Hospitalization for motor vehicle injuries among American Indians and Alaska natives in Washington

Abstract

Objective: Little is known about the epidemiology of hospitalization for motor vehicle injury among American Indians and Alaska Natives (AI/ANs) in the Pacific Northwest. Current secondary data sources are inadequate to track this significant health problem. The purpose of this study was to determine the rate of hospitalization for motor vehicle injury in this population through linkage of Indian Health Service (IHS) patient registration data to a statewide hospital discharge database. Methods: To create the numerator, IHS patient registration data were linked to Washington State hospital discharge abstracts from 1990 to 1994 for motor vehicle injury (ICD-9 E-codes 810-819). The denominator for this population was derived from the total number of IHS enrollees in 1992. Comparative numerator and denominator data for all residents were derived from the discharge database and Washington State intercensal population estimates, respectively. Results: AI/ANs experienced a nearly two-fold higher rate of motor vehicle injury hospitalization ( N = 588) compared to all residents [Incidence Ratio (I.R.): 1.82; 95% C.I. 1.52–2.19]. The greatest disparity in incidence rates occurred among 25–34 year olds (I.R. 2.18; 95% C.I. 1.53–3.10) and 35–44 year olds (I.R. 2.18; 95% C.I. 1.36–3.47). In-hospital mortality, severity of injury and length of stay were not different between the 2 groups. Median charges for American Indian hospitalizations were $6188 and the IHS was payer in, at most, 24% of hospitalizations. Conclusions: AI/ANs are at higher risk of hospitalization for motor vehicle injuries but, compared to all residents of Washington, appear to have similar severity of injuries and outcomes. Motor vehicle injury hospitalization among AI/ANs incurs substantial health care costs.