Edwin Pelfrene

Occupational stress and incidence of sick leave in the Belgian workforce: the Belstress study

Context: Sick leave is a major problem in public health. The Karasek demands/control/social support/strain (JDCS) model has been largely used to predict a wide range of health outcomes and to a lesser extent sickness absence. Study objective: The aim of the study was to test the predictive power of the JDCS model in relation with one year incidence of sick leave in a large cohort of workers. Design and setting: Cohort study conducted between 1994 and 1998 in 25 companies across Belgium. Participants: A total of 20 463 workers aged 35 to 59 years were followed up for sick leave during one year after the baseline survey. Outcomes: The outcomes were a high sick leave incidence, short spells (⩾7 days), long spells (⩾28 days), and repetitive spells of sickness absence (⩾3 spells/year). Main results: Independently from baseline confounding variables, a significant association between high strained jobs with low social support and repetitive spells of sickness absence was observed in both sexes with odds ratios of 1.32 (99% CI, 1.04 to 1.68) in men and 1.61 (99% CI, 1.13 to 2.33) in women. In men, high strained jobs with low social support was also significantly associated with high sick leave incidence, and short spells of sick leave with odds ratios of 1.38 (99% CI, 1.16 to 1.64) and 1.22 (99% CI, 1.05 to 1.44) respectively. Conclusions: Perceived high strain at work especially combined with low social support is predictive of sick leave in both sexes of a large cohort of the Belgian workforce.

Obesity, body fat distribution and incidence of sick leave in the Belgian workforce: the Belstress study

OBJECTIVES: In many studies, obesity has been associated with morbidity or mortality, but only a few have studied the relation between obesity and sick leave. Our aim is to analyse the independent effects of both adiposity and body fat distribution in relation to the 1-y incidence of sick leave in a large cohort of male and female workers covering a variety of occupations, taking into account a wide range of socio-demographic, behavioural and bioclinical variables.DESIGN AND SETTING: The baseline survey of the Belstress study was conducted in 25 companies across Belgium between 1994 and 1998. A cohort of 20 463 workers (15 557 males and 4906 females) aged 35–59 y was followed for absenteeism during 1 y. The 75th percentile of the distribution of the total annual sickness days was used as a cutoff to classify the workers with a high 1-y incidence rate of sick leave. The relation between sick leave and both obesity and body fat distribution assessed by the body mass index (BMI) and the waist circumference, respectively, was analysed by multivariate logistic regression models.RESULTS: Using a backward procedure based on the likelihood ratio, we found central abdominal fatness to be an independent predictor of sick leave in both genders (high sick-leave incidence and long spells), but not BMI. In men, the odds ratios was 1.31 (99% CI 1.12–1.52, P<0.0001) and in women it ranged from 1.32 (99% CI 1.03–1.70, P=0.005) to 1.47 (99% CI 1.14–1.90, P<0.0001). Two baseline covariables, respiratory problems and perceived health, are confounders or mediators.CONCLUSIONS: In this study, body fat distribution was associated with a high annual sick-leave incidence and long spells of sickness absence. If this link is reversible, employers may benefit from programs aiming at the prevention and treatment of central obesity.

Job stress and major coronary events: results from the Job Stress, Absenteeism and Coronary Heart Disease in Europe study.

Aims The intention of this study is to investigate the relationship of the demands/control/strain model with hard coronary events in an epidemiological, prospective, multicenter, European study. Methods and results Six cohorts (Brussels, Ghent, Lille, Barcelona, Göteborg and Malmö) from four European countries (Belgium, France, Spain and Sweden) consisting of 21 111 middle-aged male subjects participated between 1993 and 1996 in the baseline survey of the Job Stress, Absenteeism and Coronary Heart Disease in Europe (JACE) study. The Karasek strain model of psychological demands (five items)/control (nine items) was used. During a mean follow-up of 40 months 185 acute coronary events or coronary deaths were observed. Age-adjusted hazard ratios (HRs) for developing an acute coronary event were 1.46 [CI 95% confidence interval (1.08–1.97)] for high against low psychological demands and 1.53 (95% CI 1.0–2.35) for strained (high demands plus low control) against relaxed (low demands plus high control) groups. After adjustment for standard cardiovascular risk factors the HR for developing a coronary event for those above or equal to the median against those below the median of psychological demands was 1.46 (95% CI 1.08–1.97) whereas the HR for strained against relaxed groups is 1.46 (95% CI 0.96–2.25). Sensitivity analyses confirmed the robustness of the results. Conclusion In this European, multicenter, prospective, epidemiological study the Karasek job strain model was an independent predictor of acute coronary events, with the psychological demands scale emerging as the important component.

Increased absenteeism from work among aware and treated hypertensive and hypercholesterolaemic patients

Aim The ‘labelling hypothesis’ was introduced on the basis of the observation that labelling subjects with blood pressure elevation as hypertensive was associated with an increase in sickness absence. In the Belstress I study this hypothesis was analysed in the same way for the possible influence on sick leave of labelling persons with elevated cholesterol as hypercholesterolaemic. Methods and results The Belstress I cohort concerns a sample of more than 16000 men and 5000 women at work in 24 Belgian industries in various sectors. Baseline data were collected by questionnaire and clinical examination. Awareness was defined as answering positively to the question ‘did a physician ever tell you that your blood pressure/serum cholesterol was too high?’ Sick leave data were independently and objectively recorded during 1 year following the screening. Sick leave was treated in a dichotomous way whereby the event was defined as being in the highest quartile of the annual number of days of sick leave (10 days or more for men and 15 days or more for women) or as being in the highest quartile of the annual number of spells of sick leave (two spells or more for both sexes). Gender-specific logistic regression analyses were performed, with adjustment for a large set of covariates. A positive association was observed between both awareness of hypertension and awareness of hypercholesterolaemia and the various definitions of sick leave, in both sexes and after adjustment for different covariates. When dividing up aware subjects into treated versus untreated, we observed in men the highest sick leave incidence in aware and treated hypertensive patients as well as in aware and treated hypercholesterolaemic patients. In women findings were less consistent, probably due to the smaller sample size. When looking at cumulative effects by examining participants with both hypertension and hypercholesterolaemia and their level of awareness for one or both risk factors, a statistically significant gradient was noticed in men, with the highest sick leave incidence, whatever the definition, in men aware for both risk factors, followed by men aware for one. In women the same trends were observed, but no level of statistical significance was reached. Conclusion Without being able to test the effect of ‘labelling’ as such, our study provides support for the association between awareness of two different coronary risk factors and incidence of sick leave. Probably a common mechanism is at the base of these findings. Further research is needed, in order to reduce potential negative effects of screening on human wellbeing as well as on productivity.

Relationship of perceived job stress to total coronary risk in a cohort of working men and women in Belgium

Objective To examine the relationships of job strain and iso-strain psychosocial work environment exposures to ‘total coronary risk’ (TCR) in a cohort of male and female workers in Belgium. Methods The sample consists of 15 079 men and 4639 women aged 35-59 years employed in a wide range of occupations and free of any self-reported personal history of CHD. Karaseks job strain model was used to define high strain (high demands and low control), low strain, active and passive jobs. Iso-strain was defined as the combination of a high strain job with low worksite social support, and is compared to the other combinations. Total coronary risk is a composite measure based on a Framingham function assessing the risk of developing coronary heart disease (CHD) within the next 10 years; high and low levels of TCR were defined. Logistic regressions in each gender were applied to explore relationships, adjusting for age, level of education, occupational class and sector of employment. Results In male workers, the age-adjusted prevalence of high TCR is highest in (1) in the lowest quartile group of job control and (2) in the ‘high strain’ group. The multivariate logistic regressions comparing high strain, active and passive work exposures to low strain work did not indicate a significant association with high TCR. Likewise, iso-strain jobs were neither found to be associated with high TCR. Conclusion Our cross-sectional analysis provides no support for the hypothesis that the psychosocial work environment is strongly associated with the TCR estimate in healthy workers. Eur J Cardiovasc Prevention Rehab 10:345-354

Screening for breast cancer in Ghent, Belgium: first results of a programme involving the existing health services

In 1992, a population-based breast cancer screening programme was initiated in the municipality of Ghent: all women aged 40-69 years were personally invited to attend a local radiology unit for a mammogram, after being examined by a general practitioner or gynaecologist of their choice. The results of history taking, clinical breast examination, first and second reading, further investigation and primary treatment were registered. In total, 24.3% of the eligible population was screened in the period 1992-1994. The recall and biopsy rates were 2.9% and 1.4%, respectively. The cancer detection rate was 8.1 per 1000 women screened. Of all cancers detected, 88.0% (66/75) were invasive. Of these, 35.9% (23/64) measured 10 mm or less in diameter. The benign to malignant biopsy ratio was 0.7. Apart from the low participation, these results suggest that the programme is effective, compared with reference standards and the results of other studies.