Excess overdose mortality immediately following transfer of patients and their care as well as after cessation of opioid substitution therapy

Aims: To investigate clustering of all-cause and overdose deaths after a transfer of patients and their care to alternative treatment provider and after the end of opioid substitution therapy (OST) in opioid-dependent individuals in specialist addiction treatment.

Design, Setting and Participants: Mortality data were identified within a sample of 5,445 patients with opioid use disorder who had received OST treatment between 1st April 2008 and 31st December 2013 from a large mental healthcare provider in United Kingdom. We investigated the circumstances and distribution of the 332 deaths identified within the observation window with a specific focus on overdose deaths (n=103) after a planned discharge, drop-out and transfer between services.

Measurements: Crude mortality rates for overdose mortality 7/14/28/180 days after the end of treatment/transfer for overdose mortality.

Findings: Of 47 individuals who died from overdose after having been transferred between services, 9 died in the first 2 weeks (crude mortality rate [CMR] 136.4, 64.3 – 243.1 95% CI) and a further 5 died in the first month post-transfer (CMR 79.5, 44.2 – 129.7 95% CI). Of the 32 individuals who died from overdose after planned OST cessation, 5 died in the first 2 weeks (CMR 151.5, 51.1 – 319.0 95% CI) and a further 4 died in the first month post discharge (CMR 82.6, 38.4 – 151.0 95% CI).

Conclusions: In the UK, opioid-dependent people who are transferred to an alternative treatment provider for continuation of their opioid substitution therapy experience high overdose mortality rates, with substantially higher rates in the first month (especially first 14 days) following transfer.