Objectives: To investigate if exposure to an unusually low workload when ill can trigger taking sick leave.
Methods: A case-crossover design was applied to 546 sick-leave spells obtained from a cohort of 1430 employees within six Swedish workplaces. New sick-leave spells were reported from the workplaces during 3 to 12 months follow-up. Exposure was assessed in structured participant interviews at sick leave. Case and control periods from the same individual were sampled according to the matched-pair and usual-frequency approaches. Results are presented as odds ratios with surrounding 95% confidence intervals.
Results: The odds ratio of sick leave on a day with an unusually low workload was 2.57 (confidence interval, 1.07–6.16).
Conclusions: Becoming ill on a day with a lower workload than usual can trigger the decision to take sick leave.