The effect of HIV infection on overdose mortality

Mortality in the SuperMIX cohort of people who inject drugs in Melbourne, Australia: a prospective observational study

AIMS

To measure mortality rates and factors associated with mortality risk among participants in the SuperMIX study, a prospective cohort study of people who inject drugs.

DESIGN

A prospective observational study using self-reported behavioural and linked mortality data.

SETTING

Melbourne, Australia.

PARTICIPANTS/CASES

A total of 1209 people who inject drugs (67% male) followed-up between 2008 and 2019 for 6913 person-years (PY).

MEASUREMENTS

We linked participant identifiers from SuperMIX to the Australian National Death Index and estimated all-cause and drug-related mortality rates and standardized mortality ratios (SMRs). We used Cox regression to examine associations between mortality and fixed and time-varying socio-demographic, alcohol and other drug use and health service-related exposures.

FINDINGS

Between 2008 and 2019 there were 76 deaths in the SuperMIX cohort. Of those with a known cause of death (n = 68), 35 (51%) were drug-related, yielding an all-cause mortality rate of 1.1 per 100 PY [95% confidence interval (CI) = 0.88-1.37] with an estimated SMR of 16.64 (95% CI = 13.29-20.83) and overall accidental drug-induced mortality rate of 0.5 per 100 PY (95% CI = 0.36-0.71). Reports of recent use of ambulance services [adjusted hazard ratio (aHR) = 3.77, 95% CI =1.78-7.97] and four or more incarcerations (aHR = 2.78, 95% CI = 1.55-4.99) were associated with increased mortality risk.

CONCLUSIONS

In Melbourne, Australia, mortality among people who inject drugs appears to be positively associated with recent ambulance attendance and experience of incarceration.

Cross-training needs among community-based clinicians in HIV and substance use

BACKGROUND

People with double burden of HIV and substance use have poorer treatment engagement and worse treatment outcomes. Cross-training of HIV and substance use disorder clinicians can potentially enhance the scale up and quality of integrated care. Research is needed on clinicians' areas of greatest training need in order to inform training development.

METHODS

Data from semi-structured individual interviews with 16 HIV and 13 substance use disorder clinicians (N = 29) examining clinician perspectives on their training needs were analyzed using thematic analysis focused on both a priori and emergent subthemes.

RESULTS

Several key emergent subthemes were identified across the a priori themes of: 1) past training experiences; 2) gaps in training; and 3) training and supervision format/structure. Both HIV and substance use clinicians reported they had received minimal formal cross-training and had mostly been trained "on the job." Clinicians also emphasized gaps in training regarding sensitivity and anti-stigma, the latest medications for opioid use disorder, and HIV prevention/treatment and referral resources. Regarding training and supervision format, clinicians cited didactic workshops and ongoing supervision as appealing strategies.

CONCLUSIONS

Results show that lack of formal and updated training for clinicians is an important gap in providing integrated HIV and substance use treatment. Didactic workshops and ongoing support strategies that address stigma, medications for HIV and substance use disorder, and referral resources are likely to be particularly valuable.

Mortality among people who inject drugs: a prospective cohort followed over three decades in Baltimore, MD, USA

BACKGROUND AND AIMS

During the past decades, people who inject drugs (PWID) have been impacted by the development of combination antiretroviral therapy (cART) to combat HIV/AIDS, the prescription opioid crisis and increased use of lethal synthetic opioids. We measured how these dynamics have impacted mortality among PWID in an urban US city.

DESIGN

Prospective cohort study using data from the AIDS Linked to the Intravenous Experience (ALIVE).

SETTING

Baltimore, MD, USA from 1988 to 2018.

PARTICIPANTS

A total of 5506 adult PWIDs (median age at baseline 37 years).

MEASUREMENTS

Mortality was identified by linkage to National Death Index-Plus (NDI-Plus) and categorized into HIV/infectious disease (HIV/ID) deaths, overdose and violence-related (drug-related) deaths and chronic disease deaths. Person-time at risk accrued from baseline and ended at the earliest of death or study period. All-cause and cause-specific mortality were calculated annually. The Fine & Gray method was used to estimate the subdistribution hazards of cause-specific deaths accounting for competing risks.

FINDINGS

Among 5506 participants with 84 226 person-years of follow-up, 43.9% were deceased by 2018. Among all deaths, 30.5% were HIV/ID deaths, 24.4% drug-related deaths and 33.3% chronic disease deaths. Age-standardized all-cause mortality increased from 23 to 45 per 1000 person-years from 1988 to 1996, declined from 1996 to 2014, then trended upward to 2018. HIV/ID deaths peaked in 1996 coincident with the availability of cART, then continuously declined. Chronic disease deaths increased continuously as the cohort aged. Drug-related deaths declined until 2011, but increased more than fourfold by 2018. HIV/HCV infection and active injecting were independently associated with HIV/ID and drug-related deaths. Female and black participants had a higher risk of dying from HIV/ID deaths and a lower risk of dying from drug-related deaths than male and non-black participants.

CONCLUSIONS

Deaths in Baltimore, MD, USA attributable to HIV/ID appear to have declined following the widespread use of combination antiretroviral therapy. Increases in the rates of drug-related deaths in Baltimore were observed prior to and continue in conjunction with national mortality rates associated with the opiate crisis.

A syndemic examination of injecting drug use, incarceration and multiple drug-related harms in French opioid users

PURPOSE

People who inject drugs (PWID) face multiple health problems, including infectious diseases and drug overdoses. Applying syndemic and risk environment frameworks, this paper aims to examine the co-occurrence and clustering of drug-related harms and their association with incarceration experience with or without in-prison drug injection.

DESIGN/METHODOLOGY/APPROACH

The authors used data from a cross-sectional survey conducted in 2015 among 557 active opioid injectors. Self-reported data were collected through face-to-face or online questionnaires. They distinguished three harm categories, namely, viral infections, bacterial infections and overdoses, and built an index variable by summing the number of harm categories experienced, yielding a score from 0 to 3. Association between incarceration experience and co-occurrence of harms was modelled using a multinomial logistic regression.

FINDINGS

Of the 557 participants, 30% reported lifetime experience of drug-related viral infection, 46% bacterial infection and 22% drug overdose. Multinomial logistic models showed that those who injected drugs during incarceration were more likely to report two (aOR = 2.35, 95% CI: 1.03-5.36) and three (aOR = 9.72, 95% CI: 3.23-29.22) harm categories than those who had never been incarcerated. They were also more likely to report three harm categories than formerly incarcerated respondents who did not inject drugs in prison (aOR = 5.14, 95% CI: 1.71-15.48).

ORIGINALITY/VALUE

This study provides insights of the syndemic nature of drug-related harms and highlights that drug injection during incarceration is associated with co-occurring harms. Public health interventions and policy changes are needed to limit the deleterious impact of prison on PWID.

Feasibility, acceptability, concerns, and challenges of implementing supervised injection services at a specialty HIV hospital in Toronto, Canada: perspectives of people living with HIV

BACKGROUND

Substance use significantly impacts health and healthcare of people living with HIV/AIDS (PLHIV), especially their ability to remain in hospital following admission. Supervised injection services (SIS) reduce overdoses and drug-related harms, but are not often provided within hospitals/outpatient programs. Leading us to question, what are PLHIV's perceptions of hospital-based SIS?

METHODS

This mixed-methods study explored feasibility and acceptability of implementing SIS at Casey House, a Toronto-based specialty HIV hospital, from the perspective of its in/outpatient clients. We conducted a survey, examining clients' (n = 92) demand for, and acceptability of, hospital-based SIS. Following this, we hosted two focus groups (n = 14) and one-on-one interviews (n = 8) with clients which explored benefits/drawbacks of in-hospital SIS, wherein participants experienced guided tours of a demonstration SIS space and/or presentations of evidence about impacts of SIS. Data were analysed using descriptive statistics and thematic analysis.

RESULTS

Among survey participants, 76.1% (n = 70) identified as cis-male and over half (n = 49;54.4%) had been a hospital client for 2 years or less. Nearly half (48.8%) knew about clients injecting in/near Casey House, while 23.6% witnessed it. Survey participants were more supportive of SIS for inpatients (76.1%) than for outpatients (68.5%); most (74.7%) reported SIS implementation would not impact their level of service use at Casey House, while some predicted coming more often (16.1%) and others less often (9.2%). Most focus group/interview participants, believed SIS would enhance safety by reducing health harms (e.g. overdose), increasing transparency between clients and clinicians about substance use, and helping retain clients in care. Debate arose about who (e.g., in/outpatients vs. non-clients) should have access to hospital-based SIS and how implementation may shift organizational priorities/resources away from services not specific to drug use.

CONCLUSIONS

Our data showed widespread support of, and need for, hospital-based SIS among client stakeholders; however, attempts to reduce negative impacts on non-drug using clients need to be considered in the balance of implementation plans. Given the increased risks of morbidity and mortality for PLHIV who inject drugs as well as the problems in retaining them in care in a hospital setting, SIS is a key component of improving care for this marginalized group.

All-cause and cause-specific mortality among people with regular or problematic cocaine use: a systematic review and meta-analysis

AIMS

To estimate pooled all-cause and cause-specific mortality risk for people with regular or problematic cocaine use.

METHODS

Systematic review and meta-analysis of prospective or retrospective cohort studies or clinical trials (n ≥30) of people with regular or problematic cocaine use with data on all-cause or cause-specific mortality. Of 2808 papers, 28 were eligible and reported on 21 cohorts, with a total 170 019 individuals. Cohorts identified based on acute care for drug poisoning or other severe health presentation were excluded. Title/abstract screening was conducted by one reviewer; a second reviewer independently checked 10% of excluded studies. Two reviewers conducted full-text screening. Data were extracted by one reviewer and checked by a second. A customized review-specific study reporting quality/risk of bias tool was used. Data on crude mortality rates (CMR) and standardized mortality ratios were extracted for both all-cause and cause-specific mortality. Standardized mortality ratios were imputed where not provided by the author using extracted data and information from the Global Burden of Disease Study 2017. Data were pooled using a random-effects model.

RESULTS

The pooled all-cause crude mortality rate was 1.24 per 100 person-years [95% confidence interval (CI) = 0.86, 1.78; n = 16 cohorts], but with considerable heterogeneity (I²  = 98.8%). The pooled all-cause standardized mortality ratio (SMR) was 6.13 (95% CI = 4.15, 9.05; n = 16 cohorts). Suicide (SMR = 6.26, 95% CI = 2.84, 13.80), accidental injury (SMR = 6.36, 95% CI = 4.18, 9.68), homicide (SMR = 9.38, 95% CI 3.45-25.48) and AIDS-related mortality (SMR = 23.12, 95% CI = 11.30, 47.31) were all elevated compared with age and sex peers in the general population.

CONCLUSIONS

There are elevated rates of mortality among people with regular or problematic cocaine use for traumatic deaths and deaths attributable to infectious disease.

Naloxone receipt and overdose prevention care among people with HIV on chronic opioid therapy

This cross-sectional study describes naloxone rescue kit receipt among people with HIV (PWH) on chronic opioid therapy (COT) and HIV clinician opioid overdose prevention care in two clinics between 2015 and 2017. Naloxone rescue kit receipt was uncommon. History of overdose was associated with receiving naloxone but having a clinician who reported providing overdose prevention care was not. This study suggests that clinicians prescribing COT to PWH should improve overdose prevention care, including naloxone co-prescribing.

Influence of new societal factors on neovascular age-related macular degeneration outcomes

BACKGROUND

To assess the impact of unstudied societal factors for neovascular age-related macular degeneration (nAMD) on functional outcomes after anti-VEGFs.

METHODS

Charts of 94 nAMD patients treated in the Monticelli-Paradis Centre, Marseille, France, were reviewed. Phone interviews were conducted to assess societal factors, including transportation, living status, daily reading and social security scheme (SSS). Primary outcome was the impact of family support and disease burden on functional improvement in nAMD.

RESULTS

Between baseline and month 24 (M24), 42.4% of the variability in best-corrected visual acuity (BCVA) was explained by the cumulative effect of the following societal factors: intermittent out-patient follow-up, marital status, daily reading, transportation type, commuting time. No isolated societal factor significantly correlated with ETDRS BCVA severity at M24. A trend to correlation was observed between the EDTRS score at M24 and the SSS (P = 0.076), economic burden (P = 0.075), time between diagnosis and treatment initiation (P = 0.070). A significant correlation was found for the disease burdensome on the patient (P = 0.034) and low vision rehabilitation (P = 0.014).

CONCLUSIONS

Societal factors could influence functional outcomes in nAMD patients treated with anti-VEGFs. They could contribute to the healing process or sustain disease progression.

Mobile technology intervention to improve care coordination between HIV and substance use treatment providers: development, training, and evaluation protocol

Background

People living with HIV (PLWH) with a substance use disorder (SUD) tend to receive inadequate medical care in part because of a siloed healthcare system in which HIV and substance use services are delivered separately. Ideal treatment requires an interdisciplinary, team-based coordinated care approach, but many structural and systemic barriers impede the integration of HIV and SUD services. The current protocol describes the development and preliminary evaluation of a care coordination intervention (CCI), consisting of a tablet-based mobile platform for HIV and SUD treatment providers, an interagency communication protocol, and a training protocol. We hypothesize that HIV and SUD treatment providers will find the CCI to be acceptable, and that after receipt of the CCI, providers will: exhibit higher retention in dual care among patients, report increased frequency and quality of communication, and report increased rates of relational coordination.

Methods/design

A three phase approach is used to refine and evaluate the CCI. Phase 1 consists of in-depth qualitative interviews with 8 key stakeholders as well as clinical audits of participating HIV and SUD treatment agencies. Phase 2 contains functionality testing of the mobile platform with frontline HIV and SUD treatment providers, followed by refinement of the CCI. Phase 3 consists of a pre-, post-test trial with 30 SUD and 30 HIV treatment providers. Data will be collected at the provider, organization, and patient levels. Providers will complete assessments at baseline, immediately post-training, and at 1-, 3-, and 6-months post-training. Organizational data will be collected at baseline, 1-, 3-, and 6-months post training, while patient data will be collected at baseline and 6-months post training.

Discussion

This study will develop and evaluate a CCI consisting of a tablet-based mobile platform for treatment providers, an interagency communication protocol, and a training protocol as a means of improving the integration of care for PLWH who have a SUD. Results have the potential to advance the field by bridging gaps in a fragmented healthcare system, and improving treatment efficiency, work flow, and communication among interdisciplinary providers from different treatment settings.

Trial Registration: NCT02906215

An integrated approach to care attracts people living with HIV who use illicit drugs in an urban centre with a concentrated HIV epidemic

Background

People living with HIV (PLHIV) who are also marginalized by social and structural inequities often face barriers to accessing and adhering to HIV treatment and care. The Dr. Peter Centre (DPC) is a non-profit integrated care facility with a supervised injection room that serves PLHIV experiencing multiple barriers to social and health services in Vancouver, Canada. This study examines whether the DPC is successful in drawing in PLHIV with complex health issues, including addiction.

Methods

Using data collected by the Longitudinal Investigations into Supportive and Ancillary health services (LISA) study from July 2007 to January 2010, linked with clinical variables available through the British Columbia Centre for Excellence in HIV/AIDS Drug Treatment Program, we identified DPC and non-DPC clients with a history of injection drug use. Bivariable and multivariable logistic regression analyses compared socio-demographic and clinical characteristics of DPC clients (n = 76) and non-DPC clients (n = 482) with a history of injection drug use.

Results

Of the 917 LISA participants included within this analysis, 100 (10.9%) reported being a DPC client, of which 76 reported a history of injection drug use. Adjusted results found that compared to non-DPC clients with a history of injection drug use, DPC-clients were more likely to be male (AOR: 4.18, 95% CI = 2.09–8.37); use supportive services daily vs. less than daily (AOR: 3.16, 95% CI = 1.79–5.61); to have been diagnosed with a mental health disorder (AOR: 2.11; 95% CI: 1.12–3.99); to have a history of interpersonal violence (AOR: 2.76; 95% CI: 1.23–6.19); and to have ever experienced ART interruption longer than 1 year (AOR: 2.39; 95% CI: 1.38–4.15).

Conclusions

Our analyses suggest that the DPC operating care model engages PLHIV with complex care needs, highlighting that integrated care facilities are needed to support the multiple intersecting vulnerabilities faced by PLHIV with a history of injection drug use living within urban centres in North America and beyond.

No association between HIV status and risk of non-fatal overdose among people who inject drugs in Vancouver, Canada

BACKGROUND

The evidence to date on whether HIV infection increases the risk of accidental drug overdose among people who inject drugs (PWID) is equivocal. Thus, we sought to estimate the effect of HIV infection on risk of non-fatal overdose among two parallel cohorts of HIV-positive and -negative PWID.

METHODS

Data were collected from a prospective cohort of PWID in Vancouver, Canada between 2006 and 2013. During biannual follow-up assessments, non-fatal overdose within the previous 6months was assessed. Bivariable and multivariable generalized mixed-effects regression models were used to determine the unadjusted and adjusted associations between HIV status, plasma HIV-1 RNA viral load, and likelihood of non-fatal overdose.

RESULTS

A total of 1760 eligible participants (67% male, median age=42, and 42% HIV-positive at baseline) were included. Among 15,070 unique observations, 649 (4.3%) included a report of a non-fatal overdose within the previous 6months (4.4% among seropositive and 4.3% among seronegative individuals). We did not observe a difference in the likelihood of overdose by HIV serostatus in crude (odds ratio [OR]: 1.05, p=0.853) analyses or analyses adjusted for known overdose risk factors (adjusted OR [AOR]: 1.19, p=0.474). In a secondary analysis, among HIV-positive PWID, we did not observe an association between having a detectable viral load and overdose (AOR: 1.03, p=0.862).

CONCLUSIONS

Despite the evidence that HIV infection is a risk factor for fatal overdose, we found no evidence for a relationship between HIV disease and non-fatal overdose. However, overdose remains high among PWID, indicating the need for ongoing policy addressing this problem, and research into understanding modifiable risk factors that predict non-fatal overdose.

Correlates of overdose risk perception among illicit opioid users

BACKGROUND

Opioid-related mortality continues to increase in the United States. The current study assesses demographic and behavioral predictors of perceived overdose risk among individuals who use opioids illicitly. By examining these correlates in the context of established overdose risk factors, we aim to assess whether characteristics and behaviors that have been associated with actual overdose risk translate to higher perception of risk.

METHODS

We conducted a cross-sectional survey of 172 adult illicit opioid users in San Francisco, CA and used multivariable logistic regression to identify predictors of perception of high risk for opioid overdose.

RESULTS

Age (aOR=0.96, 95%CI=0.93-1.00) and number of injection days per month (0.91, 0.86-0.97) were associated with a lower odds of perceived high overdose risk. There was no independent association between use of opioid analgesics, concurrent use of opioids and benzodiazepines or cocaine, or HIV status and overdose risk perception.

CONCLUSIONS

Opioid users who injected more frequently and those who were older were less likely to perceive themselves as being at risk of overdose, notwithstanding that those who inject more are at higher risk of overdose and those who are older are at higher risk overdose mortality. In addition, despite being established overdose risk factors, there was no relationship between use of opioid analgesics, concurrent use of opioids and cocaine or benzodiazepines, or self-reported HIV status and overdose risk perception. These findings highlight key populations of opioid users and established risk factors that may merit focused attention as part of education-based overdose prevention and opioid management strategies.

Worldwide Prevalence and Trends in Unintentional Drug Overdose: A Systematic Review of the Literature

BACKGROUND

Drug overdose is an important, yet an inadequately understood, public health problem. Global attention to unintentional drug overdose has been limited by comparison with the scope of the problem. There has been a substantial increase in drug overdose incidence and prevalence in several countries worldwide over the past decade, contributing to both increased costs and mortality.

OBJECTIVES

The aim of this study was to systematically synthesize the peer-reviewed literature to document the global epidemiological profile of unintentional drug overdoses and the prevalence, time trends, mortality rates, and correlates of drug overdoses. We searched different combinations of Medical Subject Headings (MeSH) terms in PubMed for articles published from 1980 until July 2013, and we organized these results in tabular spreadsheets and compared them. We restricted the search to English-language articles that deal with unintentional overdose, focusing on 1 or more of the following key constructs: prevalence, time trends, mortality rates, and correlates. The term "overdose" as a MeSH major topic yielded 1076 publications. In addition, we searched the following combinations of nonmajor MeSH terms: "street drugs" and "overdose" yielded 180, "death" and "overdose" yielded 114, and "poisoning" and "drug users" yielded 17. There was some overlap among the searches. Based on the search and inclusion and exclusion criteria, we selected a total of 169 relevant articles for this article based on a close review of abstracts.

RESULTS

We found wide variability in lifetime prevalence of experiencing a nonfatal overdose or witnessing an overdose, and in mortality rates attributable to overdose. Lifetime prevalence of witnessed overdose among drug users (n = 17 samples) ranged from 50% to 96%, with a mean of 73.3%, a median of 70%, and a standard deviation of 14.1%. Lifetime prevalence of drug users personally experiencing a nonfatal overdose (n = 27 samples), ranged from 16.6% to 68.0% with a mean of 45.4%, a median of 47%, and a standard deviation of 14.4%. Population-based crude overdose mortality rates (n = 28 samples) ranged from 0.04 to 46.6 per 100 000 person-years. This range is likely attributable to the diversity in regions, time periods, and samples. Most studies on longitudinal trends of overdose death rates or overdose-related hospitalization rates showed increases in overdose death rates and in overdose-related hospitalization rates across time, which have led to peaks in these rates at the present time. An overall trend of increasing deaths from prescription opioid use and decreasing deaths from illicit drug use in the past several years has been noted across most of the literature. With the increase in prescription opioid overdose deaths, drug overdose is not just an urban problem: rural areas have seen an important increase in overdose deaths. Lastly, cocaine, prescription opioids, and heroin are the drugs most commonly associated with unintentional drug overdoses worldwide and the demographic and psychiatric correlates associated with unintentional drug overdoses are similar globally.

CONCLUSIONS

There is a need to invest in research to understand the distinct determinants of prescription drug overdose worldwide. Several other countries need to collect in a systematic and continuous fashion such data on sales of prescription opioids and other prescription drugs, nonmedical use of prescription drugs, and hospitalization secondary to overdoses on prescription drugs. The sparse evidence on the environmental determinants of overdose suggests a need for research that will inform the types of environmental interventions we can use to prevent drug overdose. Methodological issues for future studies include enhancing data collection methods on unintentional fatal and nonfatal overdoses, and collecting more detailed information on drug use history, source of drug use (for prescription drugs), and demographic and psychiatric history characteristics of the individual who overdosed.

Novel interventions to prevent HIV and HCV among persons who inject drugs

Persons who inject drugs (PWID) are at high risk for infection with and poor outcomes from HIV and hepatitis C virus (HCV). Well-established interventions for HIV/HCV prevention among PWID include syringe access, opioid agonist maintenance treatment, and supervised injection facilities, yet these interventions remain unavailable or inadequately resourced in much of the world. We review recent literature on biomedical and behavioral interventions to reduce the burden of HIV/HCV among PWID, with an emphasis on randomized controlled trials and quasi-experimental studies. Since 2013, there have been significant advancements in utilizing antiviral therapy and behavioral interventions for prevention among PWID, including approaches that address the unique needs of couples and sex workers. In addition, there have been significant developments in pharmacotherapies for substance use and the implementation of naloxone for opioid overdose prevention. Notwithstanding multiple ongoing structural challenges in delivering HIV/HCV prevention interventions to PWID, these emerging and rigorously evaluated interventions expand possibilities for prevention among PWID.

Overdose Education and Naloxone for Patients Prescribed Opioids in Primary Care: A Qualitative Study of Primary Care Staff

BACKGROUND

The rate of fatal unintentional pharmaceutical opioid poisonings has increased substantially since the late 1990s. Naloxone is an effective opioid antidote that can be prescribed to patients for bystander use in the event of an overdose. Primary care clinics represent settings in which large populations of patients prescribed opioids could be reached for overdose education and naloxone prescription.

OBJECTIVE

Our aim was to investigate the knowledge, attitudes and beliefs about overdose education and naloxone prescription among clinical staff in primary care.

DESIGN

This was a qualitative study using focus groups to elucidate both clinic-level and provider-level barriers and facilitators.

SETTING

Ten primary care internal medicine, family medicine and infectious disease/HIV practices in three large Colorado health systems.

METHODS

A focus group guide was developed based on behavioral theory. Focus group transcripts were coded for manifest and latent meaning, and analyzed for themes using a recursive approach that included inductive and deductive analysis.

RESULTS

Themes emerged in four content areas related to overdose education and naloxone prescription: knowledge, barriers, benefits and facilitators. Clinical staff (N = 56) demonstrated substantial knowledge gaps about naloxone and its use in outpatient settings. They expressed uncertainty about who to prescribe naloxone to, and identified a range of logistical barriers to its use in practice. Staff also described fears about offending patients and concerns about increased risk behaviors in patients prescribed naloxone. When considering naloxone, some providers reflected critically and with discomfort on their own opioid prescribing. These barriers were balanced by beliefs that prescribing naloxone could prevent death and result in safer opioid use behaviors.

LIMITATIONS

Findings from these qualitative focus groups may not be generalizable to other settings.

CONCLUSION

In addition to evidence gaps, logistical and attitudinal barriers will need to be addressed to enhance uptake of overdose education and naloxone prescription for patients prescribed opioids for pain.

Temporal trends in the survival of drug and alcohol abusers according to the primary drug of admission to treatment in Spain

BACKGROUND

Mortality of alcohol and drug abusers is much higher than the general population. We aimed to characterize the role of the primary substance of abuse on the survival of patients admitted to treatment and to analyze changes in mortality over time.

METHODS

Longitudinal study analyzing demographic, drug use, and biological data of 5023 patients admitted to three hospital-based treatment units in Barcelona, Spain, between 1985 and 2006. Vital status and causes of death were ascertained from clinical charts and the mortality register. Piecewise regression models were used to analyze changes in mortality.

RESULTS

The primary substances of dependence were heroin, cocaine, and alcohol in 3388 (67.5%), 945 (18.8%), and 690 patients (13.7%), respectively. The median follow-up after admission to treatment was 11.6 years (IQR: 6.6-16.1), 6.5 years (IQR: 3.9-10.6), and 4.8 years (IQR: 3.1-7.8) for the heroin-, cocaine-, and alcohol-dependent patients, respectively. For heroin-dependent patients, mortality rate decreased from 7.3×100person-years (p-y) in 1985 to 1.8×100p-y in 2008. For cocaine-dependent patients, mortality rate decreased from 10.7×100p-y in 1985 to <2.5×100p-y after 2004. The annual average decrease was 2% for alcohol-dependent patients, with the lowest mortality rate (3.3×100p-y) in 2008.

CONCLUSIONS

Significant reductions in mortality of alcohol and drug dependent patients are observed in recent years in Spain. Preventive interventions, treatment of substance dependence and antiretroviral therapy may have contributed to improve survival in this population.

Intertwined epidemics: national demographic trends in hospitalizations for heroin- and opioid-related overdoses, 1993-2009

The historical patterns of opiate use show that sources and methods of access greatly influence who is at risk. Today, there is evidence that an enormous increase in the availability of prescription opiates is fuelling a rise in addiction nationally, drawing in new initiates to these drugs and changing the geography of opiate overdoses. Recent efforts at supply-based reductions in prescription opiates may reduce harm, but addicted individuals may switch to other opiates such as heroin. In this analysis, we test the hypothesis that changes in the rates of Prescription Opiate Overdoses (POD) are correlated with changes in the rate of heroin overdoses (HOD). ICD9 codes from the Nationwide Inpatient Sample and population data from the Census were used to estimate overall and demographic specific rates of POD and HOD hospital admissions between 1993 and 2009. Regression models were used to test for linear trends and lagged negative binomial regression models were used to model the interrelationship between POD and HOD hospital admissions. Findings show that whites, women, and middle-aged individuals had the largest increase in POD and HOD rates over the study period and that HOD rates have increased in since 2007. The lagged models show that increases in a hospitals POD predict an increase in the subsequent years HOD admissions by a factor of 1.26 (p<0.001) and that each increase in HOD admissions increase the subsequent years POD by a factor of 1.57 (p<0.001). Our hypothesis of fungibility between prescription opiates and heroin was supported by these analyses. These findings suggest that focusing on supply-based interventions may simply lead to a shift in use to heroin rather minimizing the reduction in harm. The alternative approach of using drug abuse prevention resources on treatment and demand-side reduction is likely to be more productive at reducing opiate abuse related harm.

A simulation study of finite-sample properties of marginal structural Cox proportional hazards models

Motivated by a previously published study of HIV treatment, we simulated data subject to time-varying confounding affected by prior treatment to examine some finite-sample properties of marginal structural Cox proportional hazards models. We compared (a) unadjusted, (b) regression-adjusted, (c) unstabilized, and (d) stabilized marginal structural (inverse probability-of-treatment [IPT] weighted) model estimators of effect in terms of bias, standard error, root mean squared error (MSE), and 95% confidence limit coverage over a range of research scenarios, including relatively small sample sizes and 10 study assessments. In the base-case scenario resembling the motivating example, where the true hazard ratio was 0.5, both IPT-weighted analyses were unbiased, whereas crude and adjusted analyses showed substantial bias towards and across the null. Stabilized IPT-weighted analyses remained unbiased across a range of scenarios, including relatively small sample size; however, the standard error was generally smaller in crude and adjusted models. In many cases, unstabilized weighted analysis showed a substantial increase in standard error compared with other approaches. Root MSE was smallest in the IPT-weighted analyses for the base-case scenario. In situations where time-varying confounding affected by prior treatment was absent, IPT-weighted analyses were less precise and therefore had greater root MSE compared with adjusted analyses. The 95% confidence limit coverage was close to nominal for all stabilized IPT-weighted but poor in crude, adjusted, and unstabilized IPT-weighted analysis. Under realistic scenarios, marginal structural Cox proportional hazards models performed according to expectations based on large-sample theory and provided accurate estimates of the hazard ratio.

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, I(2) = 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.

Extension of Kaplan-Meier methods in observational studies with time-varying treatment

OBJECTIVES

Inverse probability of treatment weighted Kaplan-Meier estimates have been developed to compare two treatments in the presence of confounders in observational studies. Recently, stabilized weights were developed to reduce the influence of extreme inverse probability of treatment-weighted weights in estimating treatment effects. The objective of this research was to use adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests to examine the effect of a treatment that varies over time in an observational study.

METHODS

We proposed stabilized weight adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests when the treatment was time-varying over the follow-up period. We applied these new methods in examining the effect of an anti-platelet agent, clopidogrel, on subsequent events, including bleeding, myocardial infarction, and death after a drug-eluting stent was implanted into a coronary artery. In this population, clopidogrel use may change over time based on a patient's behavior (e.g., nonadherence) and physicians' recommendations (e.g., end of duration of therapy). Consequently, clopidogrel use was treated as a time-varying variable.

RESULTS

We demonstrate that 1) the sample sizes at three chosen time points are almost identical in the original and weighted datasets; and 2) the covariates between patients on and off clopidogrel were well balanced after stabilized weights were applied to the original samples.

CONCLUSIONS

The stabilized weight-adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests are useful in presenting and comparing survival functions for time-varying treatments in observational studies while adjusting for known confounders.

Typologies of prescription opioid use in a large sample of adults assessed for substance abuse treatment

Background

As a population, non-medical prescription opioid users are not well-defined. We aimed to derive and describe typologies of prescription opioid use and nonmedical use using latent class analysis in an adult population being assessed for substance abuse treatment.

Methods

Latent class analysis was applied to data from 26,314 unique respondents, aged 18-70, self-reporting past month use of a prescription opioid out of a total of 138,928 cases (18.9%) collected by the Addiction Severity Index-Multimedia Version (ASI-MV®), a national database for near real-time prescription opioid abuse surveillance. Data were obtained from November 2005 through December 2009. Substance abuse treatment, criminal justice, and public assistance programs in the United States submitted data to the ASI-MV database (n = 538). Six indicators of the latent classes derived from responses to the ASI-MV, a version of the ASI modified to collect prescription opioid abuse and chronic pain experience. The latent class analysis included respondent home ZIP code random effects to account for nesting of respondents within ZIP code.

Results

A four-class adjusted latent class model fit best and defined clinically interpretable and relevant subgroups: Use as prescribed, Prescribed misusers, Medically healthy abusers, and Illicit users. Classes varied on key variables, including race/ethnicity, gender, concurrent substance abuse, duration of prescription opioid abuse, mental health problems, and ASI composite scores. Three of the four classes (81% of respondents) exhibited high potential risk for fatal opioid overdose; 18.4% exhibited risk factors for blood-borne infections.

Conclusions

Multiple and distinct profiles of prescription opioid use were detected, suggesting a range of use typologies at differing risk for adverse events. Results may help clinicians and policy makers better focus overdose and blood-borne infection prevention efforts and intervention strategies for prescription opioid abuse reduction.

Mortality by causes in HIV-infected adults: comparison with the general population

Background

We compared mortality by cause of death in HIV-infected adults in the era of combined antiretroviral therapy with mortality in the general population in the same age and sex groups.

Methods

Mortality by cause of death was analyzed for the period 1999-2006 in the cohort of persons aged 20-59 years diagnosed with HIV infection and residing in Navarre (Spain). This was compared with mortality from the same causes in the general population of the same age and sex using standardized mortality ratios (SMR).

Results

There were 210 deaths among 1145 persons diagnosed with HIV (29.5 per 1000 person-years). About 50% of these deaths were from AIDS. Persons diagnosed with HIV infection had exceeded all-cause mortality (SMR 14.0, 95% CI 12.2 to 16.1) and non-AIDS mortality (SMR 6.9, 5.7 to 8.5). The analysis showed excess mortality from hepatic disease (SMR 69.0, 48.1 to 78.6), drug overdose or addiction (SMR 46.0, 29.2 to 69.0), suicide (SMR 9.6, 3.8 to 19.7), cancer (SMR 3.2, 1.8 to 5.1) and cardiovascular disease (SMR 3.1, 1.3 to 6.1). Mortality in HIV-infected intravenous drug users did not change significantly between the periods 1999-2002 and 2003-2006, but it declined by 56% in non-injecting drug users (P = 0.007).

Conclusions

Persons with HIV infection continue to have considerable excess mortality despite the availability of effective antiretroviral treatments. However, excess mortality in the HIV patients has declined since these treatments were introduced, especially in persons without a history of intravenous drug use.

Mortality among cocaine users: a systematic review of cohort studies

AIMS

To conduct a systematic review of mortality among cohort studies of cocaine users.

METHODS

Three electronic databases were searched (EMBASE, Medline and PsychINFO); other online databases were searched using online libraries and repositories of reports and literature in the drug and alcohol field, with requested contributions from trained librarians and experts. Searches and extraction were undertaken using protocols and cross-checking of decisions by two authors. Additional data were requested from study investigators where studies did not report relevant data.

RESULTS

1911 articles and 2 reports were identified from searches, with data from another four studies located from review articles. Seven cohorts of "problem" or dependent cocaine users reported data that permitted mortality rates to be estimated. Crude mortality rates ranged from 0.53 (95% CI: 0.10-1.58) to 6.16 (95% CI: 5.21-7.11) per 100 PY. Standardised mortality ratios (SMRs) reported in four studies suggested that mortality was four to eight times higher among cocaine users than age and sex peers in the general population.

CONCLUSIONS

There are limited data on the extent of elevated mortality among problematic or dependent cocaine users and it is unclear how generalisable the results of these studies may be to other populations of problematic cocaine users. Greater attention to both the method of recruitment, and the characteristics of cocaine users, would enhance our understanding of the mortality risks of problematic cocaine use.

A prospective study of alcohol consumption and HIV acquisition among injection drug users

OBJECTIVE

to estimate the effect of alcohol consumption on HIV acquisition while appropriately accounting for confounding by time-varying risk factors.

DESIGN

african-American injection drug users in the AIDS Link to Intravenous Experience cohort study. Participants were recruited and followed with semiannual visits in Baltimore, Maryland between 1988 and 2008.

METHODS

marginal structural models were used to estimate the effect of alcohol consumption on HIV acquisition.

RESULTS

at entry, 28% of 1525 participants were women with a median (quartiles) age of 37 (32-42) years and 10 (10-12) years of formal education. During follow-up, 155 participants acquired HIV and alcohol consumption was 24, 24, 26, 17, and 9% for 0, 1-5, 6-20, 21-50, and 51-140 drinks per week over the prior 2 years, respectively. In analyses accounting for sociodemographic factors, drug use, and sexual activity, hazard ratios for participants reporting 1-5, 6-20, 21-50, and 51-140 drinks per week in the prior 2 years compared to participants who reported 0 drinks per week were 1.09 (0.60-1.98), 1.18 (0.66-2.09), 1.66 (0.94-2.93), and 2.12 (1.15-3.90), respectively. A trend test indicated a dose-response relationship between alcohol consumption and HIV acquisition (P value for trend = 9.7 × 10).

CONCLUSION

a dose-response relationship between alcohol consumption and subsequent HIV acquisition is indicated, independent of measured known risk factors.

Excess mortality among injection drug users with AIDS, New York City (1999-2004)

We calculated proportions and trends in contributing causes of death among persons with AIDS (PWA) and a history of injection drug use (IDU) in New York City and compared the proportions with those among PWA with a transmission risk of high-risk heterosexual sex (HRH) and men who have sex with men (MSM). We included all 10,575 injection drug user, HRH, and MSM residents aged 13+ years with AIDS reported by September 30, 2006 , who died from 1999 through 2004. Accidental drug overdose was the most frequent contributing cause of death among IDUs (20.5%). Overdose prevention initiatives may greatly and immediately reduce deaths among PWA.

Mortality among regular or dependent users of heroin and other opioids: a systematic review and meta-analysis of cohort studies

AIMS

To review the literature on mortality among dependent or regular users of opioids across regions, according to specific causes, and related to a number of demographic and clinical variables.

METHODS

Multiple search strategies included searches of Medline, EMBASE and PsycINFO, consistent with the methodology recommended by the Meta-analysis of Observational Studies in Epidemiology (MOOSE) group; grey literature searches; and contact of experts for any additional unpublished data from studies meeting inclusion criteria. Random-effects meta-analyses were conducted for crude mortality rates (CMRs) and standardized mortality ratios (SMRs), with stratified analyses where possible. Meta-regressions examined potentially important sources of heterogeneity across studies.

RESULTS

Fifty-eight prospective studies reported mortality rates from opioid-dependent samples. Very high heterogeneity across studies was observed; pooled all-cause CMR was 2.09 per 100 person-years (PY; 95% CI; 1.93, 2.26), and the pooled SMR was 14.66 (95% CI: 12.82, 16.50). Males had higher CMRs and lower SMRs than females. Out-of-treatment periods had higher mortality risk than in-treatment periods (pooled RR 2.38 (CI: 1.79, 3.17)). Causes of death varied across studies, but overdose was the most common cause. Multivariable regressions found the following predictors of mortality rates: country of origin; the proportion of sample injecting; the extent to which populations were recruited from an entire country (versus subnational); and year of publication.

CONCLUSIONS

Mortality among opioid-dependent users varies across countries and populations. Treatment is clearly protective against mortality even in non-randomized observational studies. Study characteristics predict mortality levels; these should be taken into account in future studies.

Determinants of alcohol consumption in HIV-uninfected injection drug users

We assess the association between time fixed and time varying participant characteristics and subsequent alcohol consumption in 1968 injection drug users (median age 37 years, 28% female, 90% African-American) followed semi-annually from 1988 to 2008. Median alcohol consumption was seven drinks per week at study entry (first and third quartile: 1, 26) with 36% reporting binge drinking. Alcohol consumption and binge drinking decreased over follow-up. Older individuals and women reported consuming fewer drinks per week. Higher typical alcohol consumption was reported by those participants who reported in the prior 6 months: non-injection cocaine use, injection drug use, having one or more sex partners, or among men, a same sex partner. Associations were generally similar for drinks per week and binge drinking. This study demonstrates that in a large urban cohort of persons with a history of injection drug use, risky drug use and sexual risk behavior are associated with subsequent alcohol consumption.

Patterns of drug use and abuse among aging adults with and without HIV: a latent class analysis of a US Veteran cohort

This study characterized the extent and patterns of self-reported drug use among aging adults with and without HIV, assessed differences in patterns by HIV status, and examined pattern correlates. Data derived from 6351 HIV-infected and uninfected adults enrolled in an eight-site matched cohort, the Veterans Aging Cohort Study (VACS). Using clinical variables from electronic medical records and socio-demographics, drug use consequences, and frequency of drug use from baseline surveys, we performed latent class analyses (LCA) stratified by HIV status and adjusted for clinical and socio-demographic covariates. Participants were, on average, age 50 (range 22-86), primarily male (95%) and African-American (64%). Five distinct patterns emerged: non-users, past primarily marijuana users, past multidrug users, current high consequence multidrug users, and current low consequence primarily marijuana users. HIV status strongly influenced class membership. Non-users were most prevalent among HIV uninfected (36.4%) and current high consequence multidrug users (25.5%) were most prevalent among HIV-infected. While problems of obesity marked those not currently using drugs, current users experienced higher prevalences of medical or mental health disorders. Multimorbidity was highest among past and current multidrug users. HIV-infected participants were more likely than HIV-uninfected participants to be current low consequence primarily marijuana users. In this sample, active drug use and abuse were common. HIV-infected and uninfected Veterans differed on extent and patterns of drug use and on important characteristics within identified classes. Findings have the potential to inform screening and intervention efforts in aging drug users with and without HIV.

Alcohol consumption and risk of incident human immunodeficiency virus infection: a meta-analysis

OBJECTIVE

To analyze the relationship between alcohol consumption and incident HIV infection.

METHODS

Articles were identified via electronic and hand searches. Inclusion criteria were: incident HIV infection, preceding alcohol consumption, and association relating the two. The DerSimonian and Laird random effects model was used. For studies with more than one estimate of a given type, estimates were combined using the inverse variance weighted method. Publication bias was assessed using Begg's and Egger's tests. Heterogeneity was assessed using Q and I (2) statistics.

RESULTS

Ten studies were included. Overall alcohol consumption (any of the three types identified) increased the risk of HIV (RR 1.98, 95% CI 1.59-2.47). Alcohol consumers were at 77% higher risk (RR 1.77, 95% CI 1.43-2.19). Those consuming alcohol prior to, or at the time of, sexual relations were at an 87% increased risk (RR 1.87, 95% CI 1.39-2.50). For binge drinkers, the risk was double that of non-binge drinkers (RR 2.20, 95% CI 1.29-3.74).

CONCLUSIONS

Alcohol consumption is associated with an increased risk of incident HIV infection. Additional research is required to further investigate a possible causal role.

Trends in mortality and causes of death among women with HIV in the United States: a 10-year study

BACKGROUND

To assess trends in mortality and cause of death for women with HIV, we studied deaths over a 10-year period among participants in the Women's Interagency HIV Study, a representative US cohort.

METHODS

Deaths were ascertained by National Death Index Plus match, and causes of death determined by death certificate.

RESULTS

From 1995 through 2004, 710 of 2792 HIV-infected participants died. During this interval, the standardized mortality ratio fell from a high of 24.7 in 1996 to a plateau with a mean of 10.3 from 2001 to 2004. Over the decade, deaths from non-AIDS causes increased and accounted for the majority of deaths by 2001-2004. The most common non-AIDS causes of death were trauma or overdose, liver disease, cardiovascular disease, and malignancy. Independent predictors of mortality besides HIV-associated variables were depressive symptoms and active hepatitis B or C. Women who were overweight or obese were significantly less likely to die of AIDS than women of normal weight.

CONCLUSIONS

In the Women's Interagency HIV Study, the death rate has plateaued in recent years. Although HIV-associated factors predicted AIDS and non-AIDS deaths, other treatable conditions predicted mortality. Further gains in reducing mortality among HIV-infected women may require broader access to therapies for depression, viral hepatitis, and HIV itself.

Psychosocial and contextual correlates of opioid overdose risk among drug users in St. Petersburg, Russia

BACKGROUND

Opioid overdose in Russia is a problem that has grown more severe as heroin abuse expanded over the past decade, yet few studies have explored it in detail. In order to gain a clearer understanding of the situation, 60 drug users, both in and out of drug treatment in St. Petersburg, were interviewed concerning their overdose experience and knowledge about overdose recognition and prevention.

METHODS

Using a semi-structured interview, we sought to identify and describe local attitudes, knowledge and experience (both self-sustained and witnessed) of opioid overdose. Bi-variate and multiple logistic regressions were performed in order to identify the relationship between overdose experience and sociodemographic factors, risk behaviors, and clinical psychiatric measures.

RESULTS

We found that having experienced or witnessed an opioid overdose within the previous year was common, overdose knowledge was generally high, but nearly half the participants reported low self-efficacy for effectively intervening in an overdose situation. In bivariate analyses, self-reported family problems (i.e., perceived problematic family interactions) were positively associated with both experiencing (t56 = 2.49; p < 0.05) and with witnessing a greater number of overdoses in the previous year (rhos = 0.31; p < 0.05). Having previously overdosed [Adjusted Risk Ratio (ARR) 1.7, 95% Confidence Interval (CI) 1.1-2.6] and higher SCL-90-R somatization scores (ARR 1.2, 95% CI 0.96 - 1.5) were independently associated in multivariable analyses with self-sustained overdose experience in the past year. Greater perceived likelihood of experiencing a future overdose and concern about medical problems were independently associated with witnessing a higher number of overdoses within the previous year. Over two thirds of the participants expressed interest in receiving training in overdose prevention and response.

CONCLUSION

Opioid overdose experience is very common among drug users in St. Petersburg, Russia, and interest in receiving training for overdose recognition and prevention was high. Future research should target the development of effective overdose recognition and prevention interventions, especially ones that include naloxone distribution and involve drug users' families.

Mortality among injection drug users in Chennai, India (2005-2008)

BACKGROUND

Injection drug users (IDUs) have estimated mortality rates over 10 times higher than the general population; much of this excess mortality is HIV-associated. Few mortality estimates among IDUs from developing countries, including India, exist.

METHODS

IDUs (1158) were recruited in Chennai from April 2005 to May 2006; 293 were HIV positive. Information on deaths and causes was obtained through outreach workers and family/network members. Mortality rates and standardized mortality ratios were calculated; multivariate Poisson regression was used to identify predictors of mortality.

RESULTS

We observed 85 deaths over 1998 person-years (p-y) of follow-up [mortality rate (MR) 4.25 per 100 p-y; 95% confidence interval (CI) = 3.41-5.23]. The overall standardized mortality ratio was 11.1; for HIV-positive IDUs, the standardized mortality ratio was 23.9. Mortality risk among HIV-positive IDUs (MR: 8.88 per 100 p-y) was nearly three times that of negative IDUs (MR: 3.03 per 100 p-y) and increased with declining immune status (CD4 cells > 350: 5.44 per 100 p-y vs. CD4 cells < or = 200: 34.5 per 100 p-y). This association persisted after adjustment for confounders. The leading causes of mortality in both HIV negative and positive IDUs were overdose (n = 22), AIDS (n = 14), tuberculosis (n = 8) and accident/trauma (n = 9).

CONCLUSION

Substantial mortality was observed in this cohort with the highest rates among HIV-positive IDUs with CD4 counts of less than 350 cells/microl. Although, in these 2 years, non-AIDS deaths outnumbered 0002030-related deaths, the relative contribution of 0002030-associated mortality is likely to increase with advancing HIV disease progression. These data reinforce the need for interventions to reduce the harms associated with drug use and increase HAART access among IDUs in Chennai.

Constructing inverse probability weights for marginal structural models

The method of inverse probability weighting (henceforth, weighting) can be used to adjust for measured confounding and selection bias under the four assumptions of consistency, exchangeability, positivity, and no misspecification of the model used to estimate weights. In recent years, several published estimates of the effect of time-varying exposures have been based on weighted estimation of the parameters of marginal structural models because, unlike standard statistical methods, weighting can appropriately adjust for measured time-varying confounders affected by prior exposure. As an example, the authors describe the last three assumptions using the change in viral load due to initiation of antiretroviral therapy among 918 human immunodeficiency virus-infected US men and women followed for a median of 5.8 years between 1996 and 2005. The authors describe possible tradeoffs that an epidemiologist may encounter when attempting to make inferences. For instance, a tradeoff between bias and precision is illustrated as a function of the extent to which confounding is controlled. Weight truncation is presented as an informal and easily implemented method to deal with these tradeoffs. Inverse probability weighting provides a powerful methodological tool that may uncover causal effects of exposures that are otherwise obscured. However, as with all methods, diagnostics and sensitivity analyses are essential for proper use.

Survival of HIV-infected injection drug users (IDUs) in the highly active antiretroviral therapy era, relative to sex- and age-specific survival of HIV-uninfected IDUs

BACKGROUND

In the era of highly active antiretroviral therapy (HAART), it remains unclear whether human immunodeficiency virus (HIV)-infected injection drug users (IDUs) have durations of survival similar to those for comparable HIV-uninfected IDUs. The goal of this study was to compare survival durations of HIV-infected and HIV-uninfected IDUs for the period 1987-2004.Methods. Demographic data, drug use characteristics, and biological markers were obtained at the time of admission to a substance abuse treatment program. The outcome of interest was the duration of survival after admission, and the primary exposure was HIV infection. Vital status was ascertained by means of the mortality register by the end of 2004. Three calendar periods, which were defined on the basis of use of specific therapies, were considered: 1987-1991 (the antiretroviral monotherapy era), 1992-1996 (the dual combination therapy era and the era when methadone was introduced in Spain), and 1997-2004 (the era of HAART and of established methadone programs). We used Cox regression methods allowing for late entries to handle the contribution of persons who survived a given period and entered the following period with nonzero time. We compared HIV-uninfected and HIV-infected IDUs with adjustments for age, sex, and duration of follow-up after admission.

RESULTS

A total of 1209 IDUs were admitted to the hospital during the period from January 1987 through December 2004, and 1181 were eligible for the study. The majority (81.3%) of patients were men. The mean age (+/- standard deviation) at admission was 27.8+/-5.6 years, and the mean duration of injection drug use (+/- standard deviation) was 7.6+/-5.0 years. The prevalences of HIV and hepatitis C virus infections were 59.0% and 92.3%, respectively, and the total duration of follow-up was 10.116 person-years. Although survival duration for HIV-uninfected IDUs in 1997-2004 was similar to the duration in earlier periods, the duration for HIV-infected IDUs improved significantly since 1997 (P<.01). Furthermore, among patients admitted in the last period, the survival durations for HIV-uninfected and HIV-infected IDUs was virtually the same (relative hazard, 0.89; 95% confidence interval, 0.44-1.81).

CONCLUSIONS

The duration of survival of HIV-infected IDUs has improved substantially since 1997, reaching rates similar to the rates for HIV-seronegative IDUs who accessed the health care system in the era of HAART.

Mortality among participants in the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study

BACKGROUND

Many studies that have reported decreases in human immunodeficiency virus (HIV)-related mortality since the advent of highly active antiretroviral therapy (HAART) have also reported steady increases in non-HIV-related mortality over the same time periods. We examined temporal trends and risk factors for accident- and injury-related mortality among HIV-infected and -uninfected participants in the Women's Interagency HIV Study (WIHS) and the Multicenter AIDS Cohort Study (MACS).

METHODS

Information on causes of death was recorded for all participants in the MACS and WIHS cohort studies who died, and causes of death were categorized as accident- or injury-related deaths or not. Mortality rates were calculated by time periods, prior to the widespread use of HAART (before 1997) and after (1997-2002), and risk factors.

RESULTS

Cause of death information was available for 619 women in the WIHS who died (during the period 1994-2002) and 1830 men in the MACS who died (during the period 1984-2002). The death rates were higher for accident- or injury-related mortality in the WIHS (2.96 deaths per 1000 person-years for the HIV-infected group and 2.96 per 1000 person-years for the HIV-uninfected group), compared with the participants in MACS (0.79 deaths per 1000 person-years for the HIV-infected group and 0.63 per 1000 person-years for the HIV-uninfected group). In the final multivariate analysis, the following factors were associated with significantly higher risk in men: higher education, depressive symptoms, and a greater number of sex partners. Among women, the significant risk factors for death were decreased CD4+ T cell count, unemployment, higher alcohol use, and injection drug use.

CONCLUSION

The characteristics of the men in the MACS who died and women in the WIHS who died differ, as do the risk factors for mortality. These results characterize important target groups for interventions to reduce accident- and injury-related deaths.

The medical management of opioid dependence in HIV primary care settings

Injecting drug use is a common mode of transmission among persons with HIV/AIDS. Many HIV-infected patients meet diagnostic criteria for opioid dependence, a chronic and relapsing brain disorder. Most HIV providers, however, receive little training in substance use disorders. Opioid agonist therapy (OAT) has a stabilizing effect on opioid-dependent patients and is associated with greater acceptance of antiretroviral (ARV) therapy, higher ARV adherence, and greater engagement in HIV-related health care. Although methadone maintenance has been the OAT gold standard, methadone is available for the treatment of opioid dependence only in strictly regulated narcotic treatment programs. Buprenorphine, a partial opioid agonist approved for the office-based treatment of opioid dependence in 2002, may result in better health and substance use treatment outcomes for patients with HIV disease.