Sickness absence as a measure of health status and functioning: from the UK Whitehall II study.

STUDY OBJECTIVE: To investigate the relationship between self reported health status and sickness absence. DESIGN: Analysis of questionnaire and sickness absence data from the first phase of the Whitehall II study--a longitudinal study set up to investigate the degree and causes of the social gradient in morbidity and mortality. SETTING: London offices of 20 civil service departments. PARTICIPANTS: Altogether 6895 male and 3413 female civil servants aged 35-55 years. Analysis was conducted on 88% of participants who had complete data for the present analysis. MAIN RESULTS: A strong inverse relation between the grade of employment (measure of socioeconomic status) and sickness absence was observed. Men in the lowest grade had rates of sickness absence six times higher than those in the highest grade. For women the corresponding differences were two to five times higher. In general, the longer the duration of absence, the more strongly did baseline health predict rates of absence. However, the health measures also predicted shorter spells, although to a lesser extent. Job satisfaction was strongly related to sickness absence with higher rates in those who reported low job satisfaction. After adjusting for health status the association remained for one to two day absences, but was greatly reduced for absences longer than three days. CONCLUSION: There was a strong association between ill health and sickness absence, particularly for longer spells. The magnitude of the association may have been underestimated because of the strength of the association between grade of employment and sickness absence. It is proposed that sickness absence be used as an integrated measure of physical, psychological, and social functioning in studies of working populations.