Prospective Cohort Study of Work Functioning Impairment and Subsequent Absenteeism Among Japanese Workers.

Abstract

This study examined the association of work functioning impairment as measured by work functioning impairment scale (WFun) and subsequent sick leave. A prospective cohort study was conducted at a manufacturer in Japan, and 1263 employees participated. Information on sick leave was gathered during an 18-month follow-up period. The hazard ratios (HRs) of long-term sick leave were substantially increased for those with a WFun score greater than 25 (HR = 3.99, P = 0.003). The incidence rate ratios (IRRs) of days of short-term absence gradually increased as scores of WFun increased (IRR = 1.18, P < 0.001 in the subjects with WFun of over 25 comparing with those with WFun of 14 or less). Assessing work functioning impairment is a useful way of classifying risk for future sick leave among employees.