A sample of 320 sex offenders and 31 violent non-sex offenders, seen for psychiatric assessment between 1966 and 1974, were compared retrospectively on lifetime recidivism rates to 1999 over a minimum of 25 years. A number of criteria and data sources were used; RCMP records and hospital records were the best sources, albeit the RCMP had records for only 54.1% of the cases. Approximately three in five offenders reoffended, using sex reoffence charges or convictions or court appearances as criteria, but this proportion increased to more than four in five when all offences and undetected sex crimes were included in the analysis. Group differences in recidivism were noteworthy, with child sexual abusers and exhibitionists most likely to reoffend and incest offenders least likely. Time at large and time incarcerated played a relatively minor role overall in results, except in the case of offenders who were sexually aggressive against adult females, courtship disordered, or violent. The typical known criminal career spanned almost two decades, indicating that sex offence recidivism remained a problem over a significant part of the offenders' adult lives.

The TRST demonstrated only moderate predictive ability, and ideally, a better prediction rule should be sought. Future studies to develop better prediction rules should compare their performance with that of existing prediction rules, including the TRST and Identifying Seniors at Risk tool, and assess the effect of any new prediction rule on patient outcomes.