Occupational class, psychosocial stress and morbidity.

The association between stress and morbidity was studied in an industrial population, which consisted of both white-collar and blue-collar workers (n = 902). Information about living and working conditions, health behaviour, mental well-being and morbidity were obtained by questionnaires, interviews, clinical examinations, and physiological and biochemical measurements. The same cohort was re-examined after five and ten years. Comparison of occupational classes showed consistently that living and working conditions, psychosocial stress, and health and sickness behaviour were more deleterious among blue-collar workers and their morbidity and mortality rates were higher than among white-collar workers. The effect of stress on health was examined both cross-sectionally and longitudinally. Psychosocial stressors at work were related to mental strain, perceived health, and absenteeism. Stress symptoms were strongly associated with perceived health, locomotor symptoms, smoking, drinking, and absenteeism. None of the stress indicators were related to blood pressure. In the follow-up the baseline indicators of stress predicted future chronic illness and angina pectoris, but not hypertension or myocardial infarction. Blood pressure changes were not related to psychosocial factors. Stress did not predict mortality in the ten year follow-up. The study suggests that psychosocial stress is mostly related and may be causally linked to such indicators of morbidity as perceived health, bodily symptoms and sickness behaviour. The aetiological contribution of stress to biologically defined morbidity may be weak.