Estimating the effects of secure services on reconviction. Part 1 – predictive validity of the Offending Groups Reconviction Scale (OGRS-2) and redundancy of patient social and clinical features

 The Offender Group Reconviction Scale 2 (OGRS-2) excludes social and clinical factors that are known to be associated with offending risk in people with mental health problems, but shows similar predictive validity to structured professional judgment tools that include them. The aim of this study was to determine whether the predictive validity of OGRS-2 would be enhanced by the addition of social and clinical factors. A retrospective case note analysis was conducted on a national cohort of patients who were discharged from 35 UK medium secure between 01 April 1997 and 31 March 1998. Social factors, clinical factors and OGRS-2 probability scores were combined in a regression model using violent and any reconviction as outcomes across two-, four- and six year follow up periods. The OGRS-2 showed strong predictive validity for both any and violent reoffending, addition of social and clinical factors yielded no significant improvements. OGRS-2 may have reached an accuracy ceiling in predicting re-offending but remains effective for use alone to estimate risk of further convictions following discharge. OGRS-2 retains the well-established limitations of actuarial risk tools but can potentially aid in decision making around supervision and monitoring. OGRS-2 has potential to control for reconviction risk in reoffending outcome studies of medium secure service users.