How to measure sickness absence? Literature review and suggestion of five basic measures

Objective - To examine different sick-leave measures used in sickness absence research, and to suggest a systematic way of assessing sickness absence. Methods - A review and analysis of five major studies on sick-leave performed 1983-1988 with an epidemiological approach. Results - Terminology and measures used varied in the different studies reviewed. The choice of a certain measure was seldom discussed in relation to the aim of the study. Based on the review five measures are suggested: frequency, length, incidence rate, cumulative incidence and duration. The definition of incidence rate is new and is a measure useful in studies of recurrent events within epidemiology. Conclusions - We have reviewed sick-leave measures previously used in the literature and suggested five basic measures for assessing sick-leave.