Supporting equitable care of patients transferred from police watch-houses to the emergency department: A qualitative study of the perspectives of emergency doctors.

OBJECTIVE: People detained in short-term police custody often have complex health conditions that may necessitate emergency care, yet little is known about their management in EDs. The present study aimed to understand ED doctors' experiences and perceptions regarding the appropriateness and management of detainee transfers from police watch-houses to the EDs. METHODS: A qualitative descriptive study, using semi-structured interviews undertaken with ED doctors working in five purposively sampled EDs across Queensland, Australia. Data were analysed using inductive content analysis. RESULTS: Fifteen ED specialists and trainees participated. Participants reported that their overarching approach was to provide equitable care for watch-house detainees, as they would for any patient. This equitable approach needed to be responsive to complicating factors common to this population, including presence of police guards; restraints; complexity (physical/mental/social) of presentation; reliance on police to transport; ED doctors' often limited understanding of the watch-house environment; justice processes and uncertain legal disposition; communication with the watch-house; and detainees misreporting symptoms. Thresholds for assessment and treatment of detainees were contextualised to the needs of the patient, ED environment, and imperatives of other relevant agencies (e.g. police). Participants often relied on existing strategies to deliver quality care despite challenges, but also identified a need for additional strategies, including education for ED staff; improved communication with watch-houses; standardised paperwork; extended models of watch-house healthcare; and integrated medical records. CONCLUSIONS: Providing equitable healthcare to patients transported from watch-houses to the EDs is challenging but essential. Numerous opportunities exist to enhance the delivery of optimal care for this underserved population.

Rates and causes of death after release from incarceration among 1 471 526 people in eight high-income and middle-income countries: an individual participant data meta-analysis.

BACKGROUND: Formerly incarcerated people have exceptionally poor health profiles and are at increased risk of preventable mortality when compared with their general population peers. However, not enough is known about the epidemiology of mortality in this population-specifically the rates, causes, and timing of death in specific subgroups and regions-to inform the development of targeted, evidence-based responses. We aimed to document the incidence, timing, causes, and risk factors for mortality after release from incarceration. METHODS: We analysed linked administrative data from the multi-national Mortality After Release from Incarceration Consortium (MARIC) study. We examined mortality outcomes for 1 471 526 people released from incarceration in eight countries (Australia, Brazil, Canada, New Zealand, Norway, Scotland, Sweden, and the USA) from 1980 to 2018, across 10 534 441 person-years of follow-up (range 0-24 years per person). We combined data from 18 cohort studies using two-step individual participant data meta-analyses to estimate pooled all-cause and cause-specific crude mortality rates (CMRs) per 100 000 person-years, for specific time periods (first, daily from days 1-14; second, weekly from weeks 3-12; third, weeks 13-52 combined; fourth, weeks 53 and over combined; and fifth, total follow-up) after release, overall and stratified by age, sex, and region. FINDINGS: 75 427 deaths were recorded. The all-cause CMR during the first week following release (1612 [95% CI 1048-2287]) was higher than during all other time periods (incidence rate ratio [IRR] compared with week 2: 1·5 [95% CI 1·2-1·8], I2=26·0%, weeks 3-4: 2·0 [1·5-2·6], I2=53·0%, and weeks 9-12: 2·2 [1·6-3·0], I2=70·5%). The highest cause-specific mortality rates during the first week were due to alcohol and other drug poisoning (CMR 657 [95% CI 332-1076]), suicide (135 [36-277]), and cardiovascular disease (71 [16-153]). We observed considerable variation in cause-specific CMRs over time since release and across regions. Pooled all-cause CMRs were similar between males (731 [95% CI 630-839]) and females (660 [560-767]) and were higher in older age groups. INTERPRETATION: The markedly elevated rate of death in the first week post-release underscores an urgent need for investment in evidence-based, coordinated transitional healthcare, including treatment for mental illness and substance use disorders to prevent post-release deaths due to suicide and overdose. Temporal variations in rates and causes of death highlight the need for routine monitoring of post-release mortality. FUNDING: Australia's National Health and Medical Research Council.

Interventions to Prevent and Respond to Violence Against Justice-Involved Young Women: A Scoping Review.

Young women who have had contact with the criminal justice system (justice-involved young women) have an increased risk of being a victim of violence. However, no reviews have synthesized the evidence on interventions to prevent or respond to violence against justice-involved young women. We conducted a scoping review to identify interventions designed to prevent or respond to violence against justice-involved young women. We searched Medline, Criminal Justice Abstracts, Web of Science, and Google Scholar for peer-reviewed and gray literature published in English from January 1, 2000 until March 23, 2021. Consistent with the public health approach to violence, we included primary, secondary, and tertiary interventions. Excluding duplicates, our search returned 5,603 records, 14 of which met our inclusion criteria. We narratively synthesized the included studies, all of which were conducted in the United States. Most included studies examined a tertiary intervention (n = 10), and few examined a primary (n = 2) or secondary (n = 2) intervention. Across the Joanna Briggs Institute Critical Appraisal Tools, the percentage of items met ranged from 0% to 78%. There was some limited evidence that tertiary interventions that included cognitive behavioral therapy reduced the mental health impacts of violence victimization among justice-involved young women. There was little evidence on primary and secondary interventions. Effective and evidence-based interventions to prevent violence victimization and revictimization against justice-involved young women remains a critical gap in knowledge.

Using the Alcohol, Smoking and Substance Involvement Screening Test to predict substance-related hospitalisation after release from prison: A cohort study.

BACKGROUND AND AIMS: Poor substance use-related health outcomes after release from prison are common. Identifying people at greatest risk of substance use and related harms post-release would help to target support at those most in need. The Alcohol Smoking and Substance Involvement Screening Test (ASSIST) is a validated substance use screener, but its utility in predicting substance-related hospitalisation post-release is unestablished. We measured whether screening for moderate/high-risk substance use on the ASSIST was associated with increased risk of substance-related hospitalisation. DESIGN: A prospective cohort study. SETTING: Prisons in Queensland and Western Australia. PARTICIPANTS: Participants were incarcerated and within 6 weeks of expected release when recruited. A total of 2585 participants were followed up for a median of 873 days. MEASUREMENTS: Baseline survey data were combined with linked unit record administrative hospital data. We used the ASSIST to assess participants for moderate/high-risk cannabis, methamphetamine and heroin use in the 3 months prior to incarceration. We used International Classification of Diseases (ICD) codes to identify substance-related hospitalisations during follow-up. We compared rates of substance-related hospitalisation between those classified as low/no-risk and moderate/high-risk on the ASSIST for each substance. We estimated adjusted hazard ratios (aHR) by ASSIST risk group for each substance using Weibull regression survival analysis allowing for multiple failures. FINDINGS: During follow-up, 158 (6%) participants had cannabis-related, 178 (7%) had opioid-related and 266 (10%) had methamphetamine-related hospitalisation. The hazard rates of substance-related hospitalisation after prison were significantly higher among those who screened moderate/high-risk compared with those screening low risk on the ASSIST for cannabis (aHR 2.38, 95% confidence interval [CI] 1.74, 3.24), methamphetamine (aHR 2.23, 95%CI 1.75, 2.84) and heroin (aHR 5.79, 95%CI 4.41, 7.60). CONCLUSIONS: Incarcerated people with an Alcohol Smoking and Substance Involvement Screening Test (ASSIST) screening of moderate/high-risk substance use appear to have a significantly higher risk of post-release substance-related hospitalisation than those with low risk. Administering the ASSIST during incarceration may inform who has the greatest need for substance use treatment and harm reduction services in prison and after release from prison.

Adverse childhood experiences, morbidity, mortality and resilience in socially excluded populations: protocol for a systematic review and meta-analysis.

INTRODUCTION: Socially excluded populations, defined by homelessness, substance use disorder, sex work or criminal justice system contact, experience profound health inequity compared with the general population. Cumulative exposure to adverse childhood experiences (ACEs), including neglect, abuse and household dysfunction before age 18, has been found to be independently associated with both an increased risk of social exclusion and adverse health and mortality outcomes in adulthood.Despite this, the impact of ACEs on health and mortality within socially excluded populations is poorly understood. METHODS AND ANALYSIS: We will search MEDLINE, Cumulative Index of Nursing and Allied Health Literature, Educational Resources Information Center, PsycINFO, Applied Social Science Index and Abstracts and Criminal Justice Database for peer-reviewed studies measuring ACEs and their impact on health and mortality in socially excluded populations.Three review questions will guide our data extraction and analysis. First, what is the prevalence of ACEs among people experiencing social exclusion in included studies? Second, what is the relationship between ACEs and health and mortality outcomes among people experiencing social exclusion? Does resilience modify the strength of association between ACEs and health outcomes among people experiencing social exclusion?We will meta-analyse the relationship between ACE exposure and health outcomes classified into six a prior categories: (1) substance use disorders; (2) sexual and reproductive health; (3) communicable diseases; (4) mental illness; (5) non-communicable diseases and (6) violence victimisation, perpetration and injury. If there are insufficient studies for meta-analysis, we will conduct a narrative synthesis. Study quality will be assessed using the MethodologicAl STandards for Epidemiological Research scale. ETHICS AND DISSEMINATION: Our findings will be disseminated in a peer-reviewed journal, in presentations at academic conferences and in a brief report for policy makers and service providers. We do not require ethics approval as this review will use data that have been previously published. PROSPERO REGISTRATION NUMBER: CRD42022357565.

Intervention targets for reducing mortality between mid-adolescence and mid-adulthood: a protocol for a machine-learning facilitated systematic umbrella review.

INTRODUCTION: A rise in premature mortality-defined here as death during the most productive years of life, between adolescence and middle adulthood (15-60 years)-is contributing to stalling life expectancy in high-income countries. Causes of mortality vary, but often include substance misuse, suicide, unintentional injury and non-communicable disease. The development of evidence-informed policy frameworks to guide new approaches to prevention require knowledge of early targets for intervention, and interactions between higher level drivers. Here, we aim to: (1) identify systematic reviews with or without meta-analyses focused on intervention targets for premature mortality (in which intervention targets are causes of mortality that can, at least hypothetically, be modified to reduce risk); (2) evaluate the review quality and risk of bias; (3) compare and evaluate each review's, and their relevant primary studies, findings to identify existing evidence gaps. METHODS AND ANALYSIS: In May 2023, we searched electronic databases (MEDLINE, PubMed, Embase, Cochrane Library) for peer-reviewed papers published in the English language in the 12 years from 2012 to 2023 that examined intervention targets for mortality. Screening will narrow these papers to focus on systematic reviews with or without meta-analyses, and their primary papers. Our outcome is death between ages 15 and 60 years; with potential intervention targets measured prior to death. A MeaSurement Tool to Assess systematic Reviews (AMSTAR 2) will be used to assess quality and risk of bias within included systematic reviews. Results will be synthesised narratively due to anticipated heterogeneity between reviews and between primary studies contained within included reviews. ETHICS AND DISSEMINATION: This review will synthesise findings from published systematic reviews and meta-analyses, and their primary reviewed studies, meaning ethics committee approval is not required. Our findings will inform cross-cohort consortium development, be published in a peer-reviewed journal, and be presented at national and international conferences. PROSPERO REGISTRATION NUMBER: CRD42022355861.

Police perspectives on the economic considerations of providing healthcare in short-term custodial settings in Australia.

Providing appropriate healthcare to people in short-term police custody settings (i.e. watch-houses) is challenging due to the complexity of detainee health needs and the limitations of the custodial environment. However, little is known about how detainee healthcare is managed in Australia, including economic considerations. This study had two aims: (1) to understand police perspectives on the costs associated with the delivery of healthcare to watch-house detainees in Queensland, Australia and (2) to scope the applicability of the Prison Healthcare Expenditure Reporting Checklist (PHERC) tool for the Australian watch-house context. The study employed an exploratory qualitative descriptive approach. A purposive sample comprised 16 watch-house staff from six regions in Queensland, Australia, interviewed between April and November 2021. A key finding was that police viewed healthcare expenditure as a major, but largely unavoidable cost for Australian watch-houses. Participants reported that direct expenditure comprised mostly of in-house healthcare services (of which there were a variety of models), but also costs of medication and health-related consumables. Indirect costs included costs of escorting and guarding detainees requiring transfer to hospital for health assessment and treatment. Participants reported that the PHERC was not applicable to the Australian watch-house context. Future research should explore the cost-effectiveness of different watch-house healthcare delivery models and how best to measure this.

Advancing cross-sectoral data linkage to understand and address the health impacts of social exclusion: Challenges and potential solutions.

The use of administrative health data for research, monitoring, and quality improvement has proliferated in recent decades, leading to improvements in health across many disease areas and across the life course. However, not all populations are equally visible in administrative health data, and those that are less visible may be excluded from the benefits of associated research. Socially excluded populations - including the homeless, people with substance dependence, people involved in sex work, migrants or asylum seekers, and people with a history of incarceration - are typically characterised by health inequity. Yet people who experience social exclusion are often invisible within routinely collected administrative health data because information on their markers of social exclusion are not routinely recorded by healthcare providers. These circumstances make it difficult to understand the often complex health needs of socially excluded populations, evaluate and improve the quality of health services that they interact with, provide more accessible and appropriate health services, and develop effective and integrated responses to reduce health inequity. In this commentary we discuss how linking data from multiple sectors with administrative health data, often called cross-sectoral data linkage, is a key method for systematically identifying socially excluded populations in administrative health data and addressing other issues related to data quality and representativeness. We discuss how cross-sectoral data linkage can improve the representation of socially excluded populations in research, monitoring, and quality improvement initiatives, which can in turn inform coordinated responses across multiple sectors of service delivery. Finally, we articulate key challenges and potential solutions for advancing the use of cross-sectoral data linkage to improve the health of socially excluded populations, using international examples.

Numeracy and literacy attainment of children exposed to maternal incarceration and other adversities: A linked data study.

Parental incarceration has been associated with educational disadvantages for children, such as lower educational attainment, increased grade retention, and truancy and suspensions. However, children exposed to parental incarceration often experience other adversities that are also associated with educational disadvantage; the contribution of these co-occurring adversities has not been considered in previous research. This study aimed to investigate the educational outcomes of children exposed to (a) maternal incarceration alone and (b) maternal incarceration plus other adversities (i.e., maternal mental illness and/or child protective services [CPS] contact). We used linked administrative data for a sample of children whose mothers were incarcerated during the children's childhood (i.e., from the time of mother's pregnancy through the child's 18th birthday; n = 3828) and a comparison group of children whose mothers had not been incarcerated (n = 9570). Multivariate multinomial logistic regressions examined the association between exposure to the three adversities (i.e., maternal incarceration, maternal mental illness, and child CPS contact) and above or below average reading and numeracy attainment in Grades 3, 5, 7 and 9. At all grade levels, children exposed to maternal incarceration alone and those exposed to maternal incarceration plus other adversities had increased odds of below average numeracy and reading attainment and decreased odds of above average numeracy and reading attainment compared to children without any of the recorded exposures. Children exposed to maternal incarceration and CPS contact and those exposed to all three adversities had increased odds of below average reading and numeracy attainment compared to children exposed to maternal incarceration alone. The findings highlight the complex needs of children of incarcerated mothers that must be considered when designing and delivering educational support programs. These children would benefit from the implementation of multi-tiered, trauma-informed educational and clinical services.

Corrigendum to: Factors associated with emergency department service outcomes for people with a mental health problem brought in by police: a retrospective cohort study.

Objective This study aimed to identify factors associated with an emergency department (ED) length of stay ≥4 hours (h) and hospital admission for people with a mental health problem brought in by police. Methods We undertook a retrospective, observational cohort study of state-wide adult ED mental health presentations brought in by police from 1 January 2012 to 31 December 2017. We used multivariable logistic regression to determine factors associated with an ED length of stay ≥4 h and hospital admission. Results In total, 9325 ED presentations with a mental health problem brought in by police to Queensland EDs were included. Factors most strongly associated with an ED length of stay ≥4 h included an Australasian Triage Score (ATS) of 1, an age of 85 years or older, night shift arrival and subsequent hospital admission. For hospital admission, an ATS of 1, an age of 85 years or older and an ED length of stay ≥4 h were the strongest factors. Conclusion Findings indicate opportunities for targeted mental health models of care to better support people brought in by police to an ED. Such models should involve ED, pre-hospital providers (police and ambulance) and mental health services to support early intervention and potentially reduce the likelihood of a long ED length of stay and subsequent hospital admission.

Profile and Outcomes of Emergency Department Mental Health Patient Presentations Based on Arrival Mode: A State-Wide Retrospective Cohort Study.

INTRODUCTION: People arriving to the emergency department with mental health problems experience varying and sometimes inferior outcomes compared with people without mental health problems, yet little is known about whether or how their arrival mode is associated with these outcomes. This study describes and compares demographics, clinical characteristics, and patient and health service outcomes of adult mental health emergency department patient presentations, based on arrival mode: brought in by ambulance, privately arranged transport, and brought in by police. METHODS: Using a retrospective observational study design with state-wide administrative data from Queensland, Australia, mental health presentations from January 1, 2012, to December 31, 2017, were analyzed using descriptive and inferential analyses. RESULTS: Of the 446,815 presentations, 51.8% were brought in by ambulance, 37.2% arrived via privately arranged transport, and 11.0% were brought in by police. Compared with other arrival modes, presentations brought in by ambulance were more likely to be older and female and have more urgent triage categories and a longer length of stay. Presentations arriving by privately arranged transport were more likely than other arrival modes to present during the day, be assigned a less urgent triage category, be seen within their recommended triage time, have a shorter length of stay in the emergency department, have higher rates of discharge, and have waited longer to be seen by a clinician. Presentations brought in by police were more likely than other arrival modes to be younger and male and experience a shorter time to be seen by a clinician. DISCUSSION: Discrepancies between arrival modes indicates a need for further investigation to support inter- and intra-agency mental health care interventions.

Non-communicable disease mortality in young people with a history of contact with the youth justice system in Queensland, Australia: a retrospective, population-based cohort study.

BACKGROUND: Young people who have had contact with the criminal justice system are at increased risk of early death, especially from injuries. However, deaths due to non-communicable diseases (NCDs) in this population remain poorly described. We aimed to estimate mortality due to NCDs in people with a history of involvement with the youth justice system, compare NCD mortality rates in this population with those in the general population, and characterise demographic and justice-related factors associated with deaths caused by NCDs in people with a history of contact with the youth justice system. METHODS: In this retrospective, population-based cohort study (the Youth Justice Mortality [YJ-Mort] study), we included all people aged 10-18 years (at baseline) charged with a criminal offence in Queensland, Australia, between June 30, 1993, and July 1, 2014. We probabilistically linked youth justice records with adult correctional records and national death records up to Jan 31, 2017. Indigenous status was ascertained from youth justice and adult correctional records, with individuals identified as Indigenous in either source classified as Indigenous in the final dataset. We estimated crude mortality rates and standardised mortality ratios (SMRs) for comparisons with data from the Australian general population. We identified risk factors for NCD deaths using competing-risks regression. FINDINGS: Of 48 670 individuals aged 10-18 years (at baseline) charged with a criminal offence in Queensland, Australia, between June 30, 1993, and July 1, 2014, 11 897 (24·4%) individuals were female, 36 773 (75·6%) were male, and 13 250 (27·2%) were identified as identified as Indigenous. The median age at first contact with the youth justice system was 15 years (IQR 14-16), the median follow-up time was 13·4 years (8·4-18·4), and the median age at the end of the study was 28·6 years (23·6-33·6). Of 1431 deaths, 932 (65·1%) had a known and attributed cause, and 121 (13·0%) of these were caused by an NCD. The crude mortality rate from NCDs was 18·5 (95% CI 15·5-22·1) per 100 000 person-years among individuals with a history of involvement with the youth justice system, which was higher than among the age-matched and sex-matched Australian general population (SMR 1·67 [1·39-1·99]). Two or more admissions to adult custody (compared with none; adjusted sub-distribution hazard ratio 2·09 [1·36-3·22]), and up to 52 weeks in adult custody (compared with none; 1·98 [1·18-3·32]) was associated with NCD death. INTERPRETATION: Young people with a history of contact with the justice system are at increased risk of death from NCDs compared with age-matched and sex-matched peers in the general Australian population. Reducing youth incarceration and providing young people's rights to access clinical, preventive, and restorative services should be a priority. FUNDING: National Health and Medical Research Council.

Maternal incarceration increases the risk of self-harm but not suicide: a matched cohort study.

AIMS: Children of incarcerated mothers are at increased risk of experiencing multiple adversity such as poverty, mental illness and contact with child protection services (CPS), including being taken into out of home care (OOHC). However, little is known about whether these children are at increased risk of suicide or self-harm compared to children not exposed to maternal incarceration or about the factors that may contribute to this. We aimed to investigate differences in the risk of suicide and self-harm between children exposed to maternal incarceration and those not exposed and examine how socio-demographic factors, maternal mental illness and CPS contact (with or without OOHC) may affect these outcomes. METHODS: We used a retrospective matched cohort study design, comparing 7674 children exposed to maternal incarceration with 7674 non-exposed children. We used multivariable Cox proportional hazards regression to compare the risk of suicide and self-harm between exposed and non-exposed groups, controlling for geographical remoteness, CPS contact and maternal mental illness. RESULTS: There was no significant difference in the rate of suicide (rate ratio [RR] = 1.49; 95% confidence interval [CI]: 0.78, 2.87) or risk of suicide (adjusted hazard ratio [aHR] = 0.92; 95% CI: 0.43, 1.96) between the two groups. However, the exposed group had a significantly higher rate of self-harm (RR = 2.83; 95% CI: 2.50, 3.21) and a significantly higher risk of self-harm (aHR = 1.74; 95% CI: 1.45, 2.09) compared to those non-exposed. CPS contact with or without OOHC was independently associated with an increased risk of self-harm for both groups. CONCLUSION: Children exposed to maternal incarceration are at an increased risk of self-harm and should be prioritized to receive targeted, multimodal support that continues after the mother's release from prison. The association between CPS contact and self-harm warrants further research.

Violence-Related Death in Young Australians After Contact With the Youth Justice System: A Data Linkage Study.

Little is known outside of the United States about the risk of violence-related death among young people who have had contact with the youth justice system (justice-involved young people). We examined violence-related deaths among justice-involved young people in Queensland, Australia. In this study, youth justice records for 48,647 young people (10-18 years at baseline) who were charged, or experienced a community-based order or youth detention in Queensland, Australia (1993-2014) were probabilistically linked with death, coroner, and adult correctional records (1993-2016). We calculated violence-related crude mortality rates (CMRs) and age- and sex-standardized mortality ratios (SMRs). We constructed a cause-specific Cox regression model to identify predictors of violence-related deaths. Of 1,328 deaths in the cohort, 57 (4%) were from violence. The violence-related CMR was 9.5 per 100,000 person-years (95% confidence interval [95% CI] [7.4, 12.4]) and the SMR was 6.8 [5.3, 8.9]. Young Indigenous people had a greater risk of violence-related death than non-Indigenous people (cause-specific hazard ratio [csHR] 2.5; [1.5, 4.4]). Young people who experienced detention had more than twice the risk of violence-related death than those who were charged only (csHR 2.5; [1.2, 5.3]). We found that justice-involved young people have a risk of dying from violence that far exceeds that of the general population. The rate of violence-related death found in this study is lower than that in U.S.-based studies, which most likely reflects lower population level firearm violence in Australia. In Australia, young Indigenous people and those released from detention appear key groups to target for violence prevention efforts.

Factors associated with emergency department service outcomes for people with a mental health problem brought in by police: a retrospective cohort study.

Objective This study aimed to identify factors associated with an emergency department (ED) length of stay ≥4 hours (h) and hospital admission for people with a mental health problem brought in by police. Methods We undertook a retrospective, observational cohort study of state-wide adult ED mental health presentations brought in by police from 1 January 2012 to 31 December 2017. We used multivariable logistic regression to determine factors associated with an ED length of stay ≥4 h and hospital admission. Results In total, 9325 ED presentations with a mental health problem brought in by police to Queensland EDs were included. Factors most strongly associated with an ED length of stay ≥4 h included an Australasian Triage Score (ATS) of 1, an age of 85 years or older, night shift arrival and subsequent hospital admission. For hospital admission, an ATS of 1, an age of 85 years or older and an ED length of stay ≥4 h were the strongest factors. Conclusion Findings indicate opportunities for targeted mental health models of care to better support people brought in by police to an ED. Such models should involve ED, pre-hospital providers (police and ambulance) and mental health services to support early intervention and potentially reduce the likelihood of a long ED length of stay and subsequent hospital admission.

Health outcomes and service use patterns associated with co-located outpatient mental health care and alcohol and other drug specialist treatment: A systematic review.

ISSUES: Despite long-standing recommendations to integrate mental health care and alcohol and other drug (AOD) treatment, no prior study has synthesised evidence on the impact of physically co-locating these specialist services on health outcomes. APPROACH: We searched Medline, PsycINFO, Embase, Web of Science and CINAHL for studies examining health outcomes associated with co-located outpatient mental health care and AOD specialist treatment for adults with a dual diagnosis of substance use disorder and mental illness. Due to diversity in study designs, patient populations and outcome measures among the included studies, we conducted a narrative synthesis. Risk of bias was assessed using the MASTER scale. KEY FINDINGS: Twenty-eight studies met our inclusion criteria. We found provisional evidence that integrated care that includes co-located mental health care and AOD specialist treatment is associated with reductions in substance use and related harms and mental health symptom severity, improved quality of life, decreased emergency department presentations/hospital admissions and reduced health system expenditure. Many studies had a relatively high risk of bias and it was not possible to disaggregate the independent effect of physical co-location from other common aspects of integrated care models such as care coordination and the integration of service processes. IMPLICATIONS: There are few high-quality, peer-reviewed studies establishing the impact of co-located mental health care and AOD specialist treatment on health outcomes. Further research is required to inform policy, guide implementation and optimise practice. CONCLUSION: Integrated care that includes the co-location of mental health care and AOD specialist treatment may yield health and economic benefits.