Impact of opioid substitution therapy for Scotland's prisoners on drug-related deaths soon after prisoner release

Aim: To assess whether the introduction of a prison-based opioid substitution therapy (OST) policy was associated with a reduction in drug-related deaths (DRD) within 14 days after prison release.

Design: Linkage of Scotland's prisoner database with death registrations to compare periods before (1996-2002) and after (2003-07) prison-based OST was introduced.

Setting: All Scottish prisons.

Participants: People released from prison between 1 January 1996 and 8 October 2007 following an imprisonment of at least 14 days and at least 14 weeks after the preceding qualifying release.

Measurements: Risk of DRD in the 12 weeks following release; percentage of these DRDs which occurred during the first 14 days.

Findings: Before prison-based OST (1996-2002), 305 DRDs occurred in the 12 weeks after 80 200 qualifying releases, 3.8 per 1000 releases [95% confidence interval (CI) = 3.4-4.2]; of these, 175 (57%) occurred in the first 14 days. After the introduction of prison-based OST (2003-07), 154 DRDs occurred in the 12 weeks after 70 317 qualifying releases, a significantly reduced rate of 2.2 per 1000 releases (95% CI = 1.8-2.5). However, there was no change in the proportion which occurred in the first 14 days, either for all DRDs (87: 56%) or for opioid-related DRDs.

Conclusions: Following the introduction of a prison-based opioid substitution therapy (OST) policy in Scotland, the rate of drug-related deaths in the 12 weeks following release fell by two-fifths. However, the proportion of deaths that occurred in the first 14 days did not change appreciably, suggesting that in-prison OST does not reduce early deaths after release.