The impact of opioid agonist treatment on fatal and non-fatal drug overdose among people with a history of opioid dependence in NSW, Australia, 2001–2018: Findings from the OATS retrospective linkage study

Non-fatal overdose risk during and after opioid agonist treatment: A primary care cohort study with linked hospitalisation and mortality records

“…Evidence from observational studies is sparse on non-fatal overdose risk in this patient population, as systematic reviews have focused on the prevalence of non-fatal overdose among drug users. 5 Previous studies of non-fatal overdose reported incidence rates that varied greatly between 3·05 and 35·70 per 1000 person-years of follow-up 4 , 23 , 24 , 25 and that variability may be associated with the country where the study was conducted, the data source (self-reported events versus routinely collected data) and definition of overdose according to the ICD-10 codes that were included. The observed increased rate ratio of non-fatal overdose during the first four weeks of OAT overall follows a similar pattern to studies that have examined fatal drug overdose.…”

Does opioid agonist treatment reduce overdose mortality risk in people who are older or have physical comorbidities? Cohort study using linked administrative health data in New South Wales, Australia, 2002–17

“…The primary outcome was fatal opioid overdose of unintentional or undetermined intent. We defined opioid overdose as an underlying cause of death of ICD‐10 X42, X44, Y12 or Y14 in combination with a contributory cause of death of T40.0–T40.4 or T40.6, or an underlying cause of death of F11 or F19 with contributory causes of death from both of the above groups of codes [25, 26].…”

“…Deaths were defined as occurring in or out of OAT based on treatment episode dates, and we defined deaths in treatment as those occurring within 1 day of the end of an authority to prescribe OAT [25]. We modelled opioid overdose mortality rates according to treatment exposure which had three categories: (i) time prescribed methadone; (ii) time prescribed buprenorphine; and (iii) time out of OAT.…”

Risk of opioid-related mortality associated with buprenorphine versus methadone: A systematic review of observational studies

“…Our review included seven studies [37][38][39][40][41][42][43]. Since the number of studies was not sufficiently large for quantitative data synthesis, we conducted a systematic review without meta-analysis.…”