This experimental statistical report contains initial findings from a project that has linked data from the National Drug Treatment Monitoring System (NDTMS) held by Public Health England (PHE) with data on offenders held by the Ministry of Justice (MoJ). The aim of this report is to improve the evidence base of the links between community-based treatment for substance misuse and changes in re-offending.

This ad-hoc release includes key sections on:
• • Characteristics associated with offending in the two-years before and after starting treatment (sections 3 and 7);
• • The offending profile both before and after starting treatment (section 4 and 5);
• • Change in offending (section 6);
• • Offending during prison or treatment (section 8).

This report contains initial findings from analysing the final matched dataset to support policy development and is intended to demonstrate the potential utility in linking treatment and offending data. Future publications may follow as our investigations into the links between substance misuse, treatment and re-offending are expanded.