Association of Opioid Agonist Treatment With Mortality or Rehospitalization Following Injection Drug Use-Associated Bacterial and Fungal Infections: Linkage Cohort Study

Author: Thomas Brothers Dan Lewer Nicola Jones Samantha Colledge-Frisby Duncan Webster Michael Farrell Matthew Hickman Andrew Hayward Louisa Degenhardt Dan Lewer Louisa

Theme: Clinical Research Year: 2022


Among people with opioid use disorder following hospital discharge with injectingrelated bacterial or fungal infections, we assessed whether outpatient use of opioid agonist
treatment (OAT; i.e. methadone or buprenorphine) was associated with decreased risk of death or
infection-related rehospitalization.


We analyzed data from the Opioid Agonist Treatment Safety (OATS) Study, a populationbased, retrospective linkage cohort including all people in New South Wales, Australia, who accessed
OAT between 1 July 2001 and 28 June 2018. We included participants who survived a hospitalization
with injecting-related bacterial or fungal infections (i.e., skin and soft-tissue infection,
sepsis/bacteraemia, endocarditis, osteomyelitis, septic arthritis, or epidural/brain abscess).
Outcomes were all-cause death and rehospitalization for injecting-related infection. We used
separate Cox proportional hazards models to assess associations between each outcome and OAT
exposure, classified as time-varying by days on or off treatment. Covariates included participant
demographics, comorbidities, prior substance-use related hospitalizations and incarceration, and
index hospitalization characteristics.


The study included 8,943 participants (mean age 39 ± 11 years; 34% women). The most
common infections during participants’ index hospitalizations were skin and soft-tissue (7,021; 79%),
sepsis/bacteraemia (1,207; 14%), and endocarditis (431; 5%). Prevalence of OAT exposure was 48%
on day 1, and participants had median 2 [IQR 0-5] switches on or off treatment during follow-up.
Over median 6.56 years follow-up, 1,481 (17%) participants died and 3,653 (41%) were
rehospitalized for injecting-related infections. OAT was associated with lower hazard of death
(adjusted Hazard Ratio [aHR] 0.63, 95% confidence interval [CI] 0.57 – 0.70) and of rehospitalization
(aHR 0.89, 95% CI 0.84 – 0.96).


Following hospitalizations with injecting-related bacterial and fungal infections, OAT is
associated with reduced risk of death and recurrent infections among people with opioid use
disorder. OAT should be offered and facilitated as part of a multi-component treatment strategy for
injecting-related infections.

Disclosure of Interest Statement:

In the past 3 years, LD and MF have received untied educational
grant funding from Indivior and Seqirus.
The conference collaborators recognise the considerable contribution that industry partners make to
professional and research activities. We also recognise the need for transparency of disclosure of
potential conflicts of interest by acknowledging these relationships in publications and presentations.

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