Mortality among injection drug users identified as "out of treatment"

Population-level Outcomes and Cost-Effectiveness of Expanding the Recommendation for Age-based Hepatitis C Testing in the United States

Background

The US Centers for Disease Control and Prevention and the U.S. Preventive Services Task Force recommend one-time hepatitis C virus (HCV) testing for persons born 1945-1965 and targeted testing for high-risk persons. This strategy targets HCV testing to a prevalent population at high risk for HCV morbidity and mortality, but does not include younger populations with high incidence. To address this gap and improve access to HCV testing, age-based strategies should be considered.

Methods

We used a simulation of HCV to estimate the effectiveness and cost-effectiveness of HCV testing strategies: 1) standard of care (SOC) - recommendation for one-time testing for all persons born 1945-1965, 2) recommendation for one-time testing for adults ≥40 years (≥40 strategy), 3) ≥30 years (≥30 strategy), and 4) ≥18 years (≥18 strategy). All strategies assumed targeted testing of high-risk persons. Inputs were derived from national databases, observational cohorts and clinical trials. Outcomes included quality-adjusted life expectancy, costs, and cost-effectiveness.

Results

Expanded age-based testing strategies increased US population lifetime case identification and cure rates. Greatest increases were observed in the ≥18 strategy. Compared to the SOC, this strategy resulted in an estimated 256,000 additional infected persons identified and 280,000 additional cures at the lowest cost per QALY gained (ICER = $28,000/QALY).

Conclusions

In addition to risk-based testing, one-time HCV testing of persons 18 and older appears to be cost-effective, leads to improved clinical outcomes and identifies more persons with HCV than the current birth cohort recommendations. These findings could be considered for future recommendation revisions.

Cost-effectiveness of integrating buprenorphine-naloxone treatment for opioid use disorder into clinical care for persons with HIV/hepatitis C co-infection who inject opioids

BACKGROUND

Untreated opioid use disorder (OUD) affects the care of HIV/HCV co-infected people who inject opioids. Despite active injection opioid use, there is evidence of increasing engagement in HIV care and adherence to HIV medications among HIV/HCV co-infected persons. However, less than one-half of this population is offered HCV treatment onsite. Treatment for OUD is also rare and largely occurs offsite. Integrating buprenorphine-naloxone (BUP-NX) into onsite care for HIV/HCV co-infected persons may improve outcomes, but the clinical impact and costs are unknown. We evaluated the clinical impact, costs, and cost-effectiveness of integrating (BUP-NX) into onsite HIV/HCV treatment compared with the status quo of offsite referral for medications for OUD.

METHODS

We used a Monte Carlo microsimulation of HCV to compare two strategies for people who inject opioids: 1) standard HIV care with onsite HCV treatment and referral to offsite OUD care (status quo) and 2) standard HIV care with onsite HCV and BUP-NX treatment (integrated care). Both strategies assume that all individuals are already in HIV care. Data from national databases, clinical trials, and cohorts informed model inputs. Outcomes included mortality, HCV reinfection, quality-adjusted life years (QALYs), costs (2017 US dollars), and incremental cost-effectiveness ratios.

RESULTS

Integrated care reduced HCV reinfections by 7%, cases of cirrhosis by 1%, and liver-related deaths by 3%. Compared to the status quo, this strategy also resulted in an estimated 11/1,000 fewer non-liver attributable deaths at one year and 28/1,000 fewer of these deaths at five years, at a cost-effectiveness ratio of $57,100/QALY. Integrated care remained cost-effective in sensitivity analyses that varied the proportion of the population actively injecting opioids, availability of BUP-NX, and quality of life weights.

CONCLUSIONS

Integrating BUP-NX for OUD into treatment for HIV/HCV co-infected adults who inject opioids increases life expectancy and is cost-effective at a $100,000/QALY threshold.

Transmission dynamics for Methicilin-resistant Staphalococous areus with injection drug user

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen resistance to antibiotics including methicillin. The resistance first emerged in 1960 in a healthcare setting only after two years of using methicillin as a viable treatment for methicillin-susceptible Staphylococcus aureus. MRSA leads to infections in different parts of the body including the skin, bloodstream, lungs, or the urinary tract.

Methods

A deterministic model for methicillin-resistant Staphylococcus aureus (MRSA) with injection drug users is designed. The model incorporates transmission of MRSA among non-injection drug users and injection drug users (IDUs) who are both low-and high-risk users. A reduced MRSA transmission model with only non-IDUs is fitted to a 2008-2013 MRSA data from the Agency for Healthcare and Research and Quality (AHRQ). The parameter estimates obtained are projected onto the parameters for the low-and high-risk IDUs subgroups using risk factors obtained by constructing a risk assessment ethogram. Sensitivity analysis is carried out to determine parameters with the greatest impact on the reproduction number using the reduced non-IDUs model. Change in risk associated behaviors was studied using the full MRSA transmission model via the increase in risky behaviors and enrollment into rehabilitation programs or clean needle exchange programs. Three control effectiveness levels determined from the sensitivity analysis were used to study control of disease translation within the subgroups.

Results

The sensitivity analysis indicates that the transmission probability and recovery rates within the subgroup have the highest impact on the reproduction number of the reduced non-IDU model. Change in risk associated behaviors from non-IDUs to low-and high-risk IDUs lead to more MRSA cases among the subgroups. However, when more IDUs enroll into rehabilitation programs or clean needle exchange programs, there was a reduction in the number of MRSA cases in the community. Furthermore, MRSA burden within the subgroups can effectively be curtailed in the community by implementing moderate- and high-effectiveness control strategies.

Conclusions

MRSA burden can be curtailed among and within non-injection drug users and both low-and high-risk injection drug users by encouraging positive change in behaviors and by moderate- and high-effectiveness control strategies that effectively targets the transmission probability and recovery rates within the subgroups in the community.

High Mortality Among Non-HIV-Infected People Who Inject Drugs in Bangkok, Thailand, 2005-2012

OBJECTIVES

We examined the causes of hospitalization and death of people who inject drugs participating in the Bangkok Tenofovir Study, an HIV preexposure prophylaxis trial.

METHODS

The Bangkok Tenofovir Study was a randomized, double-blind, placebo-controlled trial conducted during 2005 to 2012 among 2413 people who inject drugs. We reviewed medical records to define the causes of hospitalization and death, examined participant characteristics and risk behaviors to determine predictors of death, and compared the participant mortality rate with the rate of the general population of Bangkok, Thailand.

RESULTS

Participants were followed an average of 4 years; 107 died: 22 (20.6%) from overdose, 13 (12.2%) from traffic accidents, and 12 (11.2%) from sepsis. In multivariable analysis, older age (40-59 years; P = .001), injecting drugs (P = .03), and injecting midazolam (P < .001) were associated with death. The standardized mortality ratio was 2.9.

CONCLUSIONS

People who injected drugs were nearly 3 times as likely to die as were those in the general population of Bangkok and injecting midazolam was independently associated with death. Drug overdose and traffic accidents were the most common causes of death, and their prevention should be public health priorities.

Examining non-AIDS mortality among people who inject drugs

Objective:

To systematically review and analyse data from cohorts of people who inject drugs (PWID) to improve existing estimates of non-AIDS mortality used to calculate mortality among PWID in the Spectrum Estimates and Projection Package.

Design:

Systematic review and meta-analysis.

Methods:

We conducted an update of an earlier systematic review of mortality among PWID, searching specifically for studies providing data on non-AIDS-related deaths. Random-effects meta-analyses were performed to derive pooled estimates of non-AIDS crude mortality rates across cohorts disaggregated by sex, HIV status and periods in and out of opioid substitution therapy (OST). Within each cohort, ratios of non-AIDS CMRs were calculated and then pooled across studies for the following paired sub-groups: HIV-negative versus HIV-positive PWID; male versus female PWID; periods in OST versus out of OST. For each analysis, pooled estimates by country income group and by geographic region were also calculated.

Results:

Thirty-seven eligible studies from high-income countries and five from low and middle-income countries were found. Non-AIDS mortality was significantly higher in low and middle-income countries [2.74 per 100 person-years; 95% confidence interval (CI) 1.76–3.72] than in high-income countries (1.56 per 100 person-years; 95% CI 1.38–1.74). Non-AIDS CMRs were 1.34 times greater among men than women (95% CI 1.14–1.57; N = 19 studies); 1.50 times greater among HIV-positive than HIV-negative PWID (95% CI 1.15, 1.96; N = 16 studies); and more than three times greater during periods out of OST than for periods on OST (N = 7 studies).

Conclusions:

A comprehensive response to injecting drug must include efforts to reduce the high levels of non-AIDS mortality among PWID. Due to limitations of currently available data, including substantial heterogeneity between studies, estimates of non-AIDS mortality specific to geographic regions, country income level, or the availability of OST should be interpreted with caution.

Mortality among people who inject drugs: a systematic review and meta-analysis

OBJECTIVE

To systematically review cohort studies of mortality among people who inject drugs, examine mortality rates and causes of death in this group, and identify participant- and study-level variables associated with a higher risk of death.

METHODS

Tailored search strings were used to search EMBASE, Medline and PsycINFO. The grey literature was identified through online grey literature databases. Experts were consulted to obtain additional studies and data. Random effects meta-analyses were performed to estimate pooled crude mortality rates (CMRs) and standardized mortality ratios (SMRs).

FINDINGS

Sixty-seven cohorts of people who inject drugs were identified, 14 of them from low- and middle-income countries. The pooled CMR was 2.35 deaths per 100 person-years (95% confidence interval, CI: 2.12-2.58). SMRs were reported for 32 cohorts; the pooled SMR was 14.68 (95% CI: 13.01-16.35). Comparison of CMRs and the calculation of CMR ratios revealed mortality to be higher in low- and middle-income country cohorts, males and people who injected drugs that were positive for human immunodeficiency virus (HIV). It was also higher during off-treatment periods. Drug overdose and acquired immunodeficiency syndrome (AIDS) were the primary causes of death across cohorts.

CONCLUSION

Compared with the general population, people who inject drugs have an elevated risk of death, although mortality rates vary across different settings. Any comprehensive approach to improving health outcomes in this group must include efforts to reduce HIV infection as well as other causes of death, particularly drug overdose.

Risk of fatal overdose during and after specialist drug treatment: the VEdeTTE study, a national multi-site prospective cohort study

BACKGROUND

Specialist drug treatment is critical to overdose prevention; methadone maintenance is effective, but we lack evidence for other modalities. We evaluate the impact of a range of treatments for opiate dependence on overdose mortality.

METHODS

Prospective cohort study of 10,454 heroin users entering treatment 1998-2001 in Italy followed-up for 10,208 person-years in treatment and 2,914 person-years out of treatment. Standardized overall mortality ratios (SMR) estimate excess mortality risk for heroin users in and out of treatment compared to the general population. Cox models compare the hazard ratio (HR) of overdose between heroin users in treatment and out of treatment.

RESULTS

There were 41 overdose deaths, 10 during treatment and 31 out of treatment, generating annual mortality rates of 0.1% and 1.1% and SMRs of 3.9 [95% confidence interval (CI) 2.8-5.4] and 21.4 (16.7-27.4), respectively. Retention in any treatment was protective against overdose mortality (HR 0.09 95% CI 0.04-0.19) compared to the risk of mortality out of treatment, independent of treatment type and potential confounders. The risk of a fatal overdose was 2.3% in the month immediately after treatment and 0.77% in the subsequent period; compared to the risk of overdose during treatment the HR was 26.6 (95% CI 11.6-61.1) in the month immediately following treatment and 7.3 (3.3-16.2) in the subsequent period.

CONCLUSIONS

We demonstrate that a range of treatments for heroin dependence reduces overdose mortality risk. However, the considerable excess mortality risk in the month following treatment indicates the need for greater health education of drug users and implementation of relapse and overdose death prevention programmes. Further investigation is needed to measure and weigh the potential benefits and harms of short-term therapies for opiate use.

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.

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.

Characterization of methadone overdose: clinical considerations and the scientific evidence

Overdosing with methadone is a growing phenomenon in Britain and other countries due to the increase in prescription and the availability of this compound. Little is known of the circumstances surrounding methadone death due to some extent to the difficulty of defining drug-related death and also the difficulty of collecting clinical and biographical data in a predominantly illegal and marginal milieu. However, the evidence points to highest risk at night (to this end manifestations of its toxicity often go unrecognized) in those whose usual tolerance has been reduced and occurring some considerable time after ingestion. Further investigations are needed to elucidate fully the mechanism and spectrum of methadone overdose. Death from methadone is eminently preventable more so because of the long-term nature of the clinical sequelae. Indeed the key issue with methadone that sets it apart from other opioids is its potential for delayed toxicity. Consequently steps should be taken to disseminate the salient facts to all those who come into contact with the drug.

Mortality of opiate users in Vienna, Austria

The purpose of this study was to investigate whether there are differences in overall and cause-specific mortality rates of opiate users in maintenance treatment and of opiate users not in any drug treatment program in Vienna, Austria. A cohort of opiate-users enrolled in maintenance treatment in Vienna and a cohort of individuals involved in opiate-related emergencies from 1995 to 1997 were retrospectively analyzed. The standardized mortality rate of opiate-users enrolled in maintenance treatment was 12.1 and that of individuals involved in opiate-related emergencies was 48.8. Excess mortality was found for all categories for both groups. In the face of the extremely high excess mortality of opiate users involved in opiate-related emergencies, measures have to be taken to get these individuals in drug treatment programs as soon as possible.

The past incidence of hepatitis C virus infection: implications for the future burden of chronic liver disease in the United States

Because chronic liver disease may develop many years after acute hepatitis C virus (HCV) infection, the past incidence of acute infections is a major determinant of the future burden of HCV-associated complications. We estimated past incidence of acute HCV infection using national seroprevalence data and relative age-specific incidence data from a sentinel counties surveillance system. Projections of the future prevalence of HCV-infected patients were derived from models that included an 85% drop in HCV infection incidence as observed for reported cases in the early 1990s. The models showed a large increase in the incidence of HCV infections from the late 1960s to the early 1980s. The degree of increase was dependent on the assumed rate of antibody loss; a model with 2.5% annual antibody loss showed annual incidence increasing from 45,000 infections (95% confidence interval [95% CI]: 0-110,000) in the early 1960s to 380,000 infections (95% CI: 250,000 to 500, 000) in the 1980s. Projections showed that although the prevalence of HCV infection may be declining currently because of the decline in incidence in the 1990s, the number of persons infected for >/=20 years could increase substantially before peaking in 2015. If the incidence of new HCV infections does not increase in the future, persons born between 1940 and 1965 will be at highest lifetime risk of acquiring the infection.

"Drug dependence" and death: survival analysis of the Baltimore ECA sample from 1981 to 1995

AIMS

Illicit drug use and dependence often are associated with premature death, but available evidence comes mainly from clinical samples. The present paper examines drug-related mortality experience over 14 years in a United States community sample.

PARTICIPANTS

Following probability sampling, 3,481 adult community household residents were recruited for the 1981 NIMH Baltimore Epidemiologic Catchment Area survey. Follow-up occurred in 1993-1996.

METHODS

Survival analyses were used to estimate median age at death and relative risk of dying in relation to drug use and dependence as assessed in 1981 using the Diagnostic Interview Schedule (DIS).

FINDINGS

Cases with DIS "drug dependence" were more likely to have died and to have a younger median age at death (p < .05), with and without statistical adjustment for confounding variables. Higher levels of drug involvement also were associated with increased age-adjusted mortality.

CONCLUSIONS

The evidence favors the hypothesis that DIS-elicited "drug dependence," as well as subthreshold drug use, help to account for premature death in this community sample.

One-year mortality rates following methadone treatment discharge

OBJECTIVES

Mortality among 507 patients in a methadone program over a 1-year period was assessed.

METHODS

Mortality was determined for patients in treatment (n = 397), and 12 months later for those discharged (n = 110).

RESULTS

Of discharged patients, 8.2% (9/110) had died, of which six were caused by heroin overdose. None of the discharged clients were in treatment at the time of death. All deaths were among clients who either dropped out of treatment or were discharged unfavorably from the program. Comparatively, only 1% (4/397) of patients died while enrolled in treatment.

CONCLUSION

Death rates, especially overdose, are high among patients who are unfavorably discharged or drop out of methadone treatment. Efforts should be made to retain these at-risk patients in methadone treatment even though treatment response may be suboptimal.

Methadone maintenance and addicts' risk of fatal heroin overdose

An admission cohort of 296 Australian methadone maintenance patients was followed over 15 years. The relative risks of death in and out of maintenance were calculated for two age groups, 20-29 and 30-39 years. Heroin addicts in both age groups were one-quarter as likely to die while receiving methadone maintenance as addicts not in treatment. This is because they were significantly less likely to die by heroin overdose or suicide while in maintenance. Methadone maintenance had no measurable effect on the risk of death through nonheroin overdose, violence or trauma, or natural causes. A meta-analysis showed the reduction in overall mortality was consistent with the results of cohort studies conducted in the United States, Sweden, and Germany. The combined results of the five studies again indicated that methadone maintenance reduced addicts' risk of death to a quarter, RR 0.25 (95% CI 0.19 to 0.33).