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

Mortality and cause of death among 1705 illicit drug users: a 37 year follow up

INTRODUCTION AND AIMS

To examine the overall mortality and causes of deaths of a large cohort of users of illicit drugs in Stockholm over 37 years.

DESIGN AND METHODS

People with substance abuse were identified through records collected by different institutions in Stockholm in 1967. Subjects were followed in registers recording mortality and cause of death and in-patient care stays until 2003.

RESULTS

More than half (n = 860) of the 1705 identified substance abusers died at an average age of 47 years, 25-30 years younger than the general population. The standardised rate ratio (SRR) for mortality was 3.3 among men and 3.5 among women. Incidence of mortality per 1000 person-years was also increased, but somewhat lower for women. The difference between these two measures is mainly explained by a lower mortality among women in general. In-patient care stays with both alcohol and drug-related diagnoses were associated with higher risk of dying among women than men: SRR = 14.5 and SRR = 4.0, respectively. Accidents and suicide were the most common cause of death among the youngest subjects (15-24 years) and cardiovascular diseases and tumours among the oldest (> or =55 years).

DISCUSSION AND CONCLUSIONS

Accidents and suicide, especially at a young age, are two common causes of death that might be prevented by increased awareness in medical personnel, along with better treatment and supportive measures.

Mortality among amphetamine users: a systematic review of cohort studies

AIMS

To report the results of a comprehensive literature search of studies of mortality among people who use amphetamines.

DESIGN AND SETTING

Three electronic databases were searched (EMBASE, Medline and PsycINFO) and "grey" literature was located. Shortlists of papers were circulated to experts to ascertain whether any important papers had been missed. Papers were hand-searched to retrieve any additional relevant articles.

MEASUREMENTS

Studies meeting inclusion criteria were prospective cohort studies examining mortality risk among dependent and problematic amphetamine users. Crude mortality rates (CMR/100PY) and standardised mortality ratios (SMRs) were the primary outcome measures considered. Data on overall mortality, and rates for specific causes of death, were of interest.

FINDINGS

2187 articles and 9 grey literature sources were obtained. After thorough review, 72 articles were identified as reporting on amphetamine-related mortality, 7 provided data from cohort studies of users. An additional study of Swedish military conscripts was identified by the authors during correspondence with other researchers. The geographic spread of cohorts was restricted to high income countries with the exception of one Thai study; reporting of standard parameters in mortality studies was often sparse. The estimated CMRs ranged from 0 in Australia to 2.95 (1.46-4.59) in Thailand. The Czech cohort reported the only SMR: 6.22 overall, males: 5.87, females: 7.84.

CONCLUSIONS

Given the widespread use of amphetamines, the known non-fatal adverse effects of use and the mortality rates reported here, cohort studies investigating the morbidity and mortality associated with such drug use should be a research priority.

Obesity and metabolic syndrome increase the risk of incident depression in older men: the health in men study

BACKGROUND

Obesity has been associated with increased risk of prevalent depression among young and middle-aged adults, but the association between obesity (and its various measures, including the metabolic syndrome [MetS]) and incident depression has not been examined adequately in the elderly.

OBJECTIVES

This study evaluated the association between various measures of obesity and incident depression over a 10-year period in a large cohort of community-based older men.

METHODS

The authors recruited 12,216 men aged 65-84 years living in Perth, Australia, between 1996 and 1998, and measured their height, weight, waist and hip circumference, and blood pressure. Participants also completed a questionnaire that included information about the clinical diagnosis and treatment for diabetes, hypertension, and high cholesterol or triglycerides. The authors then used the Western Australian Linked Data System to retrieve information about the following ICD-10 diagnoses between January 1, 1966, and December 31, 2006: depressive episode, recurrent depressive disorder, and dysthymia.

RESULTS

The authors excluded 150 men from these analyses because of prior history of depression or missing data. The mean age of our 12,066 participants was 72 +/- 4 years at the time of recruitment, and they were followed up for an average of 8 +/- 2 years. There were 3,623 deaths during follow-up, and 481 men received the diagnosis of depression. The incidence of depression was 5 per 1,000 person-years. Adjusted Cox proportional hazard models showed that men with body mass index (BMI) > or =30 had a 31% (95% confidence interval [CI] = 5%-64%) increase in the risk of depression compared with that of nonobese men (BMI <30). The association between depression and waist circumference > or =102 cm and waist/hip > or =1 did not reach statistical significance. Men with MetS at the time of recruitment had a 137% (95% CI = 60%-251%) increase in the adjusted risk of incident depression.

CONCLUSIONS

Our results indicate that obesity and MetS are associated with an increase in the risk of incident depression among older men. If this association is truly causal, reducing the prevalence of obesity and MetS could potentially lead to a decline in the prevalence and incidence of depression in later life.

Drug users seeking emergency care for soft tissue infection at high risk for subsequent hospitalization and death

OBJECTIVE

Although soft tissue infections are common among injection drug users (IDUs), little is known about the health outcomes among those who seek care for these infections. Emergency department visits are an important point-of-health-care contact for IDUs. In this prospective cohort study, we aimed to determine the hospitalization and mortality rates and factors associated with hospitalization or death among IDUs seeking emergency care for soft tissue infection.

METHOD

Participants were English-speaking IDUs, 18 years of age and older, who sought initial care for soft tissue infection in an urban emergency department. We conducted semistructured interviews, identified hospitalizations from hospital records, and identified deaths using the National Death Index. Cox proportional hazards regression was used to investigate associations between baseline characteristics and hospitalizations or death.

RESULTS

Of 211 eligible patients, 156 (74%) participated (mean age = 42 years). There were 255 subsequent hospitalizations over a mean of 3.9 years follow-up. The hospitalization rate was 42 hospitalizations per 100 person-years (95% confidence interval [CI]: 38-48). The mortality rate was 2.0 per 100 person-years (95% CI: 1.1-3.7). Factors associated with increased risk for hospitalization or death included living on the street or in a shelter (adjusted odds ratio [AOR] = 1.75, 95% CI: 1.10-2.79), being recently incarcerated (AOR = 1.90, 95% CI: 1.05-3.44), and having insurance (AOR: 1.98, 95% CI: 1.22-3.23).

CONCLUSIONS

IDUs who sought care in the emergency department for soft tissue infections were at high risk for subsequent hospitalization and death. Visits for soft tissue infections represent missed opportunities for preventive care.

Mortality among injecting drug users in Melbourne: a 16-year follow-up of the Victorian Injecting Cohort Study (VICS)

Multiple factors affect injecting drug-related mortality, many of which will vary over time and between jurisdictions. There are relatively few studies of mortality among injecting drug users (IDU) in Australia. We aimed to provide data comparable to those reported internationally on the rate of mortality among IDU in Australia. We retrospectively examined mortality among participants (N=220) from the first Australian cohort study of IDU by linking coded personal identifier records with a national death register. The overall mortality rate among those followed-up was 0.83 per 100 PY (95% CI, 0.56-1.21 per 100 PY). This rate is lower than those reported internationally but comparable to the limited Australian data from other cohorts of IDU. Mortality was higher among males, most common among those aged in their early thirties and drug-related mortality occurred typically after substantial injecting careers. Extensive experience of incarceration (>or=3 times) was associated with increased risk of mortality. These results suggest that rates of mortality among Australian IDU may be lower than those reported internationally, with low HIV prevalence and Australia's long-held harm reduction framework potentially contributing to this result. Further studies using defined cohorts followed over time are needed to examine long-term outcomes among IDU in Australia.

Mortality in heroin users 3 years after naltrexone implant or methadone maintenance treatment

Concerns that treatment for heroin dependence using naltrexone may increase suicide rates during treatment and fatal overdoses posttreatment have been expressed. There is also disquiet about mortality during induction onto methadone. We assessed mortality during specific periods following treatment with naltrexone implants or methadone. Data were assembled using the Western Australian Data Linkage System. The methadone cohort comprised all those who started methadone in Western Australia during 2001-2002: The naltrexone cohort comprised all Western Australian heroin-dependent persons who received their first implant in 2001-2002. There were 15 (2.7%) deaths in the methadone cohort (n = 553) and 6 (1.8%) deaths in the naltrexone cohort (n = 341). Mortality rates for the "initial 14-day period," "stable treatment," and "overall" were 94.47, 0.0, and 5.83 deaths/1,000 person-years for the methadone group. In the naltrexone group, the rates "during first treatment (0-6 months)," "post first treatment," and overall were 0.0, 4.21, and 3.76 deaths/1,000 person-years. The age-standardized mortality rate ratio for naltrexone compared to methadone was 0.645 (95% confidence interval = 0.123-1.17). Increased mortality during induction onto methadone was confirmed. Evidence relating naltrexone to either increased suicide or overdose was not found. Overall mortality rates for naltrexone implant were similar to those for methadone, but increased mortality during methadone induction was avoided.

Neurotoxicity of substituted amphetamines: Molecular and cellular mechanisms

The amphetamines, including amphetamine (AMPH), methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA), are among abused drugs in the US and throughout the world. Their abuse is associated with severe neurologic and psychiatric adverse events including the development of psychotic states. These neuropsychiatric complications might, in part, be related to drug-induced neurotoxic effects, which include damage to dopaminergic and serotonergic terminals, neuronal apoptosis, as well as activated astroglial and microglial cells in the brain. The purpose of the present review is to summarize the toxic effects of AMPH, METH and MDMA. The paper also presents some of the factors that are thought to underlie this toxicity. These include oxidative stress, hyperthermia, excitotoxicity and various apoptotic pathways. Better understanding of the cellular and molecular mechanisms involved in their toxicity should help to generate modern therapeutic approaches to prevent or attenuate the long-term consequences of amphetamine use disorders in humans.

Cause of death and drug use pattern in deceased drug addicts in Sweden, 2002–2003

Compared with their contemporaries, individuals abusing illicit drugs suffer a higher risk of premature death. In Sweden, a simple protocol for registration of fatalities among abusers of alcohol, pharmaceuticals, illicit drugs, or other substances, has been used by the forensic pathologists since 2001. This routine was introduced to allow for an evaluation of the cause and manner of death, and patterns of abuse among different groups of abusers. We explored the data on drug abusers (i.e. abusers of illicit drugs) subjected to a forensic autopsy 2002-2003. The Swedish forensic pathologists examined 10,273 dead victims during the study period and 7% (743/10,273) of the cases were classified as drug abusers. Toxicological analyses were carried out in 99% (736/743) and illicit drugs were detected in 70% (514/736) of these. On average, 3.8 substances (legal or illegal) were found per case. The most common substances were ethanol and morphine, detected in 43 and 35% of the cases, respectively. When exploring the importance of the different substances for the cause of death, we found that the detection of some substances, such as fentanyl and morphine, strongly indicated a poisoning, whereas certain other substances, such as benzodiazepines more often were incidental findings. In total, 50% (372/743) died of poisoning, whereas only 22% (161/743) died of natural causes. Death was considered to be directly or indirectly due to drug abuse in 47% (346/743), whereas evidence of drug abuse was an incidental finding in 21% (153/743) or based on case history alone in 33% (244/743). We believe that this strategy to prospectively categorize deaths among drug addicts constitutes a simple means of standardizing the surveillance of the death toll among drug addicts that could allow for comparisons over time and between countries.

Years of potential life lost among heroin addicts 33 years after treatment

OBJECTIVE

To examine premature mortality in terms of years of potential life lost (YPLL) among a cohort of long-term heroin addicts.

METHOD

This longitudinal, prospective study followed a cohort of 581 male heroin addicts in California for more than 33 years. In the latest follow-up conducted in 1996/97, 282 subjects (48.5%) were confirmed as deceased by death certificates. YPLL before age 65 years was calculated by causes of death. Ethnic differences in YPLL were assessed among Whites, Hispanics, and African Americans.

RESULTS

On average, addicts in this cohort lost 18.3 years (SD=10.7) of potential life before age 65. Of the total YPLL for the cohort, 22.3% of the years lost was due to heroin overdose, 14.0% due to chronic liver disease, and 10.2% to accidents. The total YPLL and YPLL by death cause in addict cohort were significantly higher than that of US population. The YPLL among African Americans was significantly lower than that among Whites or Hispanics.

CONCLUSION

The YPLL among addicts was much higher than that in the national population; within the cohort, premature mortality was higher among Whites and Hispanics compared to African American addicts.

Predictors of mortality among injecting and non-injecting HIV-negative drug users in northern Thailand

AIMS

To estimate mortality rates among HIV-negative injecting drug users (IDUs) and non-injecting drug users (non-IDUs), and to assess predictors for mortality among the IDUs.

DESIGN

Prospective cohort study in northern Thailand with 2-year follow-up.

SETTING

IDUs and non-IDUs who were admitted for detoxification treatment for opiate or amphetamine dependence in a regional drug treatment center were screened. After discharge, HIV-negative individuals were followed-up in the community.

PARTICIPANTS

A total of 821 HIV-negative drug users [346 IDUs (42%) and 475 non-IDUs, median age = 32; 51% were ethnic minorities].

MEASUREMENTS

All-cause mortality.

FINDINGS

There were 33 deaths over 1360 person-years of follow-up. The all-cause mortality rate was 39 per 1000 person-years among IDUs [standardized mortality ratio (SMR) = 13.9], and was 14 per 1000 person-years among non-IDUs (SMR = 4.4). Among male IDUs, the hazards for all-cause deaths were ethnic minority status [adjusted hazard ratio (HR) = 2.9, 95% CI = 1.2-7.2], incident HIV infection (HR = 2.8, 95% CI = 1.1-7.7) and longer duration of drug injection (HR = 1.07, 95% CI = 1.01-1.14).

CONCLUSIONS

The mortality among IDUs is high. Being from an ethnic minority, recent HIV acquisition, and a greater number of years of drug injection are predictors of mortality among the IDUs in this region.

Mortality associated with incident mental health disorders after stroke

OBJECTIVE

Sparse information is currently available about the incidence of the major psychiatric syndromes following a stroke and their long-term contribution to morbidity and mortality. This study was designed to determine: (1) the incidence of first ever mental health disorder in amongst stroke patients; (2) the 10-year mortality associated with incident post-stroke mental health disorders.

DESIGN

Retrospective cohort study.

SETTING

Entire Western Australian community.

PARTICIPANTS

First-ever stroke in 1990. Subjects with a prior recorded history of any mental health disorder were excluded from the study. Main outcomes of interest: Incident mental health diagnoses and 10-year mortality.

RESULTS

1,129 hospital stroke contacts were recorded in 1990, with 21 people dying on the same day of contact. Between 1990-2002 36.6% of the survivors received a mental health diagnosis (6.1 per 1,000 person-years): alcohol-related disorders (16.2%), dementia (12.1%), delirium (7.6%), psychotic disorders (6.7%), and depression (5.5%). Mental health disorder onset was usually within 6 months of the stroke. Patients with an incident psychotic disorder were twice as likely to die during the subsequent 10 years as post-stroke controls with no mental health disorder (risk ratio = 2.03, 95%CI = 1.39-2.95). Being a widow (HR = 1.61, 95%CI = 1.13-2.30) or having been born in 'other countries' as opposed to Australia (HR = 1.56, 95%CI = 1.15-2.11) was also associated with increased death hazard.

CONCLUSIONS

Approximately 1 in 3 patients develop a mental health disorder after stroke, although incidence estimates are relatively low. Post-stroke psychosis is associated with greater 10-year mortality, but the mechanisms underlying such an association are yet to be determined.

Methadone in pregnancy: treatment retention and neonatal outcomes

AIM

To examine the association between retention in methadone treatment during pregnancy and key neonatal outcomes.

DESIGN

Client data from the New South Wales Pharmaceutical Drugs of Addiction System was linked to birth information from the NSW Midwives Data Collection and the NSW Inpatient Statistics Collection from 1992 to 2002.

MEASUREMENTS

Obstetric and perinatal characteristics of women who were retained continuously on methadone maintenance throughout their pregnancy were compared to those who entered late in their pregnancies (less than 6 months prior to birth) and those whose last treatment episode ended at least 1 year prior to birth.

FINDINGS

There were 2993 births to women recorded as being on methadone at delivery, increasing from 62 in 1992 to 459 births in 2002. Compared to mothers who were maintained continuously on methadone throughout their pregnancy, those who entered treatment late also presented later to antenatal services, were more likely to arrive at hospital for delivery unbooked, were more often unmarried, indigenous and smoked more heavily. A higher proportion of neonates born to late entrants were born at less than 37 weeks gestation and were admitted to special care nursery more often.

CONCLUSION

Continuous methadone treatment during pregnancy is associated with earlier antenatal care and improved neonatal outcomes. Innovative techniques for early engagement in methadone treatment by pregnant heroin using women or those planning to become pregnant should be identified and implemented.

Causes of death among crack cocaine users

OBJECTIVE: The study accompanied 131 crack-cocaine users over a 5-year period, and examined mortality patterns, as well as the causes of death among them. METHOD: All patients admitted to a detoxification unit in Sao Paulo between 1992 and 1994 were interviewed during two follow-up periods: 1995-1996 and 1998-1999. RESULTS: After 5 years, 124 patients were localized (95%). By the study endpoint (1999), 23 patients (17.6%) had died. Homicide was the most prevalent cause of death (n = 13). Almost one third of the deaths were due to the HIV infection, especially among those with a history of intravenous drug use. Less than 10% died from overdose. CONCLUSIONS: The study suggests that the mortality risk among crack cocaine users is greater than that seen in the general population, being homicide and AIDS the most common causes of death among such individuals.

Prescription naloxone: a novel approach to heroin overdose prevention

The mortality and morbidity from heroin overdose have increased in the United States and internationally in the last decade. The lipid solubility allows the rapid deposition of heroin and its metabolites into the central nervous system and accounts for the "rush" experienced by users and for the toxicity. Risk factors for fatal and nonfatal heroin overdoses such as recent abstinence, decreased opiate tolerance, and polydrug use have been identified. Opiate substitution treatment such as methadone or buprenorphine is the only proven method of heroin overdose prevention. Death from a heroin overdose most commonly occurs 1 to 3 hours after injection at home in the company of other people. Numerous communities have taken advantage of this opportunity for treatment by implementing overdose prevention education to active heroin users, as well as prescribing naloxone for home use. Naloxone is a specific opiate antagonist without agonist properties or potential for abuse. It is inexpensive and nonscheduled and readily reverses the respiratory depression and sedation caused by heroin, as well as causing transient withdrawal symptoms. Program implementation considerations, legal ramifications, and research needs for prescription naloxone are discussed.

The use of record linkage to examine illicit drug use in pregnancy

AIMS

To examine the obstetric and perinatal outcomes for women with a drug-related hospital admission during pregnancy.

DESIGN

Antenatal and birth admissions to New South Wales (NSW) hospitals from the NSW Inpatient Statistics Collection were linked to birth information from the NSW Midwives Data Collection over a 5-year period (1998-2002).

MEASUREMENTS

Birth admissions were flagged as positive for drug use where a birth admission or any pregnancy admission for that birth involved an opioid, cannabis or stimulant-related International Classification of Diseases version 10 Australian modification (ICD-10AM) code.

FINDINGS

A total of 416 834 live births were analysed over a 5-year period (1998-2002). Of these, 1974 pregnancies had an opioid ICD-10AM diagnosis recorded, 552 a stimulant-related ICD-10AM and 2172 a cannabis ICD-10AM diagnosis. Births in each of the drug groups were to women who were younger, had a higher number of previous pregnancies, were indigenous, smoked heavily and were not privately insured. These women also presented later in their pregnancy to antenatal services and were more likely to arrive at hospital unbooked. Neonates born to women in each of the drug groups were more likely to be premature and were admitted to neonatal intensive care and special care nursery more often, with neonates born to women in the opioid group admitted most often.

CONCLUSIONS

Linked population level administrative data is a powerful method for examining the maternal and neonatal outcomes associated with the use of specific illicit drugs during pregnancy.

Use of Record Linkage to Examine Alcohol Use in Pregnancy

BACKGROUND

To date, no population-level data have been published examining the obstetric and neonatal outcomes for women with an alcohol-related hospital admission during pregnancy compared with the general obstetric population. This information is critical to planning and implementing appropriate services.

METHODS

Antenatal and delivery admissions to New South Wales (NSW) hospitals from the NSW Inpatient Statistics Collection were linked to birth information from the NSW Midwives Data Collection over a 5-year period (1998-2002). Birth admissions were flagged as positive for maternal alcohol use where a birth admission or any pregnancy admission for that birth involved an alcohol-related International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Australian Modification (ICD-10-AM) code. Key demographic, obstetric, and neonatal variables were compared for births to mothers in the alcohol group with births where no alcohol-related ICD10-AM was recorded.

RESULTS

A total of 416,834 birth records were analyzed over a 5-year period (1998-2002). In this time, 342 of these were coded as positive for at least 1 alcohol-related ICD-10-AM diagnosis. Mothers in the alcohol group had a higher number of previous pregnancies, smoked more heavily, were not privately insured, and were more often indigenous. They also presented later on in their pregnancy to antenatal services and were more likely to arrive at hospital unbooked for delivery. Deliveries involved less epidural and local and more general anesthesia. Cesarean sections were more common to women in the alcohol group and were performed more often for intrauterine growth retardation. Neonates born to women in the alcohol group were smaller for gestational age, had lower Apgar scores at 5 minutes, and were admitted to special care nursery more often.

CONCLUSIONS

This study shows that linked population-level administrative data provide a powerful new source of information for examining the maternal and neonatal outcomes associated with alcohol use in pregnancy.

Psychiatric severity and mortality in substance abusers: a 15-year follow-up of drug users

Previous research has shown that most transitions into abstinence happens in the stages of the drug career quickly after the first treatment episode. Mortality is somewhat reduced for patients who become abstinent, but remains high for patients who remain addicted. However, even among substance abusers who become abstinent, mortality is often higher than in the general population. A consecutive sample of drug users admitted for detoxification was followed for 15 years. Face-to-face interviews were conducted at 5-year follow-up. At 15-year follow-up, 24% were dead. Cox proportional hazard regression was conducted to predict mortality for continuous variables, and Gehan's Wilcoxon test was used to predict mortality for dichotomous variables. Psychiatric status at 5-year follow-up was predictive of 15-year mortality, whereas abstinence was not. Subjects who later died had higher scores on the Symptom Checklist 90 [SCL-90] Global Severity Index, lower meaningfulness on the Sense of Coherence scale, and lower Global Assessment of Functioning [GAF] scores at 5-year follow-up. By contrast, there were no associations between baseline drug use and antisocial personality disorder diagnoses and mortality. Psychiatric treatment, including psychotherapy, may be more life-saving for substance abusers than drug-abuse services.

The medical complications of heroin use

PURPOSE OF REVIEW

Heroin use is associated with numerous adverse sequelae. As clinical services develop, addiction psychiatrists will increasingly be called upon to help identify and manage the complications of heroin use. This review focuses on recent research into the medical complications of heroin use and looks at strategies to minimize harm associated with this practice.

RECENT FINDINGS

Mortality associated with heroin overdose has increased substantially in many countries. Parenteral use of opioid drugs is a central factor and other risk factors include polydrug use, particularly benzodiazepines and alcohol, mental health issues and environmental factors not conducive to resuscitation. Unravelling the determinants of blood-borne virus transmission continues, the focus shifting from needle sharing to inadvertent sharing of other injecting equipment. Trials addressing the challenges of antiviral therapy in injecting drug users are emerging. A greater understanding of the effects of opioids on immune functioning complements our knowledge of infection in the heroin-using group as well as possibly explaining the reduced response to vaccination in this group.

SUMMARY

Medical complications of heroin affect a number of different organ systems. The role of the addiction specialist is to be aware of these so that early diagnosis and appropriate management is instituted. The latter will generally be done in collaboration with other specialists. The addictions specialist can play a significant role in the development of clinical systems to minimize these complications.