Long working hours are inversely related to sick leave in the following 3 months: a 4-year registry study

Purpose: The aim of this study was to investigate the effects of long working hours (≥ 12h shifts) on sick leave using objective records of shift work exposure and of sick leave. Methods: A total of 1538 nurses (mean age 42.5, SD 12.0; response rate 42%) participated. Payroll and archival sick leave data over a 4-year period were retrieved from employers’ records and aggregated over every third calendar month. A multilevel negative binomial model was used to investigate the effects of exposure to long working hours, on subsequent sick leave rates the following 3months. Covariates included prior sick leave, number of shifts worked, night and evening shifts, personality, and demographic characteristics. Results: Exposure to long working hours was associated with fewer sick leave days in the subsequent 3months [adjusted model, incidence rate ratio (IRR) = 0.946, 95% CI 0.919–0.973,p&thinsp