Mortality among cocaine users: a systematic review of cohort studies

Crack cocaine and dreams: the view of users

This paper aims to describe the dream content of crack cocaine users as per their view and analyze its interference in the drug withdrawal process. This is a qualitative research with 21 crack cocaine users. Consuming crack cocaine during the dream meant a proof of failure or compensatory pleasure or warning of potential relapse; not consuming the crack cocaine meant the emergence of withdrawal symptoms or the success at overcoming drug dependence. Dream interpretation may lead users to craving and relapse. The outcomes may contribute to effective therapeutic interventions.

Changes in the prevalence and correlates of cocaine use and cocaine use disorder in the United States, 2001-2002 and 2012-2013

To present nationally representative data on changes in the prevalences of 12-month cocaine use, cocaine use disorder (CocUD) and 12-month CocUD among 12-month cocaine users between 2001 and 2002 and 2012-2013. Data were derived from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and the 2012-2013 NESARC-III. Between 2001 and 2002 and 2012-2013, prevalences of 12-month cocaine use and DSM-IV CocUD significantly increased and 12-month CocUD among 12-month users significantly decreased. Increases in risk of cocaine use were seen across nearly all sociodemographic subgroups while increases in CocUD were observed among women, those in the oldest age group, Whites, individuals with the lowest incomes and highest education, and those residing in urban areas. Prevalence of CocUD among users significantly declined overall and among men, individuals aged 30-44 years old, the never-married, respondents with incomes between $20,000 and $34,000, and those residing in the Midwest. Increases in coca cultivation in Colombia in recent years together with increases in the purity of cocaine entering the U.S. portend more significant increases in the rates of cocaine use and CocUD in the U.S. along with increases in cocaine-related morbidity and mortality. The results of this study support the continued monitoring of cocaine use and CocUD in the U.S., especially in view of the narrowing of the gender gap and shifts in race-ethnic, age and socioeconomic differentials seen between 2001 and 2002 and 2012-2013.

Palliative care for patients with a substance use disorder and multiple problems: a study protocol

BACKGROUND

The specific palliative care needs and problems of patients with a substance use disorder and multiple problems, and those of their proxies, are under recognized Besides, the organization of palliative care, including the division of health care professionals' responsibilities, is often unclear. Perspectives of patients and proxies are hardly known. We describe the outline of a study designed to explore how palliative care for patients with a substance use disorder is organized in the Netherlands and to explore problems and needs, as well as possible improvements from the healthcare professionals', patients' and proxies' perspective. The aim of this protocol paper is to provide insights in ways to conduct research with vulnerable research participants and to offer a detailed description of the study design. The broader study aims to gain insight in and formulate recommendations on how to improve palliative care for patients with a substance use disorder.

METHODS

A qualitative study with patients, proxies and healthcare professionals. Semi-structured interviews will be held with 10-15 patients who suffer from a severe substance use disorder. They are in a palliative care trajectory and either diagnosed with a chronic or life-threatening disease or, as a result of addictive behavior, a physical deterioration without the prospect of cure. Semi-structured interviews will also be held with 5-10 proxies. Healthcare professionals, volunteers and/or 'experts-by-experience' (n = 24-40) will be participating in semi-structured group interviews. All (group) interviews will be thematically analyzed. Additionally, a strengths, weaknesses, opportunities and threats (SWOT) analysis will be applied to the group interview data with the aim to summarize and concretize the findings.

DISCUSSION

Everyone has a right to an optimal end-of-life phase of life and a dignified dying process. This study will provide valuable knowledge about palliative care for patients with a substance use disorder and explicitly bring to light the needs and problems of the patients and their proxies and healthcare professionals in a palliative care phase.

Differences in mortality in a cohort of cocaine use disorder patients with concurrent alcohol or opiates disorder

AIMS

To study mortality in a cohort of cocaine use disorder patients, and compare results in those with concurrent alcohol or opiates disorder.

DESIGN, SETTING AND PARTICIPANTS

A cohort of 10 539 cocaine use disorder individuals entering drug treatment in public out-patient centres in the city of Barcelona was followed from 1997 to 2011. Participants were divided at baseline into three groups: those with only cocaine use disorder (CUD), those with cocaine and alcohol use disorder but not opioid (CAUD) and those with cocaine and opioid use disorder (COUD). Mortality was assessed through the Spanish National Mortality Register.

MEASUREMENTS

Crude mortality rates (CMR), standardized mortality ratios (SMR) and rate ratios (RR) were calculated for each group. A multivariable Cox regression model was fitted to obtain adjusted mortality hazard ratios (aHR) of CAUD and COUD with respect to CUD. Specific mortality causes were also examined.

FINDINGS

The total of 716 deaths registered resulted in a CMR = 6.0/1000 person-years (PY); 95% confidence interval (CI) = 5.1-7.0 for CUD, CMR = 5.8/1000 PY (95% CI = 4.9-6.7) for CAUD and CMR = 20.7/1000 PY (95% CI = 18.8-22.8) for COUD, with no significant differences among sexes. Compared with the general population, mortality was four times higher (SMR = 4.1, 95% CI = 3.5-4.8) among CUD, more than three times among CAUD (SMR = 3.4, 95% CI = 2.9-3.9) and more than 10 times among COUD (SMR = 11.6, 95% CI = 10.5-12.8), being always higher in women. External injuries, led by overdose, accumulated the biggest percentage of deaths among the three groups, but infectious diseases showed the highest excess mortality. Some differences regarding causes of death were observed between the three groups.

CONCLUSIONS

Mortality risk and excess mortality are significantly greater among those with cocaine and opiates use disorder than among people with only cocaine use disorder or cocaine and alcohol use disorder.

Pilot Studies Examining Feasibility of Substance Use Disorder Screening and Treatment Linkage at Urban Sexually Transmitted Disease Clinics

BACKGROUND

Sexually transmitted disease (STD) clinics provide critical public health services for screening and treatment of sexually transmitted infections throughout the United States. These settings serve high-risk populations, often on a walk-in basis, and may be promising venues for integrating substance use disorder (SUD) services.

METHODS

We report findings from 2 pilot studies conducted at Baltimore City Health Department's STD clinics. The screening study characterized rates of SUDs among STD clinic patients. Patients waiting for services completed a diagnostic interview mapping to Diagnostic and Statistical Manual of Mental Disorders, 5th Edition SUD criteria (n = 100). The Treatment Linkage Feasibility study examined the feasibility of linking STD clinic patients with opioid and/or cocaine use disorders to SUD treatment in the community (n = 21), using SUD-focused Patient Navigation services for 1 month after the STD clinic visit. Assessments were conducted at baseline and 1-month follow-up.

RESULTS

In the screening study, the majority of STD clinic patients met diagnostic criteria for alcohol and/or drug SUD (57%). Substance-specific SUD rates among patients were 35% for alcohol, 31% for cannabis, 11% for opioids, and 8% for stimulants (cocaine/amphetamines). In the Treatment Linkage Feasibility study, 57% (12/21) of participants attended at least 1 SUD service, and 38% (8/21) were actively enrolled in SUD treatment by 1-month follow-up. The sample reported significant reductions in past 30-day cocaine use from baseline to follow-up (P = 0.01).

CONCLUSIONS

SUD rates are high among STD clinic patients. STD clinics are viable settings for initiating SUD treatment linkage services. Larger-scale research on integrating SUD services in these settings is needed.

Morbidity and mortality in homeless individuals, prisoners, sex workers, and individuals with substance use disorders in high-income countries: a systematic review and meta-analysis

BACKGROUND

Inclusion health focuses on people in extremely poor health due to poverty, marginalisation, and multimorbidity. We aimed to review morbidity and mortality data on four overlapping populations who experience considerable social exclusion: homeless populations, individuals with substance use disorders, sex workers, and imprisoned individuals.

METHODS

For this systematic review and meta-analysis, we searched MEDLINE, Embase, and the Cochrane Library for studies published between Jan 1, 2005, and Oct 1, 2015. We included only systematic reviews, meta-analyses, interventional studies, and observational studies that had morbidity and mortality outcomes, were published in English, from high-income countries, and were done in populations with a history of homelessness, imprisonment, sex work, or substance use disorder (excluding cannabis and alcohol use). Studies with only perinatal outcomes and studies of individuals with a specific health condition or those recruited from intensive care or high dependency hospital units were excluded. We screened studies using systematic review software and extracted data from published reports. Primary outcomes were measures of morbidity (prevalence or incidence) and mortality (standardised mortality ratios [SMRs] and mortality rates). Summary estimates were calculated using a random effects model.

FINDINGS

Our search identified 7946 articles, of which 337 studies were included for analysis. All-cause standardised mortality ratios were significantly increased in 91 (99%) of 92 extracted datapoints and were 11·86 (95% CI 10·42-13·30; I2=94·1%) in female individuals and 7·88 (7·03-8·74; I2=99·1%) in men. Summary SMR estimates for the International Classification of Diseases disease categories with two or more included datapoints were highest for deaths due to injury, poisoning, and other external causes, in both men (7·89; 95% CI 6·40-9·37; I2=98·1%) and women (18·72; 13·73-23·71; I2=91·5%). Disease prevalence was consistently raised across the following categories: infections (eg, highest reported was 90% for hepatitis C, 67 [65%] of 103 individuals for hepatitis B, and 133 [51%] of 263 individuals for latent tuberculosis infection), mental health (eg, highest reported was 9 [4%] of 227 individuals for schizophrenia), cardiovascular conditions (eg, highest reported was 32 [13%] of 247 individuals for coronary heart disease), and respiratory conditions (eg, highest reported was 9 [26%] of 35 individuals for asthma).

INTERPRETATION

Our study shows that homeless populations, individuals with substance use disorders, sex workers, and imprisoned individuals experience extreme health inequities across a wide range of health conditions, with the relative effect of exclusion being greater in female individuals than male individuals. The high heterogeneity between studies should be explored further using improved data collection in population subgroups. The extreme health inequity identified demands intensive cross-sectoral policy and service action to prevent exclusion and improve health outcomes in individuals who are already marginalised.

FUNDING

Wellcome Trust, National Institute for Health Research, NHS England, NHS Research Scotland Scottish Senior Clinical Fellowship, Medical Research Council, Chief Scientist Office, and the Central and North West London NHS Trust.

Higher Impulsivity As a Distinctive Trait of Severe Cocaine Addiction among Individuals Treated for Cocaine or Alcohol Use Disorders

AIMS

Despite alcohol being the most often used addictive substance among addicted patients, use of other substances such as cocaine has increased over recent years, and the combination of both drugs aggravates health impairment and complicates clinical assessment. The aim of this study is to identify and characterize heterogeneous subgroups of cocaine- and alcohol-addicted patients with common characteristics based on substance use disorders, psychiatric comorbidity and impulsivity.

METHODS

A total of 214 subjects with cocaine and/or alcohol use disorders were recruited from outpatient treatment programs and clinically assessed. A latent class analysis was used to establish phenotypic categories according to diagnosis of cocaine and alcohol use disorders, mental disorders, and impulsivity scores. Relevant variables were examined in the latent classes (LCs) using correlation and analyses of variance and covariance.

RESULTS

Four LCs of addicted patients were identified: Class 1 (45.3%) formed by alcohol-dependent patients exhibiting lifetime mood disorder diagnosis and mild impulsivity; Class 2 (14%) formed mainly by lifetime cocaine use disorder patients with low probability of comorbid mental disorders and mild impulsivity; Class 3 (10.7%) formed by cocaine use disorder patients with elevated probability to course with lifetime anxiety, early and personality disorders, and greater impulsivity scores; and Class 4 (29.9%) formed mainly by patients with alcohol and cocaine use disorders, with elevated probability in early and personality disorders and elevated impulsivity. Furthermore, there were significant differences among classes in terms of Diagnostic and Statistical Manual of Mental Disorders-4th Edition-Text Revision criteria for abuse and dependence: Class 3 showed more criteria for cocaine use disorders than other classes, while Class 1 and Class 4 showed more criteria for alcohol use disorders.

CONCLUSION

Cocaine- and alcohol-addicted patients who were grouped according to diagnosis of substance use disorders, psychiatric comorbidity, and impulsivity show different clinical and sociodemographic variables. Whereas mood and anxiety disorders are more prevalent in alcohol-addicted patients, personality disorders are associated with cocaine use disorders and diagnosis of comorbid substance use disorders. Notably, increased impulsivity is a distinctive characteristic of patients with severe cocaine use disorder and comorbid personality disorders. Psychiatric disorders and impulsivity should be considered for improving the stratification of addicted patients with shared clinical and sociodemographic characteristics to select more appropriate treatments.

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.

Health outcomes associated with crack-cocaine use: Systematic review and meta-analyses

BACKGROUND

Crack-cocaine use is prevalent largely in socio-economically marginalized populations in the Americas. Its use has been associated with diverse health outcomes, yet no recent or systematic reviews of these exist.

METHODS

A systematic review of health outcomes associated with crack-cocaine use was performed, using MEDLINE, Scopus, Web of Science, CINAHL, PsycINFO, and LILACS up to October 2016. Search terms included crack-cocaine and health outcome-related keywords, targeting peer-reviewed studies on quantified health outcomes associated with crack-cocaine use. Random effects meta-analyses produced pooled odds ratios. Levels of evidence for major results were assessed using the GRADE approach. A review protocol was registered with PROSPERO (CRD42016035486).

RESULTS

Of 4700 articles returned, 302 met eligibility criteria, reporting on health outcomes for 14 of 22 ICD-10 chapters. Conclusive evidence and meta-analyses showed positive associations between crack-cocaine use and blood/sexually transmitted diseases (HIV and hepatitis C virus, others); moderate evidence and meta-analyses supported associations with neonatal health, and violence. There were mixed associations for mental and other health outcomes, yet insufficient evidence to perform meta-analyses for many categories (e.g., mortality). Most underlying research was of limited or poor quality, with crack-cocaine commonly assessed as a secondary covariate.

CONCLUSIONS

Crack-cocaine use was associated with a range of health outcomes, although it was unclear if there was direct causal impact, interactions between risk factors, or external drivers of both crack-cocaine use and outcomes. Rigorous epidemiological studies are needed to systematically assess health outcomes of crack-cocaine use and underlying pathways, also to inform evidence-based interventions.

Intentional cannabis use to reduce crack cocaine use in a Canadian setting: A longitudinal analysis

BACKGROUND

No effective pharmacotherapies exist for the treatment of crack cocaine use disorders. Emerging data suggests that cannabinoids may play a role in reducing cocaine-related craving symptoms. This study investigated the intentional use of cannabis to reduce crack use among people who use illicit drugs (PWUD).

METHODS

Data were drawn from three prospective cohorts of PWUD in Vancouver, Canada. Using data from participants reporting intentional cannabis use to control crack use, we used generalized linear mixed-effects modeling to estimate the independent effect of three pre-defined intentional cannabis use periods (i.e., before, during and after first reported intentional use to reduce crack use) on frequency of crack use.

RESULTS

Between 2012 and 2015, 122 participants reported using cannabis to reduce crack use, contributing a total of 620 observations. In adjusted analyses, compared to before periods, after periods were associated with reduced frequency of crack use (Adjusted Odds Ratio [AOR]=1.89, 95% Confidence Interval [CI]: 1.02-3.45), but not the intentional use periods (AOR=0.85, 95% CI: 0.51-1.41). Frequency of cannabis use in after periods was higher than in before periods (AOR=4.72, 95% CI: 2.47-8.99), and showed a tendency to lower frequency than in intentional cannabis use periods (AOR=0.56, 95% CI: 0.32-1.01).

CONCLUSIONS

A period of intentional cannabis use to reduce crack use was associated with decreased frequency of crack use in subsequent periods among PWUD. Further clinical research to assess the potential of cannabinoids for the treatment of crack use disorders is warranted.

Association of elevated ambient temperature with death from cocaine overdose

BACKGROUND

Ecologic data suggest that elevated outdoor temperature is correlated with mortality rates from cocaine overdose. Using non-aggregated death records, we studied the association of hot temperatures with risk of death from cocaine overdose.

METHODS

We carried out a case-crossover study of all deaths from cocaine or other drug overdose between the months of May and September, from 2000 through 2013 in Quebec, Canada. We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between maximum outdoor temperature and death from cocaine or other drug overdose. The main outcome measure was death from cocaine overdose as a function of maximum temperature the day of death and the days immediately preceding death.

RESULTS

There were 316 deaths from cocaine overdose and 446 from other drug overdoses during the study. Elevated temperature the preceding week was associated with the likelihood of death from cocaine but not other drug overdose. Compared with 20°C, a maximum weekly temperature of 30°C was associated with an OR of 2.07 for death from cocaine overdose (95% CI 1.15-3.73), but an OR of 1.03 for other drug overdoses (95% CI 0.60-1.75). Associations for cocaine overdose were present with maximum daily temperature the day of and each of the three days preceding death.

CONCLUSIONS

Elevated ambient temperature is associated with the risk of death from cocaine overdose. Public health practitioners and drug users should be aware of the added risk of mortality when cocaine is used during hot days.

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.

Impact of Cocaine Use on Acute Ischemic Stroke Patients: Insights from Nationwide Inpatient Sample in the United States

Cocaine is the third most common substance of abuse after cannabis and alcohol. The use of cocaine as an illicit substance is implicated as a causative factor for multisystem derangements ranging from an acute crisis to chronic complications. Vasospasm is the proposed mechanism behind adverse events resulting from cocaine abuse, acute ischemic strokes (AIS) being one of the few. Our study looked into in-hospital outcomes owing to cocaine use in the large population based study of AIS patients. Using the national inpatient sample (NIS) database from 2014 of United States of America, we identified AIS patients with cocaine use using International Classification of Disease, Ninth Revision (ICD-9) codes. We compared demographics, mortality, in-hospital outcomes and comorbidities between AIS with cocaine use cohort versus AIS without cocaine use cohort. Acute ischemic strokes (AIS) with cocaine group consisted of higher number of older patients (> 85 years) (25.6% versus 18.7%, p <0.001) and females (52.4% versus 51.0%, p <0.001). Cocaine cohort had higher incidence of valvular disorders (13.2% versus 9.7%, p <0.001), venous thromboembolism (3.5% versus 2.6%, p<0.03), vasculitis (0.9% versus 0.4%, p <0.003), sudden cardiac death (0.4% versus 0.2%, p<0.02), epilepsy (10.1% versus 7.4%, p <0.001) and major depression (13.2% versus 10.7%, p<0.007). The multivariate logistic regression analysis found cocaine use to be the major risk factor for hospitalization in AIS cohort. In-hospital mortality (odds ratio (OR)= 1.4, 95% confidence interval= 1.1-1.9, p <0.003) and the disposition to short-term hospitals (odds ratio (OR)= 2.6, 95% confidence interval = 2.1-3.3, p <0.001) were also higher in cocaine cohort. Venous thromboembolism was observed to be linked with cocaine use (OR= 1.5, 95% confidence interval= 1.0-2.1, p < 0.01) but less severely than vasculitis (OR= 3.0, 95% confidence interval= 1.6-5.8, p <0.001). Further prospective research is warranted in this direction to improve the outcomes for AIS and lessen the financial burden on the healthcare system of the United States.

An exploratory study of information sources and key findings on UK cocaine-related deaths

Cocaine-related deaths have increased since the early 1990s in Europe, including the UK. Being multi-factorial, they are difficult to define, detect and record. The European Monitoring Centre for Drugs and Drug Addiction commissioned research to: describe trends reported to Special Mortality Registries and General Mortality Registers; provide demographic and drug-use characteristic information of cases; and establish how deaths are identified and classified. A questionnaire was developed and piloted amongst all European Monitoring Centre for Drugs and Drug Addiction Focal Point experts/Special Mortality Registries: 19 (63%) responded; nine countries provided aggregated data. UK General Mortality Registers use cause of death and toxicology to identify cocaine-related deaths. Categorisation is based on International Classification of Diseases codes. Special Mortality Registries use toxicology, autopsy, evidence and cause of death. The cocaine metabolites commonly screened for are: benzoylecgonine, ecgonine methyl ester, cocaethylene and ecgonine. The 2000s saw a generally accelerating upward trend in cases, followed by a decline in 2009. The UK recorded 2700-2900 deaths during 1998-2012. UK Special Mortality Registry data (2005-2009) indicate: 25-44 year-olds account for 74% of deaths; mean age=34 (range 15-81) years; 84% male. Cocaine overdoses account for two-thirds of cases; cocaine alone being mentioned/implicated in 23% in the UK. Opioids are involved in most (58%) cocaine overdose cases.

Drug abuse-associated mortality across the lifespan: a population-based longitudinal cohort and co-relative analysis

PURPOSE

Nationwide data have been lacking on drug abuse (DA)-associated mortality. We do not know the degree to which this excess mortality results from the characteristics of drug-abusing individuals or from the effects of DA itself.

METHOD

DA was assessed from medical, criminal, and prescribed drug registries. Relative pairs discordant for DA were obtained from the Multi-Generation and Twin Registers. Mortality was obtained from the Swedish Mortality registry.

RESULTS

We examined all individuals born in Sweden 1955-1980 (n = 2,696,253), 75,061 of whom developed DA. The mortality hazard ratio (mHR) (95% CIs) for DA was 11.36 (95% CIs, 11.07-11.66), substantially higher in non-medical (18.15, 17.51-18.82) than medical causes (8.05, 7.77-8.35) and stronger in women (12.13, 11.52-12.77) than in men (11.14, 10.82-11.47). Comorbid smoking and alcohol use disorder explained only a small proportion of the excess DA-associated mortality. Co-relative analyses demonstrated substantial familial confounding in the DA-mortality association with the strongest direct effects seen in middle and late-middle ages. The mHR was highest for opiate abusers (24.57, 23.46-25.73), followed by sedatives (14.19, 13.11-15.36), cocaine/stimulants (12.01, 11.36-12.69), and cannabis (10.93, 9.94-12.03).

CONCLUSION

The association between registry-ascertained DA and premature mortality is very strong and results from both non-medical and medical causes. This excess mortality arises both indirectly-from characteristics of drug-abusing persons-and directly from the effects of DA. Excess mortality of opiate abuse was substantially higher than that observed for all other drug classes. These results have implications for interventions seeking to reduce the large burden of DA-associated premature mortality.

The Impact of Benzodiazepine Use on Mortality Among Polysubstance Users in Vancouver, Canada

OBJECTIVE

Illicit drug use is a well-established risk factor for increased morbidity and mortality. However, little is known about the impact of benzodiazepine use on mortality among populations of polysubstance users. This study aimed to identify the effect of benzodiazepine use on mortality among a prospective cohort of people in Canada who inject drugs (PWID).

METHODS

A cohort of PWID in Vancouver, Canada, was prospectively followed from May 1996 through November 2013. Data on participants were linked to the provincial vital statistics registry to ascertain mortality rates and causes of death. Multivariable extended Cox regression with time-dependent variables was used to investigate the relationship between benzodiazepine use and time to all-cause mortality.

RESULTS

During the study period, 2,802 participants were followed for a median of 67 months (interquartile range: 25-107). In total, 527 (18.8%) participants died, for an incidence density of mortality of 2.9 (95% confidence interval [CI] 2.7, 3.2) deaths per 100 person-years. After adjusting for HIV infection and other potential confounders, benzodiazepine use was independently associated with increased all-cause mortality (adjusted hazard ratio = 1.86, 95% CI 1.38, 2.51) and had a higher risk for mortality than all other traditional substances of abuse among this population. Results were consistent when non-overdose mortality was considered.

CONCLUSION

In this setting, benzodiazepine use was more strongly associated with mortality than any other substance of abuse. Greater recognition of the safety concerns related to benzodiazepines and strategies to prevent diversion to illicit use are needed.

Reading LINEs within the cocaine addicted brain

INTRODUCTION

Long interspersed element (LINE)-1 (L1) is a type of retrotransposon capable of mobilizing into new genomic locations. Often studied in Mendelian diseases or cancer, L1s may also cause somatic mutation in the developing central nervous system. Recent reports showed L1 transcription was activated in brains of cocaine-treated mice, and L1 retrotransposition was increased in cocaine-treated neuronal cell cultures. We hypothesized that the predisposition to cocaine addiction may result from inherited L1s or somatic L1 mobilization in the brain.

METHODS

Postmortem medial prefrontal cortex (mPFC) tissue from 30 CA and 30 control individuals was studied. An Alexafluor488-labeled NeuN antibody and fluorescence activated nuclei sorting were used to separate neuronal from non-neuronal cell nuclei. L1s and their 3' flanking sequences were amplified from neuronal and non-neuronal genomic DNA (gDNA) using L1-seq. L1 DNA libraries from the neuronal gDNA were sequenced on an Illumina HiSeq2000. Sequences aligned to the hg19 human genome build were analyzed for L1 insertions using custom "L1-seq" bioinformatics programs.

RESULTS

Previously uncataloged L1 insertions, some validated by PCR, were detected in neurons from both CA and control brain samples. Steady-state L1 mRNA levels in CA and control mPFC were also assessed. Gene ontology and pathway analyses were used to assess relationships between genes putatively disrupted by novel L1s in CA and control individuals. L1 insertions in CA samples were enriched in gene ontologies and pathways previously associated with CA.

CONCLUSIONS

We conclude that neurons in the mPFC harbor L1 insertions that have the potential to influence predisposition to CA.

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.

Excess mortality among people who report lifetime use of illegal drugs in the United States: A 20-year follow-up of a nationally representative survey

OBJECTIVE

The purpose of this study was to determine the mortality risks, over 20 years of follow-up in a nationally representative sample, associated with illegal drug use and to describe risk factors for mortality.

METHODS

We analyzed data from the 1991 National Health Interview Survey, which is a nationally representative household survey in the United States, linked to the National Death Index through 2011. This study included 20,498 adults, aged 18-44 years in 1991, with 1047 subsequent deaths. A composite variable of self-reported lifetime illegal drug use was created (hierarchical categories of heroin, cocaine, hallucinogens/inhalants, and marijuana use).

RESULTS

Mortality risk was significantly elevated among individuals who reported lifetime use of heroin (HR=2.40, 95% CI: 1.65-3.48) and cocaine (HR=1.27, 95% CI: 1.04-1.55), but not for those who used hallucinogens/inhalants or marijuana, when adjusting for demographic characteristics. Baseline health risk factors (smoking, alcohol use, physical activity, and BMI) explained the greatest amount of this mortality risk. After adjusting for all baseline covariates, the association between heroin or cocaine use and mortality approached significance. In models adjusted for demographics, people who reported lifetime use of heroin or cocaine had an elevated mortality risk due to external causes (poisoning, suicide, homicide, and unintentional injury). People who had used heroin, cocaine, or hallucinogens/inhalants had an elevated mortality risk due to infectious diseases.

CONCLUSIONS

Heroin and cocaine are associated with considerable excess mortality, particularly due to external causes and infectious diseases. This association can be explained mainly by health risk behaviors.

The prominence of smoking-related mortality among individuals with alcohol- or drug-use disorders

INTRODUCTION AND AIMS

Even though individuals with substance-use disorders have a high prevalence of tobacco smoking, surprisingly little is known about smoking-related mortality in these populations. The current retrospective cohort study aims to address this gap.

DESIGN AND METHODS

The study sample included cohorts of individuals hospitalised in California between 1990 and 2005 with alcohol- (n = 509 422), cocaine- (n = 35 276), opioid- (n = 53 172), marijuana- (n = 15 995) or methamphetamine-use (n = 36 717) disorders. Death records were linked to inpatient data. Age-, race- and sex-adjusted standardised mortality ratios (SMR) were generated for 19 smoking-related causes of death.

RESULTS

Smoking-related conditions comprised 49% (79 188/163 191) of total deaths in the alcohol, 40% (1412/3570) in the cocaine, 39% (4285/11 091) in the opioid, 42% (554/1332) in the methamphetamine and 36% (1122/3095) in the marijuana cohorts. The SMRs for all smoking-linked diseases were: alcohol, 3.57 (95% confidence interval [CI] = 3.55 to 3.58); cocaine, 2.40 (95% CI = 2.39 to 2.41); opioid, 4.26 (95% CI = 4.24 to 4.27); marijuana, 3.73 (95% CI = 3.71 to 3.74); and methamphetamine, 2.58 (95% CI = 2.57 to 2.59). The SMRs for almost all of the 19 cause-specific smoking-related outcomes were elevated across cohorts.

DISCUSSION AND CONCLUSIONS

Given the current findings, addressing tobacco smoking among persons with substance-use disorders should be a critical concern, especially given the heavy smoking-related mortality burden and the currently limited attention devoted to smoking in these populations. [Callaghan RC, Gatley JM, Sykes J, Taylor L. The prominence of smoking-related mortality among individuals with alcohol- or drug-use disorders. Drug Alcohol Rev 2018;37:97-105].

β-Blockers, Cocaine, and the Unopposed α-Stimulation Phenomenon

Cocaine abuse remains a significant worldwide health problem. Patients with cardiovascular toxicity from cocaine abuse frequently present to the emergency department for treatment. These patients may be tachycardic, hypertensive, agitated, and have chest pain. Several pharmacological options exist for treatment of cocaine-induced cardiovascular toxicity. For the past 3 decades, the phenomenon of unopposed α-stimulation after β-blocker use in cocaine-positive patients has been cited as an absolute contraindication, despite limited and inconsistent clinical evidence. In this review, the authors of the original studies, case reports, and systematic review in which unopposed α-stimulation was believed to be a factor investigate the pathophysiology, pharmacology, and published evidence behind the unopposed α-stimulation phenomenon. We also investigate other potential explanations for unopposed α-stimulation, including the unique and deleterious pharmacologic properties of cocaine in the absence of β-blockers. The safety and efficacy of the mixed β-/α-blockers labetalol and carvedilol are also discussed in relation to unopposed α-stimulation.

Crack cocaine addiction, early life stress and accelerated cellular aging among women

BACKGROUND

Early life stress (ELS) and addiction are related to age-related diseases and telomere shortening. However, the role of telomere length (TL) in crack cocaine addiction remains unknown. The purpose of this study was to investigate the TL in a sample of crack cocaine dependent-women who reported an ELS history and in a community-based sample of elderly women as a reference group for senescence.

METHODS

This study included treatment seeking crack cocaine dependents women (n=127) and elderly women without a psychiatric diagnosis (ELD, n=49). The crack cocaine sample was divided in two groups according to their Childhood Trauma Questionnaire (CTQ) scores: presence of history of childhood abuse and neglect (CRACK-ELS) and absence of ELS history (CRACK). TL was assessed by T/S ratio obtained from peripheral blood DNA using quantitative PCR assay.

RESULTS

CRACK and CRACK-ELS subjects exhibited shortened TL in comparison to the ELD group, despite their younger age. Among crack cocaine sample, CRACK-ELS group had significantly shorter telomeres than the CRACK group. Correlation analysis within crack cocaine group indicated that TL was negatively correlated with emotional abuse scores.

CONCLUSIONS

These results support previous findings associating telomere shortening with both ELS and drug addiction. This study suggests new evidence of a distinct biological phenotype for drug-dependent women with ELS. The results support the biological senescence hypothesis underpinning ELS experience.

Mortality Rates Among Substance Use Disorder Participants in Clinical Trials: Pooled Analysis of Twenty-Two Clinical Trials Within the National Drug Abuse Treatment Clinical Trials Network

BACKGROUND

Most substance use disorders (SUD) treatment clinical trials are too short and small to reliably estimate the incidence of rare events like death.

OBJECTIVE

The aim of this study is to estimate the overall mortality rates among a SUD treatment-seeking population by pooling participants from multiple clinical trials conducted through the National Institute on Drug Abuse (NIDA)-sponsored National Drug Abuse Treatment Clinical Trials Network (CTN).

PARTICIPANTS

Drug and or alcohol users (N=9866) who sought treatment and participated in one of the twenty-two CTN trials.

MEASUREMENTS

Data were collected through randomized clinical trials in national community treatment programs for SUD. Pooled analysis was performed to assess age- and gender-standardized mortality rate(s) (SM rate(s)), and mortality ratio(s) (SM ratio(s)) of CTN trial participants compared to the U.S. general population.

RESULTS

The age- and gender-SM rate among CTN trials participants was 1403 (95% CI: 862-2074) per 100,000 person years (PY) compared to 542 (95% CI: 541-543) per 100,000 PY among the U.S. general population in 2005. By gender, age-adjusted SM ratio for female CTN trial participants was over five times (SM ratio=5.35, 95% CI: 3.31-8.19)), and for male CTN trial participants, it was over three times (SM ratio=3.39, 95% CI: 2.25-4.90) higher than their gender comparable peers in the U.S. general population.

CONCLUSIONS

Age and gender-standardized mortality rates and ratios among NIDA CTN SUD treatment-seeking clinical trial participants are higher than the age and gender comparable U.S. general population. The overall mortality rates of CTN trial participants are similar to in-treatment mortality reported in large U.S. and non-U.S. cohorts of opioid users. Future analysis with additional CTN trial participants and risk times will improve the stability of estimates, especially within subgroups based on primary substance of abuse. These SUD mortality rates can be used to facilitate safety monitoring within SUD clinical trials.

Association Between Quality Measures and Mortality in Individuals With Co-Occurring Mental Health and Substance Use Disorders

IMPORTANCE

Individuals with co-occurring mental and substance use disorders have increased rates of mortality relative to the general population. The relationship between measures of treatment quality and mortality for these individuals is unknown.

OBJECTIVE

To examine the association between 5 quality measures and 12- and 24-month mortality.

DESIGN, SETTING AND PARTICIPANTS

Retrospective cohort study of patients with co-occurring mental illness (schizophrenia, bipolar disorder, post-traumatic stress disorder and major depression) and substance use disorders who received care for these disorders paid for by the Veterans Administration between October 2006 and September 2007. Logistic regression models were used to examine the association between 12 and 24-month mortality and 5 patient-level quality measures, while risk-adjusting for patient characteristics. Quality measures included receipt of psychosocial treatment, receipt of psychotherapy, treatment initiation and engagement, and a measure of continuity of care. We also examined the relationship between number of diagnosis-related outpatient visits and mortality, and conducted sensitivity analyses to examine the robustness of our findings to an unobserved confounder.

MAIN OUTCOMES MEASURE

Mortality 12 and 24 months after the end of the observation period.

RESULTS

All measures except for treatment engagement at 24 months were significantly associated with lower mortality at both 12 and 24 months. At 12 months, receiving any psychosocial treatment was associated with a 21% decrease in mortality; psychotherapy, a 22% decrease; treatment initiation, a 15% decrease, treatment engagement, a 31% decrease; and quarterly, diagnosis-related visits a 28% decrease. Increasing numbers of visits were associated with decreasing mortality. Sensitivity analyses indicated that the difference in the prevalence of an unobserved confounder would have to be unrealistically large given the observed data, or there would need to be a large effect of an unobserved confounder, to render these findings non-significant.

CONCLUSIONS AND RELEVANCE

This is the first study to show an association between process-based quality measures and mortality in patients with co-occurring mental and substance use disorders, and provides initial support for the predictive validity of the measures. By devising strategies to improve performance on these measures, health care systems may be able to decrease the mortality of this vulnerable population.

Baseline medical comorbidities in adults randomized in the STRIDE trial for psychostimulant use disorders

BACKGROUND AND OBJECTIVES

Rates of medical illnesses may be higher among individuals with substance use disorders, complicating their care. This study aimed to expand the understanding of other medical conditions in treatment-seeking adults with stimulant use disorder (SUD) using data from Stimulant Reduction Intervention using Dose Exercise (STRIDE), a randomized, multisite trial investigating exercise augmentation of treatment as usual.

METHODS

Utilizing STRIDE baseline data, we examined demographic and clinical characteristics based on the number of self-reported diagnosed medical conditions among participants meeting eligibility criteria (passing medical screening exam and maximal exercise test, non-opioid dependent, no concomitant beta blocker, or opioid replacement therapy).

RESULTS

The majority (59%) of study participants (N = 302, mean age all participants = 39 years) did not report any history of other medical problems. Those with two or more conditions were older (mean age 46 years), reported more pain and worse physical functioning, and more psychiatric disorders (average 1.44). Hypertension was more common among participants with cocaine use disorders only (present in 16%) and liver disease was more common in those with cocaine plus other stimulant use disorders (present in 7%).

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

In this sample, patients with SUD were in surprisingly good health. A subpopulation had an overall higher burden of illness with worsened physical and psychiatric functioning. Provision of coordinated care may optimize treatment outcomes for patients based on medical comorbidity burden as well as type of drug abused, although these conclusions should be considered preliminary as they are based on self-reported data.

Why young people's substance use matters for global health

During puberty, when young people are completing their education, transitioning into employment, and forming longer-term intimate relationships, a shift in emotional regulation and an increase in risky behaviour, including substance use, is seen. This Series paper considers the potential effects of alcohol, tobacco, and illicit drug use during this period on: social, psychological, and health outcomes in adolescence and young adulthood; role transitions, and later health and social outcomes of regular substance use initiated in adolescence; and the offspring of young people who use substances. We sourced consistent support for causal relations between substance use and outcomes and evidence of biological plausibility from different but complementary research designs. Many adverse health and social outcomes have been associated with different types of substance use. The major challenge lies in deciding which are causal. Furthermore, qualitatively different harms are associated with different substances, differences in life stage when these harms occur, and the quality of evidence for different substances and health outcomes varies substantially. The preponderance of evidence comes from a few high-income countries, thus whether the same social and health outcomes would occur in other countries and cultures is unclear. Nonetheless, the number of harms that are causally related to substance use in young people warrant high-quality research design interventions to prevent or ameliorate these harms.

Health outcomes associated with illicit prescription opioid injection: A systematic review

Prescription opioid injection is a growing concern among people who use illicit drugs. Little is known about the potential health-related harms of injecting prescription opioids. Therefore, the authors undertook a systematic review to identify health outcomes associated with injecting prescription opioids. PubMed, Ovid MEDLINE®, EMBASE, Journals@Ovid, CINAHL, PsycInfo, Web of Science® Core Collection, CAB Direct, and ERIC databases were searched to identify English articles published between January 1990 and February 2015 that matched the inclusion criteria. Potentially relevant articles were those examining a clinical health outcome among people who use illicit drugs, in which a sub-group injects prescription opioids. The International Classification of Diseases (ICD-10) was used to clinically classify health outcomes. In total, 31 studies that met the inclusion criteria were identified and summarized. A modified version of the Downs and Black checklist was used to assess individual study quality and identify sources of bias. Findings supported associations between prescription opioid injection and hepatitis C infection, substance dependence and other mental health indicators, and lower general health. Associations with human immunodeficiency virus, overdose, and cutaneous infection were less consistent and varied according to prescription opioid type(s). Several potential sources of bias were identified as well as a need for more longitudinal research and more rigorous confounding adjustment. The current findings highlight a need to consider the growing popularity of prescription opioid injection in efforts to reduce drug-related harm among people who inject drugs.

Impact of binge alcohol on mortality among people who inject drugs

INTRODUCTION

While the impacts of illicit drug use on mortality have been well described, the impact of poly-substance that includes alcohol has received less attention. We examined the impact of binge alcohol use on mortality among a cohort of people who inject drugs (PWID) in a Canadian setting.

METHODS

Using data derived from a prospective cohort study of PWID in Vancouver, Canada recruited between May 1996 and November 2013. We ascertained dates and causes of death through a confidential linkage with the provincial registry and examined the impact of binge alcohol use. The primary outcome of interest was all-cause mortality. We used Cox proportional hazard regression to determine factors associated with mortality, including socio-demographic characteristics, drug use patterns and other risk behaviours.

RESULTS

During the study period, 2550 individuals were followed (844 of whom were HIV positive at baseline) for a median of 75.4 months (interquartile range 37.9 113.2). Of these, 795 (31%) participants reported binge alcohol use at some time during the study period. In multivariable analyses, binge alcohol use remained independently associated with all-cause-mortality (adjusted hazard ratio=1.41; 95% confidence interval: 1.06-1.88) after adjustment for other drug use patterns.

CONCLUSIONS

Binge alcohol use was associated with time to all-cause mortality among PWID in this setting. Since alcohol use is often overlooked as a risk factor for mortality among this population, these findings highlight the continued need to incorporate addiction treatment and public health interventions and policies that address binge alcohol use to reduce alcohol related-harms.

Plasma profile of pro-inflammatory cytokines and chemokines in cocaine users under outpatient treatment: influence of cocaine symptom severity and psychiatric co-morbidity

The treatment for cocaine use constitutes a clinical challenge because of the lack of appropriate therapies and the high rate of relapse. Recent evidence indicates that the immune system might be involved in the pathogenesis of cocaine addiction and its co-morbid psychiatric disorders. This work examined the plasma pro-inflammatory cytokine and chemokine profile in abstinent cocaine users (n = 82) who sought outpatient cocaine treatment and age/sex/body mass-matched controls (n = 65). Participants were assessed with the diagnostic interview Psychiatric Research Interview for Substance and Mental Diseases according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). Tumor necrosis factor-alpha, chemokine (C-C motif) ligand 2/monocyte chemotactic protein-1 and chemokine (C-X-C motif) ligand 12 (CXCL12)/stromal cell-derived factor-1 (SDF-1) were decreased in cocaine users, although all cytokines were identified as predictors of a lifetime pathological use of cocaine. Interleukin-1 beta (IL-1β), chemokine (C-X3-C motif) ligand 1 (CX3CL1)/fractalkine and CXCL12/SDF-1 positively correlated with the cocaine symptom severity when using the DSM-IV-TR criteria for cocaine abuse/dependence. These cytokines allowed the categorization of the outpatients into subgroups according to severity, identifying a subgroup of severe cocaine users (9-11 criteria) with increased prevalence of co-morbid psychiatric disorders [mood (54%), anxiety (32%), psychotic (30%) and personality (60%) disorders]. IL-1β was observed to be increased in users with such psychiatric disorders relative to those users with no diagnosis. In addition to these clinical data, studies in mice demonstrated that plasma IL-1β, CX3CL1 and CXCL12 were also affected after acute and chronic cocaine administration, providing a preclinical model for further research. In conclusion, cocaine exposure modifies the circulating levels of pro-inflammatory mediators. Plasma cytokine/chemokine monitoring could improve the stratification of cocaine consumers seeking treatment and thus facilitate the application of appropriate interventions, including management of heightened risk of psychiatric co-morbidity. Further research is necessary to elucidate the role of the immune system in the etiology of cocaine addiction.

Impact of unstable housing on all-cause mortality among persons who inject drugs

Background

Illicit drug injecting is a well-established risk factor for morbidity and mortality. However, a limited number of prospective studies have examined the independent effect of unstable housing on mortality among persons who inject drugs (PWIDs). In this study we sought to identify if a relationship exists between unstable housing and all-cause mortality among PWIDs living in Vancouver, Canada.

Methods

PWIDs participating in two prospective cohort studies in Vancouver, Canada were followed between May 1996 and December 2012. Cohort data were linked to the provincial vital statistics database to ascertain mortality rates and causes of death. We used multivariate Cox proportional hazards regression to determine factors associated with all-cause mortality and to investigate the independent relationship between unstable housing and time to all-cause mortality.

Results

During the study period, 2453 individuals were followed for a median of 69 months (Inter-quartile range [IQR]: 34 – 113). In total, there were 515 (21.0%) deaths 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 potential confounders including HIV infection and drug use patterns, unstable housing remained independently associated with all-cause mortality (adjusted hazard ratio [AHR] = 1.30, 95% CI: 1.08 – 1.56).

Conclusions

These findings demonstrate that unstable housing is an important risk factor for mortality independent of known risk factors including HIV infection and patterns of drug use. This study highlights the urgent need to provide supportive housing interventions to address elevated levels of preventable mortality among this population.

Mortality and cause of death in a cohort of people who had ever injected drugs in Glasgow: 1982-2012

BACKGROUND

To describe all-cause and cause-specific mortality in a cohort of people who had ever injected drugs (PWID) with a low prevalence of HIV over 20-30 years.

METHODS

Using a retrospective study design, identifying data from a cohort of PWID recruited between 1982 and 1993 through in-patient drug treatment services were linked to National Records for Scotland deaths data using probabilistic record linkage. We report all-cause and cause-specific mortality rates; standardized mortality ratios (SMR) across time, gender and age were estimated.

RESULTS

Among 456 PWID, 139 (30.5%) died over 9024 person-years (PY) of follow-up. Mortality within the cohort was almost nine times higher than the general population, and remained elevated across all age groups. The greatest excess mortality rate was in the youngest age group, who were 15-24 years of age (SMR 31.6, 95% CI 21.2-47.1). Drug-related deaths declined over time and mortality was significantly higher among HIV positive participants. Although SMRs declined with follow-up, the SMR of the oldest age group (45-60) was 4.5 (95% CI 3.0-6.9). There were no significant differences in all-cause mortality rates between participants who were 25 years and older at cohort entry compared to younger participants.

CONCLUSION

Mortality rates remained higher than the general population across all age groups. Screening services that identify a history of injecting drug use may be an opportunity to address risk factors faced by an ageing population of PWID and potentially have implications for future health care planning.

Effectiveness of secondary prevention and treatment interventions for crack-cocaine abuse: a comprehensive narrative overview of English-language studies

There are an estimated several million crack-cocaine users globally; use is highest in the Americas. Most crack users are socio-economically marginalized (e.g., homeless), and feature elevated risks for morbidity (e.g., blood-borne viruses), mortality and crime/violence involvement, resulting in extensive burdens. No comprehensive reviews of evidence-based prevention and/or treatment interventions specifically for crack use exist. We conducted a comprehensive narrative overview of English-language studies on the efficacy of secondary prevention and treatment interventions for crack (cocaine) abuse/dependence. Literature searches (1990-2014) using pertinent keywords were conducted in main scientific databases. Titles/abstracts were reviewed for relevance, and full studies were included in the review if involving a primary prevention/treatment intervention study comprising a substantive crack user sample. Intervention outcomes considered included drug use, health risks/status (e.g., HIV or sexual risks) and select social outcome indicators. Targeted (e.g., behavioral/community-based) prevention measures show mixed and short-term effects on crack use/HIV risk outcomes. Material (e.g., safer crack use kit distribution) interventions also document modest efficacy in risk reduction; empirical assessments of environmental (e.g., drug consumption facilities) for crack smokers are not available. Diverse psycho-social treatment (including contingency management) interventions for crack abuse/dependence show some positive but also limited/short-term efficacy, yet likely constitute best currently available treatment options. Ancillary treatments show little effects but are understudied. Despite ample studies, pharmaco-therapeutic/immunotherapy treatment agents have not produced convincing evidence; select agents may hold potential combined with personalized approaches and/or psycho-social strategies. No comprehensively effective 'gold-standard' prevention/treatment interventions for crack abuse exist; concerted research towards improved interventions is urgently needed.

Denial of pain medication by health care providers predicts in-hospital illicit drug use among individuals who use illicit drugs

BACKGROUND

Undertreated pain is common among people who use illicit drugs (PWUD), and can often reflect the reluctance of health care providers to provide pain medication to individuals with substance use disorders.

OBJECTIVE

To investigate the relationship between having ever been denied pain medication by a health care provider and having ever reported using illicit drugs in hospital.

METHODS

Data were derived from participants enrolled in two Canadian prospective cohort studies between December 2012 and May 2013. Using bivariable and multivariable logistic regression analyses, the relationship between having ever been denied pain medication by a health care provider and having ever reported using illicit drugs in hospital was examined.

RESULTS

Among 1053 PWUD who had experienced ≥ 1 hospitalization, 452 (44%) reported having ever used illicit drugs while in hospital and 491(48%) reported having ever been denied pain medication. In a multivariable model adjusted for confounders, having been denied pain medication was positively associated with having used illicit drugs in hospital (adjusted OR 1.46 [95% CI 1.14 to 1.88]).

CONCLUSIONS

The results of the present study suggest that the denial of pain medication is associated with the use of illicit drugs while hospitalized. These findings raise questions about how to appropriately manage addiction and pain among PWUD and indicate the potential role that harm reduction programs may play in hospital settings.

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.

Examining non-AIDS mortality among people who inject drugs

Objective:

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

Design:

Systematic review and meta-analysis.

Methods:

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

Results:

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

Conclusions:

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

Correlates of polysomnographic sleep changes in cocaine dependence: self-administration and clinical outcomes

BACKGROUND

Abstinence from chronic cocaine use is associated with abnormal sleep architecture. As sleep abnormalities are associated with clinical outcome in alcohol dependence, we hypothesized a similar relationship in cocaine dependence.

METHODS

We report data from a cocaine self-administration study (N=12) and the placebo arm of a randomized clinical trial (N=20). Self-administration participants underwent three cocaine self-administration sessions during a three-week inpatient stay. Treatment participants underwent two weeks of inpatient followed by six weeks of outpatient treatment including once-weekly cognitive behavioral therapy. Measurements included polysomnography from early and late in abstinence during the inpatient stays. Clinical outcomes included amount of cocaine self-administered, urine tests, and self-reported use and withdrawal symptoms.

RESULTS

Change in slow-wave sleep from early to late abstinence (ΔSWS; p=0.05), late abstinence rapid eye movement sleep (REM; p=0.002), and late abstinence total sleep time (p=0.02) were negatively correlated with the amount of cocaine self-administered. Early abstinence REM was positively correlated with withdrawal symptoms (p=0.02). Late abstinence REM was positively correlated with percent negative urines and maximum consecutive number of days abstinent (both p<0.001). ΔSWS was positively correlated with percent negative urines (p=0.03) and participants with increased SWS had greater percent negative urines (p=0.008) and maximum consecutive number of days abstinent (p=0.009).

CONCLUSIONS

Correlations between sleep deficits and amount of cocaine self-administered, clinical outcomes, and severity of withdrawal symptoms underscore the relevance of sleep in clinical outcomes in the treatment of cocaine dependence.

Cocaine use and risk of stroke: a systematic review

BACKGROUND

Both cocaine use and strokes impact public health. Cocaine is a putative cause of strokes, but no systematic review of the scientific evidence has been published.

METHODS

All relevant bibliographic-databases were searched until January 2014 for articles on the epidemiological association between cocaine use and strokes. Search strings were supervised by expert librarians. Three researchers independently reviewed studies for inclusion and data extraction following STROBE recommendations. Quality appraisal included study validity and bias. Both ischemic and hemorrhagic strokes were considered.

RESULTS

Of 996 articles, 9 were selected: 7 case-control studies (CCS) and 2 cross-sectional (CSS) studies. One CCS (aOR=6.1; 95% CI: 3.3-11.8) and one CSS (aOR=2.33; 95% CI: 1.74-3.11) showed an association between cocaine and hemorrhagic strokes. The latter study also found a positive relationship with ischemic stroke (aOR=2.03; 95% CI: 1.48-2.79). Another CCS found the exposure to be associated with stroke without distinguishing between types (aOR=13.9; 95% CI: 2.8-69.4). One forensic CCS found that deaths with cocaine-positive toxicology presented a 14.3-fold (95% CI: 5.6-37) and 4.6-fold (95% CI: 2.5-8.5) increased risk of atherosclerosis compared to opioid-related deaths and hanging-deaths respectively. One CCS did not provide an aOR but found a statistically significant association between cocaine and hemorrhagic stroke. Three CCS and one CSS did not find any relationship between cocaine and strokes. Inadequate control for confounding was not uncommon.

CONCLUSIONS

Epidemiological evidence suggests that cocaine use increases the risk of stroke. Larger, more rigorous observational studies, including cohort approaches, are needed to better quantify this risk, and should consider stroke type, hypertension variation, frequency/length of cocaine use, amphetamines co-use, and other factors.

Characterizing longitudinal health state transitions among heroin, cocaine, and methamphetamine users

AIMS

Characterize longitudinal patterns of drug use careers and identify determinants of drug use frequency across cohorts of primary heroin, methamphetamine (MA) and cocaine users.

DESIGN

Pooled analysis of prospective cohort studies.

SETTINGS

Illicit drug users recruited from community, criminal justice and drug treatment settings in California, USA.

PARTICIPANTS

We used longitudinal data on from five observational cohort studies featuring primary users of heroin (N=629), cocaine (N=694) and methamphetamine (N=474). The mean duration of follow-up was 20.9 years.

MEASUREMENTS

Monthly longitudinal data was arranged according to five health states (incarceration, drug treatment, abstinence, non-daily and daily use). We fitted proportional hazards (PH) frailty models to determine independent differences in successive episode durations. We then executed multi-state Markov (MSM) models to estimate probabilities of transitioning between health states, and the determinants of these transitions.

FINDINGS

Across primary drug use types, PH frailty models demonstrated durations of daily use diminished in successive episodes over time. MSM models revealed primary stimulant users had more erratic longitudinal patterns of drug use, transitioning more rapidly between periods of treatment, abstinence, non-daily and daily use. MA users exhibited relatively longer durations of high-frequency use. Criminal engagement had a destabilizing effect on health state durations across drug types. Longer incarceration histories were associated with delayed transitions toward cessation.

CONCLUSIONS

PH frailty and MSM modeling techniques provided complementary information on longitudinal patterns of drug abuse. This information can inform clinical practice and policy, and otherwise be used in health economic simulation models, designed to inform resource allocation decisions.

Risks of all-cause and suicide mortality in mental disorders: a meta-review

A meta-review, or review of systematic reviews, was conducted to explore the risks of all-cause and suicide mortality in major mental disorders. A systematic search generated 407 relevant reviews, of which 20 reported mortality risks in 20 different mental disorders and included over 1.7 million patients and over a quarter of a million deaths. All disorders had an increased risk of all-cause mortality compared with the general population, and many had mortality risks larger than or comparable to heavy smoking. Those with the highest all-cause mortality ratios were substance use disorders and anorexia nervosa. These higher mortality risks translate into substantial (10-20 years) reductions in life expectancy. Borderline personality disorder, anorexia nervosa, depression and bipolar disorder had the highest suicide risks. Notable gaps were identified in the review literature, and the quality of the included reviews was typically low. The excess risks of mortality and suicide in all mental disorders justify a higher priority for the research, prevention, and treatment of the determinants of premature death in psychiatric patients.

Risks of all-cause and suicide mortality in mental disorders: a meta-review

A meta-review, or review of systematic reviews, was conducted to explore the risks of all-cause and suicide mortality in major mental disorders. A systematic search generated 407 relevant reviews, of which 20 reported mortality risks in 20 different mental disorders and included over 1.7 million patients and over a quarter of a million deaths. All disorders had an increased risk of all-cause mortality compared with the general population, and many had mortality risks larger than or comparable to heavy smoking. Those with the highest all-cause mortality ratios were substance use disorders and anorexia nervosa. These higher mortality risks translate into substantial (10-20 years) reductions in life expectancy. Borderline personality disorder, anorexia nervosa, depression and bipolar disorder had the highest suicide risks. Notable gaps were identified in the review literature, and the quality of the included reviews was typically low. The excess risks of mortality and suicide in all mental disorders justify a higher priority for the research, prevention, and treatment of the determinants of premature death in psychiatric patients.

Long term effects of cocaine on the heart assessed by cardiovascular magnetic resonance at 3T

BACKGROUND

Cocaine is an addictive, sympathomimetic drug with potentially lethal effects. The prevalence and features of cocaine cardiotoxicity are not well known. We aimed to assess these effects using a comprehensive cardiovascular magnetic resonance (CMR) protocol in a large group of asymptomatic cocaine users.

METHODS

Consecutive (n = 94, 81 males, 36.6 ±7 years), non-selected, cocaine abusers were recruited and had a medical history, examination, ECG, blood test and CMR. The CMR study included measurement of left and right ventricular (LV, RV) dimensions and ejection fraction (EF), sequences for detection of myocardial oedema and late gadolinium enhancement (LGE). Images were compared to a cohort of healthy controls.

RESULTS

Years of regular cocaine use were 13.9 ± 9. When compared to the age-matched healthy cohort, the cocaine abusers had increased LV end-systolic volume, LV mass index and RV end-systolic volume, with decreased LVEF and RVEF. No subject had myocardial oedema, but 30% had myocardial LGE indicating myocardial damage.

CONCLUSIONS

CMR detected cardiovascular disease in 71% of this cohort of consecutive asymptomatic cocaine abusers and mean duration of abuse was related to probability of LV systolic dysfunction.

Effects of disulfiram on QTc interval in non-opioid-dependent and methadone-treated cocaine-dependent patients

OBJECTIVES

Methadone and cocaine are each known to prolong the QTc interval, a risk factor for developing potentially fatal cardiac arrhythmias. Disulfiram, often administered in the context of methadone maintenance to facilitate alcohol abstinence, has been shown to have some efficacy for cocaine dependence. Disulfiram has differential effects on cocaine and methadone metabolism, but its impact on methadone- or cocaine-induced changes in QTc interval is unclear. Thus, the effects of disulfiram on QTc interval in a subset of cocaine-dependent patients participating in a 14-week, randomized, double-blind, placebo-controlled clinical trial of disulfiram were prospectively determined.

METHODS

Opioid-dependent participants were inducted onto methadone (weeks 1-2; MT) and both MT and non-opioid-dependent (UT) participants were randomized to receive disulfiram (weeks 3-14) at one of the following doses: 0, 250, 375, or 500 mg/d. Electrocardio-grams were obtained before study entry and during weeks 2 and 4.

RESULTS

Complete QTc-interval data in 23 MT and 18 UT participants were analyzed. QTc interval tended to be higher in MT participants relative to UT participants, regardless of disulfiram dose and time point, but disulfiram did not differentially alter QTc interval. QTc interval was, however, significantly greater in participants with recent cocaine use than in those with no recent use.

CONCLUSIONS

These results suggest that cocaine use and possibly MT status, but not disulfiram, are risk factors for QTc prolongation.