title: Health-care service utilization in substance abusers receiving contingency management and standard care treatments.
abstract: OBJECTIVE
  To determine the impact of standard care and contingency management treatments on the utilization of general health-care services by substance abusers. PARTICIPANTS, DESIGN AND MEASUREMENTS:  This secondary analysis pooled 1028 treatment-seeking substance abusers from five randomized clinical trials that compared the effects of standard care (SC, n = 362) to standard care plus contingency management (CM, n = 666). In each trial, subjects in the CM condition showed significantly greater reductions in substance use than their SC counterparts. For each subject, utilization of 15 general health-care services was measured 1 year prior to treatment intake and up to 9 months following treatment intake. Post-intake utilization data were pro-rated to be comparable to the 1-year pre-intake data. Paired t-tests evaluated changes in service utilization pre- and post-intake, and difference-in-differences regression models were used to estimate the impact of CM, compared to SC, on changes in the utilization of each of the 15 health services.
  
  
  METHODS
  Out-patient community substance abuse clinics in Connecticut and Massachusetts, USA.
  
  
  RESULTS
  Utilization of several types of out-patient services increased significantly between the pre- and post-intake periods [e.g. dental visits (0.47, P < 0.001), community health center visits (0.50, P < 0.001), visits to a mental health professional office (1.03, P = 0.001)], while in-patient hospital care for mental health problems decreased significantly (-3.50 nights, P < 0.001). A substantial portion of these changes occurred during the treatment period. No significant differences were found between the two treatment conditions.
  
  
  CONCLUSIONS
  Initiating out-patient substance abuse treatment is associated with changes in general health-care service utilization, independent of the type of treatment offered.
authors.affiliation: School of Public Policy, 3401 Fairfax Drive, George Mason University, Arlington, VA 22201, USA. olmstead@gmu.edu
authors.forename: Todd A
authors.initials: TA
authors.lastname: Olmstead
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Cohen
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Petry
mesh_terms: D000328:Adult; D000553:Ambulatory Care / Q000706:statistics & numerical data; D001521:Behavior Therapy / Q000379:methods*; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D016032:Randomized Controlled Trials as Topic; D019966:Substance-Related Disorders / Q000534:rehabilitation*; D016896:Treatment Outcome