Is treatment non-completion associated with increased reconviction over no treatment?

Abstract

There is accruing evidence that offenders who do not complete treatment are at greater risk of recidivism than those who do complete treatment. Profiles of non-completers show them to be high risk of reoffending compared with completers, and differences in reconviction may be explained by these baseline levels. What is unclear is whether non-completion actually increases the risk of reoffending over no treatment at all. The purpose of this review was to examine the recidivism of non-completers compared with untreated offenders of comparable risk. A systematic search of the literature relating to cognitive–behavioural interventions revealed 16 relevant studies describing 17 samples. The mean effect size (d=−0.16) of differences in reoffending between untreated offenders and treatment non-completers suggests that failing to complete treatment is associated with elevated levels of reoffending, with this effect being more pronounced in community samples (d=−0.23) than institutional samples (d=−0.15). Methodological limitations include poor risk comparability between samples and heterogeneity of non-completers, nevertheless it is possible that treatment non-completion may make some offenders more likely to reoffend.

Keywords:

• Offender
• treatment
• programmes
• non-completion
• drop-out

Acknowledgements

This paper is based upon a report prepared for HM Prison Service's Offending Behaviour Programmes Unit.