Thomas Santo

Background and aims: Comprehensive community initiatives (CCI) are prioritised in global drug strategies to address alcohol related harms. However, their impact is unclear and moderators of impact are rarely considered. We explored CCIs that address alcohol use or related harms including approaches, effectiveness and factors that strengthen impact. Method: A systematic review and meta‐analysis (PROSPERO ID CRD420251044005). Embase, Medline, CINAHL, PsycINFO and the Cochrane Database of Systematic Reviews were searched. Reference lists for English‐language articles were hand‐searched without date restriction. A meta‐analysis and qualitative synthesis were completed on any measure of alcohol use or related harms including potential moderators of impact (including community type, level of engagement, initiative combinations, duration, recency, evaluation quality and length of follow‐up). Results: The systematic review included 44 studies (from 15 419 articles), with 35 assessing alcohol use and 21 assessing alcohol‐related harms. Meta analysis included 15 outcome estimates from nine studies across three alcohol use outcomes: any recent (past month) alcohol use [six studies, n = 32 397, relative risk (RR) = 0.96, 95% confidence interval (CI) = 0.87–1.06, heterogeneity ( I ² ) = 85.6%], any lifetime alcohol use (three studies, n = 13 025, RR = 0.82, 95% CI = 0.63–1.08, I ² = 96.8%) and any recent risky drinking (six studies, n = 82 383, RR = 1.02, 95% CI = 0.95–1.10, I ² = 72.9%). Data were insufficient for meta‐analysis of additional alcohol use (e.g. frequency) or related harms outcomes. Subgroup analyses were underpowered and did not identify clear moderators of impact. Pooled estimates were imprecise, with substantial‐to‐considerable heterogeneity across outcomes ( I ² = 72.9%–96.8%; τ ² = 0.0049–0.0544) and findings varied across studies. CCIs showed possible small preventive effects on any alcohol use, but not on recent risky drinking. Qualitative analysis indicated that CCIs incorporating school‐based or parenting components showed more consistent signals of benefit compared with other initiative combinations. Conclusions: Conclusions on the impact of comprehensive community initiatives on alcohol use and harms remain tentative because estimates from existing studies are imprecise and findings vary across studies.

Introduction: We have been funded to examine post‐incarceration health and social outcomes for all people incarcerated in New South Wales, Australia, 2000–2022; assess treatment and services for drug dependence and serious mental illness; and project the impact of expanding intervention coverage. We will use a linked cohort, the Prison Outcomes STudy ( POST ), which we also describe. Methods: The POST cohort was established using linked administrative data for all adults (≥ 18 years) admitted to full‐time custody in New South Wales, 2000–2022. Custody records were probabilistically linked to 18 health, justice and mortality datasets. We report baseline sociodemographic and custody characteristics and the frequency of key post‐release events. Results: 200,486 adults, 15% women ( n = 30,698), were incarcerated, with 2,282,367 person‐years of follow‐up and 11% (257,545 person‐years) of follow‐up spent in custody. First Nations people comprised 27% of the cohort. Half (48%) of the cohort ( n = 95,563) had at least one contact with community mental health services, and 27% ( n = 54,100) had received alcohol and other drug treatment. POST will provide population‐wide evidence on health and social outcomes after custody, including the effects of treatment for drug dependence and serious mental illness. We will compare across subgroups and the outcomes of post‐release service engagement. Mathematical modelling will test the impact of expanding access to care in prison and post‐release on outcomes in the community. Discussion and Conclusions: POST will inform policy and service responses across justice, health and community settings to reduce harms among people who experience incarceration.

Background and aims: Naltrexone is a pharmacotherapeutic option for relapse prevention in opioid use disorder (OUD); however, studies highlight low rates of initiation and high rates of discontinuation as limiting its effectiveness. We aimed to (1) estimate the percentage of individuals with OUD who (having undergone withdrawal and wish to remain abstinent) initiate and discontinue naltrexone and (2) examine participant‐ and study‐level factors that contribute to variation in initiation and discontinuation rates. Methods: We undertook a systematic review, random‐effects meta‐analysis and meta‐regression searching Medline, Embase, PsychINFO and CENTRAL from database inception to 19 February 2025 for studies of any design from any geographical region involving individuals with OUD eligible to receive naltrexone as a relapse prevention pharmacotherapy (i.e. those completing opioid withdrawal and wishing to remain abstinent). Measurements included the percentage of individuals who initiate or discontinue oral, long‐acting injectable depot or implantable formulations of naltrexone at 1, 3 or 6 months. Certainty was assessed using the GRADE framework. Results: Twenty‐two studies, including 124 016 individuals, reported initiation and 95 studies, including 16 969 individuals, reported discontinuation. The pooled percentage initiating oral naltrexone among those eligible was 60.3% [95% confidence interval (CI) = 38.9%–80.0%, 2014 participants, 15 studies] and depot was 18.2% (95% CI = 2.7%–42.5%, 57 383 participants, 4 studies). The pooled percentage discontinuing oral was 50.0% (95% CI = 41.9%–58.1%, 7340 participants, 34 studies) at 1 month, 61.3% (95% CI = 50.9%–71.2%, 2347 participants, 29 studies) at 3 months and 71.0% (95% CI = 57.3%–83.0%, 1889 participants, 19 studies) at 6 months. The pooled percentage discontinuing depot was 26.1% (95% CI = 19.5%–33.3%, 3589 participants, 33 studies) at 1 month, 46.7% (95% CI = 38.4%–55.1%, 3302 participants, 33 studies) at 3 months and 60.0% (95% CI = 43.2%–75.8%, 3071 participants, 22 studies) at 6 months. Statistically significantly higher percentages initiated oral naltrexone if it was the only offered pharmacotherapy (meta‐regression coefficient 33.6%, 95% CI = 8.1%–59.2%, P = 0.014) and statistically significantly lower percentages discontinued oral naltrexone at 3 and 6 months if administration was supervised (meta‐regression coefficient −18.6%, 95% CI = −36.6% to −1.0%, P = 0.043 and −27.3%, 95% CI = −50.1% to −4.4%, P = 0.022, respectively). There was no clear evidence that study setting (i.e. if the study was conducted in routine clinical care or an investigational setting) substantially explained or contributed to the variation in any estimates. All outcomes were very low certainty. Conclusions: Very low certainty evidence suggests that, among people with opioid use disorder who have undergone withdrawal and wish to remain abstinent, a substantial percentage are willing to initiate naltrexone with marked early discontinuation.

Introduction: Opioid agonist treatment (OAT) is one of the most effective treatments for opioid dependence, but there can be barriers to accessing treatment. This study examined characteristics associated with OAT engagement—never, previous or current—among people with opioid dependence in NSW, Australia, following recent reforms to OAT access. Methods: Between October 2023 and March 2024, people with opioid dependence were recruited from services and community settings across NSW. Participants completed structured interviews on socio‐demographics, mental health disorders, substance use and use of prevention and treatment services. Logistic regression was used to examine associations between participant characteristics and engagement with OAT. Results: Of 403 participants (mean age 44; 65% male), 77% were currently receiving OAT (60% methadone, 11% sublingual buprenorphine and 27% long‐acting injectable buprenorphine), 13% previously and 9% never. Differences between OAT status groups included those currently receiving OAT reporting lower rates of homelessness and extra‐medical opioid use, and greater group therapy engagement and past‐year receipt of naloxone kits compared to those previously and never receiving OAT. Past‐month daily injecting drug use was higher among those previously and never receiving OAT; those previously receiving OAT also reported the highest rate of past‐year supervised injecting facility use and overdoses in the past 6 months. Discussion and Conclusions: Those not receiving OAT reported greater social instability, recent injecting drug use and drug‐related harm. Variation in harm reduction service use suggests tailored strategies are needed to reach those outside OAT . These findings highlight the need for integrated, diverse strategies to address dependence‐related harms.

Introduction: Kava is a plant‐based drug central to many Pacific Island cultures, yet its physiological and psychological effects remain contested and poorly understood. Additionally, the broader social, economic, and policy consequences of kava trade and consumption are unclear. This paper systematically reviewed global literature on kava to clarify its role and potential impacts across these domains.Methods: We conducted a systematic search of eight databases for records published between January 1980 and December 2022. Records on kava prevalence, social and cultural use, harms, benefits, economic impacts and policy reports were included. Data were narratively synthesised, combining qualitative and quantitative data extracted using a pre‐designed template for each outcome, including a risk of bias evaluation.Results: We included 197 records across all domains. Most prevalence records used convenience samples in populations regularly consuming kava but with varying doses and periods. The harms and benefits of kava varied; its role in liver toxicity and anxiety reduction remains unclear. However, kava's social and cultural uses in recreational and traditional contexts and its economic importance in trade, distribution and sales across Pacific Islander countries were consistently reported.Discussion and Conclusions: Kava holds social and cultural significance and is an essential trading commodity for Pacific Islander countries. Additional high‐quality studies with larger samples are necessary to better inform policies and regulations around kava's usage, distribution, and its potential harms and benefits.

Aims: This study aimed to quantify the population‐level impact of a large‐scale opioid agonist treatment (OAT) program on suicide‐related mortality among people with opioid use disorder (OUD) in New South Wales (NSW), Australia.Design: This is the first study to use dynamic mathematical modeling to explore the population‐level impact of OAT on suicide mortality. The study used a two‐part approach. First, we analyzed cohort data (2001–2017) to calculate incidence rate ratios (IRRs) and other model parameters related to OAT and suicide risk. Second, findings were applied to model outputs to estimate suicides averted by the NSW OAT program (2001–2020).Setting and participants: A cohort of 46 845 individuals who received OAT between 2001 and 2017 in community and prison settings in New South Wales, Australia.Measurements: IRRs for suicide and other model parameters were calculated for individuals on versus off OAT in community and prison settings (2001–2017). These estimates, along with model outputs, were used to determine the number and proportion of suicides averted by the OAT program (2001–2020).Findings: Receiving OAT was associated with an IRR for suicide of 0.32 [95% confidence interval (CI) = 0.25–0.40] in the community and 0.34 (95% CI = 0.10–1.10) in prison for cohort data analyses (2001–2017). Between 2001 and 2020, the OAT program in NSW averted an estimated 338 suicides [95% credible interval (CrI) = 213–492), with 325 (95% CrI = 202–476) averted in the community and 13 (95% CrI = 0–46) in prison, corresponding to a 35% (95% CrI = 27%–43%) reduction in suicides among those accessing OAT.Conclusions: The opioid agonist treatment program in New South Wales, Australia, was associated with a 35% reduction in suicide mortality among individuals with opioid use disorder receiving treatment between 2001 and 2020, providing novel evidence of its population‐level impact on suicide prevention.