A cost-effectiveness and cost-benefit analysis of contingency contracting-enhanced methadone detoxification treatment

We examined treatment costs in an ongoing study in which 102 opioid-addicted patients had been randomly assigned to either 180-day methadone detoxification or the same treatment enhanced with contingency contracting. In the latter condition, study participants received regular reinforcers contingent on negative urine toxicology screens and breath analyses for a range of drugs and alcohol. Both conditions involved psychosocial treatment, and all participants were stabilized to a daily methadone dose of approximately 80 mg during the first 4 months, followed by a 2-month taper. Individuals participating in the enhanced condition were more likely to provide continuously drug-free urine samples and alcohol-free breath samples during the final month of treatment than were participants in the control condition. Cost of treatment was calculated individually for each participant based on actual services received. First, unit cost for each service was determined, including adjusted staff salaries for direct treatment and opportunity cost of facilities utilized during service delivery. Next, we valued each patient's use of services during the first 120 days of the study and then added the cost of methadone, laboratory work, and contingent reinforcers. A subsample (n = 45) also provided data on health care utilization during treatment, which we valued using standard Medicare unit costs. The marginal cost of enhancing the standard treatment with contingency contracting was approximately 8%. An incremental cost of $17.27 produced an additional 1% increase in the number of participants providing continuously substance-free urine and breath samples during month 4 of the study. For every additional dollar spent on treatment, a $4.87 health care cost offset was realized; however, this difference was statistically insignificant due to extreme variances and small subsample size.