Mortality in a cohort of opiate and amphetamine users in Perth, Western Australia

Mortality, morbidity, and predictors of death among amphetamine-type stimulant users - a longitudinal, nationwide register study

Introduction

Use of amphetamine-type stimulants (ATS) contributes substantially to the global burden of disease. Large-scale follow-up studies of morbidity and mortality in ATS users are few. This study analysed morbidity, mortality, and potential predictors of all-cause mortality in a nationwide cohort of patients with ATS use disorder.

Methods

Data was acquired from national Swedish registers. All Swedish residents 18 years or older, with a registered ATS use diagnosis in 2013-2014 were included (N = 5,018) and followed until December 31, 2017. Comorbid diagnoses and causes of death were assessed and potential predictors of all-cause mortality were examined through Cox regression.

Results

Median age at inclusion was 36.6 years (interquartile range 27.4---48.1) and 70.5 % were men. The crude mortality rate was 24.6 per 1,000 person-years. The adjusted all-cause standardized mortality ratio was 12.4 (95 % CI [11.34-13.55]). The most common cause of death was overdose (28.9 %). Multiple drug use (hazard ratio 1.39, 95 % CI [1.14-1.70], p = 0.004), anxiety (hazard ratio 1.39, 95 % CI [1.11-1.72], p = 0.014), viral hepatitis (hazard ratio 1.85, 95 % CI [1.50-2.29], p = 0.004), and liver disease (hazard ratio 2.41, 95 % CI [1.55-3.74], p = 0.004) were predictors of all-cause mortality.

Conclusions

Multiple drug use, anxiety disorders, viral hepatitis and liver diseases were identified as risk factors for death. Our findings call for better screening, prevention, and treatment of somatic and psychiatric comorbidity among ATS users to reduce mortality.

No decline in drug overdose deaths in Norway: An ecological approach to understanding at-risk groups and the impact of interventions

Aim: This Norwegian case study examines groups at risk of drug overdose deaths, evidence-based harm reduction interventions, low-threshold services and treatment implemented, as well as trends in drug overdose deaths between 2010 and 2021. We aimed to explore the relevance of interventions for at-risk groups and discuss their potential impact on drug overdose trends. Method/data: Using an ecological approach, we analysed the following: (1) groups identified through latent profile analysis (LPA) among a sample of 413 high-risk drug users collected in 2010-2012, supplemented with other relevant studies up to 2021; (2) published information on harm-reduction interventions, low-threshold services and treatment in Norway; and (3) nationwide drug overdose mortality figures supplemented with published articles on the topic. Results: High-risk drug users in 2010-2012 commonly engaged in frequent illegal drug use, injecting and poly-drug use (including pharmaceutical opioids), which continued into following decade. The interventions implemented between 2010 and 2021 were relevant for at-risk groups identified in the surveys. However, there was no decrease in the trend of drug overdose deaths up to 2021. While relevant interventions may have mitigated a theoretical increase in mortality, new at-risk groups may have contributed to fatal outcomes associated with pharmaceutical opioids. Conclusion: The interventions were relevant to the risk groups identified among high-risk drug users and potentially effective in preventing an increase in drug overdose trends. However, tailored interventions are needed for individuals at risk of death from prescribed opioids. Comprehensive studies encompassing all at-risk populations, including both legal and non-medical users of prescription opioids, are needed.

Factors associated with suicide in people who use drugs: a scoping review

BACKGROUND

Suicide is a significant contributor to global mortality. People who use drugs (PWUD) are at increased risk of death by suicide relative to the general population, but there is a lack of information on associated candidate factors for suicide in this group. The aim of this study was to provide a comprehensive overview of existing evidence on potential factors for death by suicide in PWUD.

METHODS

A scoping review was conducted according to the Arksey and O'Malley framework. Articles were identified using Medline, CINAHL, PsycINFO, SOCIndex, the Cochrane Database of Systematic Reviews and the Campbell Collaboration Database of Systematic Reviews; supplemented by grey literature, technical reports, and consultation with experts. No limitations were placed on study design. Publications in English from January 2000 to December 2021 were included. Two reviewers independently screened full-text publications for inclusion. Extracted data were collated using tables and accompanying narrative descriptive summaries. The review was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines.

RESULTS

The initial search identified 12,389 individual publications, of which 53 met the inclusion criteria. The majority (87%) of included publications were primary research, with an uncontrolled, retrospective study design. The most common data sources were drug treatment databases or national death indexes. Eleven potential factors associated with death by suicide among PWUD were identified: sex; mental health conditions; periods of heightened vulnerability; age profile; use of stimulants, cannabis, or new psychoactive substances; specific medical conditions; lack of dual diagnosis service provision; homelessness; incarceration; intravenous drug use; and race or ethnicity. Opioids, followed by cannabis and stimulant drugs were the most prevalent drugs of use in PWUD who died by suicide. A large proportion of evidence was related to opioid use; therefore, more primary research on suicide and explicit risk factors is required.

CONCLUSIONS

The majority of studies exploring factors associated with death by suicide among PWUD involved descriptive epidemiological data, with limited in-depth analyses of explicit risk factors. To prevent suicide in PWUD, it is important to consider potential risk factors and type of drug use, and to tailor policies and practices accordingly.

Neonatal Outcomes of Infants Born to Pregnant Women With Substance Use Disorders: A Multilevel Analysis of Linked Data

OBJECTIVE

This study examines the associations of substance use disorders in pregnancy with a set of neonatal outcomes.

METHODS

This is a quantitative retrospective study. Three linked datasets of a 10-year period (2007-2016) from New South Wales, Australia, were examined. Pregnant women were identified positive for substance use disorders when at least one hospital admission during pregnancy or delivery had opioid-, or cannabis-, or stimulant-, or alcohol- or two or more of the four substance groups- related ICD-10-AM diagnostic code. As there was a hierarchical structure in the dataset, the adjusted odds ratio (AOR) was estimated using multilevel logistic regression.

FINDINGS

Of the 622,640 birth records, 1677 (0.27%) women had opioid-related, 1857 (0.30%) had cannabis-related, 552 (0.09%) had stimulant-related, 595 (0.10%) had alcohol-related and 591 (0.09%) had polysubstance-related ICD-10-AM diagnostic codes. There were significant relationships between opioid use in pregnancy and neonatal health outcomes including preterm birth (AOR 3.2; 95% CI 2.8, 3.7) and admission to the neonatal intensive care unit (NICU) (AOR 10.0; 95% CI 8.8, 11.3). Substance use disorders due to cannabis, stimulants, alcohol or polysubstance were significantly associated with preterm birth, low birthweight, low APGAR score and admission to NICU. Also, alcohol and polysubstance use disorders in pregnancy were found to be significantly associated with stillbirth.

CONCLUSION

Results demonstrate that substance use disorders in pregnancy are associated with an increased risk of adverse neonatal outcomes. Early identification of substance use disorders through screening and adherence to pharmacotherapy and other psychosocial interventions could improve neonatal outcomes.

Linking Ambulance Trip and Emergency Department Surveillance Data on Opioid-Related Overdose, Massachusetts, 2017

OBJECTIVES

Studies describing linkage of ambulance trips and emergency department (ED) visits of patients with opioid-related overdose (ORO) are limited. We linked records of patients experiencing ORO from ambulance trip and ED visit records in Massachusetts during April 1-June 30, 2017.

METHODS

We estimated the positive predictive value of ORO-capturing definitions by examining the narratives and triage notes of a sample of OROs from each data source. Because of a lack of common unique identifiers, we deterministically linked OROs to records in the counter data set on date of birth, incident date, facility, and sex. To validate the linkage strategy, we compared ambulance trip narratives with ED triage notes and chief complaints for a sample of pairs.

RESULTS

Of 3203 ambulance trips for ORO and 3046 ED visits for ORO, 82% and 63%, respectively, matched a record in the counter data set on date of birth, incident date, facility, and sex. In 200 randomly selected linked pairs from a final linked data set of 3006 paired records, only 5 (3%) appeared to be false matches.

PRACTICE IMPLICATIONS

This exercise demonstrated the feasibility of linking ORO records between 2 data sets without a unique identifier. Future analyses of the linked data could produce insights not available from analyzing either data set alone. Linkage using 2 rapidly available data sets can actively inform the state's public health opioid overdose response and allow for de-duplicating counts of OROs treated by ambulance, in an ED, or both.

Mortality among young people seeking residential treatment for problematic drug and alcohol use: A data linkage study

BACKGROUND

Young people with problematic alcohol and other drug (AOD) use are often referred to residential treatment. Subsequent mortality rates among this high-risk group is not known. This study estimates mortality rates and determines causes of death amongst young people referred to residential treatment in Sydney, Australia.

DESIGN

Retrospective data linkage study. Data of young people (13-18 years) referred to a residential treatment service 2001-2015 (n = 3256) linked with Australian death registration data, and followed up to 16 years (2001-2016).

METHODS

Mortality rates (CMRs) and standardised mortality ratios (SMRs, age-, gender-, calendar-year-adjusted) calculated using population mortality rates. Causes of death were analysed using ICD-10 codes for AOD-induced, AOD as contributory and non-AOD related causes.

RESULTS

During follow-up of the cohort (28,838 person-years), 63 people died (71.4 % males; 48 % Indigenous; median age at death = 21.9 years; median follow-up = 5.1years), with 76 % dying before aged 25 years. Overall mortality (SMR = 4.91, 95 % CI: 3.8-6.2; CMR = 2.18/1000 person-years, 95 % CI: 1.7-2.8) was significantly higher than age-gender-matched general population, particularly in females (SMR = 9.55; males: SMR = 4.11; RR: 2.3, 95 % CI: 1.3-4.1). SMRs were not significantly different between treatment groups (SMRs>5.5) and non-attend group (SMR = 3.7) (p = 0.359). Two-thirds of deaths involved AOD, with AOD-induced deaths comprising 42 % and AOD as contributory for 22 % deaths. Overdose, mainly opioids (including opiates), suicide, and transport accidents were major causes of deaths.

CONCLUSION

Very high mortality rates, particularly among females, and the high incidence of overdose and suicide emphasise early screening for those at high-risk, targeted and culturally appropriate interventions, and maximised continuing after-care accessible to young people.

Big data and predictive modelling for the opioid crisis: existing research and future potential

A need exists to accurately estimate overdose risk and improve understanding of how to deliver treatments and interventions in people with opioid use disorder in a way that reduces such risk. We consider opportunities for predictive analytics and routinely collected administrative data to evaluate how overdose could be reduced among people with opioid use disorder. Specifically, we summarise global trends in opioid use and overdoses; describe the use of big data in research into opioid overdose; consider the potential for predictive modelling, including machine learning, for prevention and monitoring of opioid overdoses; and outline the challenges and risks relating to the use of big data and machine learning in reducing harms that are related to opioid use. Future research for improving the coverage and provision of existing interventions, treatments, and resources for opioid use disorder requires collaboration of multiple agencies. Predictive modelling could transport the concept of stratified medicine to public health through novel methods, such as predictive modelling and emulated trials for evaluating diagnoses and prognoses of opioid use disorder, predicting treatment response, and providing targeted treatment recommendations.

Health literacy and changes in pattern of drug use among participants at the Stockholm Needle Exchange Program during the COVID-19 pandemic

Background and aims

People who inject drugs may be particularly vulnerable to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to underlying health problems, stigma and social vulnerabilities. Harm reduction services, including needle exchange programs (NEP), have been subjected to varying degrees of disruption in the world, especially in the beginning of the coronavirus disease 2019 (COVID-19) pandemic. Compared to responses in other countries, Sweden’s initial strategy toward limiting the spread and impact of COVID-19 was less restrictive to its citizens with no imposed general societal lockdown. In this study, we investigate changes in drug use patterns, utilization of NEP associated health services, COVID-19 health literacy and the prevalence of SARS-CoV-2 antibodies among NEP clients in Stockholm during the COVID-19 pandemic.

Methods

NEP visits and services provided (needles/syringes, HIV and hepatitis C tests and treatment, naloxone distributed) and overall mortality among NEP clients between January 1 and October 31, 2020, were used for trend analyses in comparison with corresponding 2019 data. Between July 27 and October 2, 2020, NEP clients (n = 232) responded to a 27 item COVID-19 Health Literacy Questionnaire. SARS CoV-2 IgG antibody tests (n = 779) were performed between June 15 and October 31, 2020.

Results

During the COVID-19 pandemic number of clients, client visits, naloxone distribution and HCV tests remained stable compared to 2019, while distribution of needles/syringes increased (p < 0.0001); number of HIV tests and HCV treatments decreased (p < 0.05); and mortality decreased (< 0.01). Overall, the level of health literacy concerning transmission routes and protective measures was high. SARS-CoV-2 antibody prevalence was 5.4% (95% CI 4.0–7.2).

Conclusions

The Stockholm NEP managed to maintain a high level of clients and services during the pandemic. In general, COVID-19 health literacy was adequate and the overall SARS-CoV-2 antibody prevalence was low compared to the general population, which highlights a need for prioritized and targeted COVID-19 vaccination among PWID.

Prevalence and correlates of multiple non-fatal opioid overdoses among people who inject drugs who utilise needle syringe programs in Australia

BACKGROUND

Non-fatal overdose (NFOD) is a major cause of morbidity among people who inject drugs (PWID) and multiple NFOD is associated with increased risk of fatal overdose. Despite this, few studies have examined the prevalence and correlates of drug-specific multiple NFOD. The current study aimed to determine the prevalence and correlates of recent multiple non-fatal opioid overdose (NFOOD) among PWID who access needle syringe programs (NSPs) in Australia.

METHODS

The Australian Needle and Syringe Program Survey is conducted annually and was conducted at 46 sites across Australia in 2019. Participation involves completion of a self-administered questionnaire and a capillary dried blood spot for HIV and hepatitis C virus testing. In 2019, respondents who reported a minimum of one NFOOD in the previous 12 months (recent NFOOD) were asked to complete supplementary questions regarding their last NFOOD. Bivariate and multivariate logistic regression were used to determine factors independently associated with multiple recent NFOOD.

RESULTS

A total of 222 respondents reported recent NFOOD. Respondents were predominantly male (59%), one third (39%) were aged less than 39 years and 73% reported last injecting heroin at their last NFOOD. One in two respondents (48%, n = 107) reported multiple opioid overdoses (median 3, interquartile range 2-5). The odds of reporting multiple NFOOD were higher among respondents who reported injecting in a public location at their last NFOOD (adjusted odds ratio [AOR] 2.10, 95% CI 1.14-3.90, p = 0.018) and benzodiazepine use in the 12 h prior to NFOOD (AOR 2.74, 95% CI 1.50-4.99, p = 0.001).

CONCLUSIONS

Multiple NFOOD was prevalent among PWID who utilised NSPs who reported recent NFOOD. Public injecting and benzodiazepine use were associated with increased risk of multiple NFOOD, and there is a need for interventions specifically targeting PWID who report these high risk injecting practices.

Injecting Alone is More Common among Men, Frequent Injectors and Polysubstance Users in a Sample of People Who Inject Drugs

Injecting alone increases the risk of a fatal overdose. We examined the extent of such behavior in a sample of people who inject drugs (PWID) and the typical characteristics of those injecting alone at least once during the past four weeks. A cross-sectional study. PWID recruited from the street and from low-threshold services in seven Norwegian cities in September 2017 (n = 359). Associations between characteristics and injecting alone were examined using logistic regression analysis. The independent variables were gender (female/male), age, having received overdose-prevention education (no/yes), and, in the past four weeks; homelessness/shelter use (no/yes), in opioid substitution treatment (no/yes), injecting ≥ four days a week (no/yes), and substances injected (opioids only/opioids and other/other only/central stimulants (CS) only/CS and other/CS and opioids/CS, opioids and other). The adjusted odds ratios (aOR) and 95% Confidence Intervals (CI) were reported. Of the 359 PWID, 84.4% reported having injected alone. Males were more likely than females to inject alone (aOR = 1.88 95% CI 1.00-3.54). Furthermore, those injecting frequently (aOR = 1.99 95% CI 1.02-3.86) and those injecting multiple substances (CS, opioids and other) (aOR = 2.94 95% CI 1.01-8.58) were more likely to inject alone compared to those injecting less frequently and opioids only. Although not statistically significant, the effect sizes in the logistic regression models suggest that polysubstance use may be driven by CS use. Injecting alone was common in our sample of PWID, and male gender, frequent injecting and polysubstance injecting were associated with this behavior.

Non -fatal overdose among people who inject drugs in Tehran, Iran

BACKGROUND

With increasing frequencies of non-fatal overdose in people who inject drugs (PWID), it is essential to improve our knowledge about associated risk factors for overdose to inform overdose prevention and assistance programs. The aim of present study was to determine the prevalence of non-fatal overdose and the associated risk factors among PWID in Tehran, Iran.

METHODS

Snowball sampling was used to collect data from 465 participants in Tehran using a cross-sectional survey. Consenting participants who reported drug injecting in the past month and were able to speak and comprehend Farsi enough to respond to survey questions were interviewed. The endpoint of interest was non-fatal overdose in the previous 6 months, or answering "Yes" to the question: "In the last six months, have you ever overdosed by accident? (at least once)". We used STATA v. 14 for this analysis. Statistical significance was defined as p < 0.05 for all analyses.

RESULTS

Of 465 PWIDs who participated in this study, all were male, and about half had less than a high school education. The prevalence of self-reported non-fatal overdose in the past 6 months was 38% (CI95%: 34, 43%). Our findings indicate that characteristics and behaviors that were associated with an increased risk of experiencing an overdose in the past 6 months were drug use initiation under 22 years (AOR =2.2, P < 0.05), using methamphetamine (AOR =2.8, P < 0.05), and using multiple drugs at the same time (AOR =2.1, P < 0.05). Also, more recent initiates to injecting (< 2 years) had an increased risk of experiencing an overdose in the past 6 months. The odds of experiencing a non-fatal overdose among PWIDs who regularly attended NSP were 0.6 times less than for those who did not attend regularly (OR = 0.6,95% CI: 0.2-0.9).

CONCLUSION

Methamphetamine and alcohol use were the most significant association for non-fatal overdose among PWIDs. Our results indicate that intervention and prevention initiatives seeking to reduce overdoses among PWIDs should not only be focused on the primary drug used but also the use of alcohol and poly-drug use.

Mortality among people with regular or problematic use of amphetamines: a systematic review and meta-analysis

BACKGROUND AND AIMS

Amphetamines are the second most commonly used class of illicit drugs. We aimed to produce pooled estimates of mortality risks among people with regular or dependent use of amphetamines, with a focus upon all-cause mortality as well as specific causes of death.

DESIGN

Systematic review and meta-analysis of cohorts of people with problematic use or dependence on amphetamines with data on all-cause or cause-specific mortality.

SETTING AND PARTICIPANTS

Of 4240 papers, 30 were eligible, reporting on 25 cohorts that measured all-cause mortality, drug poisoning, suicide, accidental injuries, homicide and cardiovascular mortality. Cohorts (n = 35-74 139) were in North America, several Nordic countries and Asia Pacific.

MEASUREMENT

Titles/abstracts were independently screened by one reviewer and excluded those reviewed by a second reviewer. Full-text screening was by two reviewers with discrepancies resolved via a third reviewer. We extracted data on crude mortality rates (CMR) per 100 person-years (py), standardized mortality ratios (SMRs). We imputed SMRs where possible if not reported by study authors. We also calculated mortality relative risks. Data were pooled using random-effects models; potential reasons for heterogeneity were explored using subgroup analyses and meta-regressions.

FINDINGS

Twenty-three cohorts contributed data for the pooled all-cause CMR: 1.14 per 100 py [95% confidence interval (CI) = 0.92-1.42]. Pooled cause-specific mortality rates were: drug poisoning, 0.14 per 100 py (95% CI = 0.06-0.34); cardiovascular disease, 0.13 per 100 py (95% CI = 0.06-0.29); suicide, 0.20 per 100 py (95% CI = 0.07-0.55); accidental injury, 0.20 per 100 py (95% CI = 0.08-0.47) and homicide, 0.03 per 100 py (95% CI = 0.02-0.06). There was substantial heterogeneity for all pooled CMR estimates except homicide. The pooled all-cause SMR was 6.83 (95% CI = 5.27-8.84). Pooled cause-specific SMRS were: poisoning, 24.70 (95% CI = 16.67, 36.58); homicide, 11.90 (95% CI = 7.82-18.12); suicide, 12.20 (95% CI = 4.89-30.47); cardiovascular disease, 5.12 (95% CI = 3.74-7.00) and accidental injury, 5.12 (95% CI = 2.88-9.08).

CONCLUSIONS

People with regular or dependent amphetamine use are at elevated risk of a range of causes of mortality compared with people without regular or dependent amphetamine use.

Prediction of psychiatric comorbidity on premature death in a cohort of patients with substance use disorders: a 42-year follow-up

BACKGROUND

We need to better understand how the use of different substances and psychiatric comorbidity influence premature death generally and cause-specific death by overdose, intoxication and somatic disorders in people with substance use disorders.

METHOD

A cohort of 1405 patients consecutively admitted to a Swedish detoxification unit for substance use disorders in 1970-1995 was followed-up for 42 years. Substances were identified by toxicological analyses. Mortality figures were obtained from a national registry. Causes of death were diagnosed by forensic autopsy in 594 patients deceased by 2012. Predictions were calculated by competing risks analysis.

RESULTS

Forty-two per cent of the cohort died during follow-up; more men than women (46.3% vs 30.4%). The standardised mortality ratio (SMR) was calculated as the ratio of observed deaths in males and females in specific age groups in the cohort versus expected deaths in corresponding groups in the general population. SMR was 5.68 for men (CI 95%; 5.04-6.11) and 4.98 (CI 95%; 4.08-5.88) for women. The crude mortality rate (number of deaths divided by number of person observation years) was 2.28% for men and 1.87% for women. Opiates predicted increased risk of premature death while amphetamine and cannabis predicted lower risk. Comorbid psychiatric disorders were identified in 378 cases and personality disorders in 763 cases. Primary psychoses or mood/depression and anxiety disorders predicted a higher risk of premature mortality. Death by overdose was predicted by male gender, younger age at admission to substance treatment, opiate use, and comorbid depression and anxiety syndromes. Cannabis and amphetamine use predicted a lower risk of overdose. Death by intoxication was predicted by male gender, use of sedatives/hypnotics or alcohol/mixed substances, primary psychoses and depression/anxiety syndromes. Premature death by somatic disorder was predicted by male gender and alcohol/mixed abuse.

CONCLUSION

Psychiatric comorbid disorders were important risk factors for premature drug-related death. Early identification of these factors may be life-saving in the treatment of patients with substance use disorders.

Completed Suicide Among Methamphetamine Users: A National Study

All Australian cases of methamphetamine-related suicide (2009-2015) retrieved from the National Coronial Information System were examined to determine crude mortality rates, characteristics and circumstances of death, and blood toxicology. There were 300 cases, 18.2% of all methamphetamine-related deaths, and 1.6% of all completed suicides. The mean age was 33.1 years, and 77.0% were male. The crude mortality rate was 1.9 per 10⁶ , with males having a significantly higher rate than females (2.9 vs. 0.9 per 10⁶ ). A quarter were known to have previous suicide attempts, and a history of psychosis was noted in 12.3%. In 40.7% of cases, witnesses described the decedent as having been agitated and/or aggressive immediately prior to the incident. The vast majority (85.3%), and of both sexes (males 87.0%, females 79.7%), used violent methods. Hanging (70.3%) was overwhelmingly the most frequent method among both males (70.1%) and females (71.0%). Prescription medications were frequently present: hypnosedatives (23.6%), antidepressants (19.5%), and antipsychotics (8.4%). Self-poisoning cases were significantly more likely to have antidepressants (odds ratio: 4.2) and opioids (4.9) present, but less likely to have cannabis (0.3). Methamphetamine-related suicide makes a large contribution to methamphetamine-related death and represents a substantial clinical and public health problem.

Naloxone distribution and possession following a large-scale naloxone programme

AIMS

To examine uptake following a large-scale naloxone programme by estimating distribution rates since programme initiation and the proportion among a sample of high-risk individuals who had attended naloxone training, currently possessed or had used naloxone. We also estimated the likelihood of naloxone possession and use as a function of programme duration, individual descriptive and substance use indicators.

DESIGN

(1) Distribution data (June 2014-August 2017) and date of implementation for each city and (2) a cross-sectional study among a sample of illicit substance users interviewed September 2017.

SETTING

Seven Norwegian cities.

PARTICIPANTS

A total of 497 recruited users of illegal opioids and/or central stimulants.

MEASUREMENTS

Primary outcomes: naloxone possession and use. Random-intercepts logistic regression models (covariates: male, age, homelessness/shelter use, overdose, incarceration, opioid maintenance treatment, income sources, substance use indicators, programme duration).

FINDINGS

Overall, 4631 naloxone nasal sprays were distributed in the two pilot cities, with a cumulative rate of 495 per 100 000 population. In the same two cities, among high-risk individuals, 44% and 62% reported current naloxone possession. The possession rates of naloxone corresponded well to the duration of each participating city's distribution programme. Overall, in the six distributing cities, 58% reported naloxone training, 43% current possession and 15% naloxone use. The significant indicators for possession were programme duration [adjusted odds ratios (aOR) = 1.44, 95% confidence interval (CI = 0.82-2.37], female gender (aOR = 1.97, 95% CI = 1.20-3.24) and drug-dealing (aOR = 2.36, 95% CI = 1.42-3.93). The significant indicators for naloxone use were programme duration (aOR = 1.49 95%, CI = 1.15-1.92), homelessness/shelter use (aOR = 2.06, 95% CI = 1.02-4.17), opioid maintenance treatment (OMT) (aOR = 2.07, 95% CI = 1.13-3.78), drug-dealing (aOR = 2.40, 95% CI = 1.27-4.54) and heroin injecting (aOR = 2.13, 95% CI = 1.04-4.38).

CONCLUSIONS

A large-scale naloxone programme in seven Norwegian cities with a cumulative distribution rate of 495 per 100 000 population indicated good saturation in a sample of high-risk individuals, with programme duration in each city as an important indicator for naloxone possession and use.

Mortality and Cause of Death-A 30-Year Follow-Up of Substance Misusers in Sweden

BACKGROUND

This article presents a 30-year follow-up study of a cohort of 1163 substance misusers who were in inpatient treatment in the early 1980s. Data was originally collected in the Swedish Drug Addict Treatment Evaluation (SWEDATE).

OBJECTIVES

The aim is to examine the overall mortality and identify causes of death in different groups based on self-reported most dominant substance misuse among those who have died during January 1984-December 2013.

METHODS

SWEDATE-data was linked to the National Cause of Death Register. Five mutually exclusive study groups were created based on self-reported most dominant substance misuse for the last 12 months before intake to treatment: Alcohol, Cannabis, Stimulants, Opiates, and Other. The Standardized Mortality Ratio (SMR) was calculated.

RESULTS

During the follow-up, 40% died. SMR is 10.3 for women and 11.7 for men. The study groups differed regarding SMR; 13.1 in the Alcohol group, 9.2 in the Cannabis group, 9.6 in the Stimulants group, 16.7 in the Opiates group and 10.8 in the Other group. Drug related death was the most common cause of death (28% only underlying, 19% both underlying and contributing) followed by alcohol related reasons (17% vs. 9%).

CONCLUSIONS

Alcohol misuse among substance abusers might have a negative impact on mortality rates. Methodological changes in how drug related deaths is registered affects the interpretation of the statistics of cause of death. Further analysis on the relation between drug related cause of death and drug misuse related death is needed.

Mortality and causes of death among people who inject amphetamine: A long-term follow-up cohort study from a needle exchange program in Sweden

BACKGROUND

Abuse of amphetamines is a worldwide problem with around 34 million users, and amphetamine is commonly used by people who inject drugs (PWID). Despite this, there is relatively little research on mortality and cause of death among people who use amphetamines primarily. The present study aimed to examine mortality and causes of death among people who inject amphetamine, and compare these results to the general population.

METHODS

This retrospective cohort study was based on data from The Malmö Needle Exchange Program in Sweden (MNEP) and on data from The Swedish National Cause of Death Register. Participants in the MNEP, between 1987 and 2011, with registered national identity number and amphetamine as their primary drug of injection use, were included in the study. Standardized mortality ratios (SMR) was calculated for overall mortality and categories of causes of death.

RESULTS

2019 individuals were included (mean follow-up-time 13.7 years [range 0.02-24.2 years], a total of 27,698 person-years). Of the 448 deceased, 428 had a registered cause of death. The most common causes of death were external causes (n = 162, 38%), followed by diseases of the circulatory system (n = 67, 16%). SMR were significantly elevated (8.3, 95% CI [7.5-9.1]) for the entire study population, and for every category of causes of death respectively.

CONCLUSIONS

People injecting amphetamine as a primary drug were found to have significantly elevated mortality compared with the general population, with high rates of both external and somatic causes of death.

Patterns of substance use and mortality risk in a cohort of 'hard-to-reach' polysubstance users

AIMS

To examine the mortality risk in a cohort of 'hard-to-reach' polysubstance users and its putative associations with substance use. Specifically, we estimated all-cause mortality risk as a function of individual substance use indicators, and then as a function of their complex, 'real-life' patterns as identified through latent class analysis (LCA).

DESIGN

Prospective cohort study among street- and low-threshold service-recruited polysubstance users included between September and November 2013 and followed through the National Cause of Death Registry until 31 October 2015.

SETTING

Seven Norwegian cities.

PARTICIPANTS

A total of 884 users of illegal opioids and/or stimulants. Of these, 357 were in opioid substitution treatment (OST) at the time of inclusion. Forty-four participants died during follow-up.

MEASUREMENTS

Primary outcome: all-cause mortality risk. Unadjusted and adjusted Cox proportional hazard (PH) regression models (covariates: male, age, homelessness/shelter use, overdose experience, OST status, years of injecting, individual substance use indicators, city, use patterns). LCA models estimated separately for those in and those not in OST due to measurement invariance.

FINDINGS

The crude mortality rate was 2.52 per 100 person-years. Standardized mortality ratio was 26.11 [95% confidence interval (CI) = 10.06-54.87] for women and 10.71 (95% CI = 6.39-16.81) for men. No single drug use indicator, such as 'heroin injection' or 'number of drugs used', was associated with the mortality risk. However, meaningful use patterns were identified; three OST and non-OST patterns each. The non-OST patterns 'polysubstance injectors' [hazard ratio (HR) = 3.45, 95% CI = 0.98-12.14] and 'low frequent injectors' (HR = 3.17, CI = 1.05-9.56) were associated significantly with the mortality risk even when adjusted for other known risk factors.

CONCLUSIONS

In a Norwegian prospective cohort study, 'hard-to-reach' polysubstance users had a more than 10 times higher mortality risk than the general population. Mortality risk was not a function of any single drug use indicator, but two distinct combinations of substances, frequencies and routes of administration were associated with the mortality risk.

Effect of ageing and time since first heroin and cocaine use on mortality from external and natural causes in a Spanish cohort of drug users

BACKGROUND

We aimed to assess the effect of ageing and time since first heroin/cocaine use on cause-specific mortality risk and age disparities in excess mortality among heroin (HUs) and cocaine users (CUs) in Spain.

METHODS

A cohort of 15,305 HUs and 11,905 CUs aged 15-49 starting drug treatment during 1997-2007 in Madrid and Barcelona was followed until December 2008. Effects of ageing and time since first heroin/cocaine use were estimated using a competing risk Cox model and the relative and absolute excess mortality compared to the general population through directly age-sex standardized rate ratios (SRRs) and differences (SRDs), respectively.

RESULTS

Mortality risk from natural causes increased with time since first heroin use, whereas that from overdose declined after having peaked in the first quinquennium. Significant effects of time since first cocaine use were not identified, although fatal overdose risk seemed higher in CUs after five years. Mortality risk from natural causes (HUs and CUs), injuries (HUs), and overdoses (CUs) increased with age, the latter without reaching statistical significance. Crude mortality rates from overdoses and injuries remained very high at age 40-59 among both HUs (595 and 217 deaths/100,000 person-years, respectively) and CUs (191 and 88 deaths/100,000 person-years). SRDs from all and natural causes were much higher at age 40-59 than 15-29 in both HUs (2134 vs. 834 deaths/100,000 person-years) and CUs (927 vs. 221 deaths/100,000 person-years), while the opposite occurred with SRRs.

CONCLUSION

The high mortality risk among HUs and CUs at all ages from both external and natural causes, and increased SRDs with ageing, suggest that high-level healthcare and harm reduction services should be established early and maintained throughout the lifetime of these populations.

Mortality Trends among Cocaine Users Treated between 1989 and 2013 in Northern Italy: Results of a Longitudinal Study

A total of 852 participants attending 11 centers for addiction treatment in north Italy following problems due to cocaine abuse between 1989 and 2013 were recruited. Two typologies were created: cocaine users (never heroin) (CU) and heroin and cocaine users (HCU). During the 38-year follow-up period, 4.8% of the whole cohort died. Over the whole period, tumors were the main causes of death; starting in 2010, suicide deaths became the first cause of death. Among CUs, most deaths were due to road accidents and suicide; among HCUs, most of the deaths were from opiate overdose and from cardio-circulatory system diseases. The excess mortality observed for all causes in either sex was 6.24; higher in females (15.03) as compared in males (6.23), higher in HCUs (9.06) as compared in CUs (5.21). The directly age-sex standardized mortality rates were 5.31 per 100, higher for females, declining after 2009 for all patients and after 2004 for HCUs. Multivariate analysis confirms the decreasing trend in the risk of death and shows a higher mortality risk for participants in the under-25 age group. Among cocaine users, special attention should be paid to the prevention of suicide deaths.

Hur gick det för 1960- och 1970-talets svenska narkotikamissbrukare?

What happened to the Swedish problem drug users of the 1960's and 1970's?

AimS & DESIGN

– In this study we follow a Stockholm birth cohort born in 1953 (n= 14 294) from youth to middle age. The cohort members were in their teenage years when drug abuse was established as a considerable threat to Swedish society and some of the cohort members themselves became drug abusers (n=431).

Results

– As expected, life became dramatically worse for those with documented drug abuse when young, than for the rest of the cohort members. While 72 percent of those without documented drug abuse were socially included at the age of 56, the corresponding share among those with documented drug abuse was 18 per cent. And while 5 percent in the former group were diseased at 56, this was true for 38 percent in the latter group. Supplementary analyses showed that social inclusion was also less stable among those with documented drug abuse than among the rest of the cohort, and that the flow from exclusion to inclusion was virtually nonexistent, which was not the case for those without experience of drug abuse.

Conclusions

– Gender specific analyses showed that the situation, at least in absolute terms, tended to be even worse for male drug abusers than for women. Gender differences in alcohol abuse, criminality, and with respect to parenthood are suggested as possible explanations to be further studied in future research.

Mortality of Hospitalized Drug Users in the Czech Republic

Drug users are generally thought to experience higher mortality rates than those found among the general population. This study analyzes mortality rates among different subgroups of drug users in the Czech Republic. For this project, a retrospective cohort mortality study was conducted. A cohort of 12,207 persons aged 15 to 49 who had been hospitalized for drug related behavioral disorders was followed from 1997 to 2002. The study findings indicate that direct standardized mortality for the cohort of drug users was 16.78 per 1000 person-years (PY); 22.38 for men and 11.18 per 1000 PY for women. After reaching a peak in 1998, mortality rates began to decrease and stabilized around 14 per 1,000 PY from 2000 to 2002. When compared to the rates found in the general population, drug user mortality is eight times higher than nonuser rates (SMR = 8.15; 8.13 for men and 8.22 for women). These mortality rates are highest among polyvalent drug and opiate users and lowest among stimulant users. The authors conclude that the overall mortality of opiate users in the Czech Republic is relatively low when compared with those reported in similar European and non-European studies. There were few overdoses found in the cohort, and in sharp contrast to other available studies, no AIDS related cases were observed.

Death from liver disease in a cohort of injecting opioid users in a Swedish city in relation to registration for opioid substitution therapy

INTRODUCTION AND AIMS

Injecting opioid users are at elevated risk of death. Although liver disease (especially hepatitis C) is common, its impact on mortality is low in active injectors. Because opioid substitution therapy (OST) reduces the risk of death from directly drug related causes, we hypothesised that the proportion of liver-related deaths would increase in subjects receiving OST. We investigated liver-related mortality in a cohort of injecting opioid users attending a needle exchange program (NEP) in a Swedish city in relation to OST exposure.

DESIGN AND METHODS

Participants enrolled in the NEP between 1987 and 2011 with available national identity numbers, and registered use of opioids, were included. Linkage based on national identity numbers was performed with national registers for death, emigration and prescription of OST. Participants were categorised as non-OST recipients until the registered date of first OST prescription, and hence as OST recipients. Hazard ratios were calculated by Cox regression for overall and liver-related mortality in relation to OST, with OST as a time-dependent variable.

RESULTS

Among 4494 NEP participants, 1488 opioid users were identified; 711/1488 had been prescribed OST. During a follow-up period of 15 546 person-years 368 deaths occurred. Sixteen deaths were caused by liver disease; 10 of these occurred in OST recipients. The risk of liver-related death was significantly increased in OST receiving participants (hazard ratio 3.08, 95% confidence interval [1.09, 8.68], P = 0.03).

CONCLUSIONS

Liver related mortality among opioid users was significantly elevated in OST recipients, showing the long-term importance of chronic liver disease in this population. [Jerkeman A, Håkansson A, Rylance R, Wagner P, Alanko Blomé M, Björkman P. Death from liver disease in a cohort of injecting opioid users in a Swedish city in relation to registration for opioid substitution therapy. Drug Alcohol Rev 2017;36:424-431].

Emergency department presentation and mortality rate due to overdose: A retrospective cohort study on nonfatal overdoses

BACKGROUND

The aims of this retrospective cohort study are to describe the presentation characteristics for nonfatal overdose-related complaints at the emergency departments (EDs) of the metropolitan area of Bologna (northern Italy), to estimate the subsequent risk of mortality by overdose, and to identify the profiles of the subjects most at risk.

METHODS

Records of patients admitted to 10 EDs for overdose between January 2004 and December 2012 were retrospectively evaluated. The International Classification of Diseases was used to ascertain the cause of death.

RESULTS

A total of 294 episodes of overdose involving 218 individuals were identified. The total time at risk was 1048 person-years (PY). The mortality rate for all causes was 35.48 per 1000 PY for males and 20.61 per 1000 PY for females. The mortality rate for overdose was 16.6 per 1000 PY for males and 13.74 per 1000 PY for females. In the multivariate regression analysis, the time from first ED overdose access (less than 1 year risk ratio [RR]: 7.07, 95% confidence interval [CI]: 5.32-9.39) was significantly associated with death by overdose. Males, subjects aged >30 years at presentation, patients who refused ED treatment, and those having previously contacted mental health services showed an increased mortality risk due to overdose.

CONCLUSIONS

Experiencing a nonfatal overdose within the past 12 months increases the risk of mortality compared with an overdose more than 12 months earlier. Nonfatal overdose patients presenting to an ED form a specific target for prevention projects.

Non-fatal overdoses and related risk factors among people who inject drugs in St. Petersburg, Russia and Kohtla-Järve, Estonia

Background

This study seeks to identify the prevalence of, and risk factors associated with, non-fatal overdose among people currently injecting drugs (PWID) in St. Petersburg (Russia) and in Kohtla-Järve (Estonia).

Methods

Five hundred eighty-eight study participants in Kohtla-Järve (in 2012) and 811 in St. Petersburg (in 2012–2013) were recruited using respondent driven sampling for interviewing and HIV testing.

Results

Three-quarters (76 %) of the current PWID were male. Participants from St. Petersburg were older (mean age 32.1 vs. 29.6 years, p < 0.0001) and reported a longer average duration of injecting drugs (mean duration: 13.3 vs. 10.9 years, p < 0.0001). Main drugs injected were opioids (fentanyl in Kohtla-Järve, heroin in St Petersburg). HIV prevalence was 63 % (95 % CI 59–67 %) in Kohtla-Järve and 56 % (95 % CI 52–59 %) in St. Petersburg. Two thirds of the PWID in Kohtla-Järve and St. Petersburg reported ever having experienced a drug overdose involving loss of consciousness or stopping breathing. In Kohtla-Järve, 28 % (95 % CI 24–31 %) of participants and, in St Petersburg, 16 % (95 % CI 14–19 %) of participants reported an overdose within the previous 12 months. Characteristics of injection drug use practice (longer duration of injection drug use, main drug injected), correlates of high-risk injection behaviour (higher injecting frequency, sharing), and problem alcohol use were associated with the risk of overdose within the previous 12 months. The significant factors effects did not differ between the sites.

Conclusions

PWID are at high risk for overdose. Effective overdose prevention efforts at the public health scale are therefore warranted.

Are overdoses treated by ambulance services an opportunity for additional interventions? A prospective cohort study

AIMS

To assess whether people who inject drugs (PWID) and who are treated for overdose by ambulance services have a greater mortality risk compared with other PWID, and to compare mortality risk within potentially critical time-periods (1 week, 1 month, 3 months, 6 months, 1 year, 5 years) after an overdose attendance with the mortality risk within potentially non-critical time-periods (time before and/or after critical periods).

DESIGN

A prospective cohort study.

SETTING

Oslo, Norway.

PARTICIPANTS

A total of 172 PWID street-recruited in 1997 and followed-up until the end of 2004.

MEASUREMENTS

Interview data linked to data from ambulance records, Norwegian Correctional Services, Opioid Substitution Treatment records and National Cause of Death Registry. Separate Cox regression models (one for each critical time-period) were estimated.

FINDINGS

Ambulance services treated 54% of the participants for an overdose during follow-up. The mortality rate was 2.8 per 100 person-years for those with an overdose and 3.3 for those without; the adjusted hazard ratio (HR) was 1.3 (95% CI = 0.6, 2.6, P = 0.482). Mortality risk was greater in all but the shortest critical time-period following ambulance attendance than in the non-critical periods. The mortality risk remained significantly elevated during critical periods, even when adjusted for total time spent in prison and substitution treatment. The HR ranged from 9.4 (95% CI = 3.5, 25.4) in the month after an overdose to 13.9 (95% CI = 6.4, 30.2) in the 5-year period.

CONCLUSIONS

Mortality risk among people who inject drugs is significantly greater in time-periods after an overdose attendance than outside these time-periods.

The impact of drug use patterns on mortality among polysubstance users in a Canadian setting: a prospective cohort study

Background

Illicit drug use is a well-established risk factor for morbidity and mortality. However, few studies have examined the impact of different drug use patterns on mortality among polysubstance using populations. This study aimed to identify drug-specific patterns of mortality among a cohort of polysubstance using persons who inject drugs (PWIDs).

Methods

PWIDs in Vancouver, Canada were prospectively followed between May 1996 and December 2011. Participants were linked to the provincial vital statistics database to ascertain mortality rates and causes of death. We used multivariate Cox proportional hazards regression to investigate the relationships between drug use patterns (daily alcohol use, heroin injection and non-injection use, cocaine injection, amphetamine injection and non-injection use, crack smoking and speedball injecting) and time to all-cause mortality.

Results

2330 individuals were followed for a median of 61 months (inter-quartile range: 33 – 112). In total, 466 (19.1%) individuals died for an incidence density of 3.1 (95% confidence interval [CI]: 2.8 – 3.4) deaths per 100 person-years. In multivariate analyses, after adjusting for HIV infection and other potential confounders, only daily cocaine injection remained independently associated with all-cause mortality (adjusted hazard ratio [AHR] = 1.36, 95% CI: 1.06 – 1.76).

Conclusions

Although heroin injecting is traditionally viewed as carrying the highest risk of mortality, in this setting, only daily cocaine injecting was associated with all-cause mortality. These findings highlight the urgent need to identify novel treatments and harm reduction strategies for cocaine injectors.

Gender differences in mortality and risk factors in a 13-year cohort study of street-recruited injecting drug users

BACKGROUND

Injecting drug users (IDUs) are at risk of premature mortality. This study examined gender differences in mortality, risk factors, and causes of death among IDUs.

METHODS

In a 13-year cohort study including 172 street-recruited IDUs from Oslo, Norway in 1997, interview data was merged with the National Cause of Death Registry. Crude mortality rate (CMR) and indirect standardized mortality ratio (SMR) were estimated with 95% confidence intervals (CI). A log-logistic multivariate survival analysis model was estimated for the full sample. For a smaller data set (1.1.1998-31.12.2004) the influence of substitution treatment and prison were assessed using cox regression survival analysis.

RESULTS

Eight females and 37 males died. Acute intoxications were the most common cause of death. Women were more at risk in the short-term, but more protected in the long-term. CMR was 16.0 [95% CI 8.0, 31.9] for women and 26.0 [95% CI 18.0, 35.8]) for men. SMR was 39.4 [95% CI 0.2, 220.8]) for women and 21.3 [95% CI 5.7, 54.1] for men. More women injected heroin (98% vs. 88% [x2 = 3.5, p = 0.063]), used prescription drugs (73% vs. 52% [x2 = 5.6, p = 0.018]) and combined these to inject (45% vs. 26% [x2 = 5.9, p = 0.015]). Mixing prescription drugs in heroin injections, and sex work (only women) were associated with decreased survival time. There were no gender differences in access to substitution treatment, while significantly more men had been in prison (74% vs. 51% [x2 = 7.5, p = 0.006]). The instance of substitution treatment and prison significantly decreased the mortality risk. Prison release increased the risk, but not statistically significantly.

CONCLUSIONS

There were gender differences in mortality and risk factors; sex work and prison were gender specific risk factors. These factors should be investigated further to better design future preventive measures.

Mortality, causes of death and risk factors for death among primary amphetamine users in the Swedish criminal justice system

This study examined mortality and predictors of death in 1,396 primary amphetamine users (85% males) who were interviewed with the Addiction Severity Index in the Swedish criminal justice system during 2000-2006 and followed through 2008. Forty-nine clients deceased (standardized mortality ratio 4.1 [3.0-5.4]), at least 84% of deaths were violent or drug-related (12% suicides), and Cox regression analysis indicated that death was associated with frequent use of sedatives and less frequent use of amphetamine. No female deaths were observed; death and male gender were associated in binary analysis. Implications for diagnostics and treatment are discussed.

Mortality among clients seeking treatment for buprenorphine abuse in Finland

BACKGROUND

It is unclear whether buprenorphine abuse is associated with a similar risk of death to other substance abuse. This study examined all-cause mortality rates and causes of deaths among clients seeking treatment for buprenorphine abuse.

METHODS

Structured clinical interviews were conducted with 4685 clients between January 1998 and August 2008. Records of deaths that occurred among these clients were extracted from the Official Causes of Death Register in Finland. Standardized mortality ratios (SMRs) with 95% confidence intervals (CI) were computed using national mortality rates over a 13-year follow-up to examine excess mortality. Kaplan-Meier survival analysis was used to compare survival between buprenorphine and other clients.

RESULTS

Sixty-one of 780 (7.8%) clients who sought treatment for buprenorphine abuse and 408 of 3905 (10.4%) other clients died during the 13-year follow-up period. The most common cause of death was drug-related in buprenorphine (n=25, 41.0%) and other clients (n=142, 34.8%). Survival rates were similar among buprenorphine and other clients (log-rank χ[df=1](2)=0.215, p=0.643). The SMR was 3.0 (95% CI 2.3-3.8) and 3.1 (95% CI 2.8-3.4) for buprenorphine and other clients, respectively. Excess mortality was highest among women aged 20-29 years, and more pronounced in buprenorphine clients (SMR 27.9 [95% CI 12.6-49.0]) compared to other clients (SMR 14.0 [95% CI 9.3-19.6]).

CONCLUSIONS

Clients seeking treatment for buprenorphine abuse had a three times higher mortality rate than the national average, with the excess risk highest among female clients. Overall mortality rates were similar among clients seeking treatment for buprenorphine and other substance abuse.

Suicide and other-cause mortality among heroin users in Taiwan: a prospective study

AIMS

The present study investigates one-year incidence of mortality from suicide and other causes among heroin users in Taiwan.

DESIGN

A prospective national register-based cohort study.

SETTING

All heroin users who attended the methadone maintenance treatment (MMT) programs in all treatment centers in Taiwan.

PARTICIPANTS

The sample comprised 10,842 heroin users attending MMT. Between Jan 2006 and Dec 2007, cases were identified through the multiple-center register system and followed until Dec 2008 for date and cause of death on the Taiwan national mortality database.

MEASUREMENTS

Standardized mortality ratios within one year of starting MMT were calculated as a ratio of actual versus expected numbers of deaths in the general population in Taiwan. Cox regression models were fitted to estimate the effects of gender, age, education and marital status as well as heroin related behaviors.

FINDINGS

In total, 256 cases died, 67 through suicide. The mortality rate (per 100 person-years) in the first year of all-cause and suicide was 1.71 and 0.45 respectively, representing 7.5- and 18.4-fold age- and gender-standardized mortality ratio (SMR) compared to the general population. Besides, the mortality rate in the first year of overdoses, murder, HIV, somatic was 0.19, 0.02, 0.07, and 0.75 respectively, representing 68.4-, 27.7-, 76.8-, and 4.3-fold SMR increases to the general population. Older age and unemployment were independent risk factors for mortality. Females had higher standardized mortality ratio than males for suicide and all-cause mortality.

CONCLUSIONS

Results showed higher risk of suicide and other-cause mortality among heroin users in MMT than general population. Suicide is an important contributor to overall excess mortality among heroin users in MMT, and especially among women. Suicide prevention and physical health monitoring are important components of MMT programs.

All-cause mortality in criminal justice clients with substance use problems--a prospective follow-up study

BACKGROUND

Mortality in previously incarcerated individuals is known to be elevated, with high proportions of drug-related deaths. However, there is less documentation of whether specific substance use patterns and other clinical characteristics predict increased mortality in the group.

METHODS

This is a follow-up study of mortality and causes of death in ex-prisoners with substance use problems prior to incarceration (N=4081), who were followed during an average of 3.6 years from release from prison until death or until data were censored. Baseline predictors of mortality, derived from interviews with Addiction Severity Index (ASI) in prison, were studied in a Cox regression analysis.

RESULTS

During follow-up, 166 subjects (4.1%) died. Standardized mortality ratios were 7.0 (3.6-12.2) for females and 7.7 (5.6-9.0) for males. In 84% of cases, deaths were unnatural or due to substance-related disease. Most common causes of death were accidental poisoning (27%), transport accidents (13%), poisoning/injury with undetermined intent (12%), and suicide (10%). Death was positively predicted by heroin use, overdose, and age, and negatively predicted by a history of depression.

CONCLUSIONS

A vast majority of deaths after release from prison in individuals with substance use are due to violent or substance-related causes. Significant predictors identified were mainly related to patterns of drug use, and need to be addressed upon incarceration as risk factors of death. The findings have implications for referral and treatment upon release from prison.

QTc interval screening for cardiac risk in methadone treatment of opioid dependence

BACKGROUND

Methadone represents today the gold standard of efficacy for the pharmacological treatment of opioid dependence. Methadone, like many other medications, has been implicated in the prolongation of the rate-corrected QT (QTc) interval of the electrocardiogram (ECG), which is considered a marker for arrhythmias such as torsade de pointes (TdP). Indications on the association between methadone, even at therapeutic dosages, and TdP or sudden cardiac death have been reported. On these bases, consensus and recommendations involving QTc screening of patients receiving methadone treatment have been developed to identify patients with QTc above the thresholds considered at risk for cardiac arrhythmias, and they provide these individuals with alternative treatment (reduction of methadone dosage; provision of alternative opioid agonist treatment; treatment of associated risk factors).

OBJECTIVES

To evaluate the efficacy and acceptability of QTc screening for preventing cardiac-related morbidity and mortality in methadone-treated opioid dependents.

SEARCH METHODS

We searched MEDLINE, EMBASE, CINAHL (to April 2013), the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library Cochrane Drug and Alcohol Review Group Specialised Register (Issue 3, 2013), main electronic sources of ongoing trials, specific trial databases and reference lists of all relevant papers.

SELECTION CRITERIA

Randomised controlled trials (RCTs), controlled clinical trials (CCTs) and non-randomised studies (cohort studies, controlled before and after studies, interrupted time series studies, case control studies) examining the efficacy of QTc screening for the prevention of methadone-related mortality and morbidity in opioid addicts.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and extracted data from studies.

MAIN RESULTS

The search strategy led to the identification of 872 records. Upon full-text assessment, no study was found to meet the quality criteria used for this review.

AUTHORS' CONCLUSIONS

It is not possible to draw any conclusions about the effectiveness of QTc screening strategies for preventing cardiac morbidity/mortality in methadone-treated opioid addicts. Research efforts should focus on strengthening the evidence about the effectiveness of widespread implementation of such strategies and clarifying the associated benefits and harms.

A record-linkage study of drug-related death and suicide after hospital discharge among drug-treatment clients in Scotland, 1996-2006

AIMS

To investigate the relationship between time after hospital discharge and drug-related death (DRD) and suicide among drug users in Scotland, while controlling for potential confounders.

DESIGN

Cohort study.

SETTING AND PARTICIPANTS

The 69 457 individuals who registered for drug treatment in Scotland during 1 April 1996-31 March 2006.

MEASUREMENTS

Time-at-risk was from the date of an individual's first attendance at drug treatment services after 1 April 1996 until the earlier date of death or end-of-study, 31 March 2006, and was categorized according to time since the most recent hospitalization, as during hospitalization, within 28 days, 29-90 days, 91 days to 1 year and >1 year since discharge from most recent hospital stay versus 'never admitted' (reference).

FINDINGS

Time-periods soon after discharge were associated with increased risk of DRD. DRD rates per 1000 person-years were: 87 (95% CI: 72-103) during hospitalization, 21 (18-25) within 28 days, 12 (10-15) during 29-90 days and 8.5 (7.5-9.5) during 91 days to 1 year after discharge versus 4.2 (3.7-4.7) when >1 year after most recent hospitalization and 1.9 (1.7-2.1) for those never admitted. Adjusted hazard ratios by time since hospital discharge (versus never admitted) were: 9.6 (95% CI: 8-12) within 28 days, 5.6 (4.6-6.8) during days 29-90, thereafter 4.0 (3.5-4.7) and 2.3 (2.0-2.7) when >1 year. Non-drug-related suicides were less frequent than DRDs (269 versus 1383) but a similar risk pattern was observed.

CONCLUSIONS

In people receiving treatment for drug dependence, discharge from a period of hospitalization marks the start of a period of heightened vulnerability to drug-related death.

Morbidity associated with heroin overdose presentations to an emergency department: a 10-year record linkage study

INTRODUCTION

To examine hospitalizations in a cohort of 224 patients who presented with non-fatal heroin overdose to an ED.

METHODS

A record linkage study, using the morbidity, mental health and mortality databases in the Data Linkage Unit of the Department of Health, Western Australia. The main outcome measures were hospital separations 5 years before and after entry into the cohort.

RESULTS

Before entry into the cohort, 199 (89%) patients had an admission to mental health services. These 199 had a combined total of 1367 separations, most commonly for a mental health condition, injury or poisoning. Women had more than twice the relative risk (RR) of men for all separations (RR 2.35, 95% confidence interval [CI] 1.96-2.82, P < 0.001) and for injury and poisoning separations (RR 2.04, 95% CI 1.56-2.66, P < 0.001). The highest concentrations of separations occurred within 1 year before and 1 year after entry into the cohort. There were 12 (5.4%, 95% CI 2.9-9.4%) deaths, most commonly from overdose.

CONCLUSION

Non-fatal heroin overdose ED presentations are associated with a cluster of hospitalizations around that episode, likely to be related to heroin availability. Presentation to hospital by heroin users represents an opportunity to counsel less risky behaviour.

Mortality among substance-using mothers in California: a 10-year prospective study

AIMS

To examine mortality rates and causes of death among a cohort of substance-using mothers and to identify risk factors that predict mortality.

DESIGN, SETTING, PARTICIPANTS

This is a prospective study of a cohort of 4447 substance-using mothers (pregnant or parenting) who were enrolled during 2000-02 in 40 drug abuse treatment programs across California.

METHODS

All mothers were assessed at baseline using the Addiction Severity Index. Mortality data were obtained from the National Death Index and causes of death were coded using ICD-10. Standardized mortality ratios (SMR) were calculated relative to women in the general population adjusted for age. Proportional hazard (Cox) regression was used to identify risk factors predicting death.

RESULTS

At the end of 2010, 194 deaths were confirmed, corresponding to a crude mortality rate of 4.47 per 1000 person-years and SMR of 8.4 (95% confidence interval: 7.2-9.6). Drug overdose (28.8%), cardiovascular disease (10%), and alcohol or drug disorders (8.9%) were the leading causes of death. Baseline factors associated with higher mortality included older age, being white (relative to African American or Hispanic), heroin, alcohol, cocaine or marijuana (relative to methamphetamine) as the primary drug problem, drug injection and greater severity of employment, medical/health and psychiatric problems.

CONCLUSIONS

Substance-using mothers have 8.4 times the mortality than that observed among US women of similar age. Greater severity of employment, medical/health and psychiatric problems contributed to the elevated mortality.

Self-reported drug use and mortality among a nationwide sample of Swedish conscripts - a 35-year follow-up

BACKGROUND

Drug users in clinical samples have elevated mortality compared with the general population, but little is known about mortality among users of drugs within the general population.

AIM

To determine whether self-reported use of illicit drugs and non-prescribed sedatives/hypnotics among young men in the general population is related to mortality.

METHODS

A 35-year follow-up of 48024 Swedish men, born 1949-1951 and conscripted in 1969/1970, among whom drug use was reported by 8767 subjects. Cross-record linkage was effected between individual data from the Swedish conscription and other national registers. Deaths and causes of death/1000 person-years were calculated. Cox PH regression was used to estimate hazard ratios (HRs) for death with 95% confidence intervals (95% CIs). An HR was calculated for users of different dominant drugs at conscription compared with non-users by age interval, after adjusting for confounders and hospitalisation with a drug-related diagnosis.

RESULTS

Drug users showed elevated mortality (HR 1.61, p<0.05) compared with non-users. After adjusting for risk factors, users of stimulants (HR 4.41, p<0.05), cannabis (HR 4.27, p<0.05), opioids (HR 2.83, p>0.05), hallucinogens (HR 3.88, p<0.05) and unspecified drugs (HR 4.62, p<0.05) at conscription with a drug-related diagnosis during follow-up showed an HR approaching the standard mortality ratios in clinical samples. Among other drug users (95.5%), only stimulant users showed statistically significantly increased mortality (HR 1.96, p<0.05).

CONCLUSIONS

In a life-time perspective, drug use among young men in the general population was a marker of premature death, even a long time after exposure.

Substance abuse and psychiatric co-morbidity as predictors of premature mortality in Swedish drug abusers: a prospective longitudinal study 1970-2006

BACKGROUND

Few longitudinal cohort studies have focused on the impact of substances abused and psychiatric disorders on premature mortality. The aim of the present study was to identify predictors of increased risk of drug related death and non drug related death in substance abusers of opiates, stimulants, cannabis, sedatives/hypnotics, hallucinogens and alcohol over several decades.

METHODS

Follow-up study of a consecutive cohort of 561 substance abusers, admitted to a detoxification unit January 1970 to February 1978 in southern Sweden, and followed up in 2006. Demographic and clinical data, substance diagnoses and three groups of psychiatric diagnoses were identified at first admission. Causes of death were coded according to ICD-10 and classified as drug related deaths or non drug related deaths. To identify the incidence of some probable risk factors of drug related premature death, the data were subjected to a competing risks Cox regression analysis.

RESULTS

Of 561 patients in the cohort, 11 individuals had either emigrated or could not be located, and 204/561 patients (36.4%) were deceased by 2006. The cumulative risk of drug related death increased more in the first 15 years and leveled out later on when non drug related causes of death had a similar incidence. In the final model, male gender, regular use of opiates or barbiturates at first admission, and neurosis were associated with an increased risk of drug related premature death, while cannabis use and psychosis were associated with a decreased risk. Neurosis, mainly depression and/or anxiety disorders, predicted drug related premature death while chronic psychosis and personality disorders did not. Chronic alcohol addiction was associated with increased risk of non drug related death.

CONCLUSIONS

The cohort of drug abusers had an increased risk of premature death to the age of 69. Drug related premature death was predicted by male gender, the use of opiates or barbiturates and depression and anxiety disorders at first admission. The predicted cumulative incidence of drug related death was significantly higher in opiate and barbiturate abusers over the observed period of 37 years, while stimulant abuse did not have any impact. Alcohol contributed to non drug related death.

Mortality of those who attended drug services in Scotland 1996-2006: record-linkage study

Background

We examine major causes of death amongst persons in contact with drug-treatment services across Scotland during April 1996–March 2006, hereafter Scottish Drug Misuse Database (SDMD) cohort.

Methods

Drug-treatment records were linked to national registers of deaths and hepatitis C virus (HCV) diagnoses. For eras 1996/97–2000/01 and 2001/02–2005/06, we calculated cause-specific death-rates and standardised mortality ratios (SMRs) using age-, sex- and calendar-rates of the general Scottish population. Major causes of death were identified by high SMRs (>5 across eras) or rates (>50 per 100,000 person-years in either era), and their time-specific influences characterised by proportional hazards analyses.

Results

The SDMD cohort comprised 69,456 individuals, 350,315 person-years and 2590 deaths. The overall SMR reduced from 6.4 (95% CI: 6.0–6.9) to 4.8 (95% CI: 4.6–5.0) between eras. We identified five major causes of death: drug-related (1383 deaths), homicide (118) and infectious diseases (90) with high SMRs; suicide (269) and digestive system disease (168) with high rates. HCV diagnosis marked individuals with at least double the risk of cause-specific mortality, including adjusted hazard ratio (HR) for no HCV diagnosis of 0.46 (95% CI: 0.41–0.53) for drug-related deaths (DRDs) and 0.15 (95% CI: 0.10–0.22) for death from digestive system disease. Increased DRD risk at older age (>34 years) appeared specific to HCV-diagnosed individuals (interaction: χ12=7.7, p = 0.01). Alcohol misuse increased HRs: for DRD (1.76, 95% CI: 1.50–2.06), suicide (1.88, 95% CI: 1.35–2.60), deaths from digestive system disease (3.19, 95% CI: 2.21–4.60) and non-major causes (1.87, 95% CI: 1.49–2.35). Stimulant misuse increased suicide risk: adjusted HR 1.91 (95% CI: 1.43–2.54).

Conclusions

Drug-users in Scotland are exposed to variously increased mortality risks. HCV-diagnosed individuals are particularly vulnerable, and may need additional support.

Rates and correlates of mortality amongst heroin users: findings from the Australian Treatment Outcome Study (ATOS), 2001-2009

The study aimed to determine mortality rates, standardised mortality ratios (SMRs), and correlates of mortality amongst the Australian Treatment Outcome Study (ATOS) cohort of 615 heroin users over the period 2001-2009. The cohort was followed for a total of 4820.1 person years. A total of 31 deaths (5% of the cohort) occurred across follow-up. The mean age at death was 34.5 years, and 58% were male. The most common cause of death was overdose (68%). The crude mortality rate was 6.43 per 1000 person years, with no gender difference, and the SMR was 4.56 (males=2.95, females=18.57). The only significant bivariate (hazard ratio=3.69) and multivariate (adjusted hazard ratio=3.03) correlate of mortality was a history of opioid overdose prior to baseline. Mortality rates were lower than those seen outside Australasia. Screening for overdose by those treating heroin users would be appropriate, and may contribute to reductions in overall mortality.

Causes of premature mortality in Swedish drug abusers: a prospective longitudinal study 1970-2006

AIMS

To evaluate premature mortality and causes of death from young adulthood to middle age in a cohort of drug users followed during almost four decades.

DESIGN

Follow-up study of a consecutive cohort of patients with drug abuse/dependence.

METHODS

A cohort of 561 drug abusers, admitted to a detoxification and short-term rehabilitation unit 1970-1978 was followed to December 31st, 2006. Standardized interviews and hospital records with toxicological analyses were used for demographic data, substance use and psychiatric diagnoses at admission. For Follow-up analyses, autopsy protocols including toxicology tests and death certificates were obtained for assessment of causes of death which were coded according to ICD-10. Age-group standardized mortality ratios were calculated independently for both sexes.

RESULTS

204 persons (36.4%) were deceased by 2006. SMR was 5.94 for the cohort. Compared to an age- and gender-matched population, the risk of premature death was about eighteen times higher between the ages of 20-44 and about five times higher from 45 up to the age of 69. Of 120 (59%) drug-related deaths, 43 were opiate overdoses, and 3 were overdose from amphetamine. A total of 53 (26%) persons died violent deaths: 39 suicides, of which 25 were drug-related, 3 homicides and 12 accidents. The Swedish national causes of death register underestimated drug-related death by 37% and suicide by 85% compared to the results from this study.

CONCLUSIONS

The cohort of drug abusers had an increased risk of premature often drug-related and violent death well into middle age, and to a great extent the drug addicts died from the same drug they had abused when they were first admitted for treatment. The underestimation of drug-related death and suicide in some national death cause registers could be reduced if the doctor routinely records ICD codes when issuing death certificates and autopsy protocols.

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.

Causes of death of patients with methamphetamine dependence: a record-linkage study

INTRODUCTION AND AIMS

Methamphetamine use leads to increased likelihood of premature death. The authors investigated the causes of death and risk of mortality in a large cohort of patients with methamphetamine dependence.

DESIGN AND METHODS

A cohort of 1254 subjects with methamphetamine dependence, admitted to a psychiatric centre in Taiwan from January 1990 to December 2007, was retrospectively studied. Diagnostic and sociodemographic data for each subject were extracted from the medical records based on a chart review process. Mortality data were obtained by linking to the National Death Certification System and standardised mortality ratios (SMRs) were estimated. The risk and protective factors for all-cause deaths were explored by means of survival analyses.

RESULTS

During the study period, 130 patients died. Of them, 63.1% died unnatural deaths, while the remaining 36.9% died natural deaths. The 1 year cumulative rates for unnatural and natural deaths were 0.018 and 0.006, respectively, and the 5 year rates were 0.046 and 0.023, respectively. The cohort had excessive mortality (SMR = 6.02), and women had a higher SMR for unnatural deaths than men (26.19 vs. 9.82, P = 0.001). For all-cause deaths, comorbidity with other substance use disorders was associated with increased risk of death, despite that being married was associated with a reduced risk.

DISCUSSION AND CONCLUSIONS

A substantial proportion of the deceased died natural deaths, but most died unnatural deaths. The findings show significant evidence to provide valuable insight into premature deaths among methamphetamine-dependent users. This information is valuable for development of prevention and intervention programs.