"Overall, lower levels of acquisitive offending and high-cost offending were recorded at follow-up. Among those who continued to offend, improvements in offending behaviour at follow-up, in terms of a decrease in its volume and/ or the costs associated with it, were observed. Crack users, injecting users, users with high SDS [Severity of Dependence Scores] scores, and those with previous treatment experience were more likely to offend than others at any point. However, neither referral source nor the type of treatment modalities received, were significantly associated with the level of acquisitive offending at any point (within the adjusted model)."

Source

Andrew Jones, et al. Research Report 24: The Drug Treatment Outcomes Research Study (DTORS): Final Outcomes Report. London, England: UK Government, Home Office Ministry, Research, Development & Statistics Directorate, December 2009.