Relationships Between Treatment Delivery, Program Attrition, and Reoffending Outcomes in an Intensive Custodial Sex Offender Program.

Retention of sex offenders to the completion of treatment is critical to program adherence to risk need responsivity (RNR) principles; however, it is also important to consider the potential interaction between attrition and treatment outcomes such as reoffending. The first aim of this study was to evaluate the influence of changes to treatment delivery in a residential sex offender treatment program (SOTP), including introduction of rolling groups and systematic emphasis on positive therapist characteristics, on likelihood of program noncompletion ( n = 652). Pooled regression modeling indicated that these operational interventions were associated with a significantly increased likelihood of program completion. We also examined whether variance in rates of participant attrition was related to reoffending outcomes for program completers ( n = 494). Incidence of attrition within completing participants' treatment cohorts had a significant negative association with hazard of sexual reoffending that was not accounted for by pretreatment risk. Results are discussed in terms of their implications for treatment delivery processes that aim to optimize both participant retention and treatment effectiveness.