Injury risk among medically identified alcohol and drug abusers

Background: Although nonfatal injury prevalence is higher among substance a busers than in the general population, few studies have estimated the injur y risk for clinically recognized substance abusers. The extant studies, mor eover, analyze rates of visits for injury treatment rather than rates of in jury events. This study estimates the excess risk of medically treated and hospitalized nonoccupational injury for people under age 65 with medically identified substance abuse problems and private health care coverage. Method: We conducted a retrospective cohort study by using medical claims d ata from Medstat Systems, Inc., with a longitudinal database of health care claims for 1.5 million people with health care coverage from 70 large corp orations. Claims histories for anyone who had an alcohol-related or drug-re lated primary or secondary diagnosis during 1987 to 1989 were analyzed. A r andom sample was selected from the remaining people without a substance abu se diagnosis in their medical records. Injury rates were compared among gro ups. We used logistic regression to estimate odds of medically treated and hospitalized injury, controlling for demographics. Results: Medically identified substance abusers had an elevated risk of inj ury in a 3-year period; alcohol and drug abusers had the highest risk (58%) , followed by drug-only abusers (49%), alcohol-only abusers (46%), and cont rols (38%). Alcohol and drug abusers were almost four times as likely to be hospitalized for an injury in a 3-year period when compared with controls. Injury risks were elevated substantially more for female then male substan ce abusers. Conclusions: This study greatly improves on available information about the risk of injury far drug and multiple-substance abusers. Medically identifi ed substance abusers, especially adult women, have a higher probability of injury, more hospitalized injuries, and more injury episodes per person inj ured than non-abusers. More aggressive identification and subsequent treatm ent of female substance abusers appear warranted.