estimates, when available. All unit costs were adjusted to the 2008 Consumer Price Index by using urban consumer yearly averages from the Bureau of Labor Statistics. Although we strove to derive methodologically comparable unit costs, we had to rely upon multiple sources, which is a common study limitation (39). Following Steadman et al. (17), estimated costs per unit for behavioral health services were chiefly based on the Medical Expenditure Panel Survey event files (MEPS.ahrq.gov), supplemented by cost estimates for nonmedical support services from the Clinical Antipsychotic Trials of Intervention Effectiveness (23). Estimated unit costs for criminal justice contacts were based on three sources. The estimated cost of an arrest was based on Clark et al.’s (24) study of people with co-occurring mental and substance abuse disorders. The estimated cost of a day in jail and in prison were based on McCollister et al.’s (25) study of people with substance abuse disorders, supplemented by national estimates by Perkins et al. (26) and the Pew Center (27). The estimated cost per day of traditional probation supervision is based on the national estimate by the Pew Center (27); specialty mental health supervision is estimated to cost 1.97 times more, given Texas legislative data (28) and Pew’s (27) relative estimates for regular vs. intensive supervision. Analyses Because participants were not randomly assigned to probation type, it would be misleading to statistically compare raw, average cost estimates for traditional and specialty groups. To rigorously control for potential confounders, we used Targeted Maximum Likelihood Estimation (TMLE), in tandem with a data adaptive algorithm called SuperLearner, to estimate the average difference in cost between groups. TMLE is a double-robust, semi-parametric estimator that uses estimates of both the treatment mechanism (i.e., propensity score; or probability of specialty probation assignment,
at ), which suggest that specialty effects are not an artifact of local practices (arrest rates were slightly higher in the specialty jurisdiction). Third, we applied the same unit costs across sites to service use and criminal justice contacts, to enable direct cost comparisons. Together, these points—along with sample matching, precise measurement, and strong implementation—lend substantial confidence to our results. Nevertheless, they need to be replicated in a randomized controlled trial. Conclusion Well-implemented specialty mental health probation yields substantial cost savings compared to traditional probation—and should be considered in current justice reform efforts for people with mental illness. References Steadman HJ, Osher FC, Robbins PC, et al: Prevalence of serious mental illness among jail inmates. Psychiatric Services 60: 761-765, 2009. Swanson JW, Frisman LK, Robertson AG, et al: Costs of criminal justice involvement among persons with serious mental illness in Connecticut. Psychiatric Services 64: 2013. Stepping Up Initiative: The Problem. stepuptogether.org/the-problem. Accessed November 9, 2017. Skeem JL and Peterson JK: Major risk factors for recidivism among offenders with mental illness. 2011. . Skeem JL, Manchak SM, and Peterson JK: Correctional policy for offenders with mental illness: Creating a new paradigm for recidivism reduction. Law and Human Behavior 35: 110-126, 2011.