Representativeness of trauma center registries for farm injury surveillance.

Trauma center registries are the foundation for many surveillance systems that attempt to define the frequency and spectrum of various types of injuries. To assess the representativeness of trauma center-based farm injury surveillance, we evaluated data for 1986-1991 from the Marshfield Clinic/St Joseph's Hospital, a major trauma center located in Central Wisconsin. We compared the pattern of farm injuries seen in residents of the Marshfield Epidemiologic Surveillance Area (MESA), a geographically defined, population-based surveillance area, with those from outside MESA, a nonpopulation-based mix of primary care and referral patients typical of most trauma registries. The population-based and nonpopulation-based surveillance data suggested similar patterns with respect to seasonality, circumstances of injury, and source of injury. There were significant differences with respect to the body part injured, severity of injury, and selected aspects of acute medical care. While useful for many purposes, trauma center-based injury surveillance data should be interpreted cautiously.