Low medically certified sickness absence among employees with poor health status predicts future health improvement: the Whitehall II study
- 1 Department of Epidemiology and Public Health, University College London Medical School, London, UK
- 2 Finnish Institute of Occupational Health, Helsinki, Finland
- 3 INSERM, U687, IFR69 HNSM, Saint-Maurice Cédex, France
- Professor M Kivimaki, Department of Epidemiology and Public Health, University College London Medical School, 1–19 Torrington Place, London WC1E 6BT, UK;
- Accepted 3 August 2007
- Published Online First 29 August 2007
Background: High sickness absence is associated with poor health status, but it is not known whether low levels of sickness absence among people with poor health predict future health improvement.
Objective: To examine the association between medically certified sickness absence and subsequent change in health among initially unhealthy employees.
Methods: 5210 employees (3762 men, 1448 women) whose self-rated health status remained stable (either good or poor) between data phases 1 and 2 were divided into three groups according to their rate of medically certified absences during this period (0 vs >0–5 vs >5 absence spells longer than 7 days per 10 person-years). Subsequent change in health status was determined by self-rated health at follow-up (phase 3).
Results: After adjustment for age and sex, there was a strong contemporaneous association between lower sickness absence and better health status. Among participants reporting poor health, low absence was associated with subsequent improvement in health status (odds ratio 2.66, 95% CI 1.78 to 4.02 for no absence vs >5 certified spells per 10 years). This association was only partially explained by known existing morbidity, socioeconomic position and risk factors.
Conclusions: Low levels of medically certified sickness absence seem to be associated with positive change in health status among employees in poor health. Further research is needed to examine whether lower sickness absence also marks a more favourable prognosis for specific diseases.
Funding: The Whitehall II study has been supported by grants from: the Medical Research Council; British Heart Foundation; Health and Safety Executive; Department of Health; National Heart Lung and Blood Institute (HL36310), US, NIH; National Institute on Aging (AG13196), US, NIH; Agency for Health Care Policy Research (HS06516); and the John D and Catherine T MacArthur Foundation Research Networks on Successful Midlife Development and Socio-economic Status and Health. MK, also working at the University of Helsinki, Finland, and JV were supported by the Academy of Finland (projects 105195 and 117604) and the Finnish Environment Fund, JEF is supported by the MRC (Grant number 47413), MJS by a grant from the British Heart Foundation, and MGM by an MRC Research Professorship. We thank all participating civil service departments and their welfare, personnel and establishment officers, the Occupational Health and Safety Agency, the Council of Civil Service Unions, all participating civil servants in the Whitehall II study, and all members of the Whitehall II study team.
Competing interests: None declared.