Night shift work and cardiovascular diseases among employees in Germany: five-year follow-up of the Gutenberg Health Study

OBJECTIVE

This study aimed to determine if there is an increased risk of incident cardiovascular diseases (CVD) resulting from cumulative night shift work in the German population-based Gutenberg Health Study (GHS).

METHODS

We examined working participants of the GHS at baseline and after five years. Cumulative night shift work in the 10 years before baseline was assessed and categorized as low (1-220 nights ≙ up to 1 year), middle (221-660 nights ≙ 1-3 years), and high (>660 nights ≙ more than 3 years) night shift exposure. Hazard ratios (HR) were estimated for incident "quality-assured CVD events" using Cox proportional hazard models.

RESULTS

At baseline, 1092 of 8167 working participants performed night shift work. During the follow-up, 202 incident cardiovascular events occurred. The crude incidence rates for CVD per 1000 person-years were 6.88 [95% confidence interval (CI) 4.80-9.55] for night shift workers and 5.19 (95% CI 4.44-6.04) for day workers. Cumulative incidence curves showed a higher cumulative incidence in workers exposed to night shift work compared to day workers after five years. The adjusted HR for incident CVD events were 1.26 (95% CI 0.68-2.33), 1.37 (95% CI 0.74-2.53) and 1.19 (95% CI 0.67-2.12) for employees in the low, middle and high night shift categories compared to employees without night shift work, respectively.

CONCLUSIONS

The observed tendencies indicate that night shift work might be negatively associated with cardiovascular health. We expect the continued follow-up will clarify the long-term impact of night shift work.

The Gutenberg health study: a five-year prospective analysis of psychosocial working conditions using COPSOQ (Copenhagen psychosocial Questoinnaire) and ERI (effort-reward imbalance)

Background

Psychosocial working conditions were previously analyzed using the first recruitment wave of the Gutenberg Health Study (GHS) cohort (n = 5000). We aimed to confirm the initial analysis using the entire GHS population at baseline (N = 15,010) and at the five-year follow-up. We also aimed to determine the effects of psychosocial working conditions at baseline on self-rated outcomes measured at follow-up.

Methods

At baseline, working GHS participants were assessed with either the Effort-Reward-Imbalance questionnaire (ERI) (n = 4358) or with the Copenhagen Psychosocial Questionnaire (COPSOQ) (n = 4322); participants still working after five years received the same questionnaire again (ERI n = 3142; COPSOQ n = 3091). We analyzed the association between working conditions and the outcomes job satisfaction, general health, burnout, and satisfaction with life at baseline, at follow-up and also prospectively from baseline to follow-up using linear regression models. We examined the outcome variance explained by the models (R²) to estimate the predictive performance of the questionnaires.

Results

The models’ R² was comparable to the original baseline analyses at both t0 and t1 (R² range: ERI 0.10–0.43; COPSOQ 0.10–0.56). However, selected scales of the regression models sometimes changed between assessment times. The prospective analysis showed weaker associations between baseline working conditions and outcomes after five years (R² range: ERI 0.07–0.19; COPSOQ 0.07–0.24). This was particularly true for job satisfaction. After adjusting for the baseline levels of the outcomes, fewer scales still explained some of the variance in the distribution of the outcome variables at follow-up. The models using only data from t₀ or t₁ confirmed the previous baseline analysis. We observed a loss of explained variance in the prospective analysis models. This loss was greatest for job satisfaction, suggesting that this outcome is most influenced by short-term working conditions.

Conclusions

Both the COPSOQ and ERI instruments show good criterion validity and adequately predict contemporaneously measured self-reported measurements of health and (occupational) well-being. However, the COPSOQ provides a more detailed picture of working conditions and might be preferable for improvment strategies in workplaces. Additional prospective research with shorter follow-up times would be beneficial for estimating dose-response relationships.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12240-3.

Work-life conflict and cardiovascular health: 5-year follow-up of the Gutenberg Health Study

INTRODUCTION

Work-life conflicts (WLC) may impact health, but few studies prospectively consider the impact of WLC on objective outcomes such as cardiovascular disease. Using data from the Gutenberg Health Study (GHS), we examined if WLC at baseline was associated with an increased five-year incidence of cardiovascular events (myocardial infarct, stroke, atrial fibrillation, peripheral artery disease, coronary artery disease, chronic heart failure, sudden cardiac death). We also considered if WLC was associated with incident hypertension and arterial stiffness and if the effects of WLC on cardiovascular health differ for men and women.

METHODS

A working subsample of the 15,010 GHS cohort participants completed the Copenhagen Psychosocial Questionnaire, which included five "work-privacy conflict" questions at baseline and at the five-year follow-up. Relative risks for incident hypertension due to increased WLC at baseline (WLC scores exceeding 60 out of 100) were estimated with Poisson regression in the subgroup of participants without hypertension at baseline (n = 2426). Categories of WLC at baseline and follow-up were also used to examine the risk of hypertension due to chronic/recurrent WLC. In this subgroup, we also examined the association between WLC as a continuous score ranging from 0 to 100 with change to arterial stiffness after five years using linear regression. Hazard ratios were estimated for incident cardiovascular events in a larger subsample of participants without prevalent cardiovascular disease at baseline (n = 3698) using Cox regression. We used various multivariable regression models to adjust for sex, age, socioeconomic status, occupational, household, and cardiovascular risk factors.

RESULTS

We found no association between WLC and incident hypertension or increased arterial stiffness. The fully-adjusted relative risk for WLC >60 at baseline and hypertension was 0.93 (95% 0.74-1.17). The risk of hypertension due to chronic/recurrent WLC >60 was increased but not statistically significant (RR = 1.13, 95% CI 0.83-1.54). Overall, hazard ratios for incident cardiovascular events were also not increased. However, stratifying the results by sex resulted in a hazard ratio of 1.47 (95% CI 0.54-3.98) for incident cardiovascular disease among women in the fully adjusted model.

CONCLUSIONS

Although our results were not statistically significant, they indicate that WLC is negatively impacting the cardiovascular health of women. While these results need to be confirmed with additional research and a longer follow-up, interventions to prevent WLC will promote health and could be especially beneficial for women.

Self-reported cardiovascular health of teachers: results from the 5-year follow-up of the Gutenberg Health Study cohort

Objectives

Following an exploratory approach, we examined cardiovascular disease risk factors at baseline and the 5-year incidence proportion of self-reported doctor-diagnosed cardiovascular diseases (CVD) in teachers and other occupational groups of the Gutenberg Health Study.

Methods

Study participants lived in the region of Mainz, Germany. Data from 6510 working participants without prevalent CVD at baseline (2007–2012) were analyzed. Participants were teachers (n = 215), other professionals from the health, social or educational (HSE) fields (n = 1061) or worked outside the HSE fields (n = 5234). For occupational comparisons, we estimated prevalence ratios (PR) for each CVD risk factor at baseline with robust Poisson regression analyses. We calculated crude CVD incidence rates based on the observed 5-year CVD cumulative incidence at follow-up and estimated age-weighted incidence proportions. All analyses were stratified by sex.

Results

Male non-HSE workers showed a higher prevalence of smoking and physical inactivity than male teachers (PR 2.26; 95%-CI: 1.06–4.82/PR 1.89; 95%-CI: 1.24–2.87). In contrast, non-HSE workers and other HSE professionals were less likely to have reported an unhealthy alcohol intake than teachers. Differences were attenuated after SES-adjustment. We did not detect occupational group-specific differences in CVD incidence. However, there were only two cases of CVD among the teachers.

Conclusion

Particularly male teachers showed a healthier lifestyle regarding physical inactivity and smoking. Nevertheless, occupational-medical care practitioners and researchers need to be aware of the relatively heightened prevalence of unhealthy alcohol intake in female and male teachers, and in absolute terms, the high hypertension prevalence in male teachers.

Cardiovascular health outcomes of mobbing at work: results of the population-based, five-year follow-up of the Gutenberg health study

Background

The aim of this study was to determine if there is an increased risk of incident cardiovascular disease (CVD) resulting from workplace mobbing measured with two mobbing instruments in the Gutenberg Health Study.

Methods

In this prospective study, we examined working persons younger than 65 years for the presence of mobbing at baseline and at a 5-year follow-up using a single-item and a 5-item instrument. We used multivariate models to investigate the association between mobbing and incident CVD, hypertension, and change in arterial stiffness and further stratified the models by sex.

Results

After adjustment for confounders, mobbed workers appeared to have a higher risk of incident CVD than those not mobbed (single-item HR = 1.28, 95% CI 0.73–2.24; 5-item HR = 1.57, 95% CI 0.96–2.54). With the 5-item instrument, men who reported mobbing had a higher risk of incident CVD (HR = 1.77, 95% CI 1.01–3.09), while no association was observed for women (HR = 1.05, 95% CI 0.38–2.91). There was no difference in risks between men and women with the single-item instrument. No association between mobbing and incident hypertension and arterial stiffness was seen.

Conclusions

Our results show an indication of an increased risk of incident CVD for those mobbed at baseline when using the whole study population. Differences in risks between men and women when using the five-item instrument may be due to the instrument itself. Still, it is essential to detect or prevent workplace mobbing, and if present, to apply an intervention to halt it in order to minimize its adverse effects on CVD.

Application of the ICF based Norwegian function assessment scale to employees in Germany

Background

At the interface of the occupational setting and rehabilitation, normative values for functional ability are desirable and worthwhile. The Norwegian Function Assessment Scale (NFAS) is a 39 item self-report instrument based on the International Classification of Functioning, Disability and Health (ICF). As the questionnaire was not used in a working population, we aimed to obtain functional levels of employees in Germany as measured through the NFAS.

Methods

The NFAS was included in the Study on Mental Health at Work (S-MGA) 2011/12, a representative German survey of employees aged 31 to 60 years. For descriptive analyses, 95% confidence intervals were applied through bootstrap estimation to the skewed data of the NFAS (range from 1 = 'no difficulty' to 5 = 'could not do it'). The data were analysed by age decades, professional qualification, and by disabilities, congenital diseases and accidents, stratified by sex. Linear regression analyses were conducted to estimate adjusted effects of age, professional qualification, and health limitations.

Results

The NFAS total score was 1.17 (95% CI = 1.15-1.17). Thirty-five percent of the employees' (1378 out of 3937 participants) reported the best possible functional ability (NFAS total score of 1.00). Managing and walking/standing were the NFAS' most affected domains with a score of 1.26 (95% CI = 1.23-1.27), respectively. The regression analysis confirmed more functional difficulties for elder employees, females, employees with low professional qualification, and for employees suffering from disability and accidents.

Conclusions

The study presents normative values of functional ability for the workforce. The results are useful for score interpretation in rehabilitation and return-to-work processes.

[Total Hip and Knee Arthroplasty - Utilization of Postoperative Rehabilitation]

BACKGROUND

After total hip and knee arthroplasty, patients have different options of subsequent treatment: an early postoperative rehabilitation, with or without a period at home, or only outpatient services. The aim of this study was to identify factors predicting the utilization of an early postoperative rehabilitation.

METHODS

This cross-sectoral analysis is based on claims data of AOK Baden-Württemberg (Statutory Health Insurance), Deutsche Rentenversicherung Bund and Deutsche Rentenversicherung Baden-Württemberg (German Pension Insurance). Predictors for participation in an early postoperative rehabilitation and for an interim period were determined using logistic regression analysis.

RESULTS

82.6% of 9 232 patients were going to an early postoperative rehabilitation after total hip arthroplasty. After total knee arthroplasty, 83.9% of 7 656 patients were utilizing postoperative rehabilitation. Moreover, there was less utilization of postoperative rehabilitation in young, male and foreign patients. The analysis shows that the utilization of post-acute rehabilitation was significantly predicted by sociodemographic variables (age, sex, nationality) as well as comorbidity, outpatient treatment and medication.

CONCLUSION

The results provide an indication of higher severity of patients in group "postoperative rehabilitation without a period at home". Nevertheless there are some indications for under-utilization of certain patient groups.

[Effects of a Combined Orthopedic and Psychosomatic Rehabilitation Concept]

Objective: Effects of a combined orthopedic and psychosomatic rehabilitation (VOP) concept are evaluated in contrast to psychosomatic and orthopedic rehabilitation. Therefore both mental and physical health of rehabilitants are compared. Methods: A prospective case-control study was performed in order to gather psychic strain and bodily constitution. Covariance analysis was conducted to expose significant differences between groups. Results: An equal clinically relevant reduction of psychological distress could be achieved with psychosomatic rehabilitation (N=322) and VOP (N=511). Moreover, bodily constitution could be increased by the same amount through VOP and orthopedic rehabilitation (N=135). In conclusion the therapy concept is successful in patients with both somatic and psychic problems.

Current and cumulative night shift work and subclinical atherosclerosis: results of the Gutenberg Health Study

PURPOSE

The study examines the association between exposure to current and cumulative night shift work and subclinical parameters of atherosclerosis.

METHODS

Participants of a population-based cohort study (the Gutenberg Health Study, N = 15,010) aged 35-64 years were examined at baseline (2007-2012). Investigations included measurements of arterial stiffness, vascular function [reactive hyperaemia (RH) index], and intima media thickness (IMT). Also, a complete job history (including up to 15 periods), occupational exposures, a variety of lifestyle, and dispositional variables were enquired.

RESULTS

Night shift work was performed by 1071 out of 8065 currently employed individuals. The strongest association after adjustment for age, sex, job complexity level, being a manager, overtime work, and noise appeared for more than 660 night shifts within the last 10 years and a significantly increased arterial stiffness of 0.33 m/s. This reflects a 4 % flow velocity increase for individuals with more than 660 night shifts compared to non-night workers. Regarding the entire professional life, night shift workers showed a significantly decreased vascular function by -0.054 RH index points by using the same adjustment. IMT values did not differ statistically from non-night workers. Lifestyle and dispositional factors showed an influence on all used subclinical atherosclerosis parameters.

CONCLUSIONS

The cross-sectional results demonstrate an association between night work and detrimental changes in the atherosclerotic process. The association is more pronounced with more years in night shift and is partly explained by lifestyle and dispositional factors. Longitudinal analyses are necessary to confirm the results.

[Recommendations for the Stepwise Occupational Reintegration: Can the Characteristic of the Patients Explain the Differences Between the Rehabilitation Centers?]

BACKGROUND

The first step to initiate a stepwise occupational reintegration (SOR) is the recommendation of the rehabilitation centers. Therefore rehabilitation centers have a significant impact on the use of SOR. There is evidence that the recommendation rate between the rehabilitation centers differs clearly. The present survey therefore analyses in detail the differences of the recommendation rate and examines which patient-related factors could explain the differences.

METHODS

This study is based on analysis of routine data provided by the German pension insurance in Baden-Württemberg (Rehabilitationsstatistikdatenbasis 2013; RSD). In the analyses rehabilitation measures were included if they were conducted by employed patients (18-64 years) with a muscular-skeletal system disease or a disorder of the connective tissue. Logistic regression models were performed to explain the differences in the recommendation rate of the rehabilitation centers.

RESULTS

The data of 134 853 rehabilitation measures out of 32 rehabilitation centers were available. The recommendation rate differed between the rehabilitation centers from 1.36-18.53%. The logistic regression analysis showed that the period of working incapacity 12 month before the rehabilitation and the working capacity on the current job were the most important predictors for the recommendation of a SOR by the rehabilitation centers. Also the rehabilitation centers themselves have an important influence.

DISCUSSION

The results of this survey indicate that the characteristic of the patients is an important factor for the recommendation of SOR. Additionally the rehabilitation centers themselves have an influence on the recommendation of SOR. The results point to the fact that the rehabilitation centers use different criteria by making a recommendation.

Development of a mobbing short scale in the Gutenberg Health Study

PURPOSE

Despite its highly detrimental potential, most standard questionnaires assessing psychosocial stress at work do not include mobbing as a risk factor. In the German standard version of COPSOQ, mobbing is assessed with a single item. In the Gutenberg Health Study, this version was used together with a newly developed short scale based on the Leymann Inventory of Psychological Terror. The purpose of the present study was to evaluate the psychometric properties of these two measures, to compare them and to test their differential impact on relevant outcome parameters.

METHODS

This analysis is based on a population-based sample of 1441 employees participating in the Gutenberg Health Study. Exploratory and confirmatory factor analyses and reliability analyses were used to assess the mobbing scale. To determine their predictive validities, multiple linear regression analyses with six outcome parameters and log-binomial regression models for two of the outcome aspects were run.

RESULTS

Factor analyses of the five-item scale confirmed a one-factor solution, reliability was α = 0.65. Both the single-item and the five-item scales were associated with all six outcome scales. Effect sizes were similar for both mobbing measures.

CONCLUSION

Mobbing is an important risk factor for health-related outcomes. For the purpose of psychosocial risk assessment in the workplace, both the single-item and the five-item constructs were psychometrically appropriate. Associations with outcomes were about equivalent. However, the single item has the advantage of parsimony, whereas the five-item construct depicts several distinct forms of mobbing.

The Gutenberg Health Study: measuring psychosocial factors at work and predicting health and work-related outcomes with the ERI and the COPSOQ questionnaire

Background

Several instruments have been developed to assess psychosocial workload. We compared two of these instruments, the Effort-Reward Imbalance (ERI) model and the Copenhagen Psychosocial Questionnaire (COPSOQ) with regard to congruent validity and internal validity.

Methods

This analysis is based on a population-based sample of the baseline examination of 2,783 employees from the Gutenberg Health Study (GHS). About half of the participants completed the ERI questionnaire (n = 1,342), the other half completed the COPSOQ (n = 1,441). First, the two samples were compared and descriptive analyses were carried out calculating mean values for both instruments in general, then separately for age, gender and main occupational groups. Second, we analyzed the relationship between ERI and COPSOQ scales on the workplace situation and on the workplace outcomes: job satisfaction, general health, burnout, satisfaction with life, by applying stepwise logistic regression analysis.

Results and discussion

For the majority of occupations, high effort as reflected by the ERI corresponded with high demands as reflected by the COPSOQ. Comparably, high reward (according to ERI) yielded a good agreement with high “influence and development” (according to COPSOQ). However, we could also find differences between ERI and COPSOQ concerning the intensity of psychosocial workload in some occupations (e.g., physicians/pharmacists or warehouse managers/warehousemen/transport workers). These differences point to differing theoretical concepts of ERI and COPSOQ. When the ability of ERI and COPSOQ was examined to determine the associations with health and work outcomes, burnout could be better predicted by the COPSOQ; this might be due to the fact that COPSOQ comprises the constructs “work-privacy conflict” and “emotional demand”, which are closely related to burnout. However, methodological differences between these instruments limit their direct comparability.

Conclusions

The ERI and COPSOQ instrument yielded similar results for most occupational groups. The slightly stronger association between psychosocial workload as assessed by COPSOQ and burnout might be explained by its broader approach. The ability of the ERI and COPSOQ instrument to reflect relevant risk factors for clinically manifest disorders (e.g., coronary heart disease) will be derived from subsequent prospective analyses of the GHS with the follow-up data.

Behavioral and event-related potential distraction effects with regularly occurring auditory deviants

When auditory stimulation contains infrequent task-irrelevant changes (deviants), behavioral responses to task-relevant aspects of the stimulation are prolonged. Event-related brain potentials (ERPs) show that deviants elicit mismatch negativity (MMN), P3a, and reorienting negativity (RON). Here, we examine whether distraction effects can also be elicited within fixed auditory sequences with deviant probabilities of 0.25, 0.33, and 0.5. Deviants varied either in pitch, loudness, or sound source location. In all conditions MMN and P3a were elicited, suggesting that an automatic detection of and an attentional allocation to the change occurred. With relative frequencies of 25% and 33%, deviants also yielded a RT prolongation and a RON, suggesting reorientation to the relevant task. Our study demonstrates the ability to detect frequent and predictable changes automatically and shows behavioral effects in two conditions.