Costs and benefits of combining probation and substance abuse treatment.

Aims Of The Study: We compared seamless combination of probation and treatment (where the probation officer is co-located with treatment provider or is actively engaged in treatment) to traditional probation where treatment is left to the client's choice.

Methods: Clients were randomly assigned to either seamless or traditional probation. We used a decision analytic approach which had two advantages: First it separated estimation of probability of adverse events (e.g. hospitalization) from the daily cost of the adverse event, thereby allowing use of estimates of daily costs available within the literature. Second, the reliance on daily probability of various adverse events also had the benefit of reflecting both length of the event and its intermittent re-occurrence. Subjects were 272 clients on probation in Northern Virginia and Maryland in the United States. Clients were randomly assigned to seamless and traditional probation and were followed for an average of 2.75 years (arrest information was only available for 1 year); 77% of clients participated in the follow-up interviews. At baseline, there was no statistically significant difference among the clients.

Results: During the follow-up period, clients in the seamless probation had less recidivism but the cost savings from this component (dollar 2.31 per client per follow-up day) was not sufficient to overcome increased costs due to mental hospitalization of seamless clients (dollar 13.50 per client per follow-up day), cost of delivery of seamless probation (dollar 2.58 per client per follow-up day), more frequent use of jail/prison for clients in the seamless group (dollar 2.08 per client per follow-up day) and additional treatment costs (dollar 1.24 per client per follow-up day). The expected cost of seamless probation and its consequences was dollar 38.84 per follow-up day. The expected cost of traditional probation and its consequences was dollar 21.60 per follow-up day. Seamless probation was dollar 6,293 more expensive than traditional probation per client per year.

Discussion: Sensitivity analysis suggested that the analysis was not sensitive to small change in any single cost or probability estimate. Sensitivity analysis suggested that increased supervision intensity and use of sanctions had contributed to lower cost-effectiveness.

Implications: One possible way of improving seamless probation is to improve the intensity of the substance abuse treatment while reducing the intensity of supervision to its traditional levels. This analysis was limited to 2.75 years follow-up period and does not address cost savings that might occur after this period.