Effect of Social Determinants of Health on Uncontrolled Human Immunodeficiency Virus (HIV) Infection Among Persons With HIV in San Francisco, California.

Background: In 2010-2014, the San Francisco Department of Public Health (SFDPH) established programs to rapidly link people with human immunodeficiency virus (PWH) to care and offer antiretroviral therapy (ART) at human immunodeficiency virus (HIV) diagnosis. Such programs reduced the number of PWH out of care or with detectable HIV viral load (ie, uncontrolled HIV infection). We investigated the role of social determinants of health (SDH) on uncontrolled HIV. Methods: Cross-sectional data from adult PWH diagnosed and reported to the SFDPH as of December 31, 2019, prescribed ART, and with confirmed San Francisco residency during 2017-2019 were analyzed in conjunction with SDH metrics derived from the American Community Survey 2015-2019. We focused on 5 census tract-level SDH metrics: percentage of residents below the federal poverty level, with less than a high school diploma, or uninsured; median household income; and Gini index. We compared uncontrolled HIV prevalence odds ratios (PORs) across quartiles of each metric independently using logistic regression models. Results: The analysis included 7486 PWH (6889 controlled HIV; 597 uncontrolled HIV). Unadjusted PORs of uncontrolled HIV rose with increasingly marginalized quartiles, compared to the least marginalized quartile for each metric. Adjusting for demographics and transmission category, the POR for uncontrolled HIV for PWH in the most marginalized quartile remained significant across metrics for poverty (POR = 2.0; confidence interval [CI] = 1.5-2.6), education (POR = 2.4; CI = 1.8-3.2), insurance (POR = 1.8; CI = 1.3-2.5), income (POR = 1.8; CI = 1.4-2.3), and income inequality (POR = 1.5; CI = 1.1-2.0). Conclusions: Beyond demographics, SDH differentially affected the ability of PWH to control HIV. Despite established care programs, PWH experiencing socioeconomic marginalization require additional support to achieve health outcome goals.

Smartphone-based Anterior Segment Imaging: A Comparative Diagnostic Accuracy Study of a Potential Tool for Blindness Prevalence Surveys.

PURPOSE: To determine if smartphone photography could be a useful adjunct to blindness prevalence surveys by providing an accurate diagnosis of corneal opacity. METHODS: A total of 174 patients with infectious keratitis who had undergone corneal culturing over the past 5 years were enrolled in a diagnostic accuracy study at an eye hospital in South India. Both eyes had an ophthalmologist-performed slit lamp examination, followed by anterior segment photography with a handheld digital single lens reflex (SLR) camera and a smartphone camera coupled to an external attachment that provided magnification and illumination. The diagnostic accuracy of photography was assessed relative to slit lamp examination. RESULTS: In total, 90 of 174 enrolled participants had a corneal opacity in the cultured eye and no opacity in the contralateral eye, and did not have a penetrating keratoplasty or missing photographs. Relative to slit lamp examination, the sensitivity of corneal opacity diagnosis was 68% (95%CI 58-77%) using the smartphone's default settings and 59% (95%CI 49-69%) using the SLR, and the specificity was 97% (95%CI 93-100%) for the smartphone and 97% (95%CI 92-100%) for the SLR. The sensitivity of smartphone-based corneal opacity diagnosis was higher for larger scars (81% for opacities 2 mm in diameter or larger), more visually significant scars (100% for eyes with visual acuity worse than 20/400), and more recent scars (85% for eyes cultured in the past 12 months). CONCLUSION: The diagnostic performance of a smartphone coupled to an external attachment, while somewhat variable, demonstrated high specificity and high sensitivity for all but the smallest opacities.

Association of visual impairment with disability: a population-based study.

OBJECTIVE: To determine the relationship between visual impairment and other disabilities in a developing country. METHODS: In this cross-sectional ancillary study, all individuals 50 years and older in 18 communities in the Chitwan region of Nepal were administered visual acuity screening and the Washington Group Short Set (WGSS) of questions on disability. The WGSS elicits a 4-level response for six disability domains: vision, hearing, walking/climbing, memory/concentration, washing/dressing, and communication. The association between visual impairment and disability was assessed with age- and sex-adjusted logistic regression models. RESULTS: Overall, 4719 of 4726 individuals successfully completed visual acuity and disability screening. Median age of participants was 61 years (interquartile range: 55-69 years), and 2449 (51.9%) were female. Participants with vision worse than 6/60 in the better-seeing eye were significantly more likely to be classified as having a disability in vision (OR 18.4, 95% CI 9.9-33.5), walking (OR 5.3, 95% CI 2.9-9.1), washing (OR 9.4, 95% CI 4.0-21.1), and communication (OR 5.0, 95% CI 1.7-13.0), but not in hearing (OR 0.6, 95% CI 0.006-2.2) or memory (OR 2.2, 95% CI 0.7-5.1). CONCLUSIONS: Visually impaired participants were more likely to self-report disabilities, though causality could not be ascertained. Public health programs designed to reduce visual impairment could use the WGSS to determine unintended benefits of their interventions.

Water, sanitation, and hygiene for control of trachoma in Ethiopia (WUHA): a two-arm, parallel-group, cluster-randomised trial.

BACKGROUND: WHO promotes the SAFE strategy for the elimination of trachoma as a public health programme, which promotes surgery for trichiasis (ie, the S component), antibiotics to clear the ocular strains of chlamydia that cause trachoma (the A component), facial cleanliness to prevent transmission of secretions (the F component), and environmental improvements to provide water for washing and sanitation facilities (the E component). However, little evidence is available from randomised trials to support the efficacy of interventions targeting the F and E components of the strategy. We aimed to determine whether an integrated water, sanitation, and hygiene (WASH) intervention prevents the transmission of trachoma. METHODS: The WASH Upgrades for Health in Amhara (WUHA) was a two-arm, parallel-group, cluster-randomised trial in 40 rural communities in Wag Hemra Zone (Amhara Region, Ethiopia) that had been treated with 7 years of annual mass azithromycin distributions. The randomisation unit was the school catchment area. All households within a 1·5 km radius of a potential water point within the catchment area (as determined by the investigators) were eligible for inclusion. Clusters were randomly assigned (at a 1:1 ratio) to receive a WASH intervention either immediately (intervention) or delayed until the conclusion of the trial (control), in the absence of concurrent antibiotic distributions. Given the nature of the intervention, participants and field workers could not be masked, but laboratory personnel were masked to treatment allocation. The WASH intervention consisted of both hygiene infrastructure improvements (namely, construction of a community water point) and hygiene promotion by government, school, and community leaders, which were implemented at the household, school, and community levels. Hygiene promotion focused on two simple messages: to use soap and water to wash your or your child's face, and to always use a latrine for defecation. The primary outcome was the cluster-level prevalence of ocular chlamydia, measured annually using conjunctival swabs in a random sample of children aged 0-5 years from each cluster at 12, 24, and 36 month timepoints. Analyses were done in an intention-to-treat manner. This trial is ongoing and is registered at ClinicalTrials.gov, NCT02754583. FINDINGS: Between Nov 9, 2015, and March 5, 2019, 40 of 44 clusters assessed for eligibility were enrolled and randomly allocated to the trial groups (20 clusters each, with 7636 people from 1751 households in the intervention group and 9821 people from 2211 households in the control group at baseline). At baseline, ocular chlamydia prevalence among children aged 0-5 years was 11% (95% CI 6 to 16) in the WASH group and 11% (5 to 18) in the control group. At month 36, ocular chlamydia prevalence had increased in both groups, to 32% (24 to 41) in the WASH group and 31% (21 to 41) in the control group (risk difference across three annual monitoring visits, after adjustment for prevalence at baseline: 3·7 percentage points; 95% CI -4·9 to 12·4; p=0·40). No adverse events were reported in either group. INTERPRETATION: An integrated WASH intervention addressing the F and E components of the SAFE strategy did not prevent an increase in prevalence of ocular chlamydia following cessation of antibiotics in an area with hyperendemic trachoma. The impact of WASH in the presence of annual mass azithromycin distributions is currently being studied in a follow-up trial of the 40 study clusters. Continued antibiotic distributions will probably be important in areas with persistent trachoma. FUNDING: National Institutes of Health-National Eye Institute. TRANSLATION: For the Amharic translation of the abstract see Supplementary Materials section.

Changing hygiene behaviours: a cluster-randomized trial, Ethiopia.

OBJECTIVE: To determine whether a water, sanitation and hygiene intervention could change hygiene behaviours thought to be important for trachoma control. METHODS: We conducted a cluster-randomized trial in rural Ethiopia from 9 November 2015 to 5 March 2019. We randomized 20 clusters to an intervention consisting of water and sanitation infrastructure and hygiene promotion and 20 clusters to no intervention. All intervention clusters received a primary-school hygiene curriculum, community water point, household wash station, household soap and home visits from hygiene promotion workers. We assessed intervention fidelity through annual household surveys. FINDINGS: Over the 3 years, more wash stations, soap and latrines were seen at households in the intervention clusters than the control clusters: risk difference 47 percentage points (95% confidence interval, CI: 41-53) for wash stations, 18 percentage points (95% CI: 12-24) for soap and 12 percentage points (95% CI: 5-19) for latrines. A greater proportion of people in intervention clusters reported washing their faces with soap (e.g. risk difference 21 percentage points; 95% CI: 15-27 for 0-5 year-old children) and using a latrine (e.g. risk difference 9 percentage points; 95% CI: 2-15 for 6-9 year-old children). Differences between the intervention and control arms were not statistically significant for many indicators until the programme had been implemented for at least a year; they did not decline during later study visits. CONCLUSION: The community- and school-based intervention was associated with improved hygiene access and behaviours, although changes in behaviour were slow and required several years of the intervention.

Precision of Serologic Testing from Dried Blood Spots Using a Multiplex Bead Assay.

Multiplex bead assays (MBAs) for serologic testing have become more prevalent in public health surveys, but few studies have assessed their test performance. As part of a trachoma study conducted in a rural part of Ethiopia in 2016, dried blood spots (DBS) were collected from a random sample of 393 children aged 0 to 9 years, with at least two separate 6-mm DBS collected on a filter card. Samples eluted from DBS were processed using an MBA on the Luminex platform for antibodies against 13 antigens of nine infectious organisms: Chlamydia trachomatis, Vibrio cholera, enterotoxigenic Escherichia coli, Cryptosporidium parvum, Entamoeba histolytica, Camplyobacter jejuni, Salmonella typhimurium Group B, Salmonella enteritidis Group D, and Giardia lamblia. Two separate DBS from each child were processed. The first DBS was run a single time, with the MBA set to read 100 beads per well. The second DBS was run twice, first at 100 beads per well and then at 50 beads per well. Results were expressed as the median fluorescence intensity minus background (MFI-BG), and classified as seropositive or seronegative according to external standards. Agreement between the three runs was high, with intraclass correlation coefficients of > 0.85 for the two Salmonella antibody responses and > 0.95 for the other 11 antibody responses. Agreement was also high for the dichotomous seropositivity indicators, with Cohen's kappa statistics exceeding 0.87 for each antibody assay. These results suggest that serologic testing on the Luminex platform had strong test performance characteristics for analyzing antibodies using DBS.

Clinic-Based Eye Disease Screening Using Non-Expert Fundus Photo Graders at the Point of Screening: Diagnostic Validity and Yield.

PURPOSE: The intent of this study was to determine the diagnostic accuracy of several diagnostic tests for age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma, and cataract, as well as the proportions of patients with eye disease from each of 3 enrolling clinics. DESIGN: Diagnostic accuracy study. METHODS: Patients ≥50 years old in a diabetes, thyroid, and general medicine clinic were screened using visual acuity, tonometry, and fundus photography. Photographs were graded at the point-of-screening by non-ophthalmic personnel. Participants with positive screening test results in either eye and a 10% random sample with negative results in both eyes were referred for an in-person, reference-standard ophthalmology examination. RESULTS: Of 889 participants enrolled, 229 participants failed at least 1 test in either eye, of which 189 presented for an ophthalmic examination. An additional 76 participants with completely normal screening test results were referred for examination, of which 50 attended. Fundus photography screening had the highest yield for DR (sensitivity: 67%; 95% confidence interval [CI]: 39%-87%), visual acuity screening for cataract (sensitivity: 89%; 95% CI: 86%-92%), and intraocular pressure screening for glaucoma or suspected glaucoma (sensitivity: 25%; 95% CI: 14%-40%). The burden of disease was relatively high in all 3 clinics, with at least 1 of the diseases of interest (ie, AMD, DR, glaucoma or suspected glaucoma, or cataract) detected in 25% of participants (95% CI: 17-35%) from the diabeteses clinic, 34% (95% CI: 22%-49%) from the thyroid clinic, and 21% (95% CI: 13%-32%) from the general clinic. CONCLUSIONS: Non-expert eye disease screening in health clinics may be a useful model for detection of eye disease in resource-limited settings.

Targeted Antibiotics for Trachoma: A Cluster-Randomized Trial.

BACKGROUND: Current guidelines recommend community-wide mass azithromycin for trachoma, but a targeted treatment strategy could reduce the volume of antibiotics required. METHODS: In total, 48 Ethiopian communities were randomized to mass, targeted, or delayed azithromycin distributions. In the targeted arm, only children aged 6 months to 5 years with evidence of ocular chlamydia received azithromycin, distributed thrice over the following year. The primary outcome was ocular chlamydia at months 12 and 24, comparing the targeted and delayed arms (0-5 year-olds, superiority analysis) and the targeted and mass azithromycin arms (8-12 year-olds, noninferiority analysis, 10% noninferiority margin). RESULTS: At baseline, the mean prevalence of ocular chlamydia in the 3 arms ranged from 7% to 9% among 0-5 year-olds and from 3% to 9% among 8-12 year-olds. Averaged across months 12-24, the mean prevalence of ocular chlamydia among 0-5 year-olds was 16.7% (95% confidence interval [CI]: 9.0%-24.4%) in the targeted arm and 22.3% (95% CI: 11.1%-33.6%) in the delayed arm (P = .61). The final mean prevalence of ocular chlamydia among 8-12 year-olds was 13.5% (95% CI: 7.9%-19.1%) in the targeted arm and 5.5% (95% CI: 0.3%-10.7%) in the mass treatment arm (adjusted risk difference 8.5 percentage points [pp] higher in the targeted arm, 95% CI: 0.9 pp-16.1 pp higher). CONCLUSIONS: Antibiotic treatments targeted to infected preschool children did not result in significantly less ocular chlamydia infections compared with untreated communities and did not meet noninferiority criteria relative to mass azithromycin distributions. Targeted approaches may require treatment of a broader segment of the population in areas with hyperendemic trachoma.

WASH Upgrades for Health in Amhara (WUHA): study protocol for a cluster-randomised trial in Ethiopia.

INTRODUCTION: Facial hygiene promotion and environmental improvements are central components of the global trachoma elimination strategy despite a lack of experimental evidence supporting the effectiveness of water, sanitation and hygiene (WASH) measures for reducing trachoma transmission. The objective of the WUHA (WASH Upgrades for Health in Amhara) trial is to evaluate if a comprehensive water improvement and hygiene education programme reduces the prevalence of ocular chlamydia infection in rural Africa. METHODS AND ANALYSIS: Forty study clusters, each of which had received at least annual mass azithromycin distributions for the 7 years prior to the start of the study, are randomised in a 1:1 ratio to the WASH intervention arm or a delayed WASH arm. The WASH package includes a community water point, community-based hygiene promotion workers, household wash stations, household WASH education books, household soap distribution and a primary school hygiene curriculum. Educational activities emphasise face-washing and latrine use. Mass antibiotic distributions are not provided during the first 3 years but are provided annually over the final 4 years of the trial. Annual monitoring visits are conducted in each community. The primary outcome is PCR evidence of ocular chlamydia infection among children aged 0-5 years, measured in a separate random sample of children annually over 7 years. A secondary outcome is improvement of the clinical signs of trachoma between the baseline and final study visits as assessed by conjunctival photography. Laboratory workers and photo-graders are masked to treatment allocation. ETHICS AND DISSEMINATION: Study protocols have been approved by human subjects review boards at the University of California, San Francisco, Emory University, the Ethiopian Food and Drug Authority, and the Ethiopian Ministry of Innovation and Technology. A data safety and monitoring committee oversees the trial. Results will be disseminated through peer-reviewed publications and presentations. TRIAL REGISTRATION NUMBER: (http://www.clinicaltrials.gov): NCT02754583; Pre-results.

Changing hygiene behaviours: a cluster-randomized trial, Ethiopia

Objective To investigate vaccine hesitancy leading to underimmunization and a measles outbreak in Rwanda and to develop a conceptual, community-level model of behavioural factors. Methods Local immunization systems in two Rwandan communities (one recently experienced a measles outbreak) were explored using systems thinking, human-centred design and behavioural frameworks. Data were collected between 2018 and 2020 from: discussions with 11 vaccination service providers (i.e. hospital and health centre staff); interviews with 161 children's caregivers at health centres; and nine validation interviews with health centre staff. Factors influencing vaccine hesitancy were categorized using the 3Cs framework: confidence, complacency and convenience. A conceptual model of vaccine hesitancy mechanisms with feedback loops was developed. Findings: A comparison of service providers' and caregivers' perspectives in both rural and peri-urban settings showed that similar factors strengthened vaccine uptake: (i) high trust in vaccines and service providers based on personal relationships with health centre staff; (ii) the connecting role of community health workers; and (iii) a strong sense of community. Factors identified as increasing vaccine hesitancy (e.g. service accessibility and inadequate follow-up) differed between service providers and caregivers and between settings. The conceptual model could be used to explain drivers of the recent measles outbreak and to guide interventions designed to increase vaccine uptake. Conclusion :The application of behavioural frameworks and systems thinking revealed vaccine hesitancy mechanisms in Rwandan communities that demonstrate the interrelationship between immunization services and caregivers' vaccination behaviour. Confidence-building social structures and context-dependent challenges that affect vaccine uptake were also identified.

Objectif Déterminer si une intervention au niveau de l'eau, de l'assainissement et de l'hygiène pourrait avoir une influence sur les comportements en la matière, considérés comme importants dans la lutte contre le trachome. Méthodes Nous avons mené un essai randomisé par grappes dans les régions rurales d'Éthiopie entre le 9 novembre 2015 et le 5 mars 2019. Nous avons réparti aléatoirement 20 échantillons où l'intervention consistait à développer les infrastructures d'assainissement et d'approvisionnement en eau et à promouvoir l'hygiène, et 20 échantillons n'ayant fait l'objet d'aucune intervention. Tous les échantillons du groupe d'intervention ont suivi une formation sur l'hygiène à l'école primaire, disposaient d'un point d'eau communautaire, d'un poste de lavage par ménage, de savon à domicile, et recevaient des visites de la part de travailleurs chargés d'enseigner les bonnes pratiques en matière d'hygiène. Nous avons évalué le niveau d'observance des mesures en effectuant des enquêtes annuelles au sein des foyers. Résultats En l'espace de 3 ans, le nombre de postes de lavage, de savons et de latrines dans les ménages a davantage augmenté dans le groupe d'intervention que dans le groupe de contrôle: la différence de risque s'élevait à 47 points de pourcentage (intervalle de confiance de 95%, IC: 41­53) pour les postes de lavage, à 18 points de pourcentage (IC de 95%: 12­24) pour le savon et à 12 points de pourcentage (IC de 95%: 5­19) pour les latrines. La proportion de gens déclarant se laver le visage au savon était plus grande dans le groupe d'intervention (différence de risque de 21 points de pourcentage; IC de 95%: 15­27 pour les enfants de 0 à 5 ans), tout comme celle mentionnant l'usage de latrines (différence de risque de 9 points de pourcentage; IC de 95%: 2­15 pour les enfants de 6 à 9 ans). Pour de multiples indicateurs, il a fallu attendre minimum un an après l'instauration du programme pour que les variations observées entre les groupes d'intervention et de contrôle deviennent statistiquement significatives; ces variations se sont ensuite maintenues lors des visites ultérieures. Conclusion Intervenir à l'école et au sein de la communauté a permis d'améliorer l'accès à l'hygiène et les comportements en la matière. Néanmoins, cette évolution prend du temps et plusieurs années d'intervention sont nécessaires.

Cluster-randomised trial of community-based screening for eye disease in adults in Nepal: the Village-Integrated Eye Worker Trial II (VIEW II) trial protocol.

INTRODUCTION: The majority of blindness worldwide could be prevented or reversed with early diagnosis and treatment, yet identifying at-risk and prevalent cases of eye disease and linking them with care remain important obstacles to addressing this burden. Leading causes of blindness like glaucoma, diabetic retinopathy and age-related macular degeneration have detectable early asymptomatic phases and can cause irreversible vision loss. Mass screening for such diseases could reduce visual impairment at the population level. METHODS AND ANALYSIS: This protocol describes a parallel-group cluster-randomised trial designed to determine whether community-based screening for glaucoma, diabetic retinopathy and age-related macular degeneration reduces population-level visual impairment in Nepal. A door-to-door population census is conducted in all study communities. All adults aged ≥60 years have visual acuity tested at the census visit, and those meeting referral criteria are referred to a local eye care facility for further diagnosis and management. Communities are subsequently randomised to a community-based screening programme or to no additional intervention. The intervention consists of a single round of screening including intraocular pressure and optical coherence tomography assessment of all adults ≥60 years old with enhanced linkage to care for participants meeting referral criteria. Four years after implementation of the intervention, masked outcome assessors conduct a repeat census to collect data on the primary outcome, visual acuity. Individuals with incident visual impairment receive a comprehensive ophthalmological examination to determine the cause of visual impairment. Outcomes are compared by treatment arm according to the originally assigned intervention. ETHICS AND DISSEMINATION: The trial has received ethical approval from the University of California San Francisco Institutional Review Board, Nepal Netra Jyoti Sangh and the Nepal Health Research Council. Results of this trial will be disseminated through publication in peer-reviewed journals and presentation at local and international meetings. TRIAL REGISTRATION NUMBER: NCT03752840.

Odour reduction interventions for simple pit latrines in rural Ethiopia: a randomized study.

Pit latrines are promoted in resource-limited settings, but unpleasant odours may deter their use. In this study, latrines in rural Ethiopia were randomized to the addition of cooking ash, the addition of boiling water or neither. Study staff ranked odour on a 6-point scale before and approximately 24 h after intervention. Following intervention, odour grades were on average 0.2 points lower (95% confidence interval [CI] 0.7 lower to 0.3 higher) in ash-treated latrines and 0.4 points lower (95% CI 0.9 lower to 0.1 higher) in boiled water-treated latrines, although the difference between the three groups was not statistically significant (p = 0.21). Larger studies might detect a smaller difference.

Injection Drug Use Trajectories among Migrant Populations: A Narrative Review.

BACKGROUND: Dual epidemics of injection drug use and blood-borne disease, characterized as "syndemics," are present in a range of settings. Behaviors that drive such syndemics are particularly prevalent among mobile drug-using populations, for whom cross-border migration may pose additional risks. OBJECTIVES: This narrative review aims to characterize the risk factors for injection drug use initiation associated with migration, employing a risk environment framework and focusing on the San Diego-Tijuana border region as the most dynamic example of these phenomena. METHODS: Based on previous literature, we divide migration streams into three classes: intra-urban, internal, and international. We synthesized existing literature on migration and drug use to characterize how mobility and migration drive the initiation of injection drug use, as well as the transmission of hepatitis and HIV, and to delineate how these might be addressed through public health intervention. RESULTS: Population mixing between migrants and receiving communities and the consequent transmission of social norms about injection drug use create risk environments for injection drug use initiation. These risk environments have been characterized as a result of local policy environments, injection drug use norms in receiving communities, migration-related stressors, social dislocation, and infringement on the rights of undocumented migrants. CONCLUSION: Policies that exacerbate risk environments for migrants may inadvertently contribute to the expansion of epidemics of injection-driven blood-borne disease. Successful interventions that address emerging syndemics in border regions may therefore need to be tailored to migrant populations and distinguish between the vulnerabilities experienced by different migration classes and border settings.

Epidemiology of Substance Use among Forced Migrants: A Global Systematic Review.

INTRODUCTION: Forced migration is occurring at unprecedented levels. Forced migrants may be at risk for substance use for reasons including coping with traumatic experiences, co-morbid mental health disorders, acculturation challenges and social and economic inequality. This paper aimed to systematically review the literature examining substance use among forced migrants, and identify priority areas for intervention and future research. METHODS: Seven medical, allied health and social science databases were searched from inception to September 2015 in accordance with PRISMA guidelines to identify original peer-reviewed articles describing any findings relating to alcohol and/or illicit drug use among refugees, internally displaced people (IDPs), asylum seekers, people displaced by disasters and deportees. A descriptive synthesis of evidence from quantitative studies was conducted, focusing primarily on studies which used validated measures of substance use. Synthesis of evidence from qualitative studies focused on identifying prominent themes relating to the contexts and consequences of substance use. Critical Appraisal Skills Programme (CASP) checklists were used to assess methodological quality of included studies. RESULTS: Forty-four quantitative (82% cross-sectional), 16 qualitative and three mixed-methods studies were included. Ten studies were rated as high methodological quality (16%), 39 as moderate quality (62%) and 14 as low quality (22%). The majority of research was conducted among refugees, IDPs and asylum seekers (n = 55, 87%), predominantly in high-income settings. The highest-quality prevalence estimates of hazardous/harmful alcohol use ranged from 17%-36% in camp settings and 4%-7% in community settings. Few studies collected validated measures of illicit drug use. Seven studies compared substance use among forced migrants to other migrant or native-born samples. Among eight studies which conducted multivariable analysis, male sex, trauma exposure and symptoms of mental illness were commonly identified correlates of substance use. CONCLUSION: Our understanding of substance use among forced migrants remains limited, particularly regarding persons displaced due to disasters, development and deportation. Despite a growing body of work among refugee-background populations, few studies include refugees in low and middle-income countries, where over 80% of the global refugee population resides. Findings suggest a need to integrate substance use prevention and treatment into services offered to forced migrants, particularly in camp settings. Efforts to develop and evaluate interventions to reduce substance use and related harms are needed.