Background: Mortality data has often been used to monitor the quality of cardiac care.
Objective: To investigate the under-reporting of unnatural deaths in mortality data.
Method: All patients with a main discharge diagnosis of injury (ICD-9-CM code 800-999) who died in 2003 or 2004 were identified through record linkage between hospital discharge claims data and cause of death data in Taiwan. Percentages of unnatural deaths that had been referred to the coroner and in which injury-related information was reported on the death certificate were estimated.
Results: Of 4086 known or suspected unnatural deaths, only 57% (2346/4086) were referred to the coroner, and in 71% (2889/4086) injury-related information was reported on the death certificate. The percentages of referral and reporting were lowest for deaths related to complications in medical and surgical care. In deaths related to fracture of the femur and the effects of a foreign body, many doctors report injury-related information on the death certificate but do not refer the certification of cause of death to the coroner.
Conclusions: The sensitivity of using mortality data alone to detect known or suspected unnatural deaths varied according to the types of injury and external causes. Monitoring cause of death data linked with hospital discharge record data could provide a better system for discovering these unnatural deaths.