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

Mortality among people who inject drugs - the interwoven roles of fentanyl and HIV: a community-based cohort study

BACKGROUND

Excess all-cause mortality is a key indicator for assessing direct and indirect consequences of injection drug use and data are warranted to delineate sub-populations within people who inject drugs at higher risk of death. Our aim was to examine mortality and factors associated with mortality among people who inject drugs in Estonia.

METHODS

Retrospective cohort study using data from people who inject drugs recruited in the community with linkage to death records. Standardized mortality ratios were used to compare the cohort mortality to the general population and potential predictors of death were examined through survival analysis (Cox regression). The cohort include a total of 1399 people who inject drugs recruited for cross-sectional surveys using respondent driven sampling between 2013 and 2018 in Estonia. A cohort with follow-up through 2019 was formed with linkage to national causes of death registry.

RESULTS

Among 1399 participants with 4684 person-years of follow-up, 10% were deceased by 2019. The all-cause mortality rate in the cohort was 28.9 per 1000 person-years (95% confidence interval 25.3-35.3). Being HIV positive, injecting mainly opioids (fentanyl), living in the capital region and the main source of income other than work were associated with greater mortality risk.

CONCLUSIONS

While low-threshold services have been available for a long time for people who inject drugs, there is still a need to widen the availability and integration of services, particularly the integration of HIV and opioid treatment.

The association between all-cause mortality and HIV acquisition risk groups in the United States, 2001-2014

OBJECTIVE

To investigate associations between all-cause mortality and human immunodeficiency virus (HIV) acquisition risk groups among people without HIV in the United States.

METHODS

We used data from 23,657 (NHANES) participants (2001-2014) and the Linked Mortality File to classify individuals without known HIV into HIV acquisition risk groups: people who ever injected drugs (ever-PWID); men who have sex with men (MSM); heterosexually active people at increased risk for HIV (HIH), using low income as a proxy for increased risk. We used Cox proportional hazards models to estimate adjusted and unadjusted all-cause mortality hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

Compared with sex-specific heterosexually active people at average risk for HIV (HAH), the adjusted HR (95% CI) were: male ever-PWID 1.67 (1.14, 2.46), female ever-PWID 3.50 (2.04, 6.01), MSM 1.51 (1.00, 2.27), male HIH 1.68 (1.04, 2.06), female HIH 2.35 (1.87, 2.95), and male ever-PWID 1.67 (1.14, 2.46).

CONCLUSIONS

Most people at increased risk for HIV in the US experience higher all-cause mortality than people at average risk. Strategies addressing social determinants that increase HIV risk should be incorporated into HIV prevention and other health promotion programs.

Sex- and Gender-Specific Drug Abuse Dynamics: The Need for Tailored Therapeutic Approaches

Sex and gender have been gaining ever greater attention due to their associated risks, dynamics, patterns and protective factors underlying substance abuse and addiction. Such differentiations and the clarification of complexities thereof take on even greater relevance in light of drug abuse scope worldwide. According to the 2022 World Drug Report released by the United Nations Office on Drugs and Crime (UNODC), in 2020 an estimated 284 million people worldwide aged 15-64 had used a drug within the last 12 months. The authors have set out to shed a light on determinants and contributing factors of drug abuse based on sex and gender and outline policy and medicolegal remarks aimed at delineating sex- and gender-based approaches towards drug abuse therapeutic interventions that are both therapeutically and ethically/legally viable and grounded in an evidence-based set of standards. Neurobiological data suggest that estrogen may facilitate drug taking by interacting with reward- and stress-related systems. In animal research, the administration of estrogen increases drug taking and facilitates the acquisition, escalation, and reinstatement of cocaine-seeking behavior. From a medicolegal perspective, it is of utmost importance to take into account the whole picture constituting each patient profile, which certainly includes gender factors and contributors, when outlining a therapeutic approach. Failure to do so could lead to negligence-based malpractice allegations, in light of the scientific findings representing best practices with which clinicians need to comply when caring for SUD patients.

Sex differences in susceptibility to substance use disorder: Role for X chromosome inactivation and escape?

There is a sex-based disparity associated with substance use disorders (SUDs) as demonstrated by clinical and preclinical studies. Females are known to escalate from initial drug use to compulsive drug-taking behavior (telescoping) more rapidly, and experience greater negative withdrawal effects than males. Although these biological differences have largely been attributed to sex hormones, there is evidence for non-hormonal factors, such as the influence of the sex chromosome, which underlie sex disparities in addiction behavior. However, genetic and epigenetic mechanisms underlying sex chromosome influences on substance abuse behavior are not completely understood. In this review, we discuss the role that escape from X-chromosome inactivation (XCI) in females plays in sex-associated differences in addiction behavior. Females have two X chromosomes (XX), and during XCI, one X chromosome is randomly chosen to be transcriptionally silenced. However, some X-linked genes escape XCI and display biallelic gene expression. We generated a mouse model using an X-linked gene specific bicistronic dual reporter mouse as a tool to visualize allelic usage and measure XCI escape in a cell specific manner. Our results revealed a previously undiscovered X-linked gene XCI escaper (CXCR3), which is variable and cell type dependent. This illustrates the highly complex and context dependent nature of XCI escape which is largely understudied in the context of SUD. Novel approaches such as single cell RNA sequencing will provide a global molecular landscape and impact of XCI escape in addiction and facilitate our understanding of the contribution of XCI escape to sex disparities in SUD.

Increased heroin intake and relapse vulnerability in intermittent relative to continuous self-administration: Sex differences in rats

BACKGROUND AND PURPOSE

Studies using intermittent-access drug self-administration show increased motivation to take and seek cocaine and fentanyl, relative to continuous access. In this study, we examined the effects of intermittent- and continuous-access self-administration on heroin intake, patterns of self-administration and cue-induced heroin-seeking, after forced or voluntary abstinence, in male and female rats. We also modelled brain levels of heroin and its active metabolites.

EXPERIMENTAL APPROACH

Rats were trained to self-administer a palatable solution and then heroin (0.075 mg·kg^-1 per inf) either continuously (6 h·day^-1 ; 10 days) or intermittently (6 h·day^-1 ; 5-min access every 30-min; 10 days). Brain levels of heroin and its metabolites were modelled using a pharmacokinetic software. Next, heroin-seeking was assessed after 1 or 21 abstinence days. Between tests, rats underwent either forced or voluntary abstinence. The oestrous cycle was measured using a vaginal smear test.

KEY RESULTS

Intermittent access exacerbated heroin self-administration and was characterized by a burst-like intake, yielding higher brain peaks of heroin and 6-monoacetylmorphine concentrations. Moreover, intermittent access increased cue-induced heroin-seeking during early, but not late abstinence. Heroin-seeking was higher in females after intermittent, but not continuous access, and this effect was independent of the oestrous cycle.

CONCLUSIONS AND IMPLICATIONS

Intermittent heroin access in rats resembles critical features of heroin use disorder: a self-administration pattern characterized by repeated large doses of heroin and higher relapse vulnerability during early abstinence. This has significant implications for refining animal models of substance use disorder and for better understanding of the neuroadaptations responsible for this disorder.

LINKED ARTICLES

This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.

COVID-19 impact on opioid overdose after jail release in Massachusetts

Introduction

Release from incarceration is a high-risk period for opioid overdose. Concern about COVID-19 spread in jails led to early releases; it is unknown whether pandemic era releases of persons with opioid use disorder (OUD) contributed to increases in community overdose rates.

Methods

Observational data compared overdose rates three months after release among jailed persons with OUD released before (9/1/2019-3/9/2020) and during the pandemic (3/10/2020-8/10/2020) from seven jails in Massachusetts. Data on overdoses come from the Massachusetts Ambulance Trip Record Information System and Registry of Vital Records Death Certificate file. Other information came from jail administrative data. Logistic models regressed overdose on release period, controlling for MOUD received, county of release, race/ethnicity, sex, age, and prior overdose.

Results

Pandemic releases with OUD had a higher risk of fatal overdose (adjusted odds ratio [aOR] 3.06; 95% CI, 1.49 to 6.26); 20 persons released with OUD (1.3%) experienced a fatal overdose within three months of release, versus 14 (0.5%) pre-pandemic. MOUD had no detectable relationship with overdose mortality. Pandemic release did not impact non-fatal overdose rates (aOR 0.84; 95% CI 0.60 to 1.18), though in-jail methadone treatment was protective (aOR 0.34; 95% CI 0.18 to 0.67).

Conclusions

Persons with OUD released from jail during the pandemic experienced higher overdose mortality compared to pre-pandemic, but the number of deaths was small. They did not experience significantly different rates of non-fatal overdose. Early jail releases during the pandemic were unlikely to explain much, if any, of the observed increase in community overdoses in Massachusetts.

Association of sex work and social-structural factors with non-fatal overdose among women who use drugs in Vancouver, Canada

BACKGROUND

Women who use drugs (WWUD) and engage in sex work experience disproportionate sex- and drug-related harms, such as HIV, however comparatively little is known about their overdose risk. Therefore, we examined the association between sex work and overdose and secondarily explored the association of social-structural factors, such as policing and gendered violence, with overdose.

METHODS

Data were derived from two community cohort studies based in Vancouver, Canada between 2005 to 2018. We used logistic regression with GEE to examine the associations between a) sex work and nonfatal overdose and b) social-structural and individual variables with overdose among WWUD who engaged in sex work during the study. Sex work, overdose, and other variables were time-updated, captured every six months.

RESULTS

Among 857 WWUD included, 56% engaged in sex work during the study. Forty-three percent of WWUD engaged in sex work had at least one overdose compared to 26% of WWUD who did not. Sex work was not significantly associated with an increased odds of overdose (AOR = 1.14, 95% CI: 0.93-1.40). In the exploratory analysis amongst 476 WWUD engaged in sex work, social-structural variables associated with overdose in the multivariable model included exposure to: punitive policing (OR = 1.97, 95% CI: 1.30-2.96) and physical or sexual violence (OR = 2.55, 95% CI: 1.88-3.46).

CONCLUSIONS

WWUD engaged in sex work had an increased overdose burden that may be driven by social-structural factors rather than sex work itself. Interventions that address policing and gendered violence represent potential targets for effective overdose prevention.

The Importance of Perceived Safety, Stigma and Pleasure for Solitary Injecting

Many people who inject drugs (PWID) inject when they are alone which increases the risk for drug-related mortality, and the majority of overdose-related deaths occur among solitary users in residential environments. Drawing on qualitative data from interviews with 80 PWID in Norway, this study explores the complex practices of solitary injecting. The analysis illustrates that the risk environments in which they participated involved high levels of distress, fear and stigma that made them prefer solitary injecting. This involved a perceived notion of safety from an unpredictable social environment. Stigma was described as causing additional harms and they therefore wanted to hide their drug-using practices. Finally, injecting drug use involved contextual pleasures that were maximised by injecting alone. The study illustrates how the risk environment the PWID inhabited caused additional harms, by which solitary injections was rationalized, despite its increased mortality risks. Future harm-reduction initiatives should reflect this important aspect.

Compulsory care of individuals with severe substance use disorders and alcohol- and drug-related mortality: A Swedish registry study

AIM

This study used 17 year of Swedish registry data (2003-2019) for 25,125 adults assessed for their severity of substance use to identify the baseline factors predicting the risk of being court-ordered into compulsory care and examine the association between admission to compulsory care and mortality risks due to alcohol- or drug-related causes.

METHODS AND MATERIALS

Addiction Severity Index (ASI) assessment data were linked to register data on demographic characteristics, compulsory care, and alcohol- and drug-related mortality. Cox regression models were used to identify baseline factors predictive of post-assessment admission to compulsory care in the 5 years post-substance use assessment. Discrete-time random-effect logistic regression models were used to examine the association between compulsory care duration and alcohol or drug-related mortality risks. Propensity score matching was used for validation.

RESULTS

The first models identified that younger age, female gender, and ASI composite scores for drug use, mental health and employment were significantly associated with the risk of placement in compulsory care for drugs other than alcohol. Female gender and ASI composite scores for alcohol, drug use and employment were significantly associated with compulsory care treatment for alcohol use. The second models showed that older individuals and men were more likely to die due to alcohol-related causes, while younger individuals and men were more likely to die due to drug-related causes. Length of stay in compulsory care institutions significantly increased the likelihood of dying due to substance use-related causes. Propensity scores analyses confirmed the results.

CONCLUSION

In Sweden, a significant concern is the higher likelihood of women and young individuals to be court-ordered to compulsory care. Although compulsory care is often advocated as a life-saving intervention, our findings do not provide strong support for this claim. On the contrary, our findings show that admission to compulsory care is associated with a higher risk of substance use-related mortality. Factors such as compulsory care often not including any medical or psychological therapy, together with relapse and overdose after discharge, may be possible contributing factors to these findings.

Mood regulation, alexithymia, and personality disorders in female patients with opioid use disorders

Background

Opioid use disorders are rising among females. So, there is a need for more recognition of the various factors contributing to this trend in women, to help us to plan effective interventions to this group of patients. Hence, we conducted this research to identify risk factors associated with opioid use in females including mood regulation, alexithymia, and personality disorders. The study included 60 females ranging from 18 to 45 years [30 females diagnosed with opioid use disorder according DSM-IV (case group), and 30 females with no mental illness diagnosis according to general health questionnaire (control group)]. The subjects were recruited from inpatients and outpatient clinic of Al-Abbassia Hospital, Cairo, Egypt. Both groups were assessed by the Structured Clinical Interview for DSM-IV axis II disorders (SCID II) for personality, Trait Meta-Mood Scale (TMMS) for emotional regulation and Toronto Alexithymia Scale-20 (TAS-20) for alexithymia.

Results

Regarding sociodemographic data, cases were significantly different from controls as they are less educated (P < 0.001), more 73% (22) unemployed (P <0.001) and 56.7% (17) of cases had positive family history of first degree relatives with drug use (P = 0.001).

SCID II showed more significant personality disorders diagnosis among cases as (borderline, antisocial, paranoid, schizotypal, and schizoid personality disorder) (P < 0.001, < 0.001, 0.01, 0.003, and 0.005, respectively) and also multiple personality disorders (P < 0.001) diagnosis. As regards alexithymia all cases were classified as having alexithymia 100% versus 56.7% among controls. Meanwhile, cases showed more difficulty in identifying (P < 0.001) and describing feelings (P = 0.001) and more externally oriented thinking (P = 0.010). Results of TMMS showed cases had lower total score on TMMS (p = 0.016). Signifying their inability to regulate their emotions in comparison to controls. There was no significant association between alexithymia, sociodemographic data, TMMS, and SCID II among cases group.

Conclusions

The present study found that females with opioid use disorders tend to be less educated, unemployed with positive family history of substance abuse, and diagnosed mainly with cluster A and B personality disorders. Moreover, had difficulty in identifying, describing, and regulating their emotions.

Improving Harm Reduction Services: A Qualitative Study on the Perspectives of Highly Marginalized Persons Who Inject Drugs in Montreal

Harm reduction (HR) is an alternative to the moralization of drug use and a pragmatic public health approach aimed at minimizing harms associated with use. This study sought to gain the perspectives of persons who inject drugs (PWID) on the adequacy of services provided by HR organizations in Montreal. Twenty-two semi-structured interviews and two focus groups were conducted with 30 participants. Some of the key advantages of HR perceived by participants include access to injection equipment, psychosocial support, and reduced social isolation. However, many wanted more opportunities for social insertion and greater value to be placed on their knowledge and life experiences (e.g., experiential knowledge of the street scene, drug use, sex work, or homelessness). This study suggests that PWID who access HR services in Montreal are interested in paid work opportunities in environments that promote power sharing, and activities that are conducted and managed by and for them.

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.

Postrelease mortality among persons hospitalized during their incarceration

PURPOSE

Health and mortality of people released from incarceration have received increased attention, and yet little is known about the postrelease experiences of those hospitalized during incarceration.

METHODS

For persons incarcerated and released from the North Carolina (NC) state prison system between January 1, 2008, and June 30, 2015, we examined postrelease mortality from 2008 to 2016 by history of prison hospitalization.

RESULTS

Among 111,479 released persons, 0.9% (n = 1010) were hospitalized during their incarceration, and of those, 10.5% (n = 106) died during follow-up compared with 3.2% (3511/110,469) of other released persons. Those hospitalized in prison had a higher postrelease death rate (adjusted hazard ratio: 2.44), a lower 8-year conditional probability of survival (0.80 vs. 0.94), and were more likely to die from chronic causes (79.2% vs. 51.0%) than other released persons. The postrelease standardized mortality rate among men hospitalized in prison was 3.1 times higher than that of those not hospitalized and 7.1 times the rate of all NC men.

CONCLUSIONS

People hospitalized during incarceration constitute a particularly vulnerable, yet relatively easily identifiable priority population to focus health interventions supporting continuity of care after prison release. Yet such efforts may be particularly challenging in NC and other Medicaid non-expansion states.

Preventing opioid overdose with peer-administered naloxone: findings from a rural state

BACKGROUND

In response to the opioid epidemic, naloxone distribution programs aim to prevent overdose death by making naloxone available and training people to use it. Peers of individuals at risk of opioid overdose are well-positioned to administer naloxone and prevent overdose death.

METHODS

We conducted key informant interviews with 18 individuals with past or current opioid and heroin drug use who had administered naloxone to a peer during an overdose emergency. Interviews explored individuals' experiences with administration and their recommendations for program and policy improvement. Data were systematically coded and analyzed for themes.

RESULTS

Participants sought naloxone rescue kits because they perceived high risk of overdose. They described high satisfaction with training and felt prepared to administer naloxone during overdose incidents. Overwhelmingly, participants perceived naloxone to be effective and emphasized the need to make it widely available. Findings suggest that engagement in overdose prevention strategies other than naloxone differs by gender, with females more likely than males to use multiple different strategies. Participants described that overdose experiences do not have a lasting impact on drug use behaviors.

CONCLUSIONS

Findings support the feasibility of naloxone distribution to peer opioid and heroin users and provide recommendations for policy improvement, including effective and well-advertised Good Samaritan laws and links to treatment for opioid use disorder.

Police-related barriers to harm reduction linked to non-fatal overdose amongst sex workers who use drugs: Results of a community-based cohort in Metro Vancouver, Canada

BACKGROUND

High rates of overdose and overdose-related mortality in North America represent a pressing health and social concern. Women sex workers face severe health and social inequities, which have been linked to structural factors including negative police interactions; however, little is known regarding the burden of overdose or how policing impacts overdose risk amongst sex workers who use drugs. Given this, we aimed to explore the independent effects of experiencing police-related barriers to harm reduction on non-fatal overdose amongst women sex workers who use drugs in Metro Vancouver, Canada over a 7.5-year period.

METHODS

Data were drawn from An Evaluation of Sex Workers Health Access (AESHA), a community-based open prospective cohort of women sex workers in Metro Vancouver, from 2010 to 2017. Using multivariate logistic regression with generalized estimating equations (GEE), we used a confounder modeling approach to identify the independent effect of experiencing police-related barriers to harm reduction strategies on non-fatal overdose amongst sex workers using drugs within the last six months at each study visit.

RESULTS

Amongst 624 participants, 7.7% overdosed within the last six months at baseline and 27.6% overdosed during the study period, contributing 287 non-fatal overdose events over the 7.5-year period. 68.6% reported police-related barriers to harm reduction strategies during the study. In a multivariate confounder model, exposure to police-related barriers to harm reduction strategies [AOR: 2.15, CI: 1.60-2.90] was independently associated with higher odds of non-fatal overdose after adjustment for key confounders.

CONCLUSIONS

Our findings suggest that in the context of the current overdose crisis, adversarial policing practices may undermine access to lifesaving overdose prevention services and exacerbate overdose risks for marginalized women. Findings underscore the urgent need to scale-up access and remove barriers to progressive harm reduction strategies for women sex workers.

Social inclusion of clients treated for substance abuse in Sweden in the 1980s: A 27-year follow-up

AIM

To investigate social inclusion/exclusion in terms of criminality, substance abuse and participation in the labour market in clients treated for substance abuse in Sweden in the 1980s during a follow-up period of 27 years.

METHOD

SWEDATE data are used for background information on the clients. The data were collected through interviews with clients registered for treatment in 31 in-patient treatment units in 1982 and 1983. Data on labour market status, education and medication related to drugs were collected from public registers. The study population consisted of 1132 individuals, who were followed from the year after exiting from treatment (Year 1) until the end of the follow-up (December 2013).

RESULTS

Among those who survived, the women seem to have succeeded better in terms of social inclusion both at an aggregated level and when the individual pathways were followed during the follow-up period. When comparing pathways between adverse and non-adverse groups during the follow-up period the results show movements from being adverse to non-adverse but also the opposite. In the last follow-up in 2013, the majority of the clients defined as non-adverse for the last nine years were in some way established in the labour market (including studies). In total, about two fifths of the group were in some way established in the labour market.

CONCLUSIONS

The fairly high proportion of clients moving between being adverse and non-adverse during the follow-up might support the perspective suggesting that dependence should not be considered as chronic.

Gender differences in acute recreational drug toxicity: a case series from Oslo, Norway

BACKGROUND

Female drug users report poorer physical and mental health than male drug users. We describe female and male patients treated for acute recreational drug toxicity, and look for gender differences in clinical state, treatment, and toxic agents taken.

METHODS

Retrospective case series from a primary care emergency outpatient clinic and a hospital emergency department in Oslo, Norway. All patients treated for acute recreational drug toxicity from October 2013 through March 2015 were included, except patients with lone alcohol intoxication. Patients were grouped according to whether they had taken opioids or not, as a proxy differentiation between heavy drug users and party drug users. Data from the two clinical settings were analysed separately.

RESULTS

In total, 2495 cases were included, 567 (22.7%) were women. Female patients were younger than males, median 31 vs 34 years (p < 0.001). On most comparisons of clinical variables there were no significant differences between genders. A larger proportion of females in the outpatient opioid group were hypotensive, 10.9% vs 3.9% (p < 0.001). Fewer females were intubated, none vs 21.1% (p = 0.019) in the hospital opioid group, and 6.4% vs 21.0% (p = 0.039) in the hospital non-opioid group. The proportion of gamma-hydroxybutyrate (GHB) poisoning was larger among females both at the outpatient clinic (14.4% vs 8.6%, p < 0.001) and at the hospital (60.3% vs 36.4%, p = 0.001), while the proportion of heroin poisoning was smaller among females at the outpatient clinic (37.1% vs 47.0%, p < 0.001).

CONCLUSION

One in four patients treated for acute recreational drug toxicity were women. Female patients were younger, had more frequently taken GHB and were less frequently intubated. Otherwise, the gender differences regarding clinical state and treatment were small. Although female drug users are known to report poorer health than males, we did not find that women had a more severe clinical course than men when presenting with overdose.

Mortality, cause of death and risk factors in patients with alcohol use disorder alone or poly-substance use disorders: a 19-year prospective cohort study

BACKGROUND

This study investigated cause of death, mortality rates and explored if baseline characteristics were associated with risk of death in patients with alcohol use disorder alone or poly-substance use disorders.

METHODS

This was a prospective, longitudinal study of patients followed for 19 years after entering specialized treatment for substance use disorders. At baseline 291 patients (mean age 38.3 years, standard deviation 11.4 years, 72% male) with high psychiatric co-morbidity were recruited; 130 (45%) had lifetime alcohol use disorder alone, while 161 (55%) had poly-substance use disorders. Time and causes of death were gathered from the Norwegian Cause of Death Registry. Lifetime psychiatric symptom disorders and substance use disorders at baseline were measured with The Composite International Diagnostic Interview and personality disorders at baseline were measured with The Millon Clinical Multiaxial Inventory II.

RESULTS

Patients with alcohol use disorder alone more often died from somatic diseases (58% versus 28%, p = 0.004) and more seldom from overdoses (9% versus 33%, p = 0.002) compared with patients with poly-substance use disorders. The crude mortality rate per 100 person year was 2.2 (95% confidence interval: 1.8-2.7), and the standardized mortality rate was 3.8 (95% confidence interval: 3.2-4.6) in the entire cohort during 19 years after entering treatment. Having lifetime affective disorder at baseline was associated with lower risk of death (Hazard Ratio 0.58, 95% confidence interval: 0.37-0.91). Older age was associated to increased risk of death among men (p < 0.001) and non-significantly among patients with poly-substance use (p = 0.057). The difference in association between age and risk of death was significantly different between men and women (p = 0.011) and patients with alcohol use disorder alone and poly-substance use disorders (p = 0.041).

CONCLUSIONS

Patients with alcohol use disorder alone died more often from somatic disease than patients with poly-substance use disorders, and all subgroups of patients had an increased risk of death compared with the general population. Men with long-lasting substance use disorders are a priority group to approach with directed preventive measures for somatic health before they reach 50 years of age.

The federal plan for health science and technology's response to the opioid crisis: understanding sex and gender differences as part of the solution is overlooked

The Fast-Track Action Committee on (the) Health Science and Technology Response to the Opioid Crisis recently released their draft report for public comment. This report provides the "roadmap" for a coordinated federal research and development response to the opioid crisis. Other than noting the important concerns regarding maternal and neonatal exposure to opioids, the report overlooks the laboratory, clinical, and epidemiological data that inform the need for further research on sex and gender differences in opioid addiction that have critical gender-based treatment and prevention implications. As we embark on research and development, investigations into the neurobiology of pain, opioid use, and addiction must include both females and males in model systems and, similarly, psychological and sociocultural investigations must study women and men. All data should be reported by sex and gender so that gender-specific treatment and prevention strategies derived from this research are provided to practitioners and the public. We encourage biomedical researchers and clinical care providers, as well as the public, to insist that a successful response to the opioid crisis should highlight the importance of understanding sex and gender differences in the current opioid epidemic.

Feasibility of reaching world health organization targets for hepatitis C and the cost-effectiveness of alternative strategies

New drugs for treating hepatitis C have considerably increased the probability of being cured. Treatment uptake, however, is still low. The objectives of this study were to analyse the impact of initiatives that may increase the proportion of infected people on treatment and interventions aimed at reducing the incidence of new infection among people who inject drugs. A compartmental model for Norway was used to simulate hepatitis C and related complications. We analysed 2 different screening initiatives aimed to increase the proportion of infected people on treatment. Interventions aiming at reducing the hepatitis C incidence analysed were opioid substitution therapy (OST), a clean needle and syringe programme and a combination of both. The most cost-effective strategy for increasing hepatitis C treatment uptake was screening by general practitioners while simultaneously allowing for all infected people to be treated. We estimated that this intervention reduces the incidence of hepatitis C by 2030 by 63% compared with the current incidence. The 2 harm reduction strategies both reduced the incidence of hepatitis C by about 70%. Combining an increase in the current clean needles and syringe programme with OST was clearly the most cost-effective option. This strategy would reduce the incidence of hepatitis C by 80% compared with the current incidence by 2030. Thus, interventions to reduce the burden and spread of hepatitis C are cost-effective. Reaching the WHO target of a 90% reduction in hepatitis C incidence by 2030 may be difficult without combining different initiatives.

Economic Evaluation of Direct-Acting Antivirals for Hepatitis C in Norway

PURPOSE

New direct-acting antiviral (DAA) drugs have revolutionized the treatment of hepatitis C in recent years.

OBJECTIVE

Our objective was to analyse the cost effectiveness of combinations of different DAAs compared with ribavirin and peginterferon-α-2a, taking into account rebates from tender negotiations.

METHODS

We used a compartmental model specifically developed for Norway to simulate hepatitis C and complications with and without different DAAs. All costs were based on Norwegian fees and estimates, estimating healthcare sector costs for the year 2016. We performed Monte Carlo simulations on uncertain input parameters to facilitate probabilistic sensitivity analyses.

RESULTS

For patients diagnosed with genotype 1, the combination of paritaprevir, ritonavir, ombitasvir and dasabuvir was cost effective compared with eight other available alternatives, given a cost-effectiveness threshold of €70,000 per quality-adjusted life-year. For genotype 2, the combination of sofosbuvir and ribavirin was the most effective and cost-effective alternative for all patients. Among available alternatives for patients with genotype 3, sofosbuvir in combination with peginterferon and ribavirin was the most cost-effective alternative, although the combination of daclatasvir and sofosbuvir was somewhat more effective.

CONCLUSIONS

For each of the hepatitis C genotypes 1, 2 and 3, there were combinations of DAAs that were cost effective in a Norwegian setting. As a result of recent tender negotiations in Norway, treating all diagnosed patients with hepatitis C with the most cost-effective DAAs will result in lower total expenditure on these medications compared with 2015.

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.

Risk factors associated with drug use before imprisonment in Peru

OBJECTIVE

To assess the prevalence of drug abuse before prison admission and to identify associated sociodemographic and family history risk factors, according to gender, in prisons of Peru.

MATERIALS AND METHODS

A secondary analysis was carried out with data from the First National Prisoner Census 2016, using a questionnaire of 173 items that was applied to the whole prison population of Peru. The types of drugs used before admission were analyzed according to characteristics of the penitentiary population, and generalized linear models were used to calculate prevalence ratios with 95% confidence intervals to identify possible factors associated with drug use.

RESULTS

Out of a population of 76,180 prisoners, 71,184 (93.4%) answered the survey (men 67,071, 94.2%). The overall prevalence of drug consumption before admission was 24.4% (25.3 % in men and 9.1% in women), the highest prevalence in the 18-29 age group (36.3% in men and 14.9% in women). The most commonly used drugs were marijuana (58.2%), coca paste/cocaine or crack (40.3%) and inhalants (1%). The factors most strongly associated with consumption were having a family member who consumed drugs (59.8%), history of previous imprisonment (59.1%), unemployment (48.4%), relationships at school with classmates who had problems with the law (46.9%), background of a family member who attended a penitentiary (38.4%), and history of running away from home before age 15 (35.9%).

CONCLUSIONS

In Peru, drug use is higher in the prison population than in the general population, and there are differences according to sex in the prevalence of drug use and associated factors prior to admission to a prison. The study demonstrated that childhood events, such as child abuse, having a family member imprisoned, having a family member who used drugs, or who previously abused alcohol, are factors associated with drug use in the penitentiary population. Some of these risk factors are modifiable, so it is important to consider these in the design of social and health policies focused on specific subpopulations to prevent drug use and crime.

Sex Work as an Emerging Risk Factor for Human Immunodeficiency Virus Seroconversion Among People who Inject Drugs in the SurvUDI Network

BACKGROUND

Recent analyses have shown an emerging positive association between sex work and human immunodeficiency virus (HIV) incidence among people who inject drugs (PWIDs) in the SurvUDI network.

METHODS

Participants who had injected in the past 6 months were recruited across the Province of Quebec and in the city of Ottawa, mainly in harm reduction programs. They completed a questionnaire and provided gingival exudate for HIV antibody testing. The associations with HIV seroconversion were tested with a Cox proportional hazard model using time-dependent covariables including the main variable of interest, sexual activity (sex work; no sex work; sexually inactive). The final model included significant variables and confounders of the associations with sexual activity.

RESULTS

Seventy-two HIV seroconversions were observed during 5239.2 person-years (py) of follow-up (incidence rates: total = 1.4/100 py; 95% confidence interval [CI], 1.1-1.7; sex work = 2.5/100 py; 95% CI, 1.5-3.6; no sex work = 0.8/100 py; 95% CI, 0.5-1.2; sexually inactive = 1.8/100 py; 95% CI, 1.1-2.5). In the final multivariate model, HIV incidence was significantly associated with sexual activity (sex work: adjusted hazard ratio [AHR], 2.19; 95% CI, 1.13-4.25; sexually inactive: AHR, 1.62; 95% CI, 0.92-2.88), and injection with a needle/syringe used by someone else (AHR, 2.84; 95% CI, 1.73-4.66).

CONCLUSIONS

Sex work is independently associated with HIV incidence among PWIDs. At the other end of the spectrum of sexual activity, sexually inactive PWIDs have a higher HIV incidence rate, likely due to more profound dependence leading to increased vulnerabilities, which may include mental illness, poverty, and social exclusion. Further studies are needed to understand whether the association between sex work and HIV is related to sexual transmission or other vulnerability factors.

Modelling the burden of hepatitis C infection among people who inject drugs in Norway, 1973-2030

Background

Lack of Hepatitis C virus (HCV) incidence data in (Norwegian) high-risk groups impedes the ability to make informed decisions on prevention measures. Thus we rely on modelling to estimate the incidence and burden of HCV infections.

Methods

We constructed a compartmental model for HCV infections in Norway among active and former people who inject drugs (PWIDs). We based yearly transition rates on literature. The model was fitted to absolute numbers of hepatitis C associated cirrhosis, hepatocellular carcinoma (HCC) and death from national data sources (2000–2013). We estimated the number (95%CI) of HCV infections, cirrhosis, HCC and death and disability adjusted life years (DALYs) due to HCV infections in Norway, 1973–2030. We assumed treatment rates in the projected period were similar to those in 2013.

Results

The estimated proportion of chronic HCV (including those with cirrhosis and HCC) among PWIDs was stable from 2000 (49%; 4441/9108) to 2013 (43%; 3667/8587). We estimated that the incidence of HCV among PWIDs was 381 new infections in 2015. The estimated number of people with cirrhosis, HCC, and liver transplant was predicted to increase until 2022 (1537 people). DALYs among active PWIDs estimated to peak in 2006 (3480 DALYs) and decrease to 1870 DALYs in 2030. Chronic HCV infection contributes most to the total burden of HCV infection, and peaks at 1917 DALYs (52%) in 2007. The burden of HCV related to PWID increased until 2006 with 81/100,000 DALYs inhabitants and decreased to 68/100,000 DALYs in 2015.

Conclusion

The burden of HCV associated with injecting drug use is considerable, with chronic HCV infection contributing most to the total burden. This model can be used to estimate the impact of different interventions on the HCV burden in Norway and to perform cost-benefit analyses of various public health measures.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2631-2) contains supplementary material, which is available to authorized users.

A Hazard Analysis of Risk Factors of Mortality in Individuals Who Inject Drugs in Denver CO

Despite multiple risk factors for mortality among People Who Inject Drugs (PWID), more research is warranted that examines sub-populations within PWID. Mortality data from PWID participating in longitudinal HIV prevention research in Denver were obtained from The Colorado Department of Public Health and Environment. Risk factors for both all-cause and acute-toxicity related mortality were analyzed using Cox proportional hazards regression. Two-thousand seven individuals were interviewed at baseline. Eighty-six individuals died during the time frame of the study, 58 of which were due to acute-toxicity. Disabled (HR = 3.3, p < 0.001), gay/lesbian-identified (HR = 2.6, p = 0.03), white race/ethnicity (HR = 2.4, p = 0.003), and use of a shared cooker (HR = 2.1, p = 0.01) were important adjusted risk factors. These suggest that drug and HIV interventions should utilize techniques that can address the needs of marginalized populations in addition to HIV drug risk behaviors.

Sex-Based Differences in Rates, Causes, and Predictors of Death Among Injection Drug Users in Vancouver, Canada

In the present study, we sought to identify rates, causes, and predictors of death among male and female injection drug users (IDUs) in Vancouver, British Columbia, Canada, during a period of expanded public health interventions. Data from prospective cohorts of IDUs in Vancouver were linked to the provincial database of vital statistics to ascertain rates and causes of death between 1996 and 2011. Mortality rates were analyzed using Poisson regression and indirect standardization. Predictors of mortality were identified using multivariable Cox regression models stratified by sex. Among the 2,317 participants, 794 (34.3%) of whom were women, there were 483 deaths during follow-up, with a rate of 32.1 (95% confidence interval (CI): 29.3, 35.0) deaths per 1,000 person-years. Standardized mortality ratios were 7.28 (95% CI: 6.50, 8.14) for men and 15.56 (95% CI: 13.31, 18.07) for women. During the study period, mortality rates related to infection with human immunodeficiency virus (HIV) declined among men but remained stable among women. In multivariable analyses, HIV seropositivity was independently associated with mortality in both sexes (all P < 0.05). The excess mortality burden among IDUs in our cohorts was primarily attributable to HIV infection; compared with men, women remained at higher risk of HIV-related mortality, indicating a need for sex-specific interventions to reduce mortality among female IDUs in this setting.

Gender differences in drug abuse in the forensic toxicological approach

Gender differences in substance use/abuse have been the focus of research in the last 15 years. Initiation, use patterns, acceleration of disease course, and help-seeking patterns are known to be influenced by gender differences with regard to biological, psychological, cultural and socioeconomic factors. This paper presents a systematic review of published data on gender differences in the use/abuse of psychoactive and psychotic drugs, focusing on the importance of a multidisciplinary approach. The basis for this paper was obtained by Medline searches using the search terms "human" and "gender", combined with individual drug names or "drugs of abuse". The reference lists of these papers were further checked for other relevant studies. The gender difference in drug abuse is more evident in adults than in adolescents (13-19 years): adult men are 2-3 times more likely than women to develop drug abuse/dependence disorders and approximately 4 times as likely to have an alcohol use disorder. Such prevalence rates have not been observed in adolescents. Differences between men and women involve: (i) the biological response to the drug, (ii) the progression to drug dependence, and (iii) the comorbid psychiatric diagnoses, which may be due to both sociocultural factors and innate biological differences. A crucial role played by ovarian hormones (oestrogens and progesterone) has been documented in both human and animal model studies. Epidemiological data on how particular psychobiological and physiological characteristics in females influence vulnerability to both drug addiction and toxicological consequences of drugs are still in their infancy. Significant gaps remain in our knowledge, which are primarily attributable to the lack of empirical data that only a systematic and multidisciplinary approach to the topic can generate. The introduction of gender into forensic toxicological evaluations may help elucidate the relationship between the body's absorption of abused drugs (alone or in combination) and the onset of intoxications, both lethal and none.

Interferon Lambda 4 Genotype Is Associated With Jaundice and Elevated Aminotransferase Levels During Acute Hepatitis C Virus Infection: Findings From the InC3 Collaborative

Symptomatic acute HCV infection and interferon lambda 4 (IFNL4) genotypes are important predictors of spontaneous viral clearance. Using data from a multicohort database (Injecting Cohorts [InC3] Collaborative), we establish an independent association between host IFNL4 genotype and symptoms of acute hepatitis C virus infection. This association potentially explains the higher spontaneous clearance observed in some patients with symptomatic disease.

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.

Gender differences in mortality among treated opioid dependent patients

AIMS

To assess gender differences in characteristics, mortality rates, and the causes and predictors of death among treated opioid-dependent individuals.

METHODS

Linked vital statistics data were obtained for all individuals first enrolled in publicly funded pharmacological treatment for opioid dependence in California from 2006 to 2010. Standardized mortality ratios (SMR) were calculated by gender. Cox proportional hazards models with time-varying covariates were fitted to determine the effect of gender on the hazard of all-cause mortality, controlling for covariates.

RESULTS

Over a median 2.6 years (interquartile range: 1.4-3.7), 1.031 deaths were observed, including 2.2% (259/11,564) of women and 3.7% (772/20,758) of men. Women had a greater increased risk of mortality compared to the general population (SMR 5.1 95% CI: 4.5, 5.7) than men (SMR 4.3 95% CI: 4.0, 4.6). The relative risk of death for women compared with men was 1.18 (95% CI: 1.02, 1.36). Women had a lower instantaneous hazard of all-cause mortality than men (HR 0.58, 95% CI 0.50, 0.68), controlling for other factors. Significant interaction effects indicated that among men, mortality risk was decreased by full-time employment and increased by non-daily heroin use (relative to daily use) and medical problems. Concurrent opioid and methamphetamine/cocaine use increased mortality risk among women and decreased it among men.

CONCLUSIONS

Treatment for opioid dependence is likely to reduce mortality risk among men by addressing employment and medical problems, and via interventions to reduce overdose risk after heroin abstinence, and among women by attending to the concurrent use of methamphetamine/cocaine and opioids.

Biomedical HIV Prevention Including Pre-exposure Prophylaxis and Opiate Agonist Therapy for Women Who Inject Drugs: State of Research and Future Directions

Women who inject drugs (WWID) are at higher risk of HIV compared with their male counterparts as a result of multiple factors, including biological, behavioral, and sociostructural factors, yet comparatively little effort has been invested in testing and delivering prevention methods that directly target this group. In this article, we discuss the need for expanded prevention interventions for WWID, focusing on 2 safe, effective, and approved, yet underutilized biomedical prevention methods: opiate agonist therapy (OAT) and oral pre-exposure prophylaxis (PrEP). Although both interventions are well researched, they have not been well examined in the context of gender. We discuss the drivers of women injectors' higher HIV risk, review the effectiveness of OAT and PrEP interventions among women, and explain why these new HIV prevention tools should be prioritized for WWID. There is substantial potential for impact of OAT and PrEP programs for WWID in the context of broader gender-responsive HIV prevention initiatives. Although awaiting efficacy data on other biomedical approaches in the HIV prevention research "pipeline," we propose that the scale-up and implementation of these proven, safe, and effective interventions are needed now.

Temporal trends in mortality among people who use drugs compared with the general Dutch population differ by hepatitis C virus and HIV infection status

OBJECTIVES

We aimed to identify temporal trends in all-cause and cause-specific mortality rates among people who use drugs (PWUD) compared with the general Dutch population and to determine whether mortality trends differed by hepatitis C virus (HCV)/HIV (co) infection status.

DESIGN

Longitudinal cohort study.

METHODS

Using data from the Amsterdam Cohort Studies among 1254 PWUD (1985-2012), all-cause and cause-specific standardized mortality ratios (SMRs) were calculated; SMRs were stratified by serological group (HCV/HIV-uninfected, HCV-monoinfected, and HCV/HIV-coinfected) and calendar period. Temporal trends were estimated using Poisson regression.

RESULTS

The overall all-cause SMR was 13.9 (95% confidence interval 12.6-15.3). The SMR significantly declined after 1996, especially due to a decline among women (P < 0.001). The highest SMR was observed among HCV/HIV-coinfected individuals during 1990-1996 (SMR 61.9, 95% confidence interval 50.4-76.0), which significantly declined after this period among women (P = 0.001). In contrast, SMR for HCV-monoinfected, and HCV/HIV-uninfected PWUD did not significantly change over time. The SMR for non-natural deaths significantly declined (P = 0.007), whereas the SMR for HIV-related deaths was the highest during all calendar periods.

CONCLUSIONS

We found evidence for declining all-cause mortality among PWUD compared with the general population rates. Those with HCV/HIV-coinfection showed the highest SMR. The decline in the SMR seems to be attributable to the decline in mortality among women. Mortality rates due to non-natural deaths came closer to those of the general population over time. However, HIV-related deaths remain an important cause of mortality among PWUD when compared with the general Dutch population. This study reinforces the importance of harm-reduction interventions and HCV/HIV treatment to reduce mortality among PWUD.