Evaluation of a national prison-based treatment program for sexual offenders in England and Wales.

Treatment efficacy is described for a sample of sexual offenders who had undertaken treatment in United Kingdom prisons (N = 647) and for a retrospectively selected comparison group (N = 1,910). The outcomes under observation in this study were sexual, sexual and/or violent, and general reconviction. Treatment impact was also examined in relation to offenders' risk of reconviction. The treatment group had slightly lower 2-year sexual reconviction rates than the comparison group, but these differences were not statistically significant. Significant differences were found between the treatment and comparison group for sexual and/or violent reconviction. Further analysis suggested that treatment produced a reduction in the probability of sexual and/or violent reconviction (p <.05) when other relevant variables were controlled for. General reconviction rates were consistently lower in the treatment group, but these differences were not significant.