A record-linkage study of drug-related death and suicide after hospital discharge among drug-treatment clients in Scotland, 1996-2006.

AIMS: To investigate the relationship between time after hospital discharge and drug-related death (DRD) and suicide among drug users in Scotland, while controlling for potential confounders.
DESIGN: Cohort study. SETTING AND PARTICIPANTS: The 69 457 individuals who registered for drug treatment in Scotland during 1 April 1996-31 March 2006. MEASUREMENTS: Time-at-risk was from the date of an individual's first attendance at drug treatment services after 1 April 1996 until the earlier date of death or end-of-study, 31 March 2006, and was categorized according to time since the most recent hospitalization, as during hospitalization, within 28 days, 29-90 days, 91 days to 1 year and >1 year since discharge from most recent hospital stay versus 'never admitted' (reference).
FINDINGS: Time-periods soon after discharge were associated with increased risk of DRD. DRD rates per 1000 person-years were: 87 (95% CI: 72-103) during hospitalization, 21 (18-25) within 28 days, 12 (10-15) during 29-90 days and 8.5 (7.5-9.5) during 91 days to 1 year after discharge versus 4.2 (3.7-4.7) when >1 year after most recent hospitalization and 1.9 (1.7-2.1) for those never admitted. Adjusted hazard ratios by time since hospital discharge (versus never admitted) were: 9.6 (95% CI: 8-12) within 28 days, 5.6 (4.6-6.8) during days 29-90, thereafter 4.0 (3.5-4.7) and 2.3 (2.0-2.7) when >1 year. Non-drug-related suicides were less frequent than DRDs (269 versus 1383) but a similar risk pattern was observed.
CONCLUSIONS: In people receiving treatment for drug dependence, discharge from a period of hospitalization marks the start of a period of heightened vulnerability to drug-related death.