The Effect of Integrated Medical-Substance Abuse Treatment during an Acute Illness on Subsequent Health Services Utilization

Background: The acute care hospital provides a context for engaging difficult to reach patients in substance abuse treatment (SAT); however, little is known regarding the effects of such engagement on subsequent health services utilization. We examined whether a structured day hospital (DH) intervention integrating SAT and medical care during an acute medical hospitalization would reduce subsequent emergency department (ED) use and rehospitalization compared with a control group receiving usual medical care and referral to intensive outpatient SAT. Methods: Between October 2001 and June 2002, we enrolled 390 hospitalized substance using patients in a nonrandomized clinical trial. Once stabilized, patients were assigned to either the DH intervention (n = 63) or usual care control group (n = 327). Baseline interview and chart review collected data on demographics, substance use, and acute and chronic medical conditions. Subsequent chart review collected data on ED, hospital and ambulatory care utilization in the 6 months pre-enrollment and 6 months postdischarge. Univariate and multiple logistic regression methods were used to assess the independent effects of the DH intervention on postdischarge health care utilization. Results: Overall 25%, 48%, and 42% reported ≥3 ED episodes, ≥1 rehospitalization, and ≥1 ambulatory care visit during the postdischarge period. Subjects who completed the DH intervention were significantly less likely to have ≥3 ED episodes (AOR = 0.27; 95% CI, 0.08-0.89) and more likely to have ≥1 ambulatory care visit (AOR = 4.05; 95% CI, 1.44-11.37) than the usual care group. No similarly beneficial effects were seen for patients who initiated but did not complete the DH intervention. Conclusions: A DH model that engages acutely ill substance using patients in integrated medical and substance abuse treatment can positively influence subsequent health care seeking behavior.