Interactive effects of shiftwork, age and work stress on health and well-being

Introduction. While being a relevant risk factor in itself, shiftwork may also interact with age and workplace psychosocial stressors in exerting its potential negative effects on health and well-being. Ageing may decrease tolerance to shiftwork due to reduction in chronobiological, psychophysical, social and work-related adaptability. Moreover, work stress may increase the negative effects of shiftwork on health as it may further impair the capacity to recover due to prolonged physiological internal overactivation, which may be also sustained by cognitive processes such as ruminative and anticipatory thoughts about stressors. Aim. The aim of this study was to assess, in a sample of non-medical healthcare workers, whether shiftwork on the one hand, and age and work stress on the other hand, significantly interact in affecting several health outcomes such as sleep, chronic fatigue, job satisfaction, work ability, absenteeism, injuries, cardiovascular, gastrointestinal and mental disorders. Methods. 2412 non-medical healthcare workers (nurses, midwives, rehabilitation staff and health technicians), employed in seven state-owned and private hospitals in Northern Italy, were recruited for the study. 1842 workers took part in the survey (response rate=76.4%); 81.3% were women and 18.7% men, with age ranging from 22 to 63 years and work seniority from 2 to 40 years. 49.4% were dayworkers, 4.6% shiftworkers without nights, and 46.1% shifworkers with nights. The Standard Shiftwork Index -SSI- (1), the Work Ability Index -WAI- (2) and the Effort/Reward Imbalance -ERI- (3) questionnaires were the main assessment instruments. Data were analyzed by means of multiple logistic regression analyses (Stata 9.2 package), including gender, marital status, number of children and workload as potential confounders. Results. As a whole, 33.9% of the workers reported poor or moderate work ability, 22.2% chronic fatigue, 15.3% severe sleep troubles, and 10.2% job dis-satisfaction. Effort/Reward Imbalance resulted as the most important predictor of work ability, chronic fatigue, job satisfaction, and gastrointestinal disorders. Shiftwork including nightwork was the most relevant factor related to severe sleep troubles and significantly interacted with age in affecting job satisfaction and chronic fatigue, and with ERI for gastrointestinal disorders. Age had the highest impact on cardiovascular and musculoskeletal disorders, and it was also related to increased absenteeism, job dis-satisfaction and gastrointestinal disorders. Finally, gender was the most prominent factor in predicting absenteeism, and played a significant role also in relation to work ability, musculoskeletal disorders and chronic fatigue. References 1. Barton J., Spelten E. et al. (1995).The Standard Shiftwork Index: a battery of questionnaires for assessing shiftwork-related problems. Work & Stress, 9(1), 4–30. 2. Tuomi K., Ilmarinen J., Jahkola A., Katajarinne L., Tulkki A. (1998). Work Ability Index (2nd ed.). Helsinki: Finish Institute of Occupational Health. 3. Siegrist J. & Peter R. (1996), Measuring effort–reward imbalance at work: guidelines. Dusseldorf: Heinrich Heine University.