The accuracy of death certificates in identifying work-related fatal injuries

Three national US agencies report on work-related fatal injuries, and one uses the "injury at work" designation on the death certificate to identify and characterize these fatalities. The accuracy of the "injury at work" notation has not been validated. The authors used selected external causes of death (from the International Classification of Diseases, Ninth Revision, Clinical Modification) that are highly likely to be work-related or not work-related as a standard to compare with the California death certificate "at work" designation for the years 1979-1989. Data from the National Center for Health Statistics for the years 1979-1984 were used to measure prevalence for purposes of determining the predictive value of a positive or negative work-related notation on the death certificate. The sensitivity of the "at work" designation was 77.6%, with a specificity of over 99%. Sensitivity but not specificity varied by age, sex, and specific external cause of death. The predictive value positive of the "at work" designation was about 60%, which suggests caution in using it for some epidemiologic purposes.