Associations between psychosocial work environment factors and first-time and recurrent treatment for depression: a prospective cohort study of 24,226 employees

AIMS

Adverse factors in the psychosocial work environment are associated with the onset of depression among those without a personal history of depression. However, the evidence is sparse regarding whether adverse work factors can also play a role in depression recurrence. This study aimed to prospectively examine whether factors in the psychosocial work environment are associated with first-time and recurrent treatment for depression.

METHODS

The study included 24,226 participants from the Danish Well-being in Hospital Employees study. We measured ten individual psychosocial work factors and three theoretical constructs (effort-reward imbalance, job strain and workplace social capital). We ascertained treatment for depression through registrations of hospital contacts for depression (International Statistical Classification of Diseases and Related Health Problems version 10 [ICD-10]: F32 and F33) and redeemed prescriptions of antidepressant medication (Anatomical Therapeutic Chemical [ATC]: N06A) in Danish national registries. We estimated the associations between work factors and treatment for depression for up to 2 years after baseline among those without (first-time treatment) and with (recurrent treatment) a personal history of treatment for depression before baseline. We excluded participants registered with treatment within 6 months before baseline. In supplementary analyses, we extended this washout period to up to 2 years. We applied logistic regression analyses with adjustment for confounding.

RESULTS

Among 21,156 (87%) participants without a history of treatment for depression, 350 (1.7%) had first-time treatment during follow-up. Among the 3070 (13%) participants with treatment history, 353 (11%) had recurrent treatment during follow-up. Those with a history of depression generally reported a more adverse work environment than those without such a history. Baseline exposure to bullying (odds ratio [OR] = 1.72, 95% confidence interval [95% CI]: 1.30-2.32), and to some extent also low influence on work schedule (OR = 1.27, 95% CI: 0.97-1.66) and job strain (OR = 1.24, 95% CI: 0.97-1.57), was associated with first-time treatment for depression during follow-up. Baseline exposure to bullying (OR = 1.40, 95% CI: 1.04-1.88), lack of collaboration (OR = 1.31, 95% CI: 1.03-1.67) and low job control (OR = 1.27, 95% CI: 1.00-1.62) were associated with recurrent treatment for depression during follow-up. However, most work factors were not associated with treatment for depression. Using a 2-year washout period resulted in similar or stronger associations.

CONCLUSIONS

Depression constitutes a substantial morbidity burden in the working-age population. Specific adverse working conditions were associated with first-time and recurrent treatment for depression and improving these may contribute to reducing the onset and recurrence of depression.

Emotional demands at work and risk of long-term sickness absence among 1.5 million Danish employees

Background

Emotional demands concern aspects of work requiring an emotional effort of employees and have been associated with risk of depression and long-term sickness absence (LTSA) in previous studies. Associations may, however, partly be affected by reporting bias. Further, previous studies have primarily been conducted using smaller samples in selected job groups or sectors. We, therefore, examined the association between emotional demands and LTSA using a job exposure matrix (JEM) in a nationwide cohort.

Methods

We included all employed individuals in Denmark who were 30 to 59 years old in 2000. We assessed emotional demands at work with a JEM. JEM values were categorized into quartiles based on the distribution within each year and updated annually from 2000 to 2009. LTSA was register-based, defined as ≥ 6 weeks and assessed until 2015. Individuals with LTSA from 1998 to 2000 were excluded, yielding a sample of 1,521,352 individuals. Exposure in year t was related to outcome in year t + 1 until 2009. We estimated hazard ratios (HR) and 95% confidence intervals (95%CI) using Cox regression adjusted for age, sex, income and ergonomic job demands.

Results

During 15,453,980 person-years, we identified 594,858 LTSA cases. In the fully adjusted model, individuals in the highest emotional demands quartile had a HR of 1.30 (95%CI: 1.29-1.31) compared to individuals the lowest quartile Repeating the analysis separately for women and men showed similar results.

Conclusions

Emotional demands at work were prospectively associated with an increased LTSA risk in this JEM based nationwide cohort study.

Key messages

This study found that emotional demands at work predict risk of long-term sickness absence. Future studies should focus on factors that may buffer the association between emotional demands at work and long-term sickness absence.

Emotional demands at work and risk of depressive disorder: A nationwide Danish cohort study

Background

Studies suggest that high emotional demands at work are associated with increased risk of depression. However, most previous studies have measured emotional demands using self-report and estimates may be inflated due to reporting bias. Furthermore, no study has yet accounted for the potential selection of individuals with increased risk of depressive disorder into occupations with high emotional demands.

Methods

We analyzed data from two separate nationwide register-based Danish cohorts, The Danish Work Life Course Cohort (n = 955,712; person-years=6.99 mill.), and the JEMPAD study (n = 1,680,214; person-years=21.73 mill.). We measured emotional demands annually by job exposure matrices, and depressive disorder using registers on psychiatric hospital treatment. Emotional demands were categorized as quartiles. To account for selection into jobs with high emotional demands, we adjusted for numerous confounders, including health services use before workforce entry, parental socioeconomic position, and psychiatric and somatic diagnoses. The present abstract reports preliminary results based on a subset of the study population used as a development sample (n = 16,163, person-years=168,889). Final results will be available for the conference.

Results

Preliminary findings showed a tendency towards an increased risk of depressive disorder for employees in occupations with the highest level of emotional demands (hazard ratio: 1.20 (95% CI: 0.85-1.69). The association was similar with and without adjustment for confounders and was not explained by selection into occupations with high emotional demands.

Conclusions

If confirmed in analyses of the full study population, our results suggest that high emotional demands at work may be associated with increased risk of depressive disorder, and that this association is explained by neither reporting bias nor a selection of individuals vulnerable to depression into occupations with high emotional demands.

Key messages

Emotional demands may be associated with an increased risk of depressive disorder. Further research is needed to explore the potential for workplace prevention of high emotional demands.

Sexual harassment at work: Design of a new questionnaire to measure sexual harassment

Background

Sexual harassment is a complex phenomenon and our knowledge is hampered by a lack of consensus on the definition and measurement. However, workplaces need reliable instruments that provide a nuanced understanding of sexual harassment and input for action to mitigate negative consequences. The aim of this project is to help workplaces prevent and manage sexual harassment, which include developing a new and comprehensive instrument to monitor sexual harassment (Inventory of Workplace Sexual Harassment). In this abstract, we explain the process of designing the questionnaire.

Methods

The design process follows three steps: (1) Identification of a theoretical and conceptual framework, (2) item development and (3) field testing. First, we identified relevant theoretical and conceptual frameworks, which we discussed with an expert group consisting of researchers and stakeholders (employer and trade unions). Second, we developed items based on expert inputs and previous surveys. We adapted the first version of the questionnaire following a feedback round with the expert group. Third, we will complete field testing in 2019-2020. Field testing encompasses cognitive interviews (n = 15) and in-depth interviews with men and women exposed to sexual harassment to assess clarity and relevance (in 2019), and a pilot study at 15 workplaces to assess prevalence and usability (in 2020).

Results

Based on the theoretical and conceptual model from Fitzgerald et al, we developed a preliminary version, consisting of 22 items that cover three domains: (1) unwanted sexual attention, (2) gender harassment and (2) sexual coercion. The survey draws on questions from SEQ-DoD and Bergen Sexual Harassment Scale. Results from field testing will be available for the conference.

Conclusions

The Inventory of Workplace Sexual Harassment will provide a comprehensive and validated measurement of workplace sexual harassment and will help workplaces prevent and manage sexual harassment.

Key messages

Sexual harassment is a complex and multifaceted phenomenon, but our knowledge is hampered by a lack of consensus on the definition and measurement. This study contributes with a new instrument measuring the prevalence of workplace sexual harassment and tools for prevention and management of sexual harassment.

Job control and risk of disability pension in the nationwide Danish Work Life Course Cohort

Background

A large number of studies have found job control to be consistently associated with an increased risk of disability pension. However, most previous studies have measured job control by self-report, introducing possible reporting bias inflating the risk estimates. Furthermore, previous studies have not accounted for the potential selection of individuals with pre-existing risk factors for disability pensioning into low control jobs.

Methods

We analyzed data from the nationwide register-based Danish Work Life Course Cohort (DAWCO; n = 960,562 with approx. 6 million person-years). We measured job control annually by a job exposure matrix, based on a scale of five self-reported items from The Danish Work Environment Cohort Study, and disability pension using registers on public transfer payments. To account for potential selection into occupations with lower levels of job control, we included numerous life course confounders, including parental socioeconomic position and psychiatric and somatic diagnoses.

Results

Employees in jobs with lower levels of job control had increased risk of disability pensioning. The association attenuated after adjustment for confounders but was not explained by selection into job groups with lower levels of job control (hazard ratio: 1.16 (95% CI: 1.03-1.31).

Conclusions

Our findings suggest that lower levels of job control are associated with an increased risk of disability pension, and that this association is explained by neither reporting bias nor a selection of individuals with an increased risk of disability pensioning into job groups with lower levels of job control.

Key messages

Lower levels of job control appear associated with an increased risk of disability pension independent of life course confounders. Further research is needed on preventive measures in occupations with low levels of job control.

Work stress, migration background and risk of long-term sickness absence in Denmark

Background

Work stress may increase risk of long-term sickness absence, but little is known if this association differs by migration background. In this study, we examined the prospective association between effort-reward imbalance at work and risk of long-term sickness absence in individuals with and without migration background in the Danish workforce.

Methods

We included 59,468 respondents from a nationwide survey on work and health, 3,226 with a migration background (immigrants or first generation descendants of immigrants) and 56,242 without a migration background. Effort-reward imbalance was assessed by self-report. Migration background and long-term sickness absence (spells ≥6 weeks) were assessed by national register data. Using Cox regression, we estimated the association between effort-reward imbalance and onset of long-term sickness absence during 12 months follow-up separately for participants with and without a migration background, adjusted for age, sex, education and previous long-term sickness absence.

Results

The effort-reward imbalance score at baseline was similar for respondents with and without a migration background. The hazard ratio for long-term sickness absence during follow-up per 1 standard deviation increment in effort-reward imbalance at baseline was 1.26 (95% CI: 1.16-1.37) and 1.16 (95% CI: 1.13-1.20) for respondents with and without a migration background, respectively.

Conclusions

Work stress, measured by effort-reward imbalance, is associated with an increased risk of long-term sickness absence in workers with and without a migration background in Denmark. Although the estimate was higher in workers with a migration background, confidence intervals overlapped indicating that associations were similar in both groups. The results suggest that prevention activities on effort-reward imbalance and long-term sickness absence should not be prioritized by migration background but should be offered to the whole workforce.

Key messages

Work stress, measured by effort-reward imbalance, is associated with an increased risk of long-term sickness absence in workers with and without a migration background in Denmark. The results suggest that prevention activities on effort-reward imbalance and long-term sickness absence activities should be offered to the whole workforce.

Job strain as a risk factor for clinical depression: systematic review and meta-analysis with additional individual participant data

BACKGROUND

Adverse psychosocial working environments characterized by job strain (the combination of high demands and low control at work) are associated with an increased risk of depressive symptoms among employees, but evidence on clinically diagnosed depression is scarce. We examined job strain as a risk factor for clinical depression.

METHOD

We identified published cohort studies from a systematic literature search in PubMed and PsycNET and obtained 14 cohort studies with unpublished individual-level data from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium. Summary estimates of the association were obtained using random-effects models. Individual-level data analyses were based on a pre-published study protocol.

RESULTS

We included six published studies with a total of 27 461 individuals and 914 incident cases of clinical depression. From unpublished datasets we included 120 221 individuals and 982 first episodes of hospital-treated clinical depression. Job strain was associated with an increased risk of clinical depression in both published [relative risk (RR) = 1.77, 95% confidence interval (CI) 1.47-2.13] and unpublished datasets (RR = 1.27, 95% CI 1.04-1.55). Further individual participant analyses showed a similar association across sociodemographic subgroups and after excluding individuals with baseline somatic disease. The association was unchanged when excluding individuals with baseline depressive symptoms (RR = 1.25, 95% CI 0.94-1.65), but attenuated on adjustment for a continuous depressive symptoms score (RR = 1.03, 95% CI 0.81-1.32).

CONCLUSIONS

Job strain may precipitate clinical depression among employees. Future intervention studies should test whether job strain is a modifiable risk factor for depression.

Informal caregiving as a risk factor for type 2 diabetes in individuals with favourable and unfavourable psychosocial work environments: A longitudinal multi-cohort study

AIM

To examine whether informal caregiving is associated with increased risk of type 2 diabetes (T2D), and whether job strain and social support at work modify the association.

METHODS

Individual participant's data were pooled from three cohort studies-the French GAZEL study, the Swedish Longitudinal Occupational Survey of Health (SLOSH) and the British Whitehall II study-a total of 21,243 study subjects. Informal caregiving was defined as unpaid care for a closely related person. Job strain was assessed using the demand-control model, and questions on co-worker and supervisor support were combined in a measure of social support at work. Incident T2D was ascertained using registry-based, clinically assessed and self-reported data.

RESULTS

A total of 1058 participants developed T2D during the up to 10 years of follow-up. Neither informal caregiving (OR: 1.09, 95% CI: 0.92-1.30) nor high job strain (OR: 1.04, 95% CI: 0.86-1.26) were associated with T2D risk, whereas low social support at work was a risk factor for T2D (OR: 1.18, 95% CI: 1.02-1.37). Also, informal caregivers who were also exposed to low social support at work were at higher risk of T2D (OR: 1.40, 95% CI: 1.08-1.82) compared with those who were not informal caregivers and had high social support at work (multiplicative test for interaction, P=0.04; additive test for interaction, synergy index=10).

CONCLUSION

Informal caregiving was not independently associated with T2D risk. However, low social support at work was a risk factor, and informal caregivers with low social support at work had even higher risks of T2D.

Job strain and the risk of severe asthma exacerbations: a meta-analysis of individual-participant data from 100 000 European men and women

Background

Many patients and healthcare professionals believe that work‐related psychosocial stress, such as job strain, can make asthma worse, but this is not corroborated by empirical evidence. We investigated the associations between job strain and the incidence of severe asthma exacerbations in working‐age European men and women.

Methods

We analysed individual‐level data, collected between 1985 and 2010, from 102 175 working‐age men and women in 11 prospective European studies. Job strain (a combination of high demands and low control at work) was self‐reported at baseline. Incident severe asthma exacerbations were ascertained from national hospitalization and death registries. Associations between job strain and asthma exacerbations were modelled using Cox regression and the study‐specific findings combined using random‐effects meta‐analyses.

Results

During a median follow‐up of 10 years, 1 109 individuals experienced a severe asthma exacerbation (430 with asthma as the primary diagnostic code). In the age‐ and sex‐adjusted analyses, job strain was associated with an increased risk of severe asthma exacerbations defined using the primary diagnostic code (hazard ratio, HR: 1.27, 95% confidence interval, CI: 1.00, 1.61). This association attenuated towards the null after adjustment for potential confounders (HR: 1.22, 95% CI: 0.96, 1.55). No association was observed in the analyses with asthma defined using any diagnostic code (HR: 1.01, 95% CI: 0.86, 1.19).

Conclusions

Our findings suggest that job strain is probably not an important risk factor for severe asthma exacerbations leading to hospitalization or death.

Job strain in relation to body mass index: pooled analysis of 160 000 adults from 13 cohort studies

BACKGROUND

Evidence of an association between job strain and obesity is inconsistent, mostly limited to small-scale studies, and does not distinguish between categories of underweight or obesity subclasses.

OBJECTIVES

To examine the association between job strain and body mass index (BMI) in a large adult population.

METHODS

We performed a pooled cross-sectional analysis based on individual-level data from 13 European studies resulting in a total of 161 746 participants (49% men, mean age, 43.7 years). Longitudinal analysis with a median follow-up of 4 years was possible for four cohort studies (n = 42 222).

RESULTS

A total of 86 429 participants were of normal weight (BMI 18.5-24.9 kg m(-2) ), 2149 were underweight (BMI < 18.5 kg m(-2) ), 56 572 overweight (BMI 25.0-29.9 kg m(-2) ) and 13 523 class I (BMI 30-34.9 kg m(-2) ) and 3073 classes II/III (BMI ≥ 35 kg m(-2) ) obese. In addition, 27 010 (17%) participants reported job strain. In cross-sectional analyses, we found increased odds of job strain amongst underweight [odds ratio 1.12, 95% confidence interval (CI) 1.00-1.25], obese class I (odds ratio 1.07, 95% CI 1.02-1.12) and obese classes II/III participants (odds ratio 1.14, 95% CI 1.01-1.28) as compared with participants of normal weight. In longitudinal analysis, both weight gain and weight loss were related to the onset of job strain during follow-up.

CONCLUSIONS

In an analysis of European data, we found both weight gain and weight loss to be associated with the onset of job strain, consistent with a 'U'-shaped cross-sectional association between job strain and BMI. These associations were relatively modest; therefore, it is unlikely that intervention to reduce job strain would be effective in combating obesity at a population level.