96-week retention in treatment with extended-release subcutaneous buprenorphine depot injections among people with opioid dependence: Extended follow-up after a single-arm trial.

BACKGROUND: The most recent formulation of buprenorphine treatment is extended-release depot injections (BUP-XR) that are administered subcutaneously by health care professionals. This study aimed to observe treatment outcomes of BUP-XR delivered in standard practice during a 96-week follow-up period in a community setting. METHODS: This study is an extension of the CoLAB study, a prospective single-arm, multicentre, open label trial (N=100, 7 sites in Australia) among people with opioid dependence who received monthly injections of BUP-XR to evaluate the retention in treatment. Participants were followed for 96 weeks, comprising 48 weeks of the CoLAB study followed by a 48-week extension. RESULTS: Of 100 participants at baseline, 47 were retained on BUP-XR at 96 weeks. The median time retained on monthly depot was 90 weeks. Heroin use (adjusted OR=0.19, P=0.012) in the month prior to baseline was associated with lower odds of retention on BUP-XR. Older age at first opioid use (adjusted OR= 1.08, P=0.009) and longer duration in OAT at baseline (adjusted OR= 1.12, P=0.001) were associated with increased retention. Prevalence of past four-weeks opioid use was estimated at 4% at 96 weeks of treatment (prevalence 0.04, 95%CI: 0.00-0.11) compared to 15% at baseline. Quality of life and medication treatment satisfaction improved over time for those retained in treatment. CONCLUSION: This is one of the few studies to describe long term (96 week) retention in treatment with BUP-XR in a community setting. It displayed retention rates with 47% of participants completing 96 weeks of treatment with BUP-XR. Patient reported outcomes suggest improvements in client wellbeing. FUNDING: Indivior.

Improving the quality of antenatal screening and early intervention for alcohol and other drug use: protocol for a multi-stage approach to systems reform.

BACKGROUND: Alcohol, tobacco and illicit drug use during pregnancy can cause significant harm to women and their developing fetuses. Despite recommendations for abstinence during pregnancy, some women continue to use, making screening for substance use during antenatal clinic attendances an important strategy for reducing risk. This study aims to improve the rates of screening and intervention for substance use among pregnant women, including appropriate referral for those who may be substance-dependent. The protocol outlined here focuses on a multi-stage implementation study. METHODS: This study will occur in four phases. Phase 1 will identify a baseline rate of screening and subsequent care at the antenatal clinics of two, South Australian hospital-based maternity services, through a retrospective case note audit. Rates of self-reported substance use identified in the case notes will also be compared against representative data from Adelaide Primary Health Network to establish rates of over or underreporting. Phase 2 will involve an online Training Needs Analysis of midwifery staff working at those services, to assess their knowledge, attitudes, beliefs, and commitment to the care of women who use substances during pregnancy. Phase 3 will involve a training package for all midwifery staff at those services, focused on routine screening for substance use, and how to provide appropriate care. Outcome measures from phase 2 will be reassessed during phase 3 and any changes since training will be evaluated. Phase 4 will then repeat phase 1 to compare the changes in rates of both screening and any associated intervention before and after training. DISCUSSION: From a public health perspective, this project has the potential to make a significant impact on reducing risk of harm from substance use disorders among pregnant women, and contribute to better health outcomes for their children. TRIAL REGISTRATION:  This trial has been pre-registered under the Open Science Framework. REGISTRATION: https://doi.org/10.17605/OSF.IO/73FDZ .

Trends in use of medicines for opioid agonist treatment in Australia, 2013-2022.

BACKGROUND: There are limited longitudinal data on national patterns of opioid agonist treatment (OAT). This study describes 10-year trends in the sales of OAT medicines in Australia. METHODS: A descriptive and time-series analysis of methadone, sublingual (SL) buprenorphine (+/-naloxone), and long-acting injectable (LAI) buprenorphine sold in Australia between 2013 and 2022 was performed. Total units sold were converted into an estimate of the number of clients that could be treated over a 28-day period with that amount of medicine ('client-months'). RESULTS: Between January 2013 and December 2022, the estimated number of client-months on: any OAT increased by 50 % to 53,501, methadone decreased (-8.5%), SL buprenorphine increased (+78%), and LAI buprenorphine increased substantially after September 2019. In January 2013, 78 % of OAT client-months received methadone. By December 2022, 48 % received methadone, 26 % SL buprenorphine, and 26 % LAI buprenorphine. Between 2013 to 2022, OAT client-months per capita were highest in the state of New South Wales. Over the study period, greater increases in OAT were observed in very remote areas (88%) compared to major cities (53%). The number of client-months in non-community pharmacy settings remained stable from 2013 to 2019/20, before increasing markedly. The introduction of LAI buprenorphine was associated with an immediate, sustained increase of 1,636 OAT client-months, and further increases of 190 OAT client-months each month. CONCLUSION: Patterns of OAT have shifted over the last 10-years with buprenorphine (SL/LAI) now the most common OAT used in Australia. The introduction of LAI buprenorphine has expanded OAT access, particularly in non-community pharmacy settings, and in remote areas.

Building workforce capacity to address substance use in primary health care: preliminary results from a mixed-methods pilot program.

BACKGROUND: Primary health care is critical to the prevention of alcohol, tobacco and other drug-related harms. Scaling-up screening, brief intervention and referral to treatment (SBIRT) within primary health care can reduce the burden of substance-related diseases, and improve downstream healthcare services. Building knowledge, skills and confidence among general practitioners (GPs), particularly in rural, regional and remote areas, to deliver SBIRT is an essential step. Therefore, this study aimed to pilot test a skills-based training program for GPs designed to build capacity for SBIRT delivery. METHODS: This pilot study investigated the acceptability of a structured, educational skills-based training program among GPs, as well as its preliminary effectiveness in inducing changes in confidence to deliver SBIRT, and in increasing knowledge about low-risk alcohol guidance. The training package was designed by experts in addiction medicine and public health, and involved a series of online webinars and in-person workshops at four locations across the South Eastern NSW Primary Healthcare Network catchment. RESULTS: A total of 18 GPs registered for the training, with six completing the final webinar. The GPs who completed all sessions demonstrated increases in confidence to deliver SBIRT and alcohol guidance knowledge from baseline. Qualitative feedback found the program acceptable, and GPs were able to successfully implement learnings into practice, and promote to colleagues. CONCLUSIONS: The results indicated the potential of this program at a national level, but highlighted the need for a range of additional incentives to encourage uptake and ongoing implementation.

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.

AIMS: To quantify the association between opioid agonist treatment (OAT) and overdose death by age group; test the hypothesis that across different age groups, opioid overdose mortality is lowest during OAT with buprenorphine compared with time out of treatment or OAT with methadone; and test associations between OAT and opioid overdose mortality in the presence of chronic circulatory, respiratory, liver and kidney diseases. DESIGN: Retrospective observational cohort study using linked administrative data. SETTING: New South Wales, Australia. PARTICIPANTS: A total of 37 764 people prescribed OAT, 1 August 2002 and 31 December 2017. MEASUREMENTS: OAT exposure, opioid overdose mortality and key confounders were measured using linked population data sets on OAT entry and exit, hospitalization, mental health care, incarceration and mortality. ICD-10 codes were used to define opioid overdose mortality and chronic disease groups of interest. FINDINGS: Relative to time out of treatment, time in OAT was associated with a lower risk of opioid overdose death across all age groups and chronic diseases. Among people aged 50 years and older, there was weak evidence that buprenorphine may be associated with greater protection against opioid overdose death than methadone [generalized estimating equation (GEE) adjusted incident rate ratio (aIRR) = 0.47; 95% confidence interval (CI) = 0.21, 1.02; marginal structural models (MSM) aIRR = 0.49; 95% CI = 0.17, 1.41]. Buprenorphine was associated with greater protection against overdose death than methadone for clients with circulatory (MSM aIRR = 0.27; 95% CI = 0.11, 0.67) or respiratory (MSM aIRR = 0.26; 95% CI = 0.07, 0.94) diseases, but not liver (MSM aIRR = 0.59; 95% CI = 0.14, 2.43) or kidney (MSM aIRR = 1.16; 95% CI = 0.31, 4.36) diseases. CONCLUSIONS: Opioid agonist treatment (OAT) appears to reduce mortality risk in people with opioid use disorder who are older or who have physical comorbidities. Opioid overdose mortality during OAT with buprenorphine appears to be lower and reduced in clients with circulatory and respiratory diseases compared with OAT with methadone.

Substance use in the emergency department: Screening for risky drug use, using the ASSIST-Lite.

INTRODUCTION: Substance use is a common contributing factor to emergency department (ED) presentations. While screening, brief intervention, and referral to treatment for alcohol and tobacco is common in ED settings, it is not routinely conducted for illicit substances. This study aimed to deploy the ASSIST-Lite to screen for risky use of alcohol and other drugs in the ED, to identify differences in risk based on between demographic characteristics. METHOD: All ED attenders, aged 18 years or older, deemed well enough to participate were approached. Recruitment occurred at the Royal Adelaide Hospital ED between May and June 2017. Participants were asked to self-complete the ASSIST-Lite in the ED waiting room. Overall, 632 people were approached, of which 479 (75.8%) agreed to participate. RESULTS: Alcohol (72.2%), tobacco (27.1%) and cannabis (15.2%) were most commonly reported. Eighty-nine participants reported moderate- or high-risk use of two substances, and a further 49 individuals reported moderate- or high-risk use of three or more substances. Across most substances, age, gender and employment status was associated with risky substance use, with higher likelihood of risk reported by males, unemployed and younger participants. Unemployment was also significantly associated with increased risk severity for both moderate and high-risk illicit use. DISCUSSIONS AND CONCLUSIONS: The rate of risky illicit and polysubstance use found here highlight the need more focused research in ED settings. The findings also provide support for more routine screening, and early intervention approaches; and suggest the need for active referral pathways through an alcohol and other drug consultation liaison service.

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.

BACKGROUND: There are critical periods of mortality risk at onset and cessation of opioid agonist treatment. We aim to determine whether non-fatal overdose followed the same pattern as fatal overdose, comparing the first 4 weeks of treatment and treatment cessation and the remainder time off treatment, with the remainder treatment time, to determine intervention markers. METHODS: Retrospective cohort study of people with a history of opioid agonist treatment using linked New South Wales data. The incidence of non-fatal overdose hospitalization; emergency department presentation; and fatal overdose from national death records were compared. Rates were calculated using generalized estimating equations adjusting for demographics, year, and recent health and incarceration events. RESULTS: The remainder time in OAT had the lowest incidence of overdose for all outcomes and is the reference level for the adjusted incident rate ratios (aIRR). Fatal overdose was lowest in treatment and highest in the first four weeks out of treatment, aIRR of 12.83 (95% CI 10.0-16.4). Whereas the highest overdose rate for non-fatal opioid overdose was in the first four weeks in treatment, aIRR of 3.11 (95% CI 2.19-4.42). CONCLUSIONS: Retention on opioid agonist treatment is protective against drug related overdose. There is elevated risk of non-fatal overdose at treatment initiation that is not evident for fatal overdose, but the first month of treatment cessation is a critical period for both non-fatal and fatal overdose. These findings emphasize the importance of treatment retention and interventions for polysubstance overdose at cessation.

'The Drug Survey App': a protocol for developing and validating an interactive population survey tool for drug use among Aboriginal and Torres Strait Islander Australians.

BACKGROUND: Disadvantage and transgenerational trauma contribute to Aboriginal and Torres Strait Islander (Indigenous) Australians being more likely to experience adverse health consequences from alcohol and other drug use than non-Indigenous peoples. Addressing these health inequities requires local monitoring of alcohol and other drug use. While culturally appropriate methods for measuring drinking patterns among Indigenous Australians have been established, no similar methods are available for measuring other drug use patterns (amount and frequency of consumption). This paper describes a protocol for creating and validating a tablet-based survey for alcohol and other drugs ("The Drug Survey App"). METHODS: The Drug Survey App will be co-designed with stakeholders including Indigenous Australian health professionals, addiction specialists, community leaders, and researchers. The App will allow participants to describe their drug use flexibly with an interactive, visual interface. The validity of estimated consumption patterns, and risk assessments will be tested against those made in clinical interviews conducted by Indigenous Australian health professionals. We will then trial the App as a population survey tool by using the App to determine the prevalence of substance use in two Indigenous communities. DISCUSSION: The App could empower Indigenous Australian communities to conduct independent research that informs local prevention and treatment efforts.

Examining the cost and impact of dosing fees among clients in opioid agonist treatment: Results from a cross-sectional survey of Australian treatment clients.

INTRODUCTION: Opioid agonist treatment (OAT) clients frequently bear costs associated with their treatment, including dosing fees. This study aimed to explore the financial and social impact of dosing fees upon clients. METHODS: Cross-sectional survey of people who use opioids regularly (N = 402) between December 2017 and March 2018, conducted in Australia. Dosing fees were calculated and expressed as percentage of income, by OAT type. Consequences and strategies for difficulties making payments were examined as proportions. RESULTS: A total of N = 360 participants had ever been in OAT and N = 245 participants currently engaged in OAT reported data on dosing fees, of them 53% (n = 129) reported paying dosing fees. Compared to clients with high levels of dosing supervision, those with moderate or low levels of supervision were more likely to pay dosing fees. The median 28-day dosing fee was AUD$110 (interquartile range AUD$80); median 28-day income was AUD$1520 (interquartile range AUD$700). For those who paid dosing fees, the fee comprised <10% of total monthly income for 70% of participants; however, 23% of participants paid fees comprising 10% to <20%, and 7% of participants paid fees comprising 20% or more of monthly income. Among those that had ever been in OAT, 72% experienced difficulties in paying treatment costs; 36% left treatment earlier than intended and 25% had been excluded due to payment difficulties. DISCUSSION AND CONCLUSIONS: Negative consequences of treatment costs to clients, particularly dosing fees, are evident. These costs impact treatment access and retention that may negatively impact clients' physical health, mental health and social wellbeing.

Outcomes of a single-arm implementation trial of extended-release subcutaneous buprenorphine depot injections in people with opioid dependence.

BACKGROUND: Opioid agonist treatment (OAT) is an effective intervention for opioid dependence. Extended-release buprenorphine injections (BUP-XR) may have additional potential benefits over sublingual buprenorphine. This single-arm trial evaluated outcomes among people receiving 48 weeks of BUP-XR in diverse community healthcare settings in Australia, permitting examination of outcomes when BUP-XR is delivered in standard practice. METHODS: Participants were recruited from a network of specialist public drug treatment services, primary care and some private practices in three states. Following a minimum 7 days on 8-32 mg of sublingual buprenorphine (±naloxone), participants received monthly subcutaneous BUP-XR injections administered by a healthcare practitioner and completed monthly research interviews. The primary endpoint was retention in treatment at 48 weeks. FINDINGS: Participants (n = 100) were 28% women, mean age 44 years with a long history of OAT (median 5.8 years); heroin was the most common opioid of concern (58%). Treatment retention at 24 and 48 weeks was 86% and 75%, respectively. Participants with past-month injecting drug use (OR 0.23; 95%CI: 0.09-0.61) or heroin use (OR 0.23; 95%CI: 0.08-0.65) at baseline had lower odds of being retained in treatment to 48 weeks. Reductions in multiple forms of extra-medical drug use were observed. Improvements in quality of life, participation in employment, and treatment satisfaction measures were also observed. INTERPRETATION: This real-world implementation study of BUP-XR demonstrated high retention and treatment satisfaction. This study provides important additional data on the uptake and experience of clients, with relevance for policy makers, health service planners, administrators, and practitioners. FUNDING: Indivior. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03809143.

A clinical research priority setting study for issues related to the use of methamphetamine and emerging drugs of concern in Australia.

INTRODUCTION: This study aimed to gather a range of opinions, including those of affected people (consumers, concerned others) to identify clinical research priorities for methamphetamine and emerging drugs of concern in Australia, to guide the work of the National Centre for Clinical Research on Emerging Drugs (NCCRED). METHODS: A priority setting study was conducted (February-March 2019) in four phases: online stakeholder survey, thematic analysis of responses, rapid literature review, expert panel ranking of priorities against predetermined criteria. RESULTS: Forty-seven respondents completed the survey, including people identifying as one or more of: researcher (53%, n = 25), clinician (45%; n = 21), family/friend/caregiver of someone who uses methamphetamine/emerging drugs (15%, n = 7) and consumer of methamphetamine/emerging drugs (13%, n = 6). Expert panel, evidence-informed top-ranked clinical research priorities for methamphetamine were: strategies to overcome barriers to intervention uptake, pilot medication trials for adults seeking treatment, and communication strategies regarding evidence-based treatments. For emerging drugs of concern, top-ranked priorities were: piloting community-located drug checking, feasibility of social media/other opportunities to alert consumers of emerging risks, GHB overdose and withdrawal management, and impacts of an early warning information system on reducing harms. DISCUSSION AND CONCLUSIONS: We demonstrate feasibility of a structured, collaborative clinical research priority setting process. Results have informed the establishment of NCCRED; using the identified priorities to guide seed funding, fellowships/scholarships and research programs. Broader uptake of this methodology by policymakers/research funders would assist to embed areas of concern identified by affected communities and other stakeholders in research prioritisation.

Revision of the Australian guidelines to reduce health risks from drinking alcohol.

INTRODUCTION: The Australian guidelines to reduce health risks from drinking alcohol were released in 2020 by the National Health and Medical Research Council. Based on the latest evidence, the guidelines provide advice on how to keep the risk of harm from alcohol low. They refer to an Australian standard drink (10 g ethanol). RECOMMENDATIONS: •Guideline 1: To reduce the risk of harm from alcohol-related disease or injury, healthy men and women should drink no more than ten standard drinks a week and no more than four standard drinks on any one day. The less you drink, the lower your risk of harm from alcohol. •Guideline 2: To reduce the risk of injury and other harms to health, children and people under 18 years of age should not drink alcohol. •Guideline 3: To prevent harm from alcohol to their unborn child, women who are pregnant or planning a pregnancy should not drink alcohol. For women who are breastfeeding, not drinking alcohol is safest for their baby. CHANGES AS RESULT OF THE GUIDELINE: The recommended limit for healthy adults changed from two standard drinks per day (effectively 14 per week) to ten per week. The new guideline states that the less you drink, the lower your risk of harm from alcohol. The recommended maximum on any one day remains four drinks (clarified from previously "per drinking occasion"). Guidance is clearer for pregnancy and breastfeeding, and for people aged less than 18 years, recommending not drinking.

The effect of person, treatment and prescriber characteristics on retention in opioid agonist treatment: a 15-year retrospective cohort study.

BACKGROUND AND AIMS: There is limited evidence on the relationship between retention in opioid agonist treatment for opioid dependence and characteristics of treatment prescribers. This study estimated retention in buprenorphine and methadone treatment and its relationship with person, treatment and prescriber characteristics. DESIGN: Retrospective longitudinal study. SETTING: New South Wales, Australia. PARTICIPANTS: People entering the opioid agonist treatment programme for the first time between August 2001 and December 2015. MEASUREMENTS: Time in opioid agonist treatment (primary outcome) was modelled using a generalized estimating equation model to estimate associations with person, treatment and prescriber characteristics. FINDINGS: The impact of medication type on opioid agonist treatment retention reduced over time; the risk of leaving treatment when on buprenorphine compared with methadone was higher among those who entered treatment earlier [e.g. 2001-03: odds ratio (OR) = 1.59, 95% confidence interval (CI) = 1.45-1.75] and lowest among those who entered most recently (2013-15: OR = 1.23, 95% CI = 1.11-1.36). In adjusted analyses, risk of leaving was reduced among people whose prescriber had longer tenure of prescribing (e.g. 3 versus 8 years: OR = 0.94, 95% CI = 0.93-0.95) compared with prescribers with shorter tenure. Aboriginal and Torres Strait Islander people, being of younger age, past-year psychosis disorder and having been convicted of more criminal charges in the year prior to treatment entry were associated with increased risk of leaving treatment. CONCLUSION: In New South Wales, Australia, retention in buprenorphine treatment for opioid dependence, compared with methadone, has improved over time since its introduction in 2001. Opioid agonist treatment retention is affected not only by characteristics of the person and his or her treatment, but also of the prescriber, with those of longer prescribing tenure associated with increased retention of people in opioid agonist treatment.

Perceptions of injectable opioid agonist treatment (iOAT) among people who regularly use opioids in Australia: findings from a cross-sectional study in three Australian cities.

BACKGROUND AND AIMS: Not all people experiencing opioid dependence benefit from oral opioid agonist treatment. The aim of this study was to examine perceptions of (supervised) injectable opioid agonist treatment (iOAT) (described as 'an opioid similar to heroin self-injected at a clinic several times a day') among people who regularly use opioids and determine how common iOAT eligibility criteria accord with interest in iOAT. DESIGN: Cross-sectional survey SETTING: Sydney, Melbourne and Hobart, Australia PARTICIPANTS: A total of 344 people (63% male) who use opioids regularly and had ever injected opioids, interviewed December 2017-March 2018. The mean age of participants was 41.5 years [standard deviation (SD) = 8.5]. MEASUREMENTS: Primary outcome measures were interest in iOAT, factors associated with interest and the proportion of participants who would be eligible using common criteria from trials and guidelines. We examined willingness to travel for iOAT, medication preferences and perspectives on whom should receive iOAT. FINDINGS: Overall, 53% of participants (n = 182) believed that iOAT would be a good treatment option for them. Participants who believed that iOAT was a good treatment option for them were more likely to be male [adjusted odds ratio (aOR) = 1.76, 95% confidence interval (CI) = 1.10-2.82], have used heroin in the past month (aOR = 6.03, 95% CI = 2.86-12.71), currently regularly inject opioids (aOR = 1.84, 95% CI = 1.16-2.91) and have met ICD-10 criteria for opioid dependence (aOR = 3.46, 95% CI = 1.65-7.24). Those interested in iOAT had commenced more treatment episodes (aOR =1.06, 95% CI = 1.00-1.12). Among those interested in iOAT (n = 182), 26% (n = 48) met common eligibility criteria for iOAT. CONCLUSIONS: Interest in injectable opioid agonist treatment does not appear to be universal among people who regularly use opioids. Among study participants who expressed interest in injectable opioid agonist treatment, most did not meet common eligibility criteria.

Quality of life as a predictor of time to heroin relapse among male residents following release from compulsory rehabilitation centres in Vietnam.

INTRODUCTION AND AIMS: Quality of life (QOL) is a relevant and quantifiable outcome of drug dependence treatment. We assessed health-related QOL for people released from three centre-based compulsory treatment (CCT) centres in Vietnam, using the EQ-5D. The study aimed to examine the prognostic value of health-related QOL in relation to time to relapse to heroin use among the participants. DESIGN AND METHODS: Two hundred and eight CCT participants with heroin dependence were interviewed at release, and at 3, 6 and 12 months post-release. Health-related QOL was measured with the EQ-5D. Kaplan-Meier survival models were fitted using Cox modelling to examine the rate, timing and prediction of the number of days to heroin relapse and to examine the predictability of the health-related QOL measures for days to relapse. Relapse was defined as first time of heroin use. RESULTS: The study found a substantial relapse rate (85.6%) among participants within 12 months following release from CCT centres; the mean number of days to relapse was 57.7 (SD = 31.6). There was no statistically significant change over time in the mean values of health-related QOL (P = 0.11). While the total index score (across the five pre-specified EQ-5D domains) did not have a significant effect in predicting cumulative relapse, lower scores on the Visual Analogue Scale of the EQ-5D were significantly (P < 0.05) predictive of cumulative relapse, with adjusted hazard ratios for relapse of 0.987 (P = 0.013). DISCUSSION AND CONCLUSIONS: EQ-5D Visual Analogue Scale score is a useful predictor of cumulative heroin relapse among participants released from CCT centres.

Hospitalisations for non-fatal overdose among people with a history of opioid dependence in New South Wales, Australia, 2001-2018: Findings from the OATS retrospective cohort study.

BACKGROUND: To examine, among a cohort of opioid dependent people with a history of opioid agonist treatment (OAT), the frequency and incidence rates of non-fatal overdose (NFOD) hospital separations over time, by age and sex. METHODS: Retrospective cohort study of people with a history of OAT using state-wide linked New South Wales (NSW) data. The incidence of NFOD hospital separations involving an opioid, sedative, stimulant or alcohol was defined according to the singular or combination of poisoning/toxic effect using ICD-10-AM codes. Crude incidence rates were calculated by gender, age group and calendar year. RESULTS: There were 31.8 (31.3-32.3) NFOD per 1,000 person-years (PY). Opioid NFOD incidence was higher in women than men: incidence rate ratio (IRR) 1.11 per 1,000PY; 95 %CI: [1.06-1.17]; women had higher sedative NFOD rates than men, IRR 1.27 per 1,000PY [1.21-1.34]. Participants ≤25 years, 26-30yrs, and 31-35yrs had higher incidence of opioid NFOD compared to 46+yrs, with IRRs of: 1.45 per 1,000PY; [1.32-1.59]; 1.20 per 1,000PY; [1.11-1.30] and 1.22 per 1,000PY; [1.13-1.32], respectively. Between 2006-7 and 2016-17, the cohort accounted for 19 % of NSW opioid NFOD episodes, 12 % of sedative, 14 % of stimulant and 5 % of acute alcohol-related NFOD. CONCLUSIONS: Hospital stays due to NFOD are a relatively frequent occurrence among opioid-dependent people. There are clear differences in rates and substances involved by sex, age and over time. Evidence-based interventions that prevent overdose among people who are opioid dependent need to be delivered to scale, including widespread community provision of naloxone.

Retention of opioid agonist treatment prescribers across New South Wales, Australia, 2001-2018: Implications for treatment systems and potential impact on client outcomes.

BACKGROUND: There has been much research on the efficacy and effectiveness of opioid agonist treatment (OAT), but less on its implementation and sustainability. A challenge internationally has been recruiting and retaining prescribers. This paper aims to characterise the prescribers in terms of OAT prescribing behaviours. METHODS: Retrospective cohort study in New South Wales, Australia. Participants were 2199 OAT prescribers between 1 st August 2001-19th September 2018.We examined trends in initiation and cessation of OAT prescribers. Adjusted hazard ratios were calculated to estimate prescriber retention, adjusting for year of initiation, practice type, client load and treatment prescribed. RESULTS: The rate of prescribers ceasing OAT prescribing has been increasing over time: a prescriber who initiated between 2016-2017 had over four times the risk of cessation compared with one who initiated before 2001, AHR: 4.77; [3.67-6.21]. The highest prescriber cessation rate was in prescribers who had prescribed for shorter time periods. The annual percentage of prescribers who ceased prescribing among those who prescribed for ≤5 years increased from 3% in 2001 to 20 % in 2017. By 2017 more prescribers were discontinuing prescribing than new prescribers were starting. Approximately 87 % (n = 25,167) of OAT clients were under the care of 20 % of OAT prescribers (n = 202); half had been prescribing OAT for 17+ years. CONCLUSIONS: OAT prescribing is increasingly concentrated in a small group of mature prescribers, and new prescribers are not being retained. There is a need to identify and respond to the reasons that contribute to newer prescribers to cease prescribing and put in place strategies to increase retention and broaden the base of doctors involved in such prescribing.