Estimating deaths from industrial injury by capture-recapture: a cautionary tale

Capture-recapture methods are increasingly being used to improve surveillance for a number of diseases. However, concerns persist regarding the validity of estimates obtained.

Capture-recapture methods were applied to estimate the ability of four separate data sources on occupational fatalities to predict the 237 deaths ('gold standard') we determined from a special in-depth study of medical examiner records.

Capture-recapture results based upon the four sources vary according to different models. However, both separately and in aggregate of industry type and cause of death, most models seriously underestimate the gold standard, and give a misleading impression of precision of the estimate of hidden individuals. It is commonly believed that reliable estimates from such methods require lists with high coverage and parsimonious models. Here, to obtain an estimate consistent with the gold standard, the list with almost complete coverage must be discarded and a complex model fitted. It is argued that this conclusion is of widespread application.