Illicit drug use and emergency room utilization

Objective. To provide an empirical examination of the effect that chronic i llicit drug use has on emergency room (ER) utilization, controlling for the potential biases introduced by correlation between unobservable determinan ts of chronic illicit drug use and ER utilization. Data Sources/Study Setting. From the National Household Survey on Drug Abus e 1994 (NHSDA94). Study Design. Chronic illicit drug use and ER utilization are analyzed for 5,384 females and 4,177 males in 1994. The study uses a two-stage estimatio n technique. In the first stage, sociodemographic, drug use history, and dr ug use risk variables are used to estimate the probability that the subject is a chronic illicit drug user (CDU). In the second stage, the first-stage estimates provide information needed to test for the possibility of bias i n the estimation of ER utilization. This bias is the result of the correlat ion between unobservable influences on the probability that the person is a CDU and the probability that he or she uses an ER. Data Collection/Extraction Methods. The data were collected through a multi stage stratified sampling design. With the use of this methodology, the res ulting data set provides the most comprehensive information on household dr ug use. Principal Findings. Without a correction for the possibility of endogeneity bias, chronic illicit drug use is a positive (for both males and females) and a significant (for females only) determinant of the probability of usin g an ER for medical treatment. After a correction for endogeneity, the infl uence of chronic drug use remains positive and significant for females and becomes significant for males. The corresponding change in probability for females is from 6 percent to 30 percent, while for males the increase is fr om an insignificant 0.1 percent to a significant 36 percent change. Conclusions. We estimate that chronic drug-using females and males, after a djustments for bias, increase the probability that they use an ER by more t han 30 percent compared to their casual or non-drug-using counterparts. The refore, policymakers and health services providers may consider designing p rograms to bring primary care and prevention services to facilities where d rug users are more likely to seek access to care, within an ER setting.