Prevalence and risk factors associated with HIV and tuberculosis in people who use drugs in Abidjan, Ivory Coast

Prevalence of HIV in slums area: a systematic review and meta-analysis

BACKGROUND

Human Immunodeficiency Virus (HIV) remains a significant global health burden, particularly affecting vulnerable populations residing in slum areas which is characterized by overcrowding, poverty, and limited access to healthcare services, create an environment conducive to the transmission and spread of HIV. Despite the recognition of this issue, there is a lack of comprehensive understanding regarding the prevalence of HIV in slums. The aim of this study was to systematically synthesize the existing global evidence on HIV prevalence in slum populations.

METHODS

A rigorous systematic literature review was conducted by searching multiple electronic databases, including Medline via PubMed, Scopus, Embase, Web of Sciences, and Directory of Open Access Journals (DOAJ), covering the period from January 1, 1990, to March 31, 2023. The quality and risk of bias for each included study were assessed using the Newcastle-Ottawa Scale. The pooled prevalence with its corresponding 95% confidence interval (CI) was calculated using a random-effects model with the Freeman-Tukey double arcsine transformation. The degree of heterogeneity among the studies was evaluated using the I2 test. Publication bias was also assessed using Egger's test. Additionally, subgroup analysis was performed to explore potential factors contributing to the observed heterogeneity.

RESULTS

A systematic examination of the relevant literature resulted in the inclusion of a total of 22 studies for the purpose of this meta-analysis. These studies collectively assessed a sizable cohort consisting of 52,802 participants. Utilizing a random-effects model, an estimation of the overall prevalence of HIV in the slum area was determined to be 10% (95% CI: 7-13%). Further delineation through subgroup analysis based on the gender revealed a higher prevalence of HIV among women, standing at 13% (95% CI: 8-19%, 18 studies: I2 = 98%), as opposed to men, where the prevalence was found to be 8% (95% CI: 6-12%, 16 studies: I2 = 95%). A geographical breakdown of the included studies revealed that Africa exhibited the highest prevalence, with a figure of 11% (95% CI: 9-13%, 18 studies: I2 = 98%). Subsequently, studies conducted in the American continent reported a prevalence of 9% (95% CI: 7-11%, 2 studies: I2 = 57%). The Asian continent, on the other hand, displayed the lowest prevalence of 1% (95% CI: 0-3%, 2 studies: I2 = 94%). Notably, studies employing rapid tests indicated a prevalence of 13% (95% CI: 9-17%, 6 studies: I2 = 94%), while those relying on self-reported data reported a lower prevalence of 8% (95% CI: 5-11%, 6 studies: I2 = 99%). Moreover, studies utilizing ELISA reported a prevalence of 9% (95% CI: 6-12%, 10 studies: I2 = 96%). Finally, it was determined that studies conducted in upper-middle-income countries reported a higher prevalence of 20% (95% CI: 16-24%, 5 studies: I2 = 45%), whereas studies conducted in lower- and middle-income countries reported a prevalence of 8% (95% CI: 6-10%, 12 studies: I2 = 98%).

CONCLUSION

The current study elucidates the troublingly high prevalence of HIV infection within slums area. Also, this finding underscores the urgent necessity for targeted and tailored interventions specifically aimed at curtailing the spread of HIV within slums. Policymakers must take cognizance of these results and devote their efforts towards the implementation of effective strategies to mitigate gender disparities, address poverty alleviation, and empower the inhabitants of these marginalized areas.

Alarming Tuberculosis Rate Among People Who Inject Drugs in Vietnam

BACKGROUND

The tuberculosis (TB) epidemic is not homogeneous in the general population but presents high-risk groups. People who inject drugs (PWID) are such a group. However, TB among PWID remains largely undocumented. Our goal was to assess the prevalence of TB and the risk factors associated with TB among PWID in Vietnam.

METHODS

We implemented a cross-sectional survey among 2 community-based cohorts of human immunodeficiency virus (HIV)-positive and HIV-negative PWID in Hai Phong. Participants were screened for TB using questions on TB symptoms. Those who reported any symptom were accompanied by peers to the TB clinic for chest x-ray. If the latter was abnormal, a sputum was collected to perform an Xpert MTB/RIF test.

RESULTS

A total of 885 PWID were screened for TB. For both cohorts, most PWID were male (>90.0%), with a median age of 42 years. Beside heroin injection, 52.5% of participants reported smoking methamphetamine, and 63.2% were on methadone. Among HIV-positive PWID (N = 451), 90.4% were on antiretroviral therapy and 81.6% had a viral load <1000 copies/mL. Using a complete-case analysis, the estimated TB prevalence was 2.3% (95% confidence interval [CI], 1.0-4.5) and 2.1% (95% CI, 0.8-4.2) among HIV-positive and HIV-negative people, respectively. Living as a couple, arrest over the past 6 months, homelessness, and smoking methamphetamine were independently associated with TB but not HIV infection.

CONCLUSIONS

In the context of very large antiretroviral therapy coverage, this extremely high rate of TB among PWID requires urgent actions.

A cohort study revealed high mortality among people who inject drugs in Hai Phong, Vietnam

OBJECTIVE

To estimate the residual mortality rate among people who inject drugs (PWID) in a Low-Middle Income Countries context where the HIV epidemic has been controlled and methadone coverage is high.

STUDY DESIGN AND SETTING

PWID from Haiphong, Vietnam, were recruited through three annual respondent-driven sampling surveys that fueled two cohorts of PWID with HIV (n = 761) and without HIV (n = 897), with bi-annual follow-up. Presumed causes of death were ascertained from medical records and/or interviews of participants family.

RESULTS

Among the 1658 participants with a median follow-up of 2 years, 67 and 36 died in the HIV-positive and HIV-negative cohort, respectively, yielding crude mortality rates of 4.3 (95% Confidence interval (CI): 3.3-5.4) per 100 person-years of follow-up (PYFU) and 1.9 (CI: 1.4-2.6) per 100 PYFU. In the HIV-positive cohort, in which 81% of participants had undetectable viral load, the two main causes of death were tuberculosis and HIV-related diseases. In the HIV-negative cohort, the two main causes of death were liver-related diseases and overdose. In a time-dependent multivariable model, "unsuppressed viral load" was associated with increased risk of mortality, whereas "being on methadone" or "being employed" was associated with a lower risk.

CONCLUSION

Despite a very successful HIV and methadone program, the mortality remains high among PWID in Vietnam, largely due to curable infectious diseases such as tuberculosis and viral hepatitis.

The burden of HIV infection among men who purchase sex in low- and middle-income countries - a systematic review and meta-analysis

Background

Since the start of the HIV epidemic, transactional sexual relationships have been considered to present a high risk of HIV transmission to both the client and the person offering the sexual service. However, prevention research and programs have focused predominantly on sex workers rather than on their clients, who are generally men. To support effective and targeted interventions, we undertook a systematic review and meta-analysis of the evidence of the prevalence of HIV infection among men who purchase sex (MWPS) in low- and middle-income countries (LMICs), and the association between HIV infection and purchase of sex.

Methods

We included articles that reported from LMICs on the prevalence of HIV in MWPS and those that reported on HIV prevalence among both MWPS and non-MWPS in the same study, or any information which allowed calculation of the prevalence. We defined MWPS as heterosexual males (not men who purchase sex or individuals of other sexual orientation) who purchased sex mostly from women (and not men), or who have had sexual contact with female sex workers (FSWs). We searched Medline, Global Health, Scopus, Embase and Cinahl for articles published up until 1 March 2020. Meta-analysis was conducted using a random effects model to estimate the pooled HIV prevalence and the relative risk (RR) of HIV infection associated with purchasing sex.

Results

Of 34862 studies screened, we included 44 studies (59515 men, 47753 MWPS) from 21 countries. The pooled HIV prevalence among MWPS was 5% (95%CI: 4%-6%; I² = 95.9%, p < 0.001). The pooled HIV prevalence calculated from studies that reported data collected pre-2001 was highest, i.e. 10% (95% CI: 6%-14%; I² = 91.2%, p < 0.001), compared to studies whose data was collected between 2001–2010, i.e. 4% (95%CI: 2%-6%; I² = 96.6%, p < 0.001), and from 2011 and beyond, i.e. 3% (95% CI: 2%-5%; I² = 94.3%, p < 0.001). For studies which included comparisons of HIV infection among MWPS and non-MWPS, the relative risk of HIV infection was consistently higher among MWPS than among non-MWPS within the same study, with the overall pooled relative risk of 1.95 (95%CI: 1.56–2.44; I² = 84.3%, p < 0.001), and 2.85 (95%CI: 1.04–7.76; I² = 86.5%, p < 0.001) for more recent studies.

Conclusions

This review represents the first comprehensive assessment of the burden of HIV among MWPS in LMICs. We found that HIV prevalence was elevated compared to the population as a whole, and that there was a strong association between purchasing sex and HIV prevalence. Despite a reduction over time in prevalence, these data highlight that MWPS need better access to HIV preventive interventions.

Prevalence and management of tuberculosis among people who use drugs in Abidjan, Ivory Coast

Background Although people who use drugs (PWUD) are a high-risk group for tuberculosis (TB), there is practically no data on TB prevalence in Ivory Coast. The aim of the study was to estimate pulmonary TB prevalence and assess the cascade of care with confirmed pulmonary TB (TB+) among PWUD in Abidjan. Methods The study targeted adult people who had used heroin and/or cocaine/crack in the previous six months. A first part consisted in a cross-sectional prevalence estimation survey using mobile facility testing in smoking spots. A multivariable logistic regression was performed to determine the factors associated with TB infection. In a second part, all participants who tested positive for pulmonary TB were offered follow-up for the duration of their treatment and invited to participate in a community-based support program (e.g. family mediation visits or self-support groups). Results Between October 2016 and May 2017, 545 PWUD were informed about the survey and 532 agreed to participate. Most of them were male (n = 484; 91.0%) single (n = 434; 81.6%), with an average age of 34.9 (SD 8.3) years. Drugs most commonly consumed were heroin and crack (n = 530; 99.6% and n = 353; 66.4% respectively) and were inhaled (i.e. smoked). Out of the 531 participants with an Xpert MTB/RIF® test result, 52 were diagnosed with pulmonary TB, i.e. a prevalence of 9.8%, 95% CI [7.5%-12.7%]. Among them, 17.3% had rifampicin-resistant TB. Factors significantly associated with TB infection in the multivariable analysis were: having been recruited in Treichville smoking spot (OR=2.0 [1.1 - 3.7]; p = 0.03), being unemployed (OR = 1.8 [1.0 - 3.4]; p = 0.05), and being co-infected with HIV (OR=3.3 [1.2 - 8.1]; p = 0.01); 60.0% of the patients were successfully treated. Conclusion TB prevalence among the PWUD is high. The community-based support model enables good treatment efficacy among this usually hard-to-reach population.

Clinical ultrasonography in patients who inject drugs (the CUPID protocol): an illustrated case series

In 2017, there were ≈47,600 opioid overdose-related deaths in the United States. US emergency department (ED) visits for suspected opioid overdose increased by 30% between July 2016 and September 2017.2 The current US opioid epidemic makes it critical for emergency physicians to be aware of common and uncommon infectious and non-infectious complications of injection drug use. Point-of-care ultrasound has become a widely available, non-invasive diagnostic tool in EDs across the United States and worldwide. The increasing population of injection drug use patients is at risk for serious morbidity and mortality from an array of disease states amenable to ultrasound-based diagnosis. We propose a protocol for clinical ultrasonography in patients who inject drugs (the CUPID protocol), a focused, 3-system point-of-care ultrasound approach emphasizing cardiovascular, thoracic, and musculoskeletal imaging. The protocol is a screening tool, designed to detect high risk infectious and noninfectious complications of injection drug use.

Systematic Review and Meta-Analysis of Global Prevalence of HBsAg and HIV and HCV Antibodies among People Who Inject Drugs and Female Sex Workers

The main objective of this study was to evaluate the prevalence of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), hepatitis C virus (HCV) and hepatitis B virus (HBV) and their co-infections among people who inject drugs (PWID) and female sex workers (FSWs). Data sources were searched from January 2008 to October 2018 in different databases. Data were analyzed in Stata 16 software using the Metaprop command. The results showed that the prevalence of HIV, HCV and HBV among PWID was 15%, 60% and 6%, respectively. The prevalence of HIV, HCV and HBV among FSWs was 5%, 1% and 3%, respectively. The prevalence of HIV/HCV, HIV/HBV, HCV/HBV and HIV/HCV/HBV co-infections among PWID was 13%, 2%, 3% and 2%, respectively. The prevalence of HIV/HCV and HIV/HBV co-infections among FSWs was 3% and 1%, respectively. The results show that the prevalence of HCV and HIV infections in PWID and the prevalence of HIV in FSWs is higher than their prevalence in the general population. Interventions for the prevention of HIV and HCV in PWID appear to be poor, and may not be sufficient to effectively prevent HIV and HCV transmission.

HIV testing and engagement with the HIV treatment cascade among men who have sex with men in Africa: a systematic review and meta-analysis

BACKGROUND

HIV disproportionately affects gay, bisexual, and other men who have sex with men (MSM) in Africa, where many countries criminalise same-sex behaviour. We assessed changes in the engagement of African MSM with HIV testing and treatment cascade stages over time, and the effect of anti-LGBT legislation and stigma.

METHODS

We systematically searched Embase, Global Health, MEDLINE, Scopus, and Web of Science for peer-reviewed cross-sectional or longitudinal studies recruiting at least ten MSM, published from Jan 1, 1980, to Oct 10, 2018. We extracted or derived estimates of HIV testing, engagement with the HIV treatment cascade, or both among African MSM from published reports. We derived pooled estimates using inverse-variance random-effects models. We used subgroup and meta-regression analysis to assess associations between testing and status awareness outcomes and study and participant characteristics, including the severity of country-level anti-LGBT legislation.

FINDINGS

Our searches identified 75 independent eligible studies that provided estimates for 44 993 MSM across one or more of five testing and treatment cascade outcomes. HIV testing increased significantly over time overall, with pooled proportions of MSM ever tested for HIV of 67·3% (95% CI 62·1-72·3; 44 estimates) and tested in the past 12 months of 50·1% (42·4-57·8, 31 estimates) after 2011, which were 14·8 percentage points and 17·9 percentage points higher than before 2011, respectively. After 2011, ever testing was highest in southern Africa (80·0%), and lowest in northern Africa (34·4%), with the greatest increase in western Africa (from 42·4% to 70·9%). Levels of testing ever, in the past 12 months, and status awareness were statistically significantly lower in countries with the most severe anti-LGBT legislation compared with countries with the least severe legislation (57·4% vs 71·6%, p=0·0056; 35·5% vs 49·3%, p=0·010; 6·7% vs 22·0%, p=0·0050). Few estimates were available for later stages of the treatment cascade. Available data after 2011 suggest that the pooled proportion of MSM HIV-positive aware has remained low (18·5%, 12·5-25·3; 28 estimates), whereas proportions of current antiretroviral therapy (ART) use were 23·7% (15·5-33·0; 13 estimates) among all MSM living with HIV and 60·1% (48·6-71·1; five estimates) among MSM HIV-positive aware of their status. Pooled levels of viral suppression among MSM currently on ART were 75·6% (64·4-85·5; four estimates), but only 24·7% (18·8-31·2; four estimates) among all MSM living with HIV.

INTERPRETATION

Despite improvements in HIV testing among MSM in Africa, HIV status awareness, ART coverage, and viral suppression remain much lower than required to achieve UNAIDS 90-90-90 targets. Further studies are urgently needed to provide more accurate estimates of levels of status awareness, engagement in care, ART coverage, and viral suppression among MSM to inform prevention efforts aimed at improving access to HIV services for MSM. Severe anti-LGBT legislation might be associated with lower HIV testing and status awareness; therefore, further research is needed to assess the effect of such legislation on HIV testing and engagement with the HIV treatment cascade among MSM.

FUNDING

US National Institutes of Health, UK Medical Research Council.

HIV prevalence, related risk behaviors, and correlates of HIV infection among people who use drugs in Cambodia

Background

Although HIV prevalence in Cambodia has declined to 0.6% among the general population, the prevalence remains high among female sex workers (14.0%) and men who have sex with men (2.3%). Over the past 10 years, the number of people who use drugs (PWUDs) has increased considerably. PWUDs, especially people who inject drugs (PWIDs), who have multiple sex partners or unprotected sex contribute to a higher HIV prevalence. This paper aims to estimate the prevalence of HIV across PWUD groups and to identify factors associated with HIV infection.

Methods

Respondent-driven sampling (RDS) was used to recruit 1626 consenting PWUDs in 9 provinces in 2012. Questionnaires and blood specimens were collected. HIV prevalence estimates were calculated using RDSAT 7.1. Individual weightings for HIV were generated with RDSAT and used for a weighted analysis in STATA 13. Multivariate logistic regression was used to identify the independent factors associated with HIV prevalence.

Results

Most of the PWUDs were men (82.0%), and 7.3% were PWIDs. Non-PWIDs, especially users of amphetamine-type stimulants (ATS), represented the larger proportion of the participants (81.5%). The median age for of the PWUDs was 24.0 years (IQR: 20–29). The HIV prevalence among the PWUDs was 5.1% (95% CI: 4.1–6.2), 24.8%, among PWIDs and 4.0% among non-PWIDs. The HIV prevalence among female PWIDs was 37.5, and 22.5% among male PWIDs. Four factors were independently associated with HIV infection: female sex, with AOR = 7.8 (95% CI: 3.00–20.35); age groups 21–29 and older (AOR = 10.3, 95% CI: 1.2–20.4); and using drugs for ≥12 months (AOR = 4.0, 95% CI: 1.38–11.35). Finally, injecting drugs remained a strong predictor of HIV infection, with an AOR = 4.1 (95% CI: 1.53–10.96).

Conclusion

HIV prevalence remains high among PWIDs. Harm reduction efforts, such as needle and syringe provision programs, must improve their coverage. Innovative strategies are needed to reach sub-groups of PWUDs, especially women who inject drugs. Furthermore, the large proportion of non-PWIDs, especially ATS users, should not be ignored. Therefore, combined HIV prevention and harm reduction programs should integrate ATS users.

The Opioid Epidemic in Africa And Its Impact

Purpose of review

Opioid use disorder (OUD) is a global phenomenon and is on the rise in Africa, denoting a shift from historical patterns of drug transport to internal consumption. In contrast, opioids for clinical pain management in Africa remain among the least available globally. This region also has the highest HIV and HCV disease burden, and the greatest shortages of health workers and addiction treatment. We undertook a systematic review of the literature to describe opioid use in Africa and how it is being addressed.

Recent findings

A total of 84 articles from 2000 to 2018 were identified. Descriptions of country-specific populations and patterns of opioid misuse were common. A smaller number of articles described interventions to address OUD.

Summary

OUD occurs in sub-Saharan Africa, with attendant clinical and social costs. Evidence-based policies and health system resources are needed to promote OUD prevention and management, and infectious disease transmission reduction.

Illicit Drug Users in the Tanzanian Hinterland: Population Size Estimation Through Key Informant-Driven Hot Spot Mapping

We mapped hot spots and estimated the numbers of people who use drugs (PWUD) and who inject drugs (PWID) in 12 regions of Tanzania. Primary (ie, current and past PWUD) and secondary (eg, police, service providers) key informants identified potential hot spots, which we visited to verify and count the number of PWUD and PWID present. Adjustments to counts and extrapolation to regional estimates were done by local experts through iterative rounds of discussion. Drug use, specifically cocaine and heroin, occurred in all regions. Tanga had the largest numbers of PWUD and PWID (5190 and 540, respectively), followed by Mwanza (3300 and 300, respectively). Findings highlight the need to strengthen awareness of drug use and develop prevention and harm reduction programs with broader reach in Tanzania. This exercise provides a foundation for understanding the extent and locations of drug use, a baseline for future size estimations, and a sampling frame for future research.

"They accept me, because I was one of them": formative qualitative research supporting the feasibility of peer-led outreach for people who use drugs in Dakar, Senegal

BACKGROUND

Peer outreach harm reduction initiatives are being developed with and for people who use drugs in Dakar, Senegal. This is in response to growing injecting drug use across the West Africa region and linked emerging epidemics of HIV and hepatitis C. We undertook formative qualitative research to explore the feasibility and potential of peer outreach in this context and in particular how outreach could be linked to fostering community-level processes of change.

METHODS

We undertook a total of 44 semi-structured qualitative interviews. Thirty-four interviews were with people who used drugs (comprised of 25 participants who had injected at least once in their life) and included 11 peer educators who delivered "awareness-raising" harm reduction activities. We also interviewed 10 service providers involved in the planning and monitoring of peer outreach initiatives. We used thematic analysis to identify key characteristics of how peer-led outreach is being delivered, beneficiary need, and the nature of the social networks in which the awareness-raising activities operate.

RESULTS

Through interviews with peer educators, people who use drugs, and service providers, four main overlapping themes are identified as follows: peer educators as a bridge to responsibilization through awareness-raising activities, awareness-raising activities as an enactment of recovery, awareness raising through social network diffusion, and the contexts and constraints of peer outreach engagement through awareness-raising activities.

CONCLUSIONS

The study results suggest that peer education is on a trajectory to develop into a central role for harm reduction interventions in Dakar, Senegal. This research shows how peer education is bound in processes of responsibilization and self-change, which link to varying possibilities for risk reduction or recovery. For peer education to achieve a range of significant goals, broader structural and system changes should be implemented in the region. We caution that without such changes, awareness-raising activities and the role of peer educators may instead become part of state- and agency-sponsored processes of seeking to responsibilize individuals for health and harm reduction.

Major genotype families and epidemic clones of Mycobacterium tuberculosis in Omsk region, Western Siberia, Russia, marked by a high burden of tuberculosis-HIV coinfection

This population-based study characterized Mycobacterium tuberculosis isolates from HIV-positive and HIV-negative tuberculosis (TB) patients in the Omsk region in Western Siberia, Russia. We sought to gain insight into the major genotype families and epidemic and endemic clones of M. tuberculosis in the area with a high burden and adverse trend of TB/HIV coinfection. The study collection included M. tuberculosis isolates from 207 newly-diagnosed patients with pulmonary TB; 55 (26.5%) of patients were HIV-infected. The M. tuberculosis isolates were subjected to drug susceptibility testing and molecular typing based on spoligotyping and analysis of the robust genotype and cluster-specific markers. Patients with disseminated TB disease were more prevalent in the HIV-positive (34.5%) than in the HIV-negative group (4.6%) (P < .001). The Beijing genotype was predominant (62.3% of isolates), and its major subtypes were 94-32-cluster (Central Asian/Russian strain, n = 80) and B0/W148-cluster (successful Russian strain, n = 28). The main non-Beijing families were represented by Latin-American Mediterranean (14.5%), T family (11.1%), Ural (5.8%), and Haarlem (3.9%). Under multivariate logistic regression analysis, MDR was associated with Beijing genotype and not associated with HIV coinfection status (P < .001). Beijing genotype isolates were found more frequently in TB/HIV patients than in TB HIV-negative patients (74.5% versus 57.9%, respectively; P = .031). The non-Beijing genotypes were mainly drug susceptible except for the drug-resistant Ural SIT262 isolates. To summarize, the alarming situation in the Omsk region in Siberia regarding TB/HIV coinfection is seriously influenced by the active circulation of M. tuberculosis isolates of MDR-associated Beijing genotype. Among the non-Beijing families, emergence of the drug-resistant Ural family strains of spoligotype SIT262 warrants attention.

Health outcomes associated with crack-cocaine use: Systematic review and meta-analyses

BACKGROUND

Crack-cocaine use is prevalent largely in socio-economically marginalized populations in the Americas. Its use has been associated with diverse health outcomes, yet no recent or systematic reviews of these exist.

METHODS

A systematic review of health outcomes associated with crack-cocaine use was performed, using MEDLINE, Scopus, Web of Science, CINAHL, PsycINFO, and LILACS up to October 2016. Search terms included crack-cocaine and health outcome-related keywords, targeting peer-reviewed studies on quantified health outcomes associated with crack-cocaine use. Random effects meta-analyses produced pooled odds ratios. Levels of evidence for major results were assessed using the GRADE approach. A review protocol was registered with PROSPERO (CRD42016035486).

RESULTS

Of 4700 articles returned, 302 met eligibility criteria, reporting on health outcomes for 14 of 22 ICD-10 chapters. Conclusive evidence and meta-analyses showed positive associations between crack-cocaine use and blood/sexually transmitted diseases (HIV and hepatitis C virus, others); moderate evidence and meta-analyses supported associations with neonatal health, and violence. There were mixed associations for mental and other health outcomes, yet insufficient evidence to perform meta-analyses for many categories (e.g., mortality). Most underlying research was of limited or poor quality, with crack-cocaine commonly assessed as a secondary covariate.

CONCLUSIONS

Crack-cocaine use was associated with a range of health outcomes, although it was unclear if there was direct causal impact, interactions between risk factors, or external drivers of both crack-cocaine use and outcomes. Rigorous epidemiological studies are needed to systematically assess health outcomes of crack-cocaine use and underlying pathways, also to inform evidence-based interventions.