Sexual Abuse: A Journal of Research and Treatment [saj] pp325-sebu-363774 March 6, 2002 10:13 Style ﬁle version Nov. 19th, 1999
Sexual Abuse: A Journal of Research and Treatment, Vol. 14, No. 2, April 2002 (
First Report of the Collaborative Outcome Data
Project on the Effectiveness of Psychological
Treatment for Sex Offenders
R. Karl Hanson,
Andrew J. R. Harris,
Janice K. Marques,
Vernon L. Quinsey,
and Michael C. Seto
This meta-analytic review examined the effectiveness of psychological treatment
for sex offenders by summarizing data from 43 studies (combined n = 9,454).
Averaged across all studies, the sexual offence recidivism rate was lower for the
treatment groups (12.3%) than the comparison groups (16.8%, 38 studies, un-
weighted average). A similar pattern was found for general recidivism, although
the overall rates were predictably higher (treatment 27.9%, comparison 39.2%,
30 studies). Current treatments (cognitive–behavioral, k = 13; systemic, k = 2)
were associated with reductions in both sexual recidivism (from 17.4 to 9.9%) and
general recidivism (from 51 to 32%). Older forms of treatment (operating prior to
1980) appeared to have little effect. Future directions for improving the quality of
sex offender treatment outcome evaluations are discussed.
KEY WORDS: sex offender treatment; evaluation; recidivism; meta-analysis.
The views expressed are those of the authors and do not necessarily reﬂect the positions of the
Association for the Treatment of Sexual Abusers, the Department of the Solicitor General of Canada,
the Correctional Service of Canada, or the California Department of Mental Health.
Corrections Research, Department of the Solicitor General of Canada, Ottawa, Canada.
Clearwater Treatment Centre, Monroe, Washington.
California Department of Mental Health, Sacramento, California.
University of Tennessee–Memphis, Memphis, Tennessee.
Queen’s University, Kingston, Ontario.
Centre for Addiction and Mental Health, Toronto, Ontario.
To whom correspondence should be addressed at Corrections Research, Department of the Solicitor
General of Canada, 340 Laurier Avenue West, Ottawa,Canada K1A 0P8; e-mail: firstname.lastname@example.org.
2002 Plenum Publishing Corporation