Duration of work disability: a comparison of self-report and administrative data.

BACKGROUND: Studies have used insurer-reported compensable days absent as an outcome measure when studying work-related injury or illness. Compared to self-reported days absent, insurer data are less expensive to collect. Previous work has identified that insurer-claims data consistently underestimate the duration of days absent when compared to self-report. The objective of this study was to examine the agreement between the number of self-reported days absent from work following a compensable work-related injury and the number of insurer-reported compensation days paid, and to examine factors associated with the magnitude of the discrepancy between the number of self-reported days absent and the number of insurer-reported compensated days paid.
METHODS: One hundred sixty six respondents who experienced a work-related injury were interviewed approximately 200 days post-injury to assess the number of days absent from work. The number of days compensated by the insurer was compared to self-report using descriptive statistics and linear regression.
RESULTS: Respondents who had yet to experience a return-to-work (RTW) had the largest median discrepancy followed by respondents with an unsustained RTW and finally sustained RTW. Respondents with upper extremity injuries, lower education, and lower RTW self-efficacy showed greater discrepancy between self-reported and compensated days absent. Among respondents who self-reported fewer days absent than insurer-compensated days absent an inverse relationship between firm size and discrepancy was noted.
CONCLUSIONS: Researchers should be aware of the discrepancies between self-reported and compensated days absent. Future studies planning to incorporate days absent as an outcome variable should carefully consider what measure would be more appropriate and potentially collect both self-report and administrative data to assess the discrepancy. Copyright 2006 Wiley-Liss, Inc.