Pre-AIDS mortality and morbidity among injection drug users in Amsterdam and Baltimore: an ecological comparison

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.

Community-based interventions to prevent fatal overdose from illegal drugs: a systematic review protocol

INTRODUCTION

Drug overdose is the most frequent cause of death among people who misuse illegal drugs. People who inject these drugs are 14-17 times more likely to die than their non-drug using peers. Various strategies to reduce drug-related deaths have failed to meet target reductions. Research into community-based interventions for preventing drug overdose deaths is promising. This review seeks to identify published studies describing community-based interventions and to evaluate their effectiveness at reducing drug overdose deaths.

METHODS AND ANALYSIS

We will systematically search key electronic databases using a search strategy which groups terms into four facets: (1) Overdose event, (2) Drug classification, (3) Intervention and (4) Setting. Searches will be limited where possible to international literature published in English between 1998 and 2014. Data will be extracted by two independent reviewers using a predefined table adapted from the Cochrane Collaboration handbook. The quality of included studies will be evaluated using the Cochrane Collaboration's tool for assessing risk of bias. We will conduct a meta-analysis for variables which can be compared across studies, using statistical methods to control for heterogeneity where appropriate. Where clinical or statistical heterogeneity prevents a valid numerical synthesis, we will employ a narrative synthesis to describe community-based interventions, their delivery and use and how effectively they prevent fatal overdoses.

ETHICS AND DISSEMINATION

We will publish findings from this systematic review in a peer-reviewed scientific journal and present results at national and international conferences. It will be disseminated electronically and in print.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42015017833.

Continuing HIV risk in New York City injection drug users: the association of syringe source and syringe sharing

Sterile syringe access is an important means to reduce HIV risk, but many injection drug users (IDU) who obtain syringes from sterile sources continue to share syringes. We examined the factors associated with continuing syringe sharing in New York City. We recruited 500 active IDU in 2005 through respondent-driven sampling. In multiple logistic regression, not obtaining all syringes in the past year exclusively from sterile sources was associated with increased syringe sharing. Ensuring adequate syringe availability as well as engaging and retaining nonusers and inconsistent users in sterile syringe services may increase sterile syringe access and decrease syringe sharing.

The association between change in social network characteristics and non-fatal overdose: results from the SHIELD study in Baltimore, MD, USA

BACKGROUND

Social network factors have been reported to be associated with non-fatal overdose. Yet, few studies have examined how changes in social network characteristics may influence overdose risk. The purpose of this study was to examine the relationship between changes in social network and non-fatal overdose.

METHODS

Data for this study came from 659 participants enrolled in the Self-Help in Eliminating Life-Threatening Diseases (SHIELD) study, who reported details about their non-fatal overdose experience between enrollment and a follow-up visit. Social network characteristics were described at both time points and net change in network composition was calculated.

RESULTS

The sample was predominately male (56%), African-American (96%) and unemployed (78%). Experience of non-fatal overdose between time points was reported by 15%. Older age was associated with non-fatal overdose. Interaction between incarceration status and drug use was statistically significant. Protective factors were having a denser network at baseline and a network that became denser after adjusting for gender, homelessness, incarceration, drug use and total network size.

CONCLUSIONS

Drug users' social networks are an important target for overdose prevention interventions. Further research on overdose risk and movement of specific network members in and out of networks is warranted.

Non-fatal overdose and subsequent drug treatment among injection drug users

Overdose is a leading cause of death among illicit drug users. Nine hundred twenty-four injection drug users (IDUs) in Baltimore, Maryland, were interviewed to characterize overdose events and determine the circumstances under which they lead to drug treatment. Overall, 366 (39.7%) reported at least one non-fatal drug overdose. Most (96.2%) used heroin on the day of their last overdose and almost half (42.6%) used heroin and alcohol but few (4.1%) used tranquilizers or benzodiazepines. Five percent were in drug treatment when the overdose occurred and 7.1% had been incarcerated 2 weeks prior. One in four IDUs (26.2%) sought drug treatment within 30 days after their last overdose of whom 75% enrolled. Speaking with someone about drug treatment after the overdose was associated with treatment seeking (AOR 5.22; 95% CI: 3.12, 8.71). Family members were the most commonly cited source of treatment information (53.7%) but only those who spoke with spouses, crisis counselors and hospital staff were more likely to seek treatment. Not being ready for treatment (69.6%) and not viewing drug use as a problem (30.7%) were the most common reasons for not seeking treatment and being placed on a waiting list was the most common reason for not subsequently enrolling in treatment (66.7%). Of the IDUs treated by emergency medical technicians, ER staff or hospital staff, only 17.3%, 26.2% and 43.2% reported getting drug treatment information from those sources, respectively. Interventions that provide drug treatment information and enhance motivation for treatment in the medical setting and policies that reduce barriers to treatment entry among motivated drug users are recommended.

Using cohort studies to estimate mortality among injecting drug users that is not attributable to AIDS

BACKGROUND

Injecting drug use (IDU) and associated mortality appear to be increasing in many parts of the world. IDU is an important factor in HIV transmission. In estimating AIDS mortality attributable to IDU, it is important to take account of premature mortality rates from other causes to ensure that AIDS related mortality among injecting drug users (IDUs) is not overestimated. The current review provides estimates of the excess non-AIDS mortality among IDUs.

METHOD

Searches were conducted with Medline, PsycINFO, and the Web of Science. The authors also searched reference lists of identified papers and an earlier literature review by English et al (1995). Crude mortality rates (CMRs) were derived from data on the number of deaths, period of follow up, and number of participants. In estimating the all-cause mortality, two rates were calculated: one that included all cohort studies identified in the search, and one that only included studies that reported on AIDS deaths in their cohort. This provided lower and upper mortality rates, respectively.

RESULTS

The current paper derived weighted mortality rates based upon cohort studies that included 179 885 participants, 1,219,422 person-years of observation, and 16,593 deaths. The weighted crude AIDS mortality rate from studies that reported AIDS deaths was approximately 0.78% per annum. The median estimated non-AIDS mortality rate was 1.08% per annum.

CONCLUSIONS

Illicit drug users have a greatly increased risk of premature death and mortality due to AIDS forms a significant part of that increased risk; it is, however, only part of that risk. Future work needs to examine mortality rates among IDUs in developing countries, and collect data on the relation between HIV and increased mortality due to all causes among this group.

Do young heroin users in Madrid, Barcelona and Seville have sufficient knowledge of the risk factors for unintentional opioid overdose?

To identify the self-perceived reasons for unintentional opioid overdose of young heroin users in three Spanish cities and their agreement with objective risk factors for overdose. Computer-Assisted Personal Interviews (CAPI) were held with 991 street-recruited current heroin users aged 18-30. The general reasons for overdose and the reasons for the last overdose suffered were explored with open-ended (OEQs) and pre-coded questions (PCQs). Limited knowledge of overdose risk factors was defined as mention of fewer than two objective risk factors for unintentional overdose in the OEQ. Univariate, bivariate, and logistic regression methods were used. 77.8% (Seville), 64.9% (Madrid) and 57.2% (Barcelona) of participants have limited knowledge of overdose risk factors. Residence in Seville and not having attended courses or meetings on overdoses were significantly associated with limited knowledge, after adjusting for other factors. The most frequently identified general reasons in OEQ or PCQ were using heroin in large amounts (66.8%), together with tranquilizers (62.0%), adulterated (60.7%), or purer than usual (57.6%). Most reasons were selected more frequently in PCQ than in OEQ, especially rapid injection of the entire dose and using heroin shortly after using tranquilizers or alcohol, by injection, or after a period of abstinence. The results were similar for overdoses suffered by participants. Most young heroin users do not have sufficient knowledge of overdose risk factors, especially the use of heroin by injection, after a period of abstinence, or together with alcohol or methadone. Specific informational or educational programs adapted to the local context are critically needed.

AIDS incidence and mortality in injecting drug users: the AjUDE-Brasil II Project

This paper presents AIDS incidence and mortality among injecting drug users (IDUs) reached by the AjUDE-Brasil II Project. From a cross-sectional survey, 478 IDUs were interviewed in three Brazilian cities: Porto Alegre, São José do Rio Preto, and Itajaí. The cohort was followed up in the Brazilian surveillance database for AIDS and mortality during 2000 and 2001. AIDS incidence was 1.1 cases per 100 person-years, and the mortality rate was 2.8 deaths per 100 person-years. AIDS cases only occurred in IDUs who reported ever having shared injecting equipment. Female gender (RR = 5.30), homelessness (RR = 6.16), and report of previous sexual relations with same-sex partners (RR = 6.21) were associated with AIDS. Deaths occurred only among males. Homelessness (RR = 3.00), lack of income (RR = 2.65), HIV seropositive status (RR = 4.52), and no history of incarceration (RR = 3.71) were also associated with death. These findings support evidence that gender and socioeconomic conditions are both determinants of morbidity and mortality in Brazilian IDUs.

The effect of HIV infection on overdose mortality

OBJECTIVES

To quantify the association of HIV infection with overdose mortality and explore the potential mechanisms.

DESIGN

A prospective cohort study.

METHODS

A total of 1927 actively injecting drug users who were HIV seronegative at baseline, of whom 308 later HIV seroconverted, were followed semi-annually for death from 1988 to 2001. Survival analyses using marginal structural and standard Cox models were used to evaluate the effect of HIV infection on the risk of overdose mortality.

RESULTS

Overdose death rates were higher in HIV-seropositive than HIV-seronegative drug users: 13.9 and 5.6 per 1000 person-years, respectively (P < 0.01). The hazard ratio (HR) was 2.54 [95% confidence interval (CI) 1.47, 4.38] for the marginal structural model and 2.06 (95% CI 1.25, 3.38) for the standard Cox model, both adjusted for demographics, drug injection characteristics, alcohol abuse, substance abuse treatment, and sexual orientation. Adjusting for possible time-varying mediators (i.e. drug use, medical conditions and healthcare access) in extended marginal structural models reduced the effect of HIV on overdose mortality by 30% (HR 1.82, 95% CI 1.01, 3.30). Abnormal liver function was associated with a higher risk of overdose mortality (HR 2.00, 95% CI 1.05, 3.84); adjustment for this further reduced the effect of HIV on overdose mortality.

CONCLUSION

HIV infection was associated with a higher risk of overdose mortality. Drug use behavior, systematic disease and liver damage associated with HIV infection appeared to account for a substantial portion of this association. The data suggest a group to target with interventions to reduce overdose mortality rates.

Hospitalization for depressive syndrome in a cohort of HIV-infected patients contaminated through injecting drug use: MANIF 2000 cohort, France, 1995-1999

The objective of this study was to estimate the relative impact of hospitalization for depressive syndrome (DS) on all causes of hospitalization and characterize individuals more likely to experience hospitalization for DS in the French cohort study, Manif 2000, of patients HIV infected through injection drug use. We selected all patients followed-up to the 24-month visit (C24) who missed no more than one visit. Using medical records, dates and causes of hospitalizations, were collected retrospectively. A Poisson regression model based on generalized estimating equations was used to identify factors associated with hospitalization for DS. During the study period, 223 hospitalizations were recorded for 120 of the 335 selected patients. DS was the second reason for hospitalization after infections, accounting for 14.3% of the total number of hospitalizations. DS was reported in 32 hospitalizations and involved 24 patients, five of them being hospitalized more than once for the same cause. Factors independently associated with hospitalization for DS were history of multiple incarceration (RR = 2.1, 95% CI: 1.0-4.7), polydrug use (RR = 2.6, 95% CI: 1.1 -5.9) and lack of stable relationship (RR = 4.2, 95% CI: 1.6- 11. 1). In the HAART era, DS represents an important cause of hospitalization of HIV-infected injecting drug users, mainly concerning patients presenting no stable relationship and signs of social instability. Scheduled psychiatric consultations for these patients would permit us to identify those for whom major depression might lead to hospitalization and provide them with timely and appropriate care.

Racial/ethnic disparities in overdose mortality trends in New York City, 1990-1998

Racial/ethnic disparities in health and disease have been present in the United States for the past century. Although differences such as individual access to health care and health-related behaviors account for some of these health disparities, it is likely that a combination of individual and contextual-level factors determine the differential rates of disease between racial/ethnic groups. We studied fatal accidental drug overdose in New York City between 1990 and 1998 to describe differences in racial/ethnic patterns over time and to develop hypotheses about factors that might contribute to these differences. During this period, rates of overdose death were consistently higher among blacks and Latinos compared to whites. In addition, cocaine was more common among black decedents, while opiates and alcohol were more common among Latino and white decedents. Differences in situational factors, such as differential likelihood of activating emergency medical response, may in part explain the consistently higher overdose mortality rates observed among minorities. Further study to determine the individual and contextual factors that explain these observed disparities in overdose death may identify effective areas for public health intervention and provide insight into factors underlying racial/ethnic disparities in other health outcomes.

Suicide among heroin users: rates, risk factors and methods

The current paper examines critically the literature on suicide rates, suicide risk factors and methods employed for suicide among heroin users, and compares these to those of the general population. Heroin users have a death rate 13 times that of their peers, and deaths among heroin users attributed to suicide range from 3-35%. Overall, heroin users are 14 times more likely than peers to die from suicide. The prevalence of attempted suicide is also many orders of magnitude greater than that of community samples. The major general population risk factors for suicide also apply to heroin users (gender, psychopathology, family dysfunction and social isolation). Heroin users, however, have extremely wide exposure to these factors. They also carry additional risks specifically associated with heroin and other drug use. Drugs as a method of suicide play a larger role in suicide among heroin users than in the general population. Heroin, however, appears to play a relatively small role in suicide among this group. Overall, suicide is a major clinical issue among heroin users. It is concluded that suicide is a major problem that treatment agencies face, and which requires targeted intervention if the rates of suicide among this group are to decline.

Factors associated with non-fatal heroin overdose: assessing the effect of frequency and route of heroin administration

AIMS

To examine risk factors associated with non-fatal heroin overdose, particularly frequency and route of heroin administration.

DESIGN

Data from cross-sectional surveys were analysed as a case-control and as a case cross-over design.

SETTING AND PARTICIPANTS

2556 subjects treated for heroin dependence in 164 outpatient facilities in Spain.

MEASUREMENTS

Prevalence of overdose involving emergency care in the 12 months before treatment admission. CASE CONTROL DESIGN: Odds ratio (OR) adjusted by logistic regression. CASE-CROSSOVER DESIGN: Estimated relative risk (RR) of transient risk of injecting heroin.

FINDINGS

The prevalence of overdose was 10%. In the case control analysis the cumulative risk of overdose increased as the frequency of heroin use decreased. However, among daily heroin users this risk increased as the frequency of heroin injection rose, with an OR of 6.0 (95% CI: 3.9-9.6) for daily injectors versus non-injectors. Sniffers had a higher risk than smokers among non-daily users, but not among daily users. Other factors associated with increased risk of overdose were: tranquilizers, alcohol or cocaine use, living in certain regions and being long-term HIV+ 0. In the case-crossover analysis, the RR for injecting heroin versus using other routes immediately before overdose was 15.9 (95% CI: 9.5-26.6), and was much higher for non-daily heroin users than for daily users.

CONCLUSIONS

These findings suggest that the rapid entry of a large quantity of heroin into the blood (as occurs when injecting) involves a high risk of overdose, especially when the heroin tolerance level is low (as occurs in sporadic users).

Predictors and prevention of nonfatal overdose among street-recruited injection heroin users in the San Francisco Bay Area, 1998-1999

OBJECTIVES

This study sought to determine prevalence of and risk factors for nonfatal recent overdose among street-recruited injection heroin users.

METHODS

From August 1998 through July 1999, 1427 heroin injectors were recruited from 6 inner-city neighborhoods in the San Francisco Bay Area, Calif, and interviewed. Factors hypothesized to be associated with recent overdose were analyzed with logistic regression.

RESULTS

Of the 1427 participants, 684 (48%) had had an overdose, 466 (33%) had experienced 2 or more overdose events, and 182 (13%) had had a recent overdose. In multiple logistic regression, being younger (adjusted odds ratio [OR] for each year of increasing age = 0.95; 95% confidence interval [CI] = 0.94, 0.97), having been arrested 3 or more times in the past year (adjusted OR = 2.50; 95% CI = 1.61, 3.87), drinking 4 or more alcoholic drinks per day (adjusted OR = 2.05; 95% CI = 1.37, 3.05), and having participated in methadone detoxification during the past year (adjusted OR = 1.47; 95% CI = 1.03, 2.09) were independently associated with recent overdose. Being homeless; identifying as gay, lesbian, bisexual, or transgender; having spent 5 or more years in prison or jail; and having engaged in sex work also were associated with recent overdose.

CONCLUSIONS

Targeted interventions that decrease risk for overdose are urgently needed.

Dose-effect relationship between overdose mortality and prescribed methadone dosage in low-threshold maintenance programs

The present study evaluates the effectiveness of low-threshold methadone maintenance in reducing overdose mortality. In a prospective cohort study conducted in Amsterdam, 498 Dutch injecting drug users (IDU) provided 1,969 person years of follow-up (1989-1995). Forty-four IDU died in this period, 15 due to illicit drug overdose. Compared to IDU not in maintenance, the adjusted relative risk for overdose mortality among those receiving 5-50 mg, 55-70 mg, and 75+ mg were 0.35, 0.13, and 0.11, respectively (p < .05). Also current injection use and HIV-seropositivity were independent predictors for overdose mortality. Whereas previous studies indicated effectiveness of methadone-assisted detoxification and high-dose maintenance programs in reducing mortality, the present study findings suggest that low-threshold maintenance programs also reduce overdose mortality, with higher dosages being most protective.