Service use and cost by mentally ill chemical abusers: Differences by retention in a therapeutic community

Purpose: Earlier research estimated the incremental costs and outcomes of a modified therapeutic community (modified TC) for mentally ill chemical abusers (MICAs) relative to a treatment-as-usual (TAU) control group. The present study extended the cost analysis by disaggregating the modified TC group into clients who completed the program (completers) and clients who dropped out (separaters). Methods: Bivariate and multivariate analyses were conducted to estimate differences in treatment and other service costs among completers, separaters, and TAU. Subjects were sequentially assigned to the modified TC (n = 171) or TAU (n = 47), and the analysis period covered 12 months post-baseline. Using a standardized instrument to collect resource use and cost data, the estimated weekly cost per client in the modified TC was $554, with completers showing a larger average cost of treatment ($27,595) than separaters ($9,986). Results: The average TAU subject had a much higher cost for other (non-modified TC) services ($29,795) relative to separaters ($22,048) or completers ($1,986). These findings suggest that, from baseline to the 12-month follow-up, the total cost of modified TC treatment and other services for completers may be slightly lower than the total cost for separaters or TAU subjects. Since the modified TC group had better outcomes than the TAU group, and the completers had better outcomes than the separaters, the modified TC program could be an effective mechanism to reduce the costs of service utilization as well as improve clinical outcomes. Implications: This detailed investigation into service utilization and cost provides policy-makers and program directors with valuable information regarding potentially cost-effective interventions and further underscores the importance of retention in treatment for this vulnerable population.