissertations indexed by the queried databases and returned by our search strategies, for which the full text was available, either in English or German or for which an English version was available. All articles had to be published between 1 January 2012 and 31 December 2022.We considered all observational studies as eligible, including retrospective or prospective cohorts, as well as cross-sectional studies. Interventional studies were only considered eligible if they included baseline measurements before any intervention was applied.Articles of type: case reports, case series, or secondary literature ;Articles for which full text was impossible to source: conference abstracts and posters and unpublished data;Retracted articles;Patients under treatment for which pre-treatment data were unavailable;Patients suffering from illness for which pre-illness data were unavailable;Studies completed in silico, in vitro, or in vivo on nonhuman subjects.Reasons for the exclusion of articles were:We have searched the following electronic databases: PubMed, Embase, Scopus, ScienceDirect, ProQuest, and Lilacs, as well as Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, International Clinical Trials Registry Platform (of the WHO) and EBSCO Open Dissertations and Katalog der Deutschen Nationalbibliothek. The searches were performed in January 2023. We analyzed articles published in English or German or for those with English or German versions available. Only articles published and available in the mentioned databases between 1 January 2012 and 31 December 2022 were taken into consideration.Search strategies were established following a PICO model: population of study (athletes excluding athletes suffering from illness or under treatment for which no baseline data was available), intervention (indoor sports), comparison (outdoor sports), and outcome (vitamin D mean). The search query used for each database is available in One author  and VFC for the other databases executed the searches in the databases. Results were downloaded in available standard formats and then centralized using Clarivate EndNote, which was then used to remove duplicates. Remaining information about each article, meaning its title, authors, and web link, was introduced in a common database and then randomly assigned to two blinded authors for the screening of the title. Results were compared between the authors, and differences in opinion were solved by discussion. The remaining articles were then assigned to two authors (VFC and AVB) for abstract and full-text screening, as well as quality assessment and data extraction. Disagreements were solved by a third author (MB). All authors agreed with the final articles included in the meta-analysis.Vitamin D concentrations that were expressed in nmol/L were converted to ng/mL in order to allow pooling.Quality assessment was undertaken by two blinded authors (AVB and VFC), and disagreements were solved by discussion. The Newcastle–Ottawa scale  was usedIn terms of the scales’ design, the NOS tools have sections dedicated to selection, comparability, and either exposure or outcome; however, the maximum score for each section differs between scales . SubsequData extraction was undertaken by two blinded authors  following a standardized form and collecting the following information: mean, standard deviation, and sample size, as well as type of training (outdoor/indoor) and the following optional fields: gender, season , race , and latitude. For articles that reported subgroup-level data, we extracted data pertaining to the smallest nonoverlapping subgroups available. In order to avoid the ecological fallacy ,30, analmeta [metafor [All statistical analyses were performed using R (R Foundation)  with RStmeta  and meta[metafor .2 value [2 value over 75% as significant heterogeneity, and the DerSimonian-Laird τ2 estimate [2 fixed-effects test proposed by Borenstein and Higgins [We assessed heterogeneity using the I2 value , defininestimate . In all  Higgins  and thenθ is an intercept term signifying the effect size for 2 has a similar interpretation to linear regression, i.e., it can be interpreted as the fraction of variability that is explained by the predictor, while the test of moderators is an ANOVA omnibus test for the whole model and is analogous to the F-test in linear regression [Meta-regressions were performed following a mixed-effects, standard-error-weighted least squares model, using restricted maximum likelihood (REML) fitting. Similar to an ordinary least squares regression model, the equation of a mixed-effects meta-regression takes on the following form:gression .Small-study bias was evaluated by visual examination of funnel plots, as well as by means of Egger’s test , which iThe significance threshold was 0.05 for all tests.The database search identified 709 published articles and 38 clinical trial protocols. After removing duplicates, title screening was performed, which removed articles without the study topic or not matching the inclusion criteria. A total of 100 articles remained for abstract and full-text screening, and 33 articles remained in the final meta-analysis. We identified 21 cross-sectional studies, 10 cohort studies, 1 randomized controlled trial (RCT), and 1 before-and after study without a control group .For cross-sectional studies, the risk of bias was generally high, with a median score of 5 (of 10) and a maximum of 7 (in only two studies), with the main issues referring to sample selection. Specifically, only four studies were awarded at least 1 point (of 3) in this section: three received the point for sample representativeness , one article justified its sample size by power analysis, and one study reported a low non-respondent rate (of the two studies that reported response rates). One study  receiveSimilar deficiencies were observed for cohort studies: 2 of 10 articles received a point for cohort representativeness; regarding outcome assessments, 2 of 12 articles used self-reported outcomes, and none used blinded assessment. The comparability of the cohorts was mostly satisfactory (eight studies controlled for at least one factor), and other items were generally without issues; overall, a median score of 6.5 of 9 was obtained.The one identified RCT, that of Wyon et al. , had an The issues encountered in the single identified before-and-after study  refer toThe complete results for all articles, including scores for each item, are presented in Publication bias was evaluated by means of funnel plots and funnel plot asymmetry testing . While relatively symmetrical, the funnel plot for all included studies  shows wiIn order to verify whether heterogeneity in the study conditions obscures the presence of publication bias, we recreated the funnel plot and performed Egger’s test for studies grouped by season and type of sport (indoor or outdoor sport). The results are presented in To elucidate the differential influence of indoor and outdoor training on serum vitamin D concentration, we performed random-effects pooling after defining subgroups based on the type of sport. As meta-analysis software does not allow for nested subgroups, we first subsetted for the variables which we had previously identified as possible confounders, namely season and race.2 = 100%, τ2 = 76.55, p < 0.001).We first performed pooling on all available observations , obtaining a pooled mean vitamin D concentration of 29.32 ng/mL (95% CI: 27.49–31.14). The values show a very high level of heterogeneity (Iout = 2734) compared to the indoor group , leading to a mean difference of 3.73 ng/mL in favor of the outdoor group. The fixed-effects test for the subgroup differences suggests a trend toward significance . The forest plot is provided in After subsetting according to the type of training, we identified a numerically larger vitamin D concentration in the outdoor group  and the indoor  groups suffer from very high heterogeneity.Nonetheless, even after subsetting for the type of training, both the outdoor  compared to indoor athletes , for a mean difference of 9.85 ng/mL . Seasonality was comparable in the two subgroups, with one exception: Kim et al. [Subgroup analyses for Asian athletes  show a sm et al.  recruitem et al.  was perfout = 183) compared to the indoor group , the two confidence intervals are wide and overlapping, and the subgroup test fails to achieve significance (p = 0.12) partially due to the small pooled sample size in the indoor group.Very few available studies (five samples from two studies) provided data for African-American athletes . While tout = 1792) compared to indoor training , without reaching significance .In the case of Caucasian athletes , while t2 values of 95 and 96% for outdoor and indoor studies, respectively, compared to 100 and 99% in the overall analysis) but not for Caucasian athlete studies; heterogeneity is markedly reduced for African-American studies, but this can be attributed to the fact that very few studies remain for analysis.Performing the analyses within groups defined by self-reported race has led to a slight reduction in heterogeneity for the studies of Asian athletes  compared to indoor athletes , which is not statistically significant (p = 0.67).For spring studies , there is a minimal mean difference of 0.88 ng/mL in favor of outdoor athletes  compared to indoor athletes . Nonetheless, this fails to reach statistical significance (p = 0.40).For summer studies , the mean serum vitamin D is higher by 3.83 ng/mL in outdoor athletes  in indoor athletes in autumn studies . There were nine outdoor studies, providing 10 samples and nout = 479 observations; eight indoor studies were available, from which we extracted 10 samples and nin = 510 observations.Contrary to expectations, serum vitamin D is  higher  compared to indoor athletes . However, the subgroup test shows no significant differences (p = 0.35)For winter studies , the mean serum vitamin D is higher by 2.93 ng/mL in outdoor athletes   and Mill2 values are rather small , indicating that they are only responsible for a minor share of the variation in vitamin D levels.In the bivariate models, the only significant predictors of vitamin D levels are latitude and the type of sport. However, the Rt-test for the slope coefficient, they are not included in this table. Significant predictors are marked with an asterisk in the first column, while the intercept is significant in all models.The results of each bivariate regression are presented in θ represents the mean vitamin D level of athletes in the autumn studies.The effect of season was investigated by means of multivariate regression. In this case, the regression equation has the following form:2 value is rather high, indicating that 27.88% of the variance in vitamin D levels is explained by seasonality. In total, 72 studies were included, and the results are presented below in The coefficients of spring and winter are highly significant, indicating that vitamin D levels for athletes measured in spring and winter tend to be significantly lower compared to the ones in autumn. Summer has a slight positive effect on vitamin D levels but fails to reach statistical significance. Nonetheless, the RFinally, a multivariate model encompassing indoor/outdoor sport, season, and latitude was created, as described in the equation below:2 = 31.06%), it is a relatively small improvement compared to the season-only model and is also rather complex, with five coefficients, apart from the intercept, applied on a relatively small number of observations (n = 66).The results see  indicate2 value is rather high (52.98%), but may be inflated due to the large number of predictors and, implicitly, overfitting. Moreover, the impact of seasonality becomes less obvious, with winter being the only predictor which is significant at a 0.05 level of confidence.Considering the observations highlighted in Vitamin D is involved in multiple aspects of the metabolism and the workings of the human body, in the regulation of calcium levels, parathyroid hormone and calcitonin production, and bone mineral density, as well as in innate immunity , respiraTo date, our meta-analysis is the first to quantify the impact of indoor/outdoor training on serum vitamin D levels and complements the work of Farrokhyar et al. . While F2 = 3.69%).When ignoring the possibility of confounding, the effect of the type of training is statistically significant, albeit small in magnitude ; the amount of variance in vitamin D levels explained by indoor/outdoor training is likewise minimal  on 40 observations, leading to 6.67 observations per predictor, lower than the 10 observations per predictor recommended by the Cochrane Handbook to prevent overfitting (itself a recommendation based on a rule of thumb for ordinary least squares regression) ,30. MoreLatitude is known to impact vitamin D levels due to different zenith angles and lengths of days, as well as local weather and cloudiness . Some stRegarding gender, studies undertaken on the general population did not agree on whether there are significant differences between the vitamin D levels of females and males  research.Nonetheless, the limitations intrinsic to meta-analyses remain, namely their observational and post hoc character and, implicitly, their inability to infer causality. A limitation specific to meta-regression is its propensity to overfit, as well as its low power. While we managed to obtain a relatively large number of studies, its ability to correctly evaluate large models with multiple predictors is still limited. Our choice of confounding variables to analyze, namely race and season, has certain advantages and limitations as described above. Finally, while we tried to avoid the ecological fallacy, i.e., attributing group-level effects to individuals, its presence cannot be excluded entirely in any meta-regression.We have identified that the type of training influences serum vitamin D concentrations, i.e., that outdoor training is associated with a slightly higher vitamin D concentration, at least when controlling for the season, latitude, and Asian/Caucasian race. This suggests that the impact of indoor/outdoor training is highly dependent on the presence of covariates; moreover, the impact of training type is of a rather low numerical and clinical magnitude. Likewise, vitamin D levels are significantly influenced by the season, i.e., the impact of winter is nearly double that of the training type. Consequently, a practical observation is that outdoor training alone is not sufficient in increasing vitamin D levels, and supplementation to correct insufficiency and deficiency should not be guided by the type of training alone.On a theoretical level, we have proven that meta-regression can serve a role in filling gaps in the literature by investigating between-group differences when very few comparative studies exist, showing potential as a complement to primary observational studies.