The Reliability of Self-reported Sick Absenteeism: A Pilot Study

Abstract
This investigation addresses the reliability of self-reports of sick leave. Although sick leave is an objective measure which is often relevant for determining outcome and cost-benefit, obtaining records from employeers or insurance companies may be a considerable task. Consequently, we compared reports of sick leave during the last month made by 66 patients with musculoskeletal pain problems on the Outcome Evaluation Questionnaire with records from their insurance office. Results indicated good reliability with a correlation of r =.95, similar distributions, and no indication of systematic over or under reporting. Indeed, some examples are provided where part of the discrepancy may depend on idiosyncrasies in the insurance records or lack of clear definitions rather than poor accuracy on the patient's part. Our results suggest that self-reports of sick leave are reliable for recent time periods and a duration of one month.