Sickness absence and psychiatric disorder : epidemiological findings and methodological considerations

Abstract: Psychiatric disorder is an important health problem among people of working age, with consequences for work capacity and sickness absence. Increased knowledge of sickness absence and psychiatric disorder is important for early detection of psychiatric disorders and appropriate rehabilitation measures.The occurrence of psychiatric sick-leave (sick-leave spells >7 days) during the years 1985, 1986 and 1987 was analysed in the county of Östergotland (400 000 inhabitants). Women working in male-dominated occupational groups, such as industrial work and as craftsmen, had the highest incidence. Men working in extremely female-dominated occupational groups, social workers and secretaries, had the highest incidence among all men. Occupational groups with an equal sex distribution had the lowest psychiatric sick-leave. More women were sick-listed, but men had more sick-leave days. There were small sex differences in the pattern of sickleave diagnosis.The role of psychiatric disorder for sick-leave in all diagnoses (not only psychiatric) was analysed in a stratified sample of 292 women selected from a population-based study of the female general population ofGoteborg (425 000 inhabitants). Women with psychiatric disorders according to a research interview had higher general sickness absence over ten years (1981-1990) both regarding spells and length, also when stratified for age, functional capacity, physical health, marital status, motherhood and socio-economic group. Single women with children did not have any increased sick-leave unless they had a psychiatric disorder. Women with psychiatric disorders also had an increased number of sick-leave days in diseases of the locomotor system, the digestive system and in mental illness. Women with alcohol problems had high sick-leave due to· diseases of the locomotor system. Eighty-nine per cent of the women with psychiatric disorders were sick-listed at least once 1989-1990 but only 16% were sick-listed with mental illness. Unrecognised psychiatric disorder is suggested as an explanation.In the methodological studies, critical evaluations of population at risk, sick-leave measures and estimation of person-time were made. Five sick-leave measures; frequency, length, duration, cumulative incidence and incidence rate, were defined and tested in a pilot study. Results from the pilot study showed that women with 1-7 sick-leave days over a year had a better self-reported health than women without any sick-leave and those with more than 8 days. Methods for assessing recurrency, duration and intensity within an epidemiological framework need to be developed.In conclusion, psychiatric disorder is an important factor in sickness absence, especially in the number of sick-leave days. The relation between psychiatric morbidity, environmental factors and individual coping behaviour for sickness absence is not clear, and further research is needed. Epidemiological and clinical research from a gender perspective is needed, with a focus on the health care and the social insurance systems. Prevention and rehabilitation programs should focus on the interplay between somatic illness, mental health and the use of health services and the sickness insurance.