Regional mortality data, which are compiled according to place-of-residence of the decedent, are an important reference for regional health planning and resource allocation. However, it would be inappropriate to apply these data to studies of environmental risk factors if a large proportion of fatal motor vehicle traffic injuries (MVTI) in fact occur outside the resident county. The aim of this study was to determine the proportion and characteristics of residents of a rural area of Taiwan who died from MVTIs that occurred outside the county of residence. We also explored the relationships among the place-of-occurrence, place-of-death, and place-of-residence of these decedents. The families or neighbors of residents of Huatung Area (eastern Taiwan) who died from MVTIs in 1994 or 1995 were interviewed to identify the place-of-occurrence of the MVTI. Of the 882 Huatung Area residents who died as a result of an MVTI during the study period and for whom relevant data were available, the MVTI occurred outside the resident county in 207 (23%) cases. Residents whose MVTI occurred outside the county of residence were more likely to be youths (aged 15–24) or young adults (aged 25–44) and driving automobiles or trucks. Of the 866 cases in which the exact place was known, the place-of-occurrence and the place-of-death (recorded on the death certificate) were in the same county in 849 (98%). Because a high proportion of fatal MVTIs occurred outside the resident county, the mortality rate calculated according to place-of-residence does not accurately reflect the environmental risk factors in this area. The finding that the characteristics of those whose MVTI occurred outside the county differed from those decedents whose MVTI occurred within the county indicates that there are two target groups for prevention programs. In addition, at least in Huatung Area, the place-of-death recorded on the death certificate could serve as a surrogate for the place-of-occurrence in epidemiologic studies.
