Comparing Costs of Traditional vs. Specialty Probation for People with Serious Mental Illness

Objective:  People with mental illness are over-represented in the justice system.  Specialty mental health probation reduces the likelihood of re-arrest for these people. This study tests whether specialty probation also yields cost savings over traditional probation, when criminal justice and behavioral healthcare costs are examined for two years after placement.

Methods:  A longitudinal matched study of 359 people with mental illness on probation at prototypic specialty and traditional agencies. Compared to traditional officers, specialty officers supervised smaller caseloads, established better relationships with supervisees, and participated more in their treatment. Participants and officers were assessed and administrative databases were integrated to capture service use and criminal justice contacts. Unit costs were attached to these data (arrests x cost-per-arrest) to estimate costs each participant incurred over 2-years.  Cost differences were estimated using machine learning algorithms combined with Targeted Maximum Likelihood Estimation (TMLE), a double robust estimator that accounts for associations between confounders and both treatment assignment and outcomes.

Results:  On average, specialty probation costs an estimated $11,826 (p <.0005) less per participant than traditional probation, with overall savings of about 51%.  There were no significant group differences in criminal justice costs alone; specialty caseload costs were offset by reduced recidivism.  However, for behavioral healthcare alone, specialty probation costs an estimated $14,049 (p <.0005) less per client than traditional probation. Greater outpatient costs were more than offset by reduced emergency, inpatient, and residential costs.

Conclusions: Well-implemented specialty probation yields substantial savings—and should be considered in current justice reform efforts for people with mental illness.