The reflections of health service providers on implementing contingency management for methamphetamine use disorder in Australia.

INTRODUCTION: Contingency management (CM) is the most effective treatment for reducing methamphetamine use. We sought to understand why CM has not been taken up to manage methamphetamine use disorder in Australia. METHODS: Six focus groups (4-8 participants per group) were conducted with health workers from agencies in Australia that provided drug-related health care to people who use methamphetamine. These agencies had no previous experience delivering CM for substance use. The potential acceptability and feasibility of implementing CM in their services were discussed. RESULTS: Participants felt that it would be beneficial to have an evidence-based treatment for methamphetamine use disorder. This sentiment was offset by concerns that CM conflicted with a client-centred harm-reduction approach and that it dictated the goal of treatment as abstinence. It was also perceived as potentially coercive and seen to reify the power imbalance in the therapeutic relationship and therefore potentially reinforce stigma. There was also concern about the public's perception and the political acceptability of CM, who would fund CM, and the inequity of providing incentives only to clients with a methamphetamine use disorder. Some concerns could be ameliorated if the goals and structure of CM could be tailored to a client's needs. DISCUSSION AND CONCLUSIONS: Many healthcare workers were keen to offer CM as an effective treatment option for people with methamphetamine use disorder, but CM would need to be sufficiently flexible to allow it to be tailored to client needs and implemented in a way that did not adversely impact the therapeutic relationship.

Patterns of drug use among people who inject drugs: A global systematic review and meta-analysis.

BACKGROUND: A better understanding of global patterns of drug use among people who inject drugs can inform interventions to reduce harms related to different use profiles. This review aimed to comprehensively present the geographical variation in drug consumption patterns among this population. METHODS: Systematic searches of peer reviewed (PsycINFO, Medline, Embase) and grey literature published from 2008-2022 were conducted. Data on recent (past year) and lifetime drug use among people who inject drugs were included. Data were extracted on use of heroin, amphetamines, cocaine, benzodiazepines, cannabis, alcohol, and tobacco; where possible, estimates were disaggregated by route of administration (injecting, non-injecting, smoking). National estimates were generated and, where possible, regional, and global estimates were derived through meta-analysis. RESULTS: Of 40,427 studies screened, 394 were included from 81 countries. Globally, an estimated 78.1 % (95 %CI:70.2-84.2) and 71.8 % (65.7-77.2) of people who inject drugs had recently used (via any route) and injected heroin, while an estimated 52.8 % (47.0-59.0) and 19.8 % (13.8-26.5) had recently used and injected amphetamines, respectively. Over 90 % reported recent tobacco use (93.5 % [90.8-95.3]) and recent alcohol use was 59.1 % (52.6-65.6). In Australasia recent heroin use was lowest (49.4 % [46.8-52.1]) while recent amphetamine injecting (64.0 % [60.8-67.1]) and recent use of cannabis (72.3 % [69.9-74.6]) were higher than in all other regions. Recent heroin use (86.1 % [78.3-91.4]) and non-injecting amphetamine use (43.3 % [38.4-48.3]) were highest in East and Southeast Asia. Recent amphetamine use (75.8 % [72.7-78.8]) and injecting heroin use (84.8 % (81.4-87.8) were highest in North America while non-injecting heroin use was highest in Western Europe (45.0 % [41.3-48.7]). CONCLUSION: There is considerable variation in types of drugs and routes of administration used among people who inject drugs. This variation needs to be considered in national and global treatment and harm reduction interventions to target the specific behaviours and harms associated with these regional profiles of use.

Associations Between Supported Accommodation and Health and Re-offending Outcomes: a Retrospective Data Linkage Study.

Following release from prison, housing and health issues form a complex and mutually reinforcing dynamic, increasing reincarceration risk. Supported accommodation aims to mitigate these post-release challenges. We describe the impact of attending Rainbow Lodge (RL), a post-release supported accommodation service for men in Sydney, Australia, on criminal justice and emergency health outcomes. Our retrospective cohort study using linked administrative data includes 415 individuals referred to RL between January 2015 and October 2020. Outcomes of interest were rates of criminal charges, emergency department (ED) presentations and ambulance attendance; and time to first reincarceration, criminal charge, ED presentation and ambulance attendance. The exposure of interest was attending RL; covariates included demographic characteristics, release year and prior criminal justice and emergency health contact. Those who attended RL (n = 170, 41%) more commonly identified as Aboriginal or Torres Strait Islander (52% vs 41%; p = 0.025). There was strong evidence that attending RL reduced the incidence criminal charges (adjusted rate ratio [ARR] = 0.56; 95% confidence interval [CI] 0.340.86; p = 0.009). Absolute rates indicate a weak protective effect of RL attendance on ED presentation and ambulance attendance; however, adjusted analyses indicated no evidence of an association between attending RL and rates of ED presentations (ARR = 0.88; 95% CI = 0.65-1.21), or ambulance attendance (ARR = 0.82; 95% CI = 0.57-1.18). There was no evidence of an association between attending RL and time to first reincarceration, charge, ED presentation or ambulance attendance. Greater detail about reasons for emergency health service contact and other self-report outcome measures may better inform how supported accommodation is meeting its intended aims.

Global, regional, and country-level coverage of testing and treatment for HIV and hepatitis C infection among people who inject drugs: a systematic review.

BACKGROUND: People who inject drugs are disproportionately affected by HIV and hepatitis C virus (HCV) infections, while there is little global data on HIV and HCV testing and treatment coverage of this population. We conducted a systematic review to evaluate country-level, regional, and global coverage of HIV and HCV testing and treatment among people who inject drugs. METHODS: We did a systematic review, and searched bibliographic databases (MEDLINE, Embase, and PsycINFO) and grey literature for studies published between Jan 1, 2017, and April 30, 2022, that evaluated the proportion of people who inject drugs who received testing or treatment for HIV or HCV. For each country, we estimated the proportion of people who inject drugs tested for HIV antibodies in the past 12 months (recent), people who inject drugs ever tested for HCV antibodies and HCV RNA, people who inject drugs with HIV currently receiving antiretroviral therapy, and people who inject drugs with HCV ever receiving HCV antiviral treatment. Regional and global estimates, weighted by the population size of people who inject drugs, were generated where sufficient data were available. This study is registered with PROSPERO (CRD42020173974). FINDINGS: 512 documents reported data eligible for analyses, including 337 peer-reviewed articles, 27 conference abstracts or presentations, and 148 documents from grey literature or supplementary searches. Data of recent HIV antibody testing were available for 67 countries and ever having had HCV antibody testing were available for 49 countries. Globally, an estimated 48·8% of people who inject drugs were recently tested for HIV antibodies (95% uncertainty interval [UI] 43·3-54·2%; range 0·9-86·0%), and 47·1% had ever been tested for HCV antibodies (95% UI 43·4-51·0%; range 0·0-93·3%). HCV RNA testing data were available from three countries. Coverage of HIV antibody testing was high (>75%) in four countries and for HCV antibody testing in 15 countries. The estimated uptake of current HIV treatment (18 countries) ranged from 2·6% to 81·9%, and the estimated uptake of ever having HCV treatment (23 countries) ranged from 1·8% to 88·6% across countries. Uptake of HIV treatment was high in two countries, and of HCV treatment in one country. INTERPRETATION: HIV and HCV testing and treatment uptake among people who inject drugs was highly variable, and suboptimal in most countries. Strategies to improve access to HIV and HCV care among people who inject drugs and the availability of public health surveillance are urgently required. FUNDING: Australian National Health and Medical Research Council and UK National Institute for Health and Care Research Health Protection Research Unit in Behavioural Science and Evaluation.

Prevalence and incidence of emergency department presentations and hospital separations with injecting-related infections in a longitudinal cohort of people who inject drugs.

People who inject drugs are at risk of acute bacterial and fungal injecting-related infections. There is evidence that incidence of hospitalizations for injecting-related infections are increasing in several countries, but little is known at an individual level. We aimed to examine injecting-related infections in a linked longitudinal cohort of people who inject drugs in Melbourne, Australia. A retrospective descriptive analysis was conducted to estimate the prevalence and incidence of injecting-related infections using administrative emergency department and hospital separation datasets linked to the SuperMIX cohort, from 2008 to 2018. Over the study period, 33% (95%CI: 31-36%) of participants presented to emergency department with any injecting-related infections and 27% (95%CI: 25-30%) were admitted to hospital. Of 1,044 emergency department presentations and 740 hospital separations, skin and soft tissue infections were most common, 88% and 76%, respectively. From 2008 to 2018, there was a substantial increase in emergency department presentations and hospital separations with any injecting-related infections, 48 to 135 per 1,000 person-years, and 18 to 102 per 1,000 person-years, respectively. The results emphasize that injecting-related infections are increasing, and that new models of care are needed to help prevent and facilitate early detection of superficial infection to avoid potentially life-threatening severe infections.

Effect of incarceration and opioid agonist treatment transitions on risk of hospitalisation with injection drug use-associated bacterial infections: A self-controlled case series in New South Wales, Australia.

BACKGROUND: Transitional times in opioid use, such as release from prison and discontinuation of opioid agonist treatment (OAT), are associated with health harms due to changing drug consumption practices and limited access to health and social supports. Using a self-controlled (within-person) study design, we aimed to understand if these transitions increase risks of injection drug use-associated bacterial infections. METHODS: We performed a self-controlled case series among a cohort of people with opioid use disorder (who had all previously accessed OAT) in New South Wales, Australia, 2001-2018. The outcome was hospitalisation with injecting-related bacterial infections. We divided participants' observed days into time windows related to incarceration and OAT receipt. We compared hospitalization rates during focal (exposure) windows and referent (control) windows (i.e., 5-52 weeks continuously not incarcerated or continuously receiving OAT). We estimated adjusted incidence rate ratios (aIRR) using conditional logistic regression, adjusted for time-varying confounders. RESULTS: There were 7590 participants who experienced hospitalisation with injecting-related bacterial infections (35% female; median age 38 years; 78% hospitalised with skin and soft-tissue infections). Risk for injecting-related bacterial infections was elevated for two weeks following release from prison (aIRR 1.45; 95%CI 1.22-1.72). Risk was increased during two weeks before (aIRR 1.89; 95%CI 1.59-2.25) and after (aIRR 1.91; 95%CI 1.54-2.36) discontinuation of OAT, and during two weeks before (aIRR 3.63; 95%CI 3.13-4.22) and after (aIRR 2.52; 95%CI 2.09-3.04) OAT initiation. CONCLUSION: Risk of injecting-related bacterial infections varies greatly within-individuals over time. Risk is raised immediately after prison release, and around initiation and discontinuation of OAT. Social contextual factors likely contribute to excess risks at transitions in incarceration and OAT exposure.

Injection Drug Use Frequency Before and After Take-Home Naloxone Training.

Importance: Concerns that take-home naloxone (THN) training may lead to riskier drug use (as a form of overdose risk compensation) remain a substantial barrier to training implementation. However, there was limited good-quality evidence in a systematic review of the association between THN access and subsequent risk compensation behaviors. Objective: To assess whether THN training is associated with changes in overdose risk behaviors, indexed through injecting frequency, in a cohort of people who inject drugs. Design, Setting, and Participants: This cohort study used prospectively collected self-reported behavioral data before and after THN training of participants in The Melbourne Injecting Drug User Cohort Study (SuperMIX). Annual interviews were conducted in and around Melbourne, Victoria, Australia, from 2008 to 2021. SuperMIX participants were adults who regularly injected heroin or methamphetamine in the 6 months preceding their baseline interview. The current study included only people who inject drugs who reported THN training and had participated in at least 1 interview before THN training. Exposure: In 2017, the SuperMIX baseline or follow-up survey began asking participants if and when they had received THN training. The first THN training date that was recorded was included as the exposure variable. Subsequent participant interviews were excluded from analysis. Main Outcomes and Measures: Injecting frequency was the primary outcome and was used as an indicator of overdose risk. Secondary outcomes were opioid injecting frequency, benzodiazepine use frequency, and the proportion of the time drugs were used alone. Fixed-effects generalized linear (Poisson) multilevel modeling was used to estimate the association between THN training and the primary and secondary outcomes. Time-varying covariates included housing status, income, time in study, recent opioid overdose, recent drug treatment, and needle and syringe coverage. Findings were expressed as incidence rate ratios (IRRs) with 95% CIs. Results: There were 1328 participants (mean [SD] age, 32.4 [9.0] years; 893 men [67.2%]) who completed a baseline interview in the SuperMIX cohort, and 965 participants completed either a baseline or follow-up interview in or after 2017. Of these 965 participants, 390 (40.4%) reported THN training. A total of 189 people who inject drugs had pretraining participant interviews with data on injecting frequency and were included in the final analysis (mean [SD] number of interviews over the study period, 6.2 [2.2]). In fixed-effects regression analyses adjusted for covariates, there was no change in the frequency of injecting (IRR, 0.91; 95% CI, 0.69-1.20; P = .51), opioid injecting (IRR, 0.95; 95% CI, 0.74-1.23; P = .71), benzodiazepine use (IRR, 0.96; 95% CI, 0.69-1.33; P = .80), or the proportion of reported time of using drugs alone (IRR, 1.04; 95% CI, 0.86-1.26; P = .67) before and after THN training. Conclusions and Relevance: This cohort study of people who inject drugs found no evidence of an increase in injecting frequency, along with other markers of overdose risk, after THN training and supply. The findings suggest that THN training should not be withheld because of concerns about risk compensation and that advocacy for availability and uptake of THN is required to address unprecedented opioid-associated mortality.

Typology of laws restricting access to methadone treatment in the United States: A latent class analysis.

BACKGROUND: In the United States, methadone treatment for opioid use disorder is only available at opioid treatment programs (OTPs). In addition to federal regulations, states can enact laws which shape access to OTPs. We aimed to define classes of states according to restrictiveness of state OTP laws and examine population characteristics associated with class membership. METHODS: A set of laws was extracted from a database of statutes and regulations governing OTPs in 49 states and the District of Columbia as of June 2021. Latent class analysis of laws was used to estimate the probability of class membership for each state. Class-weighted multinomial logistic regression analysis assessed state-level correlates of class membership and adjusted Relative Risk Ratio (aRRR) and 95% confidence intervals (95%CI) were generated. RESULTS: States (n = 50) were assigned to three classes; Class 1) High restrictiveness on patient experience, low restrictiveness on access to service (n = 13); Class 2) Medium restrictiveness on patient experience, high restrictiveness on access to service (n = 14); Class 3) Low restrictiveness on patient experience, low restrictiveness on access to service (n = 23). States with a higher probability of membership in Classes with higher restrictiveness had higher rates of unemployment (Class 1 vs Class 3, aRRR:1.24; 95%CI:1.06-1.45), and Black residents (Class 2 vs Class 3, aRRR:1.10; 95%CI:1.04-1.15), and lower likelihood of Medicaid coverage of methadone (Class 1 vs Class 3, aRRR:0.25; 95%CI:0.07-0.88). States with a higher probability of membership in Classes with higher restrictiveness also had higher rates of potential indicators for opioid use disorder treatment need, including rates of opioid dispensing (Class 1 vs Class 3, aRRR:1.06; 95%CI:1.02-1.10, Class 2 vs Class 3, aRRR:1.07; 95%CI:1.03-1.11) and HIV diagnoses attributed to injection (Class 1 vs Class 3, aRRR:3.92; 95%CI:1.25-12.22). CONCLUSIONS: States with indicators of greater potential need for opioid use disorder treatment have the most restrictions, raising concerns about unmet treatment need.

Perspectives and sentiments on contingency management from people who use methamphetamine.

INTRODUCTION: Contingency management (CM) is currently the most efficacious treatment for methamphetamine use, yet it is rarely available in routine care. We examined the viewpoints of people who use methamphetamine on CM as a potential treatment for methamphetamine use disorder. METHODS: Semi-structured qualitative interviews with 30 Australians aged 18 years or older who had used methamphetamine at least weekly in the past 6 months. RESULTS: Participants reported overall positive attitudes towards CM as a potential treatment option for methamphetamine use disorder. However, there was need for greater flexibility in meeting participant treatment goals (e.g., reduced use or complete abstinence), with particular concern about the viability of initiating abstinence, both in terms of the sufficiency of the initial financial incentive and managing withdrawal symptoms. There was strong interest in the use of digital technologies to provide remote CM, particularly around the convenience and flexibility this offered. Despite this, participants remained keen to access adjunctive treatment and support services but stressed that engagement with these additional services should not be mandatory. Marketing of CM will need to address preconceptions about drug-testing used in abstinence-based CM being punitive (especially urine testing) and its connotations with criminal justice interventions. DISCUSSION AND CONCLUSION: Positive attitudes towards CM bode well for potential uptake should CM be made available in routine clinical practice. However, there is a need to adapt CM to ensure it is feasible and attractive to people who are seeking treatment for methamphetamine use disorder.

Incidence of suicide and self-harm among people with opioid use disorder and the impact of opioid agonist treatment: A retrospective data linkage study.

BACKGROUND: Rates of suicide and self-harm are elevated among people with opioid use disorder (OUD). This study examined incidence of self-harm and suicide among people who have entered OAT and assessed the impact of different OAT exposure periods on these events. METHOD: We conducted a retrospective population-based cohort study of all OAT recipients (N = 45,664) in New South Wales, Australia (2002-2017), using linked administrative data. Incidence rates of self-harm hospitalisations and suicide deaths were estimated per 1000 person-years (PY). The first 28 days of an OAT episode, ≥ 29 days on OAT, the first 28 days off OAT, and ≥ 29 days off OAT (maximum four years post-OAT) were exposure periods. Poisson regression models with generalised estimating equations estimated the adjusted incidence rate ratios (ARR) of self-harm and suicide by OAT exposure periods, adjusting for covariates. RESULTS: There were 7482 hospitalisations (4148 individuals) for self-harm and 556 suicides, equating to incidence rates of 19.2 (95% confidence intervals [CI]=18.8-19.7) and 1.0 (95%CI=0.9-1.1) per 1000 PY, respectively. Opioid overdose was implicated in 9.6% of suicides and 28% of self-harm hospitalisations. Compared to ≥ 29 days on OAT, the incidence rate of suicide was elevated in the 28 days following OAT cessation (ARR=17.4 [95%CI=11.7-25.9]), and the rate of self-harm hospitalisations was elevated during the first 28 days of OAT (ARR=2.2 [95%CI=1.9-2.6]) and the 28 days after leaving OAT (ARR=2.7 [95%CI=2.3-3.2]). CONCLUSIONS: OAT may reduce suicide and self-harm risk among people with OUD; however, OAT initiation and cessation are critical periods for targeting self-harm and suicide prevention interventions.

Epidemiology of injecting drug use, prevalence of injecting-related harm, and exposure to behavioural and environmental risks among people who inject drugs: a systematic review.

BACKGROUND: People who inject drugs are exposed to various and changing risk environments and are at risk of multiple harms related to injecting drug use (IDU). We aimed to undertake a global systematic review of the prevalence of IDU, key IDU-related harms (including HIV, hepatitis C virus [HCV], and hepatitis B virus [HBV] infection and overdose), and key sociodemographic characteristics and risk exposures for people who inject drugs. METHODS: We systematically searched for data published between Jan 1, 2017, and March 31, 2022, in databases of peer-reviewed literature (MEDLINE, Embase, and PsycINFO) and grey literature as well as various agency or organisational websites, and disseminated data requests to international experts and agencies. We searched for data on the prevalence, characteristics, and risks of people who inject drugs, including gender, age, sexuality, drug-use patterns, HIV, HCV, and HBV infections, non-fatal overdose, depression, anxiety, and injecting-related disease. Additional data were extracted from studies identified in our previous review. Meta-analyses were used to pool the data where multiple estimates were available for a country. We present country, regional, and global estimates for each variable examined. FINDINGS: We screened 40 427 reports published between 2017 and 2022, and the 871 eligible reports identified were added to the 1147 documents from the previous review. Evidence of IDU was documented in 190 of 207 countries and territories, and 14·8 million people (95% uncertainty interval [UI] 10·0-21·7) aged 15-64 years globally were estimated to inject drugs. Existing evidence suggests that there might be 2·8 million (95% UI 2·4-3·2) women and 12·1 million (95% UI 11·0-13·3) men who inject drugs globally, and that 0·4% (95% CI 0·3-1·3) of people who inject drugs identify as transgender. The amount of available data on key health and social risks among people who inject drugs varied widely across countries and regions. We estimated that 24·8% (95% CI 19·5-31·6) of people who inject drugs globally had experienced recent homelessness or unstable housing, 58·4% (95% CI 52·0-64·8) had a lifetime history of incarceration, and 14·9% (95% CI 8·1-24·3) had recently engaged in sex work, with substantial geographical variation. Injecting and sexual risk behaviour varied considerably geographically, as did risks of harms. Globally, we estimated that 15·2% (95% CI 10·3-20·9) of people who inject drugs are living with HIV, 38·8% (95% CI 31·4-46·9) have current HCV infection, 18·5% (95% CI 13·9-24·1) have recently overdosed, and 31·7% (95% CI 23·6-40·5) have had a recent skin or soft tissue infection. INTERPRETATION: IDU is being identified in a growing number of countries and territories that comprise more than 99% of the global population. IDU-related health harms are common, and people who inject drugs continue to be exposed to multiple adverse risk environments. However, quantification of many of these exposure and harms is inadequate and must be improved to allow for better targeting of harm-reduction interventions for these risks. FUNDING: Australian National Health and Medical Research Council.

Global coverage of interventions to prevent and manage drug-related harms among people who inject drugs: a systematic review.

BACKGROUND: Harm reduction and treatment programmes are essential for reducing harms for people who inject drugs (PWID). We aimed to update estimates from a 2017 review of global coverage of needle and syringe exchange programmes (NSPs), opioid agonist treatment (OAT), and other harm reduction services that target PWID (eg, take-home naloxone [THN] programmes, supervised consumption facilities, and drug checking services). METHODS: We did a systematic review of available evidence from peer-reviewed and grey literature databases for studies published between Jan 1, 2017, and May 31, 2022. Programmatic data were collected on the availability of services, the number of sites, people accessing services, and equipment distributed in countries where there is evidence of injecting drug use. National estimates of coverage of OAT (ie, number of people accessing OAT per 100 PWID) and NSPs (ie, number of needles and syringes distributed per PWID per year) were generated where available using the most recent data. Regional and global estimates were derived and compared with WHO indicators. The study was registered with PROSPERO (CRD42020173974). FINDINGS: We included 195 studies and found there were 90 countries implementing OAT (75% of the PWID population) and 94 countries implementing NSPs (88% of the global PWID population). Only five countries (2% of the global PWID population) are providing high coverage of both services. Far fewer countries were implementing THN programmes (n=43), supervised consumption facilities (n=17), and drug checking services (n=26), with nine countries implementing all five services. Globally, we estimated there were 18 (95% uncertainty interval [UI] 12-27) people accessing OAT per 100 PWID, and 35 (95% UI 24-52) needles and syringes being distributed per person who injects drugs per year. More countries reported high (OAT 24; NSPs 10), moderate (OAT 8; NSPs 15), and low (OAT 38; NSPs 47) coverage of services compared with the previous review. INTERPRETATION: Global coverage of OAT and NSPs has increased modestly in the past 5 years but remains low for most countries. Programmatic data on other key harm reduction interventions are scarce. FUNDING: Australian National Health and Medical Research Council.

Associations between the prevalence of chronic hepatitis B among people who inject drugs and country-level characteristics: An ecological analysis.

INTRODUCTION: Globally, hepatitis B virus (HBV) is a leading cause of liver disease. People who inject drugs (PWID) are at greater risk than the general population of contracting HBV. This risk could depend on societal factors in different countries. We investigated the associations between country-level chronic HBV prevalence in PWID with national indicators of development and prevalence of HIV and hepatitis C virus (HCV). METHODS: We used global systematic review data on chronic HBV prevalence (hepatitis B surface antigen-positive) among PWID and country-level sociodemographic characteristics from online databases. National random-effects meta-analysis estimates of HBV prevalence were the outcome in linear regression models testing for associations with country-level characteristics. RESULTS: The study included 131,710 PWID from 304 estimates in 55 countries: the pooled HBV prevalence among PWID in the countries analysed was 4.5% (95% CI 3.9-5.1), the highest regional pooled prevalence was in East and Southeast Asia (17.6% [13.3-22.3]), and the lowest was in Western Europe (1.7% [1.4-2.1]). In multivariable models, no indicators of development were associated with HBV prevalence, but there was evidence of positive associations between HBV prevalence in the general population and among PWID, and evidence of HIV and HCV prevalence in PWID being associated with HBV prevalence in PWID: multivariable coefficients 0.03 (95% CI 0.01-0.04); p < 0.001, and 0.01 (95% CI 0.00-0.03); p = 0.01, respectively. DISCUSSION AND CONCLUSIONS: HBV prevalence among PWID was associated with HIV and HCV prevalence among PWID and background HBV prevalence in the general population, highlighting the need for improving harm reduction in PWID and implementation of HBV vaccination, especially where HBV is endemic.

Prevalence of mental disorders among people with opioid use disorder: A systematic review and meta-analysis.

BACKGROUND: Opioid use disorder (OUD) and mental disorders are major public health issues and comorbidity is common. Among people with OUD, comorbid mental disorders are associated with poorer health outcomes. To our knowledge, this is the first systematic review and meta-analysis to estimate prevalence of specific mental disorders among people with OUD. METHODS: We searched Embase, MEDLINE, and PsycInfo from 1990 to 2021 for observational studies of depression, anxiety, post-traumatic stress disorder (PTSD), bipolar, personality, and other pre-specified mental disorders among people with OUD. We pooled current and lifetime estimates of each disorder using random-effects meta-analyses with 95% Confidence Intervals (CIs). Meta-regressions and stratified analyses were used to assess heterogeneity of prevalence estimates by methodological factors and sample characteristics. FINDINGS: Of the 36,971 publications identified, we included data from 345 studies and 104,135 people with OUD in at least one pooled estimate. Among people with OUD, the prevalence of current depression was 36.1% (95%CI 32.4-39.7%), anxiety was 29.1% (95%CI 24.0-33.3%), attention-deficit/hyperactivity disorder was 20.9% (95%CI 15.7-26.2%), PTSD was 18.1% (95%CI 15.4-20.9%), and bipolar disorder was 8.7% (95%CI 6.7-10.7%). Lifetime prevalence of anti-social personality disorder was 33.6% (95%CI 29.1-38.0%) and borderline personality disorder was 18.2% (95% CI 13.4-23.1%). Sample characteristics and methodological factors, including sex, were associated with variance of multiple prevalence estimates. INTERPRETATION: Our findings emphasise the need for access to mental disorder treatment among people with OUD. Specific mental disorder estimates may inform clinical guidelines, treatment services, and future research for people with OUD, including subpopulations with distinct treatment needs.

Opioid agonist treatment and risk of death or rehospitalization following injection drug use-associated bacterial and fungal infections: A cohort study in New South Wales, Australia.

BACKGROUND: Injecting-related bacterial and fungal infections are associated with significant morbidity and mortality among people who inject drugs (PWID), and they are increasing in incidence. Following hospitalization with an injecting-related infection, use of opioid agonist treatment (OAT; methadone or buprenorphine) may be associated with reduced risk of death or rehospitalization with an injecting-related infection. METHODS AND FINDINGS: Data came from the Opioid Agonist Treatment Safety (OATS) study, an administrative linkage cohort including all people in New South Wales, Australia, who accessed OAT between July 1, 2001 and June 28, 2018. Included participants survived a hospitalization with injecting-related infections (i.e., skin and soft-tissue infection, sepsis/bacteremia, endocarditis, osteomyelitis, septic arthritis, or epidural/brain abscess). Outcomes were all-cause death and rehospitalization for injecting-related infections. OAT exposure was classified as time varying by days on or off treatment, following hospital discharge. We used separate Cox proportional hazards models to assess associations between each outcome and OAT exposure. The study included 8,943 participants (mean age 39 years, standard deviation [SD] 11 years; 34% women). The most common infections during participants' index hospitalizations were skin and soft tissue (7,021; 79%), sepsis/bacteremia (1,207; 14%), and endocarditis (431; 5%). During median 6.56 years follow-up, 1,481 (17%) participants died; use of OAT was associated with lower hazard of death (adjusted hazard ratio [aHR] 0.63, 95% confidence interval [CI] 0.57 to 0.70). During median 3.41 years follow-up, 3,653 (41%) were rehospitalized for injecting-related infections; use of OAT was associated with lower hazard of these rehospitalizations (aHR 0.89, 95% CI 0.84 to 0.96). Study limitations include the use of routinely collected administrative data, which lacks information on other risk factors for injecting-related infections including injecting practices, injection stimulant use, housing status, and access to harm reduction services (e.g., needle exchange and supervised injecting sites); we also lacked information on OAT medication dosages. CONCLUSIONS: Following hospitalizations with injection drug use-associated bacterial and fungal infections, use of OAT is associated with lower risks of death and recurrent injecting-related infections among people with opioid use disorder.

Prevalence and factors associated with hospitalisation for bacterial skin infections among people who inject drugs: The ETHOS Engage Study.

BACKGROUND: Injecting-related skin and soft tissue infections (SSTIs) are a preventable cause of inpatient hospitalisation among people who inject drugs (PWID). This study aimed to determine the prevalence of hospitalisation for SSTIs among PWID, and identify similarities and differences in factors associated with hospitalisation for SSTIs versus non-bacterial harms related to injecting drug use. METHODS: We performed cross-sectional analyses of baseline data from an observational cohort study of PWID attending drug treatment clinics and needle and syringe programs in Australia. Logistic regression models were used to identify factors associated with self-reported hospitalisation for (1) SSTIs (abscess and/or cellulitis), and (2) non-bacterial harms related to injecting drug use (e.g., non-fatal overdose; hereafter referred to as non-bacterial harms), both together and separately. RESULTS: 1851 participants who injected drugs in the previous six months were enrolled (67% male; 85% injected in the past month; 42% receiving opioid agonist treatment [OAT]). In the previous year, 40% (n = 737) had been hospitalised for drug-related causes: 20% (n = 377) and 29% (n = 528) of participants were admitted to hospital for an SSTI and non-bacterial harm, respectively. Participants who were female (adjusted odds ratio [aOR]: 1.53, 95% CI: 1.19-1.97) or homeless (aOR: 1.59, 95% CI: 1.16-2.19) were more likely to be hospitalised for an SSTI, but not a non-bacterial harm. Both types of hospitalisation were more likely among people recently released from prison. CONCLUSIONS: Hospitalisation for SSTIs is common among PWID. Community-based interventions to prevent SSTIs and subsequent hospitalisation among PWID will require targeting of at-risk groups, including women, people experiencing homelessness, and incarcerated people upon prison release.

The impact of opioid agonist treatment on hospitalisations for injecting-related diseases among an opioid dependent population: A retrospective data linkage study.

BACKGROUND: Injecting-related bacterial and fungal infections cause substantial illness and disability among people who use illicit drugs. Opioid agonist treatment (OAT) reduces injecting frequency and the transmission of blood borne viruses. We estimated the impact of OAT on hospitalisations for non-viral infections and examine trends in incidence over time. METHODS: We conducted a retrospective cohort study using linked administrative data. The cohort included 47 163 individuals starting OAT between August 2001 and December 2017 in New South Wales, Australia, with 454 951 person-years of follow-up. The primary outcome was hospitalisation for an injecting-related disease. The primary exposure was OAT status (out of OAT, first four weeks of OAT, and OAT retention [i.e., more than four weeks in treatment]). Covariates included demographic characteristics, year of hospitalisation, and recent clinical treatment. RESULTS: 9122 participants (19.3%) had at least one hospitalisation for any injecting-related disease. Compared to time out of treatment, retention on OAT was associated with a reduced rate of injecting-related diseases (adjusted rate ratio[ARR]=0.92; 95%CI 0.87-0.97). The first four weeks of treatment was associated with an increased rate (ARR 1.53, 95%CI 1.38-1.70), which we believe is explained by referral pathways between hospital and community OAT services. The age-adjusted incidence rates of hospitalisations for any injecting-related disease increased from 34.8 (95% CI =30.2-40.0) per 1000 person-years in 2001 to 54.9 (95%CI=51.3-58.8) in 2017. INTERPRETATION: Stable OAT is associated with reduced hospitalisations for injecting-related bacterial infections; however, OAT appears insufficient to prevent these harms as the rate of these infections is increasing in Australia.

Mood and Anxiety Symptoms in Persons Taking Prescription Opioids: A Systematic Review with Meta-Analyses of Longitudinal Studies.

OBJECTIVE: To review evidence from longitudinal studies on the association between prescription opioid use and common mood and anxiety symptoms. DESIGN: We conducted a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. METHODS: We searched PubMed, Embase, and PsycINFO for search terms related to opioids AND (depression OR bipolar OR anxiety OR post-traumatic stress disorder [PTSD]). Findings were summarized narratively, and random-effects meta-analyses were used to pool effect sizes. RESULTS: We identified 10,290 records and found 10 articles that met our inclusion criteria. Incidence studies showed that people who used prescription opioids had an elevated risk of any mood outcome (adjusted effect size [aES] = 1.80 [95% confidence interval = 1.40-2.30]) and of an anxiety outcome (aES = 1.40 [1.20-1.80]) compared with those who did not use prescription opioids. Associations with depression were small and not significant after adjustment for potential confounders (aES = 1.18 [0.98-1.41]). However, some studies reported an increased risk of depressive symptoms after increased (aES = 1.58 [1.30-1.93]) or prolonged opioid use (aES = 1.49 [1.19-1.86]). CONCLUSIONS: Mental health should be considered when opioids are prescribed because some patients could be vulnerable to adverse mental health outcomes.