Search tips
Search criteria 


Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
AIDS. Author manuscript; available in PMC 2012 April 19.
Published in final edited form as:
PMCID: PMC3329893

HIV infection and risk of overdose: a systematic review and meta-analysis


Drug overdose is a common cause of non-AIDS death among people with HIV and the leading cause of death for people who inject drugs. People with HIV are often exposed to opioid medications during their HIV care experience; others may continue to use illicit opioids despite their disease status. In either situation, there may be a heightened risk for nonfatal or fatal overdose. The potential mechanisms for this elevated risk remain controversial. We systematically reviewed the literature on the HIV–overdose association, meta-analyzed results, and investigated sources of heterogeneity, including study characteristics related to hypothesize biological, behavioral, and structural mechanisms of the association. Forty-six studies were reviewed, 24 of which measured HIV status serologically and provided data quantifying an association. Meta-analysis results showed that HIV seropositivity was associated with an increased risk of overdose mortality (pooled risk ratio 1.74, 95% confidence interval 1.45, 2.09), although the effect was heterogeneous (Q = 80.3, P <0.01, I2 = 71%). The wide variability in study designs and aims limited our ability to detect potentially important sources of heterogeneity. Causal mechanisms considered in the literature focused primarily on biological and behavioral factors, although evidence suggests structural or environmental factors may help explain the greater risk of overdose among HIV-infected drug users. Gaps in the literature for future research and prevention efforts as well as recommendations that follow from these findings are discussed.

Keywords: fatal, HIV, mortality, opioid, overdose


Drug overdose is a common cause of non-AIDS death among people with HIV and the leading cause of death for people who inject drugs [16]. People with HIV are often exposed to opioid medications during their HIV care experience; others may continue to use illicit opioids despite their disease status. Either scenario may present a heightened risk for fatal and nonfatal opioid overdose. Recently, both the US President’s Emergency Plan for AIDS Relief and the Global Fund to Fight AIDS, Tuberculosis and Malaria ( issued guidance that they will support overdose prevention activities, acknowledging the growing toll that overdose takes on people with HIV [7,8].

Opiates and synthetic and semisynthetic opioid drugs (hereafter referred to collectively as opioids) are important medications for the treatment of pain and end-stage disease. However, this class of drugs also has the potential for the development of physical dependence, abuse, and addiction. Opioids include oxycodone, hydrocodone, hydromorphone, fentanyl, morphine, and methadone. Indeed, heroin, an illegal opiate, is one of the most common drugs of abuse worldwide. The WHO reports that approximately 13.5 million people use opioids, including 9.2 million heroin users [9]. Many opioid users have a history of injection; similarly, many injectors report past opioid use. The global number of IDUs is estimated at 11–22 million people [10].

Injection drug use represents a major route of infection for HIV, accounting for up to 80% of new HIV infections in eastern Europe and central Asia [9]. Additionally, HIV-infected IDUs can act as a bridge population for transmission of HIV to the larger population. Injection-related HIV-epidemics exist in countries throughout the world, with incidence ranging from 1.5% in Australia and New Zealand to 17% in east/south-east Asia, 27% in eastern Europe, and 29% in Latin America [11].

Although the association between HIV infection and injection drug use has been well documented, the potential association between HIV and overdose has received less attention. In addition to the high rates of opioid mortality among IDUs [2,12,13], nonfatal overdose events are also common. Lifetime nonfatal overdose rates among heroin users range from 29 to 68% [1417], and among illicit users of prescription opioids in the USA ranges from 28 [18] to 38% [19]. Nonfatal overdose is associated with significant morbidity, including pneumonia, renal failure, mental impairment, and cardiac arrhythmia [20]. The strongest predictor of experiencing an overdose is prior overdose [20,21], with most users reporting multiple overdose experiences in their lifetime [18,21,22].

Over the past two decades, investigators have considered a biological connection between HIV seropositivity and an elevated risk of overdose, whereas others dismiss detected associations as uncontrolled residual confounding [23]. Proposed biological mechanisms include underlying disorder (due to HIV infection) [3,24], abnormal liver function or pulmonary problems [13,25], poor physical health [26], medical complications from injecting [27], and reduction in CD4+ cell counts [28]. Additionally, some authors suggest a behavioral connection between HIV seropositivity and an elevated riskof overdose, namely drug use and risk-taking behaviors [1,25,29,30]. There may also be other important structural and environmental influences that have not been thoroughly considered.

Recent research pertaining to HIV [3134], drug use [34,35], and overdose [21,36] describe elements of the ‘risk environment’ that can affect these health outcomes. For example, an opioid overdose is more likely to be fatal if the user is alone rather than in the presence of others. Injury epidemiology draws upon the Haddon matrix [37] to guide risk factor identification, prevention, and control that relate not only to host (patient), agent (the opioid), and environment (setting/context) factors but also to the timing of the injury: pre-event, during event, and postevent. Although few investigators have critically examined the shared biological, behavioral, and structural risks associated with HIV infection and overdose, a comprehensive understanding of this nexus could hold enormous promise for public health interventions and could also provide potentially lifesaving information to healthcare professionals, who prescribe opioid medications to patients with HIV or who interact with HIV-infected opioid users.

This study aimed to systematically review the literature on the putative association of HIV infection with overdose, meta-analyze results, explore sources of heterogeneity, and investigate biological, behavioral, and structural causal mechanisms of association.


We performed a search of the PubMed database, conducted from July to September 2010, using combinations of the terms: HIV, drug, overdose, heroin, naloxone, narcan, buprenorphine, methadone, opiate/opioid, fatal, fatality, death, mortality, morbidity, and nonfatal. We identified 251 unique articles that fitted our search criteria. All abstracts were read to identify potentially suitable manuscripts; 69 were identified as possibly relevant and were read completely. Of these, 23 were identified as irrelevant, and data were extracted from the remaining 46 studies using a standardized format. Inclusion criteria for articles were as follows: those presenting original research, being written in English, and being published in a peer-reviewed journal. There were no limitations on publication date or geography.

Extracted data were entered in a database with 28 distinct fields corresponding broadly to study details [design, period, population, HIV status (serological evidence, self-report)]; exposure and outcome definition and measurement; quantification of an association between HIV infection and overdose (or lack thereof); discussed causal mechanisms (biological, behavioral, environmental, none); and study limitations. Double data extraction was performed, with consensus on the extracted content reached by discussion, and final review of material by the first author.

To be eligible for the meta-analysis, studies must have reported measures of association [odds ratio (OR), relative risk (RR), hazard ratio] or sufficient data to calculate an unadjusted RR (i.e., overdose incidence by HIV status in a cohort design; OR and prevalence of overdose among HIV-uninfected in a cross-sectional or case–control design) with upper and lower confidence interval (CI) limits or standard errors. Adjusted effect measures were used in the analysis when included in the studies. Studies were pooled for analysis; ORs were transformed into RRs following standard methods [3840].

When detected, we explored sources of variability extracted from the systematic review, including crude vs. adjusted analysis; cross-sectional vs. cohort design; US study location vs. outside of the USA; clinic-based population (yes/no); IDU only vs. mixed/unknown IDU status population; pre-HAART, post-HAART, and both pre-HAART and post-HAART era; year of study; calculated vs. reported measure of association; and fatal vs. nonfatal/both overdose outcomes. The Q-statistic and I2-statistic evaluated heterogeneity of effects [38]. Categorical data on potential sources of heterogeneity were assessed with Q-statistics comparing categories; continuous data were assessed using mixed-effects meta-regression. We used Comprehensive Meta-Analysis version 2 software (Biostat, Englewood, New Jersey, USA, 2005) [39] to generate summary estimates of the effects of HIV infection on overdose risk. Random effects models were employed to more accurately account for differences in sampling, methods, and aims among the reviewed studies [40]. To assess for publication bias, we checked for asymmetry in funnel plots of effects against standard errors and applied Egger’s test [41]. We first present the meta-analysis findings, and then summarize causal mechanisms of the HIV–overdose association from the systematic review.


Of the 46 studies reviewed, six were case series or chart reviews, seven were cross sectional, and 33 were prospective or retrospective cohort studies. Studies spanned 15 countries, were published from 1988 to 2010, and reported data collected retrospectively or prospectively over a 29-year period (1977–2006). Table 1 [14,13,2330,4274] details reviewed studies.

Table 1
Detailed summary of the 46 systematically reviewed studies.


A total of 27 studies were eligible for inclusion in the meta-analysis [1,2,13,25,29,30,4260,75]. Of these, 22 were prospective or retrospective cohort designs, five were cross-sectional designs; 17 were conducted outside of the USA; and 16 used clinic-based samples. Participants were mostly IDUs (n = 16), or a mixture of participants of injecting and noninjecting or of unknown injecting status (n = 11). Overdose outcomes tended to pertain to fatal (n = 21) rather than nonfatal (n = 6) events. All but three studies [26,44,52] employed HIV serological testing to verify HIV status. Examination of funnel plots of effects showed no evidence of publication bias (data not shown); an Egger’s test was not significant (t = 1.07, P = 0.29).

The pooled RR across the 27 studies was 1.60 (CI 1.16, 2.21); the Q-statistic was statistically significant and the I2-statistic was 94%. Figure 1a reports the forest plot. Covariates tested for sources of variation showed that only one factor was significant at the P value less than 0.10 level: study population type (IDU only vs. mixed or unknown IDU status).

Fig. 1
Meta-analyses of the effect of HIV infection on overdose risk among drug users

HIV biologically tested

Three large studies did not collect HIV status biologically [26,44,52] and may have fundamentally underestimated the HIV–overdose association by ‘missing’ a large number of truly HIV-infected people who may not have known their status or underreported their HIV infection status. Pooling effects across the 24 studies reporting HIV status biologically returned an overall RR of 1.74 (CI 1.45, 2.09); the Q-statistic was statistically significant (Q = 80.3, P <0.01) and the I2-statistic was 71%. Figure 1b reports the forest plot. Testing for heterogeneity showed a statistically significant source was study population type (Q = 4.57, P = 0.03). Studies with IDU only population types (n = 14) had pooled RR of 1.48 (CI 1.17, 1.86), but heterogeneity remained high (Q-statistic significant, I2 = 73%). Studies with a mixed (IDU, non-IDU) or unknown IDU status population (n = 10) had pooled RR of 2.18 (CI 1.66, 2.87); the Q-statistic was not statistically significant and the I2-statistic was 40%. A trend indicated study design as an additional source of heterogeneity across the 24 studies (Q = 3.71, P = 0.05) in which cross-sectional designs (n = 4) had a pooled RR of 2.41 (CI 1.65, 3.51); the Q-statistic was not significant and the I2-statistic was 44%. Cohort studies (n = 20) had a pooled RR of 1.59 (CI 1.32, 1.92); the Q-statistic was significant and the I2-statistic was 65%. Other potential sources of heterogeneity were not significant by Q-statistic or meta-regression.

Causal mechanisms considered in studies with positive associations

Proposed causal mechanisms for observed associations between HIV infection and overdose risk encompassed biological and behavioral factors and considered HIVas a potential confounder as well as a mediator of the association. Still, some authors dismissed a detected association as speculative. Biological explanations considered how aspects of HIV itself could elevate this risk through clinical status, immunosuppression, opportunistic infections, and poorer physical health [1,2426,30, 46,59]. Some authors named more specific mechanisms of action, focusing on pulmonary conditions or infections more common in people with HIV that are likely to exacerbate the respiratory depression that causes death from overdose [13,25]. Several studies posited that conditions that affect the body’s ability to metabolize [e.g. liver disorder, co-infection with hepatitis B virus or hepatitis C virus (HCV)], which are also more common in people with HIV, could explain the observed association between HIV and overdose [13,24,25,46,58]. Wang et al. [25] systematically tested the mediating impact of some of these biological factors on the observed HIV–overdose association, determining that HIV immunosuppression and associated multisystem disorder (respiratory/pulmonary) accounted for a 20% reduction in effect. Abnormal liver functioning reduced the association by 12–35% [25].

Few studies examined patient HIV treatment status or HIV treatment adherence, although treatment was raised as a mediator of overdose risk. Assessing this association was impossible because investigators used population-level mortality data that indicated HIV status, but not treatment history. Oftentimes, even if HIV treatment status and adherence were assessed, direct comparisons between these variables and rates of overdose were not considered. In some instances, CD4 cell counts, which may serve as a proxy for HIV disease state, were assessed. Among this limited number of studies, findings varied, with some suggesting greater risk [24,61,76] and others no association [28,50] between lower CD4 cell counts and heightened overdose risk.

Behavioral factors that could explain the observed association of HIV infection and overdose risk were also raised. Authors discussed how high-risk lifestyle and psychiatric comorbidities could simultaneously explain overdose events and HIV status [1,26,29,30,48,59,62]. Although several studies raised whether HIV-infected drug users have more suicidal tendencies and, therefore, may engage in riskier drug use [30,58], research has not found such evidence [59]. Indeed, residual confounding from high-risk behaviors of HIV-infected drug users, frequent injectors, shooting gallery use, syringe sharing, or other ‘risk-taking personality’ traits appeared to produce small (15%) reductions in observed HIV–overdose effects [25]. Other authors suggest that drug users tend to reduce injecting behaviors after HIV diagnosis and also as HIV infection advances [46]. One study [63] found that people who knew their HIV status were more likely to reduce opioid consumption, rather than engage in other overdose preventive behaviors.

Structural factors as causal mechanisms

Seven studies measured structural and environmental risks for overdose. Factors considered in these studies included access to medication-assisted therapy (MAT) for opioid dependence, homelessness, neighborhood poverty and socioeconomic status, incarceration, and isolation or using drugs alone. Of the studies reviewed, several found that access to and enrollment in methadone treatment greatly reduced HIV-infected IDUs’ risk of overdose [42,51,57]. Research has shown homeless and poor drug users to be at increased risk of overdose and that receiving government welfare payments were associated with lower overdose risk [43,45,57]. Tardiff et al. [45] found that high neighborhood poverty was associated with an increased risk of being HIV-positive, and that opioid overdose was more likely to occur among HIV-positive than HIV-negative decedents in New York City. Prison time, including lifetime incarceration and recent prison release, was another significant structural contributor to overdose risk [4,43]. Seaman et al. [4] observed that the risk of death from an overdose was eight times higher within 2 weeks of being released in an HIV-infected IDU cohort [43]. A case series of HIV-infected hospital patients, who died a non-AIDS death, found that 38 of 64 deaths were drug-involved intoxications (59%), 15 of which (39%) had recently been released from prison [24]. Surprisingly, the authors do not remark on history of incarceration among the decedents, although a contemporaneous analysis on the same population mentions alterations to tolerance due to abstinence, such as recent return from prison, as an explanation for overdose risk in the predominantly injection-transmitted HIV cohort [76]. An intriguing study by Neira-León et al. [63] showed that HIV-infected IDUs were no more likely than HIV-uninfected IDUs to use drugs alone, and that this environmental overdose risk factor was responsive to intervention, either medical care or overdose prevention education.


This article is the first to systematically review and meta-analyze the literature on the putative association between HIV infection and overdose risk. Among 46 studies extracted and reviewed in this undertaking, 24 reported data sufficient for inclusion in a meta-analysis and tested for HIV-infection biologically. Despite the heterogeneous pool of studies, the meta-analysis results suggest that people who use drugs have a 74% greater risk of overdose if they are HIV-infected compared with their counterparts who are not HIV-infected.

Causal mechanisms discussed in the literature to explain the increased risk tended to consider biological and behavioral factors, but other factors may also influence this association, including environmental and structural factors. Only seven studies (15%) systematically reviewed and considered environmental or structural factors in the analysis of overdose risk factors. Data from these studies suggest that environmental and structural risk factors shown previously to increase overdose risk also affect HIV-infected populations and, to the extent that they are more pronounced in people with HIV, could help explain some of the higher overdose risk associated with HIV status. The limited number of studies indicates a need for future research to consider the role these factors may play in overdose risk for HIV-infected and uninfected persons.

Similarities in risk and protective factors for HIV and overdose suggest an opportunity to reduce HIV transmission and overdose mortality by scaling-up established prevention interventions and extending existing legal and policy tools, most notably HAART, MAT, and prescribed naloxone.


Too few studies examined HIV treatment status or adherence to quantify its mediation of overdose risk. Wang et al. [25] provided the most compelling evidence of a biological component, particularly immunosuppression and multisystem disorder, to the HIV–overdose association. It is, therefore, biologically plausible that HAART’s benefits for HIV-infected patients could also extend to protection against overdose for people who use drugs. Yet, even when HIV treatment is received, potential medication interactions with continued street drug use may contribute to persistent overdose risk. For instance, several antiretroviral medications are known to increase or decrease methadone and other street drug blood levels or have known interactions with benzodiazepines and marijuana [77,78], both of which may be used therapeutically and abused. As people with a substance use disorder are often excluded from randomized clinical trials, it may be challenging to anticipate many of the side-effects and consequences of new antiretroviral medications in this population. Several published reviews offer basic clinical guidance on these topics [7780]. Further research is needed to better understand specific HIV medication interactions and how to reduce risk of overdose in substance using patients.

Access to HAART medications, prescribed by providers prepared to prevent and manage potential interactions between antiretrovirals and drugs with abuse potential, may be viewed as a protective factor against overdose for HIV-infected drug users. Efforts to ensure that all HIV-infected drug users have adequate and stable access to HAART have the potential to reduce mortality due to AIDS and to overdose.

Medication-assisted therapy

Numerous studies including several examined in this systematic review [30,51,57] have established receipt of MAT, particularly methadone and buprenorphine therapies, as protective against fatal overdose. MAT reduces illicit drug use, decreases HIV risk behavior, and decreases drug-associated crime [8186]. Access to adequate MAT also increases compliance for antiretroviral therapy among HIV-infected patients [8790]. On a community level, providing both MAT and HAART can reduce the transmission of HIV from opioid users to others, helping to reduce the overall incidence and prevalence of HIV [81,85,86,90,91]. The Joint United Nations Programme on HIV/AIDS estimates that there are only eight people receiving MAT for every 100 people who inject drugs globally [92]. We note that studies have found increased overdose risk immediately following dropout or cessation across a variety of treatment types, although the risk is lowest with MAT [93], so relapse and overdose prevention are important while in treatment.


One public health intervention to decrease overdose-associated morbidity and mortality is the distribution of naloxone to at-risk drug users, their families, and friends. Naloxone is a prescription medication with no abuse potential that reverses an opioid overdose and is part of the standard emergency medical response to an opioid overdose [94,95]. Such programs train people in overdose prevention, response, and naloxone administration. Between 1996 and 2010, US programs, at more than 155 sites located in 16 states, have documented over 10 000 overdose reversals with naloxone by over 50 000 trained bystanders [96101], with mounting evidence linking program enrollment to reductions in community opioid overdose mortality [97,102,103].

Targeting naloxone provision to HIV-infected opioid users has the potential to reduce fatal overdose in this population. Physicians who care for HIV-infected opioid users could prescribe naloxone to at-risk patients, including patients who are opioid injectors, who illicitly use prescription opioids, who are prescribed long-acting opioids, or who are diagnosed with other conditions or illnesses known to increase overdose risk. Programs that provide care and support to HIV-infected people could also distribute naloxone, given sufficient medical oversight of the prescribing practices. Syringe exchange programs are a common mechanism for distributing naloxone and, in places with high HIV prevalence among injectors, provide a means of reaching people at high overdose risk. Countries (or states) with formularies for HIV-related medications could consider adding naloxone to these lists; it is already on WHO’s Model List of Essential Medicines [104].

Limitations of reviewed studies

We detected important methodological limitations in the reviewed studies, which warrant mention. First, studies varied immensely in their definition of ‘overdose’, more often failing to define it. In some cases, intentionality was not addressed, which may have increased outcome measurement variability. Fatal drug overdose as cause of death was sometimes defined by a committee of study investigators; others employed standard disease classification [105]. Nonfatal overdose may have been ascertained by self-report – typically without defining or describing symptoms of overdose – or by administrative record of the victim’s admittance to a hospital or response by emergency medical services. Both approaches may be severely flawed. Self-reported overdose may be subject to response bias: if HIV-infected persons are more likely to report nonfatal overdoses because of heightened awareness of their health status, associations could be biased away from the null. Furthermore, for studies conducted in places where police also attend emergency calls and may arrest those at the injury scene on drug-related charges, relying upon administratively defined nonfatal overdoses may severely underestimate the total number of events and introduce selection bias if certain types of drug users are less likely to call for help. It is also likely that nondifferential error in self-reported overdose occurred, but would likely have resulted in a bias toward the null hypothesis for these studies. Another challenge to this review was verification of drug treatment status and HIV adherence, as they were poorly cataloged. Employing more systematic definitions of overdose, expanding the use of computer-assisted technology to improve validity of responses, better tracking treatment attendance and exposure; also, cataloging disease progression and adherence to HIV medication regimens would greatly facilitate comparisons across studies for future meta-analyses and could better inform readers of these important details.

Study strengths and limitations

This study has several strengths. First, we comprehensively searched the available literature, including a broad range of study types, populations, and outcomes, and pooled available evidence to investigate and quantify the association of HIV with overdose risk. Second, this study applied theories relevant to the exposure and outcome from infectious disease epidemiology and injury epidemiology. In doing so, our review extends previous discussions in single studies that limited the putative causal association between HIV and overdose risk to only biological factors. As with many findings from the HIV field [106108], considering the effects of extra-medical interventions and influences can be revealing, clinically significant, and can point the way toward approaches that may have larger public health impact.

This study has some potential limitations that suggest avenues of future research. First, the meta-analyzed results reflected a high degree of variability across studies, but we were unable to determine many statistically significant sources of heterogeneity from the tested covariates. The relatively small number of studies, especially those providing covariates such as MAT, HCV, and HIV treatment status and adherence, limited our ability to test heterogeneity sources. To accommodate heterogeneity levels, we report pooled effects from random effects models, as recommended [40]. Second, we were unable to adequately review studies on structural and environmental risk factors that may differentially augment the risk of or constitute causal mechanisms of overdose in people with HIV. The topic of structural risk is an active area of inquiry in overdose [21,36], other injury health outcomes such as motor vehicle accidents [109,110] as well as in HIV transmission [31,33]. A third limitation was the sparse literature on behavioral factors, especially one’s social network composition, size, and supportiveness that may exert causal influences on overdose risk that differ by HIV status. Fourth, few reviewed articles were identified in resource-poor countries, or in locations with current injection-driven epidemics. To address all of these significant limitations, there is a clear indication for future research. Longitudinal studies of health outcomes for participants with HIV should consider including nonfatal overdose as a sentinel health event and exploring fatal overdose as a primary outcome, especially for observational and treatment intervention studies with people using opioids. In places where opioids are increasingly being prescribed to treat chronic pain (e.g. USA, Canada), the population at risk, and that should be considered in longitudinal studies of overdose, may extend beyond those with a history of substance use disorder or infected by injection drug use. Finally, the reviewed articles included those published only in English and studies conducted in humans. Although English-language articles represent the majority of research published on this subject, roughly 10% of the 317 database search results were not in English, making it possible that we overlooked important non-English language contributions.


This systematic review and meta-analysis found evidence of a positive association between HIV status and overdose risk. There may be biological, behavioral, and structural mechanisms influencing the greater risk of overdose for people with HIV. Future research to explore these mechanisms is indicated. Expanded access to existing effective interventions to reduce overdose risk is warranted for drug users infected with or at risk of HIV. Healthcare providers who treat HIV-infected patients with a history of substance use disorder and/or who prescribe opioid medications should consider counseling patients on how to reduce their risk of overdose. Healthcare providers may also consider prescribing naloxone to patients, discussing the option of initiating buprenorphine therapy, or offering a referral to another MAT, as appropriate.


T.C.G. conceived of the study, reviewed articles, performed analysis, and participated in manuscript writing. S.K.M. and M.A.Y. reviewed articles, assisted with analysis, and participated in manuscript writing. E.R.P. performed the meta-analysis and participated in manuscript writing. J.D.R. provided feedback on the study approach, interpretation of data, and reviewed manuscript drafts.

The authors are grateful to Nickolas Zaller, Sarah Bowman, Roxanne Saucier, Nabarun Dasgupta, and R. Douglas Bruce for their thoughtful comments and edits to earlier drafts of this manuscript.

This work was supported in part by a grant from the Centers for Disease Control and Prevention (CDC) (R21CE001846-01 to T.C.G.); award number K24DA022112 from the National Institutes of Health, National Institute on Drug Abuse (NIH/NIDA); and by grant number P30-AI-42853 from the National Institutes of Health, Center for AIDS Research (NIH/CFAR).

This work was also made possible in part through the support of training grant number 5T32DA013911 from the National Institutes of Health, National Institute on Drug Abuse (NIH/NIDA).


The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of NIH, NIDA, CDC, or CFAR.

Conflicts of interest

The authors declare no conflicts of interest.


1. Eskild A, Magnus P, Samuelsen SO, Sohlberg C, Kittelsen P. Differences in mortality rates and causes of death between HIV positive and HIV negative intravenous drug users. Int J Epidemiol. 1993;22:315–320. [PubMed]
2. Ferreros I, Lumbreras B, Hurtado I, Pérez-Hoyos S, Hernández-Aguado I. The shifting pattern of cause-specific mortality in a cohort of human immunodeficiency virus-infected and non-infected injecting drug users. Addiction. 2008;103:651–659. [PubMed]
3. Penning R, Fromm E, Betz P, Kauert G, Drasch G, von Meyer L. Drug death autopsies at the Munich Institute of Forensic Medicine (1981–1992) Forensic Sci Int. 1993;62:135–139. [PubMed]
4. Seaman SR, Brettle RP, Gore SM. Mortality from overdose among injecting drug users recently released from prison: database linkage study. BMJ. 1998;316:426–428. [PMC free article] [PubMed]
5. EMCDDA. Annual report on the state of drugs problem in Europe. Lisbon, Portugal: European Monitoring Centre for Drugs and Drug Addiction; 2010.
6. Sackoff JE, Hanna DB, Pfeiffer MR, Torian LV. Causes of death among persons with AIDS in the era of highly active antiretroviral therapy: New York City. Ann Intern Med. 2006;145:397–406. [PubMed]
7. The U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) Comprehensive HIV prevention for people who inject drugs, revised guidance. Washington, District of Columbia: Office of the Global AIDS Coordinator; 2010. [Accessed 5 August 2011]. p. 13.
8. Harm reduction for people who use drugs: information note. Geneva, Switzerland: The Global Fund; 2011. The Global Fund to Fight AIDS Tuberculosis and Malaria; p. 6.
9. World Health Organization. Opiates: facts and figures. Geneva, Switzerland: WHO Press; 2011. [Accessed 4 August 2011].
10. United Nations Office on Drugs and Crime. World drug report 2009. Vienna, Austria: United Nations Office on Drugs and Crime; 2009.
11. World Health Organization, UNAIDS Joint United Nations Program on HIV/AIDS. HIV prevention among injecting drug users. Paper to the 24th Meeting of the UNAIDS Programme Coordinating Board; Geneva, Switzerland: UNAIDS; Jun, 2009. [Accessed 5 August 2011]. p. 25.
12. Hickman M, Hope V, Coleman B, Parry J, Telfer M, Twigger J, et al. Assessing IDU prevalence and health consequences (HCV, overdose and drug-related mortality) in a primary care trust: implications for public health action. J Public Health (Oxf) 2009;31:374–382. [PubMed]
13. Solomon SS, Celentano DD, Srikrishnan AK, Vasudevan CK, Anand S, Kumar MS, et al. Mortality among injection drug users in Chennai, India (2005–2008) AIDS. 2009;23:997–1004. [PMC free article] [PubMed]
14. Darke S, Zador D. Fatal heroin ’overdose’: a review. Addiction. 1996;91:1765–1772. [PubMed]
15. Seal KH, Kral AH, Gee L, Moore LD, Bluthenthal RN, Lorvick J, et al. Predictors and prevention of nonfatal overdose among street-recruited injection heroin users in the San Francisco Bay Area, 1998–1999. Am J Public Health. 2001;91:1842–1846. [PubMed]
16. Sherman SG, Cheng Y, Kral AH. Prevalence and correlates of opiate overdose among young injection drug users in a large U.S. city. Drug Alcohol Depend. 2007;88:182–187. [PMC free article] [PubMed]
17. Pollini RA, McCall L, Mehta SH, Vlahov D, Strathdee SA. Nonfatal overdose and subsequent drug treatment among injection drug users. Drug Alcohol Depend. 2006;83:104–110. [PMC free article] [PubMed]
18. Havens JR, Oser CB, Knudsen HK, Lofwall M, Stoops WW, Walsh SL, et al. Individual and network factors associated with nonfatal overdose among rural Appalachian drug users. Drug Alcohol Depend. 2011;115:107–112. [PMC free article] [PubMed]
19. Green TC, Grimes Serrano JM, Licari A, Budman SH, Butler SF. Women who abuse prescription opioids: findings from the Addiction Severity Index-Multimedia Version Connect prescription opioid database. Drug Alcohol Depend. 2009;103:65–73. [PMC free article] [PubMed]
20. Warner-Smith M, Darke S, Lynskey M, Hall W. Heroin overdose: causes and consequences. Addiction. 2001;96:1113–1125. [PubMed]
21. Green TC, Grau LE, Blinnikova KN, Torban M, Krupitsky E, Ilyuk R, et al. Social and structural aspects of the overdose risk environment in St. Petersburg, Russia. Int J Drug Policy. 2009;20:270–276. [PMC free article] [PubMed]
22. Piper T, Rudenstine S, Stancliff S, Sherman S, Nandi V, Clear A, et al. Overdose prevention for injection drug users: lessons learned from naloxone training and distribution programs in New York City. Harm Reduct J. 2007;4:3. [PMC free article] [PubMed]
23. Goedert JJ, Fung MW, Felton S, Battjes RJ, Engels EA. Cause-specific mortality associated with HIV and HTLV-II infections among injecting drug users in the USA. AIDS. 2001;15:1295–1302. [PubMed]
24. Brettle RP, Chiswick A, Bell J, Busuttil A, Wilson A, Povey S, et al. Pre-AIDS deaths in HIV infection related to intravenous drug use. QJM. 1997;90:617–629. [PubMed]
25. Wang C, Vlahov D, Galai N, Cole SR, Bareta J, Pollini R, et al. The effect of HIV infection on overdose mortality. AIDS. 2005;19:935–942. [PubMed]
26. Brugal MT, Barrio G, DeLa Fuente F, Regidor E, Royuela L, Suelves JM. Factors associated with nonfatal heroin overdose: assessing the effect of frequency and route of heroin administration. Addiction. 2002;97:319–327. [PubMed]
27. Fingerhood M, Rastegar DA, Jasinski D. Five year outcomes of a cohort of HIV-infected injection drug users in a primary care practice. J Addict Dis. 2006;25:33–38. [PubMed]
28. Lyles CM, Margolick JB, Astemborski J, Graham NM, Anthony JC, Hoover DR, et al. The influence of drug use patterns on the rate of CD4+ lymphocyte decline among HIV-1-infected injecting drug users. AIDS. 1997;11:1255–1262. [PubMed]
29. Goedert JJ, Pizza G, Gritti FM, Costigliola P, Boschini A, Bini A, et al. Mortality among drug users in the AIDS era. Int J Epidemiol. 1995;24:1204–1210. [PubMed]
30. van Ameijden EJ, Langendam MW, Coutinho RA. Dose-effect relationship between overdose mortality and prescribed methadone dosage in low-threshold maintenance programs. Addict Behav. 1999;24:559–563. [PubMed]
31. Rhodes T. Risk environments and drug harms: a social science for harm reduction approach. Int J Drug Policy. 2009;20:193–201. [PubMed]
32. Rhodes T, Kimber J, Small W, Fitzgerald J, Kerr T, Hickman M, et al. Public injecting and the need for ’safer environment interventions’ in the reduction of drug-related harm. Addiction. 2006;101:1384–1393. [PubMed]
33. Rhodes T, Singer M, Bourgois P, Friedman SR, Strathdee SA. The social structural production of HIV risk among injecting drug users. Soc Sci Med. 2005;61:1026–1044. [PubMed]
34. Marshall BD, Kerr T, Qi J, Montaner JS, Wood E. Public injecting and HIV risk behaviour among street-involved youth. Drug Alcohol Depend. 2010;110:254–258. [PMC free article] [PubMed]
35. Kerr T, Small W, Moore D, Wood E. A micro-environmental intervention to reduce the harms associated with drug-related overdose: evidence from the evaluation of Vancouver’s safer injection facility. Int J Drug Policy. 2007;18:37–45. [PubMed]
36. Marshall BD, Milloy MJ, Wood E, Montaner JS, Kerr T. Reduction in overdose mortality after the opening of North America’s first medically supervised safer injecting facility: a retrospective population-based study. Lancet. 2011;377:1429–1437. [PubMed]
37. Haddon W., Jr On the escape of tigers: an ecologic note. Am J Public Health. 1970;60:2229–2234. [PubMed]
38. Higgins JP, Thompson SG. Quantifying heterogeneity in a meta-analysis. Stat Med. 2002;21:1539–1558. [PubMed]
39. Borenstein M, Hedges L, Rothstein H. Comprehensive meta-analysis. Englewood, New Jersey: Biostat; 2005.
40. DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials. 1986;7:177–188. [PubMed]
41. Sterne JA, Egger M. Funnel plots for detecting bias in meta-analysis: guidelines on choice of axis. J Clin Epidemiol. 2001;54:1046–1055. [PubMed]
42. Brugal MT, Domingo-Salvany A, Puig R, Barrio G, García de Olalla P, de la Fuente L. Evaluating the impact of methadone maintenance programmes on mortality due to overdose and aids in a cohort of heroin users in Spain. Addiction. 2005;100:981–989. [PubMed]
43. Ochoa KC, Davidson PJ, Evans JL, Hahn JA, Page-Shafer K, Moss AR. Heroin overdose among young injection drug users in San Francisco. Drug Alcohol Depend. 2005;80:297–302. [PubMed]
44. Quaglio G, Talamini G, Lechi A, Venturini L, Lugoboni F, Mezzelani P, et al. Study of 2708 heroin-related deaths in north-eastern Italy 1985–98 to establish the main causes of death. Addiction. 2001;96:1127–1137. [PubMed]
45. Tardiff K, Marzuk PM, Leon AC, Hirsch CS, Portera L, Hartwell N. HIV infection among victims of accidental fatal drug overdoses in New York City. Addiction. 1997;92:1017–1022. [PubMed]
46. Vlahov D, Tang AM, Lyles C, Rezza G, Thomas D, Cohn S, et al. Increased frequency of overdose deaths among HIV-infected injection drug users. Addict Res. 2000;8:311–326.
47. Zaccarelli M, Gattari P, Rezza G, Conti S, Spizzichino L, Vlahov D, et al. Impact of HIV infection on non-AIDS mortality among Italian injecting drug users. AIDS. 1994;8:345–350. [PubMed]
48. Cattaneo C, Nuttall PA, Molendini LO, Pellegrinelli M, Grandi M, Sokol RJ. Prevalence of HIV and hepatitis C markers among a cadaver population in Milan. J Clin Pathol. 1999;52:267–270. [PMC free article] [PubMed]
49. Cohen MH, French AL, Benning L, Kovacs A, Anastos K, Young M, et al. Causes of death among women with human immunodeficiency virus infection in the era of combination antiretroviral therapy. Am J Med. 2002;113:91–98. [PMC free article] [PubMed]
50. Kohli R, Lo Y, Howard AA, Buono D, Floris-Moore M, Klein RS, et al. Mortality in an urban cohort of HIV-infected and at-risk drug users in the era of highly active antiretroviral therapy. Clin Infect Dis. 2005;41:864–872. [PubMed]
51. Langendam MW, van Brussel GH, Coutinho RA, van Ameijden EJ. The impact of harm-reduction-based methadone treatment on mortality among heroin users. Am J Public Health. 2001;91:774–780. [PubMed]
52. Manfredi R, Sabbatani S, Agostini D. Trend of mortality observed in a cohort of drug addicts of the metropolitan area of Bologna, North-Eastern Italy, during a 25-year-period. Coll Antropol. 2006;30:479–488. [PubMed]
53. Muga R, Roca J, Egea JM, Tor J, Sirera G, Rey-Joly C, et al. Mortality of HIV-positive and HIV-negative heroin abusers as a function of duration of injecting drug use. J Acquir Immune Defic Syndr. 2000;23:332–338. [PubMed]
54. Palepu A, Khan NA, Norena M, Wong H, Chittock DR, Dodek PM. The role of HIV infection and drug and alcohol dependence in hospital mortality among critically ill patients. J Crit Care. 2008;23:275–280. [PubMed]
55. Scheer S, McQuitty M, Denning P, Hormel L, Stephens B, Katz M, et al. Undiagnosed and unreported AIDS deaths: results from the San Francisco Medical Examiner. J Acquir Immune Defic Syndr. 2001;27:467–471. [PubMed]
56. Smith DK, Gardner LI, Phelps R, Hamburger ME, Carpenter C, Klein RS, et al. Mortality rates and causes of death in a cohort of HIV-infected and uninfected women, 1993–1999. J Urban Health. 2003;80:676–688. [PMC free article] [PubMed]
57. Tyndall MW, Craib KJ, Currie S, Li K, O’Shaughnessy MV, Schechter MT. Impact of HIV infection on mortality in a cohort of injection drug users. J Acquir Immune Defic Syndr. 2001;28:351–357. [PubMed]
58. van Haastrecht HJ, van Ameijden EJ, van den Hoek JA, Mientjes GH, Bax JS, Coutinho RA. Predictors of mortality in the Amsterdam cohort of human immunodeficiency virus (HIV)-positive and HIV-negative drug users. Am J Epidemiol. 1996;143:380–391. [PubMed]
59. van Haastrecht HJ, Mientjes GH, van den Hoek AJ, Coutinho RA. Death from suicide and overdose among drug injectors after disclosure of first HIV test result. AIDS. 1994;8:1721–1725. [PubMed]
60. Stoneburner RL, Des Jarlais DC, Benezra D, Gorelkin L, Sotheran JL, Friedman SR, et al. A larger spectrum of severe HIV-1: related disease in intravenous drug users in New York City. Science. 1988;242:916–919. [PubMed]
61. De Palo VA, Millstein BH, Mayo PH, Salzman SH, Rosen MJ. Outcome of intensive care in patients with HIV infection. Chest. 1995;107:506–510. [PubMed]
62. Prins M, Hernández Aguado IH, Brettle RP, Robertson JR, Broers B, Carré N, et al. Pre-AIDS mortality from natural causes associated with HIV disease progression: evidence from the European Seroconverter Study among injecting drug users. AIDS. 1997;11:1747–1756. [PubMed]
63. Neira-León M, Barrio G, Bravo MJ, Brugal MT, de la Fuente L, Domingo-Salvany A, et al. Infrequent opioid overdose risk reduction behaviours among young adult heroin users in cities with wide coverage of HIV prevention programmes. Int J Drug Policy. 2011;22:16–25. [PubMed]
64. Bargagli AM, Schifano P, Davoli M, Faggiano F, Perucci CA, Group VS. Determinants of methadone treatment assignment among heroin addicts on first admission to public treatment centres in Italy. Drug Alcohol Depend. 2005;79:191–199. [PubMed]
65. Carvajal MJ, Vicioso C, Santamaria JM, Bosco A. AIDS and suicide issues in Spain. AIDS Care. 1995;7(Suppl 2):S135–S138. [PubMed]
66. Eskild A, Magnus P, Sohlberg C, Kittelsen P, Olving JH, Teige B, et al. Slow progression to AIDS in intravenous drug users infected with HIV in Norway. J Epidemiol Community Health. 1994;48:383–387. [PMC free article] [PubMed]
67. Krentz HB, Kliewer G, Gill MJ. Changing mortality rates and causes of death for HIV-infected individuals living in Southern Alberta, Canada from 1984 to 2003. HIV Med. 2005;6:99–106. [PubMed]
68. Laurichesse HA, Mortimer J, Evans BG, Farrington CP. Pre-AIDS mortality in HIV-infected individuals in England, Wales and Northern Ireland, 1982–1996. AIDS. 1998;12:651–658. [PubMed]
69. Mezzelani P, Quaglio GL, Venturini L, Lugoboni F, Friedman SR, Des Jarlais DC. A multicentre study on the causes of death among Italian injecting drug users. AIDS has overtaken overdose as the principal cause of death. AIDS Care. 1998;10:61–67. [PubMed]
70. Miller CL, Kerr T, Strathdee SA, Li K, Wood E. Factors associated with premature mortality among young injection drug users in Vancouver. Harm Reduct J. 2007;4:1. [PMC free article] [PubMed]
71. Mirakbari SM, Innes GD, Christenson J, Tilley J, Wong H. Do co-intoxicants increase adverse event rates in the first 24 h in patients resuscitated from acute opioid overdose? J Toxicol Clin Toxicol. 2003;41:947–953. [PubMed]
72. Selwyn PA, Alcabes P, Hartel D, Buono D, Schoenbaum EE, Klein RS, et al. Clinical manifestations and predictors of disease progression in drug users with human immunodeficiency virus infection. N Engl J Med. 1992;327:1697–1703. [PubMed]
73. Talaie H, Shadnia SH, Okazi A, Pajouhmand A, Hasanian H, Arianpoor H. The prevalence of hepatitis B, hepatitis C and HIV infections in non-IV drug opioid poisoned patients in Tehran-Iran. Pak J Biol Sci. 2007;10:220–224. [PubMed]
74. van Asten L, Zangerle R, Hernández Aguado I, Boufassa F, Broers B, Brettle RP, et al. Do HIV disease progression and HAART response vary among injecting drug users in Europe? Eur J Epidemiol. 2005;20:795–804. [PubMed]
75. Aidala A, Cross JE, Stall R, Harre D, Sumartojo E. Housing status and HIV risk behaviors: implications for prevention and policy. AIDS Behav. 2005;9:251–265. [PubMed]
76. Seaman SR, Brettle RP, Gore SM. Pre-AIDS mortality in the Edinburgh City Hospital HIV cohort. Stat Med. 1997;16:2459–2474. [PubMed]
77. Gruber VA, McCance-Katz EF. Methadone, buprenorphine, and street drug interactions with antiretroviral medications. Curr HIV/AIDS Rep. 2010;7:152–160. [PMC free article] [PubMed]
78. Bruce RD, Kresina TF, McCance-Katz EF. Medication-assisted treatment and HIV/AIDS: aspects in treating HIV-infected drug users. AIDS. 2010;24:331–340. [PubMed]
79. Bruce RD, Altice FL, Gourevitch MN, Friedland GH. Pharmacokinetic drug interactions between opioid agonist therapy and antiretroviral medications: implications and management for clinical practice. J Acquir Immune Defic Syndr. 2006;41:563–572. [PubMed]
80. Bruce RD, McCance-Katz E, Kharasch ED, Moody DE, Morse GD. Pharmacokinetic interactions between buprenorphine and antiretroviral medications. Clin Infect Dis. 2006;43(Suppl 4):S216–S223. [PubMed]
81. Bruce RD. Methadone as HIV prevention: high volume methadone sites to decrease HIV incidence rates in resource limited settings. Int J Drug Policy. 2010;21:122–124. [PMC free article] [PubMed]
82. Connock M, Juarez-Garcia A, Jowett S, Frew E, Liu Z, Taylor R, et al. Methadone and buprenorphine for the management of opioid dependence: a systematic review and economic evaluation. Health Technol Assess. 2007;11:1–171. [PubMed]
83. Keen J, Rowse G, Mathers N, Campbell M, Seivewright N. Can methadone maintenance for heroin-dependent patients retained in general practice reduce criminal conviction rates and time spent in prison? Br J Gen Pract. 2000;50:48–49. [PMC free article] [PubMed]
84. Kinlock TW, Gordon MS, Schwartz RP, Fitzgerald TT, O’Grady KE. A randomized clinical trial of methadone maintenance for prisoners: results at 12 months postrelease. J Subst Abuse Treat. 2009;37:277–285. [PMC free article] [PubMed]
85. Mattick RP, Ali R, White JM, O’Brien S, Wolk S, Danz C. Buprenorphine versus methadone maintenance therapy: a randomized double-blind trial with 405 opioid-dependent patients. Addiction. 2003;98:441–452. [PubMed]
86. Mattick RP, Breen C, Kimber J, Davoli M. Methadone maintenance therapy versus no opioid replacement therapy for opioid dependence. Cochrane Database Syst Rev. 2009:CD002209. [PubMed]
87. Moatti JP, Carrieri MP, Spire B, Gastaut JA, Cassuto JP, Moreau J. Adherence to HAART in French HIV-infected injecting drug users: the contribution of buprenorphine drug maintenance treatment. The Manif 2000 study group. AIDS. 2000;14:151–155. [PubMed]
88. Roux P, Carrieri MP, Villes V, Dellamonica P, Poizot-Martin I, Ravaux I, et al. The impact of methadone or buprenorphine treatment and ongoing injection on highly active anti-retroviral therapy (HAART) adherence: evidence from the MANIF2000 cohort study. Addiction. 2008;103:1828–1836. [PubMed]
89. Springer SA, Chen S, Altice FL. Improved HIV and substance abuse treatment outcomes for released HIV-infected prisoners: the impact of buprenorphine treatment. J Urban Health. 2010;87:592–602. [PMC free article] [PubMed]
90. Metzger D, Woody G, O’Brian C. Drug Treatment as HIV prevention: a research update. J Acquir Immune Defic Syndr. 2010;55:s32–s36. [PMC free article] [PubMed]
91. Gowing LR, Farrell M, Bornemann R, Sullivan LE, Ali RL. Brief report: methadone treatment of injecting opioid users for prevention of HIV infection. J Gen Intern Med. 2006;21:193–195. [PMC free article] [PubMed]
92. Mathers BM, Degenhardt L, Ali H, Wiessing L, Hickman M, Mattick RP, et al. HIV prevention, treatment, and care services for people who inject drugs: a systematic review of global, regional, and national coverage. Lancet. 2010;375:1014–1028. [PubMed]
93. Davoli M, Bargagli AM, Perucci CA, Schifano P, Belleudi V, Hickman M, et al. Risk of fatal overdose during and after specialist drug treatment: the VEdeTTE study, a national multi-site prospective cohort study. Addiction. 2007;102:1954–1959. [PubMed]
94. Sporer KA. Acute heroin overdose. Ann Intern Med. 1999;130:584–590. [PubMed]
95. Sporer KA, Kral AH. Prescription naloxone: a novel approach to heroin overdose prevention. Ann Emerg Med. 2007;49:172–177. [PubMed]
96. Seal KH, Thawley R, Gee L, Bamberger J, Kral AH, Ciccarone D, et al. Naloxone distribution and cardiopulmonary resuscitation training for injection drug users to prevent heroin overdose death: a pilot intervention study. J Urban Health. 2005;82:303–311. [PMC free article] [PubMed]
97. Maxwell S, Bigg D, Stanczykiewicz K, Carlberg-Racich S. Prescribing naloxone to actively injecting heroin users: a program to reduce heroin overdose deaths. J Addict Dis. 2006;25:89–96. [PubMed]
98. Galea S, Worthington N, Piper TM, Nandi VV, Curtis M, Rosenthal DM. Provision of naloxone to injection drug users as an overdose prevention strategy: early evidence from a pilot study in New York City. Addict Behav. 2006;31:907–912. [PubMed]
99. Doe-Simkins M, Walley AY, Epstein A, Moyer P. Saved by the nose: bystander-administered intranasal naloxone hydrochloride for opioid overdose. Am J Public Health. 2009;99:788–791. [PubMed]
100. Sherman SG, Gann DS, Tobin KE, Latkin CA, Welsh C, Bielenson P. The life they save may be mine’: diffusion of overdose prevention information from a city sponsored programme. Int J Drug Policy. 2009;20:137–142. [PubMed]
101. Yokell M, Green TC, Bowman S, McKenzie M, Rich J. opioid overdose prevention and naloxone distribution in Rhode Island. Med Health Rhode Island. 2011;94:240–242. [PMC free article] [PubMed]
102. Walley AY. Implementation and evaluation of Massachusetts’ overdose education and naloxone distribution program. American Public Health Association Annual Conference; 2011; Washington, DC, USA..
103. Walley AY, Xuan Z, Hackman H, Ozonoff A, Quinn E, Pierce C, et al. Is implementation of bystander overdose education and naloxone distribution associated with lower opioid-related overdose rates in Massachusetts?. Association of Medical Education and Research on Substance Abuse; 2011; Arlington, VA, USA.
104. World Health Organization. WHO model list of essential medicines, 17th list. Geneva, Switzerland: WHO Press; 2011. pp. 1–45.
105. World Health Organization. International statistical classification of diseases and related health problems: tenth revision (ICD-10) 2. Geneva, Switzerland: WHO Press; 1994.
106. Pouget ER, Kershaw TS, Niccolai LM, Ickovics JR, Blankenship KM. Associations of sex ratios and male incarceration rates with multiple opposite-sex partners: potential social determinants of HIV/STI transmission. Public Health Rep. 2010;125(Suppl 4):70–80. [PMC free article] [PubMed]
107. Blankenship KM, Smoyer AB, Bray SJ, Mattocks K. Black-white disparities in HIV/AIDS: the role of drug policy and the corrections system. J Health Care Poor Underserved. 2005;16:140–156. [PMC free article] [PubMed]
108. Blankenship KM, Bray SJ, Merson MH. Structural interventions in public health. AIDS. 2000;14(Suppl 1):S11–S21. [PubMed]
109. Vaca FE, Kohl V. Pediatric pedestrian injury. Top Emerg Med. 2006;28:30–38.
110. Vaca FE, Anderson CL, Herrera H, Patel C, Silman EF, Deguzman R, et al. Crash injury prediction and vehicle damage reporting by paramedics. West J Emerg Med. 2009;10:62–67. [PMC free article] [PubMed]