The study includes a national cohort of all patients (n = 3221) in OMT in Norway 1997-2003. Patients were followed over a 9-year period, before, during, and after treatment. Criminal convictions were studied on a day-to-day basis in relation to treatment status. A time-continuous estimate of the probability of convictions within the population for all days during observation was calculated.
Changes in convictions were evident before changes of treatment status. During the 3 years prior to OMT, the convictions rate was approximately 0.4% per day. Prior to OMT, convictions decreased to about 0.2% per day on the day of treatment initiation. During the weeks before dropping out of treatment, convictions increased. The patterns during periods of transition were the same across gender, age and pre-treatment conviction-levels.
The results of the present study suggest that an important purpose of treatment may be to consolidate rather than to initiate behaviour change. More generally, the results support the utility of a broader temporal perspective upon the process of behaviour change that is not associated exclusively with the effects of the treatment intervention.