Opioid overdose mortality in Australia, 1964-1997: birth-cohort trends

Risk markers for fatal and non-fatal prescription drug overdose: a meta-analysis

BACKGROUND

Drug overdose is a public health crisis in the United States, due in part to the unintended consequences of increases in prescribing of opioid analgesics. Many clinicians evaluate risk markers for opioid-related harms when prescribing opioids for chronic pain; however, more data on predictive risk markers are needed. Risk markers are attributes (modifiable and non-modifiable) that are associated with increased probability of an outcome. This review aims to identify risk markers associated with fatal and non-fatal prescription drug overdose by synthesizing findings in the existing peer-reviewed and grey literature. Eligible cohort, case-control, cross-sectional, and case-cohort studies were reviewed and data were extracted for qualitative and quantitative synthesis.

FINDINGS

Summary odds ratios (SOR) were estimated from 29 studies for six risk markers: sex, age, race, psychiatric disorders, substance use disorder (SUD), and urban/rural residence. Heterogeneity was assessed and effect estimates were stratified by study characteristics. Of the six risk markers identified, SUD had the strongest association with drug overdose death (SOR = 5.24, 95% confidence interval (CI) = 3.53 - 7.76), followed by psychiatric disorders (SOR = 3.94, 95% CI = 3.09 - 5.01), white race (SOR = 2.28, 95% CI = 1.93 - 2.70), the 35-44 year age group relative to the 25-34 year reference group (SOR = 1.52, 95% CI = 1.31 - 1.76), and male sex (SOR = 1.33, 95% CI = 1.17 - 1.51).

CONCLUSIONS

This review highlights fatal and non-fatal prescription drug risk markers most frequently assessed in peer-reviewed and grey literature. There is a need to better understand modifiable risk markers and underlying reasons for drug misuse in order to inform interventions that may prevent future drug overdoses.

Property Crime and Income Generation by Heroin Users

This paper provides a detailed analysis of patterns of income generation among 202 active heroin users in South West Sydney. We explore both sources of income and the relative contribution of different types of income generating activities, including drug sales and related activities, property crime, prostitution, legitimate income and avoided expenditures. Despite claims that heroin use leads inevitably to property crime, drug market activities accounted for a greater proportion of drug user income in this sample. Results indicate that law enforcement crackdowns that reduce opportunities for generating income from the drug market may increase property crime by heroin users.

Understanding trends in Australian alcohol consumption-an age-period-cohort model

AIMS

To decompose Australian trends in alcohol consumption into their age, period (survey year) and cohort (birth year/generation) components. In particular, we aimed to test whether recent declines in overall consumption have been influenced by reductions in drinking among recently born cohorts.

DESIGN

Seven cross-sectional waves of the Australian National Drug Strategy Household Survey (1995-2013). Age, period and cohort effects were estimated using a linear and logistic cross-classified random-effects models (CCREMs).

SETTING

Australia

PARTICIPANTS

A total of 124 440 Australians (69 193 females and 55 257 males), aged 14-79 years.

MEASUREMENTS

Whether or not respondents consumed alcohol in the 12 months prior to the survey and, for those who did, the estimated volume of pure alcohol consumed, derived using standard quantity-frequency survey questions.

FINDINGS

Controlling for age and period effects, there was significant variation in drinking participation and drinking volume by birth cohort. In particular, male cohorts born between the 1965 and 1974 and female cohorts born between 1955 and 1974 reported higher rates of drinking participation (P < 0.05), while the most recent cohorts (born in the 1990s) had lower rates of participation (P < 0.01). Among drinkers, the most recently born cohort also had sharply lower average consumption volumes than older cohorts for both men and women (P < 0.01).

CONCLUSION

Recent birth cohorts (born between 1995 and 1999) in Australia report significantly lower rates of both drinking participation and drinking volume than previous cohorts, controlling for their age distribution and overall changes in population drinking. These findings suggest that the recent decline in alcohol consumption in Australia has been driven by declines in drinking among these recently born cohorts. These trends are consistent with international shifts in youth drinking.

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.

The abject failure of drug prohibition

For more than 50 years, like most other countries Australian drug policy relied heavily on law enforcement: politicians emphasised criminal justice measures and the overwhelming majority of government expenditure in response to drugs was allocated to drug law enforcement. Yet during the last half-century, drug markets expanded and became more dangerous. Even worse, deaths, disease, crime, corruption and violence increased substantially. Evidence that supply control is effective is scant yet there is abundant evidence of its serious adverse effects. The limited data available show that drug law enforcement is not cost-effective. However, ample data confirm that drug treatment and harm reduction are effective and cost-effective. Although the heroin shortage in Australia since 2000 is one of the most pronounced and protracted decreases in heroin supply worldwide, there is little evidence that Australian drug law enforcement contributed significantly. International leaders declare increasingly that the international drug control system has failed comprehensively. For many producer and transit countries, the cost of drug prohibition has been devastating. The academic debate about drug policy is now largely over. A number of countries have begun searching for politically feasible alternatives. Whether it is fair and just for the majority of a community to punish those with a minority taste in drugs is the most fundamental question in drug policy and the case for doing so is weak. Drug prohibition has proved to be an expensive way of making a bad problem worse: its major success has been as a political strategy.

The impact of opioid substitution therapy on mortality post-release from prison: retrospective data linkage study

AIMS

Release from prison is a high-risk period for mortality. We examined the impact of opioid substitution therapy (OST), for opioid dependence during and after incarceration, upon mortality post-release.

DESIGN

A cohort was formed of all opioid-dependent people who entered OST between 1985 and 2010 and who, following first OST entry, were released from prison at least once between 2000 and 2012. We linked data on OST history, court and prison records and deaths.

SETTING

New South Wales (NSW), Australia.

PARTICIPANTS

A total of 16,453 people released from prison 60,161 times.

MEASUREMENTS

Crude mortality rates (CMRs) were calculated according to OST retention; multivariable Cox regressions for post-release periods were undertaken to examine the association between OST exposure (a time-dependent variable) and mortality post-release, for which covariates were updated per-release.

FINDINGS

There were 100,978 person-years (PY) post-release; 1050 deaths occurred. Most received OST while incarcerated (76.5%); individuals were receiving OST in 51% of releases. Lowest post-release mortality was among those continuously retained in OST post-release CMR 4 weeks post-release = 6.4 per 1000 PY; 95% confidence interval (CI) = 5.2, 7.8, highest among those with no OST (CMR = 36.7 per 1000 PY; 95% CI = 28.8, 45.9). Multi-factorial models showed OST exposure in the 4 weeks post-release reduced hazard of death by 75% (adjusted hazard ratio 0.25; 95% CI = 0.12, 0.53); OST receipt in prison had a short-term protective effect that decayed quickly across time.

CONCLUSION

In New South Wales, Australia, opioid substitution therapy in prison and post-release appears to reduce mortality risk in the immediate post-release period.

Australia's response to HIV among people who inject drugs

Australia's prompt and effective response to HIV among people who inject drugs is recognized internationally. In the early 1980s, there was growing awareness of the evolving threat presented by HIV. Despite erroneous but commonly held assumptions that people who inject drugs generally disregard their health, injecting drug users contributed significantly to Australia's response to HIV. They formed peer-based organizations which advocated for: engaging affected communities in policy development and implementation; funding for peer education; and access to sterile injecting equipment. While government fear of appearing to condone injecting illicit drugs delayed the bi-partisan political support needed to implement programs to provide readily accessible sterile injecting equipment, needles and syringe programs were established relatively quickly. Strong evidence supports the effectiveness, safety, and cost-effectiveness of Australia's early, decisive, and pragmatic public health and human rights-based approach. Without a comprehensive package of harm reduction and peer-based responses, HIV epidemics can develop rapidly among and from people who inject drugs.

A response to the opioid overdose epidemic: naloxone nasal spray

Opioid overdose morbidity and mortality is recognized to have epidemic proportions. Medical and public health agencies are adopting opioid harm reduction strategies to reduce the morbidity and mortality associated with overdose. One strategy developed by emergency medical services and public health agencies is to deliver the opioid antidote naloxone injection intranasally to reverse the effects of opioids. Paramedics have used this route to quickly administer naloxone in a needle-free system and avoiding needle-stick injuries and contracting a blood-born pathogen disease such as hepatitis or human immunodeficiency virus. Public health officials advocate broader lay person access since civilians are likely witnesses or first responders to an opioid overdose in a time-acute setting. The barrier to greater use of naloxone is that a suitable and optimized needlefree drug delivery system is unavailable. The scientific basis for design and study of an intranasal naloxone product is described. Lessons from nasal delivery of opioid analgesics are applied to the consideration of naloxone nasal spray.

8-OH-DPAT abolishes the pulmonary C-fiber-mediated apneic response to fentanyl largely via acting on 5HT1A receptors in the nucleus tractus solitarius

Intravenous bolus injection of morphine causes a vagal-mediated brief apnea (∼3 s), while continuous injection, via action upon central μ-opioid receptor (MOR), arrests ventilation (>20 s) that is eliminated by stimulating central 5-hydroxytryptamine 1A receptors (5HT(1A)Rs). Bronchopulmonary C-fibers (PCFs) are essential for triggering a brief apnea, and their afferents terminate at the caudomedial region of the nucleus tractus solitarius (mNTS) that densely expresses 5HT(1A)Rs. Thus we asked whether the vagal-mediated apneic response to MOR agonists was PCF dependent, and if so, whether this apnea was abolished by systemic administration of 8-hydroxy-2-(di-n-propylamino)tetral (8-OH-DPAT) largely through action upon mNTS 5HT(1A)Rs. Right atrial bolus injection of fentanyl (5.0 μg/kg, a MOR agonist) was performed in the anesthetized and spontaneously breathing rats before and after: 1) selective blockade of PCFs' conduction and subsequent bivagotomy; 2) intravenous administration of 5HT(1A)R agonist 8-OH-DPAT; 3) intra-mNTS injection of 8-OH-DPAT; and 4) intra-mNTS injection of 5HT(1A)R antagonist WAY-100635 followed by 8-OH-DPAT (iv). We found the following: First, fentanyl evoked an immediate apnea (2.5 ± 0.4 s, ∼6-fold longer than the baseline expiratory duration, T(E)), which was abolished by either blocking PCFs' conduction or bivagotomy. Second, this apnea was prevented by systemic 8-OH-DPAT challenge. Third, intra-mNTS injection of 8-OH-DPAT greatly attenuated the apnea by 64%. Finally, intra-mNTS microinjection of WAY-100635 significantly attenuated (58%) the apneic blockade by 8-OH-DPAT (iv). We conclude that the vagal-mediated apneic response to MOR activation depends on PCFs, which is fully antagonized by systemic 8-OH-DPAT challenge largely via acting on mNTS 5HT(1A)Rs.

Increasing US mortality due to accidental poisoning: the role of the baby boom cohort

AIMS

In this study we examine whether the recent, sharp increase in mortality in the United States due to accidental poisoning since 2000 is the result of the aging of the baby boom cohort or, instead, a historical trend apparent among decedents of all ages.

DESIGN

We conducted an age-period-cohort analysis using data from the US Vital Statistics and the US Census covering the period 1968-2007.

SETTING AND PARTICIPANTS

The United States population aged 15-64 years.

MEASUREMENTS

Cause of death and demographic data as recorded on death certificates.

FINDINGS

The increase in mortality due to accidental poisoning since the year 2000 stems primarily from a historical period effect across all ages for whites, but results in large part from a rate spike in the baby boom cohort among blacks. For all demographic groups baby boomers had higher odds of death due to accidental poisoning than the cohorts that came before and after them. Historical influences acting across all ages led to an increase in accidental poisoning mortality that was almost 10-fold for whites and threefold for blacks over the study period.

CONCLUSIONS

While the recent, sharp increase in accidental poisoning mortality stems in part from the aging of the baby boom cohort, substantially more of the increase results from influences unique to recent years that have affected all age groups. These results point to the need to bolster overdose prevention programs and policies as the historical increase in accidental poisoning mortality appears to continue unabated.

Impact of supervision of methadone consumption on deaths related to methadone overdose (1993-2008): analyses using OD4 index in England and Scotland

OBJECTIVE

To evaluate the impact of introduction of supervision of methadone dosing on deaths related to overdose of methadone in Scotland and England between 1993 and 2008 while controlling for increased prescribing of methadone.

DESIGN

Analysis of annual trends in deaths related to overdose of methadone in relation to defined daily doses of methadone prescribed.

SETTING

Scotland and England. Population Deaths in which methadone was coded as the only drug involved or as one of the drugs implicated.

MAIN OUTCOME MEASURE

Annual OD4-methadone index (number of deaths with methadone implicated per million defined daily doses of methadone prescribed in that year).

RESULTS

OD4-methadone declined substantially over the four epochs of four years between 1993 and 2008. It decreased significantly (P<0.05) in 10 of 12 epoch changes: in Scotland from 19.3 (95% confidence interval 15 to 24) to 4.1 (2.8 to 5.4) and finally to 3.0 (2.4 to 3.5) for methadone only deaths (and from 58 to 29 to 14 for deaths with any mention of methadone); in England from 27.1 (25 to 29) to 24.8 (23 to 27) and finally to 5.8 (5.3 to 6.3) for methadone only deaths (and from 46 to 42 to 12 for deaths with any mention of methadone). The decreases in OD4-methadone were closely related to the introduction of supervised dosing of methadone in both countries, first in Scotland (1995-2000) and later in England (1999-2005). These declines occurred over periods of substantial increases in prescribing of methadone (18-fold increase in defined daily doses per million population annually in Scotland and sevenfold increase in England).

CONCLUSIONS

Introduction of supervised methadone dosing was followed by substantial declines in deaths related to overdose of methadone in both Scotland and England. OD4-methadone index analyses, controlled for substantial increases in methadone prescribing in both countries, identified at least a fourfold reduction in deaths due to methadone related overdose per defined daily dose (OD4-methadone) over this period.

Randomized controlled trial comparing the effectiveness and safety of intranasal and intramuscular naloxone for the treatment of suspected heroin overdose

AIMS

Traditionally, the opiate antagonist naloxone has been administered parenterally; however, intranasal (i.n.) administration has the potential to reduce the risk of needlestick injury. This is important when working with populations known to have a high prevalence of blood-borne viruses. Preliminary research suggests that i.n. administration might be effective, but suboptimal naloxone solutions were used. This study compared the effectiveness of concentrated (2 mg/ml) i.n. naloxone to intramuscular (i.m.) naloxone for suspected opiate overdose.

METHODS

This randomized controlled trial included patients treated for suspected opiate overdose in the pre-hospital setting. Patients received 2 mg of either i.n. or i.m. naloxone. The primary outcome was the proportion of patients who responded within 10 minutes of naloxone treatment. Secondary outcomes included time to adequate response and requirement for supplementary naloxone. Data were analysed using multivariate statistical techniques.

RESULTS

A total of 172 patients were enrolled into the study. Median age was 29 years and 74% were male. Rates of response within 10 minutes were similar: i.n. naloxone (60/83, 72.3%) compared with i.m. naloxone (69/89, 77.5%) [difference: -5.2%, 95% confidence interval (CI) -18.2 to 7.7]. No difference was observed in mean response time (i.n.: 8.0, i.m.: 7.9 minutes; difference 0.1, 95% CI -1.3 to 1.5). Supplementary naloxone was administered to fewer patients who received i.m. naloxone (i.n.: 18.1%; i.m.: 4.5%) (difference: 13.6%, 95% CI 4.2-22.9).

CONCLUSIONS

Concentrated intranasal naloxone reversed heroin overdose successfully in 82% of patients. Time to adequate response was the same for both routes, suggesting that the i.n. route of administration is of similar effectiveness to the i.m. route as a first-line treatment for heroin overdose.

Changes in the initiation of heroin use after a reduction in heroin supply

Increasing heroin use in Australia over the past 30 years has been associated with a decline in the age of initiation to heroin use. The 2001 Australian heroin shortage was used to assess the effects of a reduction in heroin supply on age of initiation into heroin injecting. Data collected from regular injecting drug users (IDU) over the period 1996 - 2004 as part of the Australian Illicit Drug Reporting System were examined for changes in self-reported age of first heroin use after the onset of the heroin shortage. Estimates were also made of the number of young people who may not have commenced injecting heroin during the heroin shortage. The proportion of IDU interviewed in the IDRS who were aged <or=24 years decreased from 46% in 1996 to 12% in 2004, with the most marked drop in 2001, the year in which there was an abrupt and marked reduction in heroin availability. Of those who reported first injecting between 1993 and 2000, similar proportions reported heroin and amphetamine as the first drug injected. After 2000, methamphetamine was the drug most often reported as being the first injected. Estimates suggested that between 2745 and 10,560 young people may not have begun to inject heroin in 2001 as a result of reduced heroin supply. If around one in four of these young users had progressed to regular or dependent heroin use, then there may have been a reduction of between 700 and 2500 dependent heroin users. There was an increase in amphetamine injecting but it is unclear to what extent any reduction in heroin injecting has been offset by increased amphetamine injecting. Reduced heroin availability probably resulted in a reduction in the number of new heroin injectors in Australia. Efforts need to be made to reduce the chances that young people who have initiated methamphetamine injecting do not move to heroin injecting when the heroin supply returns.

Characteristics of non-fatal opioid overdoses attended by ambulance services in Australia

OBJECTIVE

To examine the feasibility of establishing a database on non-fatal opioid overdose in order to examine patterns and characteristics of these overdoses across Australia.

METHODS

Unit record data on opioid overdose attended by ambulances were obtained from ambulance services in the five mainland States of Australia for available periods, along with information on case definition and opioid overdose management within these jurisdictions. Variables common across States were examined including the age and sex of cases attended, the time of day and day of week of the attendance, and the transportation outcome (whether the victim was left at the scene or transported to hospital).

RESULTS

The monthly rate of non-fatal opioid overdose attended by ambulance was generally highest in Victoria (Melbourne) followed by NSW, with the rates substantially lower in the remaining States over the period January 1999 to February 2001. Non-fatal opioid overdose victims were most likely to be male in all States, with the proportion of males highest in Victoria (77%), and were aged around 28 years with ages lowest in Western Australia (m=26) and highest in NSW (m=30). Most of the attendances occurred in the afternoon/early evening and towards the later days of the working week in all States. The rates of transportation varied according to ambulance service practice across the States with around 94% of cases transported in Western Australia and around 18% and 29% of cases transported in Melbourne and NSW respectively.

CONCLUSIONS

It is feasible to establish a database of comparable data on non-fatal opioid overdoses attended by ambulances in Australia. This compilation represents a useful adjunct to existing surveillance systems on heroin (and other opioid) use and related harms.

Using latent class analysis (LCA) to analyze patterns of drug use in a population of illegal opioid users

BACKGROUND

The objective of this paper is to empirically determine a categorization of illegal opioid users in Canada in order to describe and analyze drug use patterns within this population.

METHODS

Drug use patterns of 679 eligible illegal opioid users outside treatment from the OPICAN study, a pan-Canadian cohort (recruited March to December, 2002) involving the cities of Toronto, Montreal, Vancouver, Edmonton and Quebec City, were empirically examined using latent class analysis. These latent classes were then further analyzed for associations using chi-square and t-test statistics.

FINDINGS

The opioid and other drug user sample surveyed were categorized into three latent classes. Class 1 (N=256) was characterized by the use of Tylenol 3 and benzodiazepines along with high levels of depression and self-reported pain. Class 2 (N=68) was described by the non-injection use of both heroin and crack while having a high level of homelessness. Class 3 (N=344) was shown to consist of injection drug users of heroin and cocaine exhibiting the highest levels of HIV and Hepatitis C infections amongst the classes.

CONCLUSIONS

Using latent class analysis we found distinct patterns of drug use amongst illegal opioid users differing in terms of type of drugs co-used, social context, and co-morbid pathologies. These data may be useful as the empirical basis for the planning of specific prevention and treatment interventions.

Prescribing naloxone to actively injecting heroin users: a program to reduce heroin overdose deaths

Heroin overdose deaths have increased alarmingly in Chicago over the past decade. Naloxone, an opioid antagonist with no abuse potential, has been used to reverse opiate overdose in emergency medical settings for decades. We describe here a program to educate opiate users in the prevention of opiate overdose and its reversal with intramuscular naloxone. Participant education and naloxone prescription are accomplished within a large comprehensive harm reduction program network. Since institution of the program in January 2001, more than 3,500 10 ml (0.4 mg/ml) vials of naloxone have been prescribed and 319 reports of peer reversals received. The Medical Examiner of Cook County reported a steady increase in heroin overdose deaths since 1991, with a four-fold increase between 1996 and 2000. This trend reversed in 2001, with a 20% decrease in 2001 and 10% decreases in 2002 and 2003.

Buprenorphine Use: The International Experience

The confluence of the heroin injection epidemic and the human immunodeficiency virus (HIV) infection epidemic has increased the call for expanded access to effective treatments for both conditions. Buprenorphine and methadone are now listed on the World Health Organization's Model Essential Drugs List. In France, which has the most extensive experience, buprenorphine has been associated with a dramatic decrease in deaths due to overdose, and buprenorphine diversion appears to be associated with inadequate dosage, social vulnerability, and prescriptions from multiple providers. Other treatment models (in the United States, Australia, Germany, and Italy) and buprenorphine use in specific populations are also reviewed in the present article. In countries experiencing a dual epidemic of heroin use and HIV infection, such as former states of the Soviet Union and other eastern European and Asian countries, access to buprenorphine and methadone may be one potential tool for reducing the spread of HIV infection among injection drug users and for better engaging them in medical care.

The "lessons" of the Australian "heroin shortage"

Heroin use causes considerable harm to individual users including dependence, fatal and nonfatal overdose, mental health problems, and blood borne virus transmission. It also adversely affects the community through drug dealing, property crime and reduced public amenity. During the mid to late 1990s in Australia the prevalence of heroin use increased as reflected in steeply rising overdose deaths. In January 2001, there were reports of an unpredicted and unprecedented reduction in heroin supply with an abrupt onset in all Australian jurisdictions. The shortage was most marked in New South Wales, the State with the largest heroin market, which saw increases in price, dramatic decreases in purity at the street level, and reductions in the ease with which injecting drug users reported being able to obtain the drug. The abrupt onset of the shortage and a subsequent dramatic reduction in overdose deaths prompted national debate about the causes of the shortage and later international debate about the policy significance of what has come to be called the "Australian heroin shortage". In this paper we summarise insights from four years' research into the causes, consequences and policy implications of the "heroin shortage".

Age differentials in the impacts of reduced heroin: effects of a "heroin shortage" in NSW, Australia

BACKGROUND

This paper uses a unique event, the Australian heroin shortage, to see whether an abrupt, substantial and sustained change in heroin supply had different effects on harms related to heroin use among younger and older heroin users.

METHOD

Indicator data were examined by age group on the number of persons entering treatment for heroin and amphetamine dependence, arrests for heroin use/possession and number of drug related deaths in NSW, Australia. Data were analysed using times series analysis.

RESULTS

There was a 41% reduction in the number of new registrations for opioid pharmacotherapy per month among 25-34 year olds, and a 26% reduction among 15-24 year olds, but no apparent changes among older age groups. Similarly, reductions in the number of non-pharmacological heroin treatment episodes were most pronounced among younger age groups. There was a 49% reduction in the number of heroin possession/use offences among those aged 15-24 years, compared to declines of 31-40% among older age groups. Declines in heroin related deaths were greatest among 15-24 year olds (65% reduction). There was no change in other drug related deaths in any age group.

CONCLUSIONS

A reduction in heroin supply was followed by greater reductions in heroin related harms among younger than older people, across a number of outcome domains.

The impact of a reduction in drug supply on demand for and compliance with treatment for drug dependence

BACKGROUND

In early 2001, Australia experienced a sudden, dramatic and sustained decrease in heroin availability that was accompanied by sharp increases in price and decreases in street level purity--the so-called "heroin shortage". These unprecedented changes occurred in a context of widespread treatment availability, which made it possible for the first time to examine the impact of a sharp reduction in heroin supply in New South Wales (NSW) on entry to and adherence with treatment for heroin dependence. Given the evidence of drug substitution by some users, the current paper also examines the effects of the shortage on entry to treatment for other forms of drug dependence.

METHODS

Interrupted time-series analysis of the number of persons entering opioid pharmacotherapy and other treatment modalities in NSW for heroin dependence and for the treatment for other types of drug dependence.

FINDINGS

The heroin shortage was associated with a reduction in the number of younger persons entering opioid pharmacotherapy. There was a dramatic decrease in the number of persons entering heroin withdrawal or "assessment only" treatment episodes. There appear to have been small improvements in adherence to and retention in heroin treatment after the reduction in heroin supply. Relatively small increases were observed in numbers being treated for cocaine dependence.

CONCLUSIONS

In the context of good treatment provision, a reduction in heroin supply appeared to produce modest improvements in intermediate outcomes. Supply and demand reduction measures, when both are implemented successfully, may be complementary.

Effects of a sustained heroin shortage in three Australian States

BACKGROUND

In early 2001 in Australia there was a sudden and dramatic decrease in heroin availability that occurred throughout the country that was evidenced by marked increases in heroin price and decreases in its purity.

AIM

This study examines the impact of this change in heroin supply on the following indicators of heroin use: fatal and non-fatal drug overdoses; treatment seeking for heroin dependence; injecting drug use; drug-specific offences; and general property offences. The study was conducted using data from three Australian States [New South Wales (NSW), Victoria (VIC) and South Australia (SA)].

METHODS

Data were obtained on fatal and non-fatal overdoses from hospital emergency departments (EDs), ambulance services and coronial systems; treatment entries for heroin dependence compiled by State health departments; numbers of needles and syringes distributed to drug users; and data on arrests for heroin-related incidents and property-related crime incidents compiled by State Police Services. Time-series analyses were conducted where possible to examine changes before and after the onset of the heroin shortage. These were supplemented with information drawn from studies involving interviews with injecting drug users.

RESULTS

After the reduction in heroin supply, fatal and non-fatal heroin overdoses decreased by between 40% and 85%. Despite some evidence of increased cocaine, methamphetamine and benzodiazepine use and reports of increases in harms related to their use, there were no increases recorded in the number of either non-fatal overdoses or deaths related to these drugs. There was a sustained decline in injecting drug use in NSW and VIC, as indicated by a substantial drop in the number of needles and syringes distributed (to 1999 levels in Victoria). There was a short-lived increase in property crime in NSW followed by a sustained reduction in such offences. SA and VIC did not show any marked change in the categories of property crime examined in the study.

CONCLUSIONS

Substantial reductions in heroin availability have not occurred often, but in this Australian case a reduction had an aggregate positive impact in that it was associated with: reduced fatal and non-fatal heroin overdoses; reduced the apparent extent of injecting drug use in VIC and NSW; and may have contributed to reduced crime in NSW. All these changes provide substantial benefits to the community and some to heroin users. Documented shifts to other forms of drug use did not appear sufficient to produce increases in deaths, non-fatal overdoses or treatment seeking related to those drugs.

Underlying causes of cocaine, amphetamine and opioid related deaths in Australia

OBJECTIVE

To examine the characteristics of deaths in Australia where opioids, cocaine or amphetamines were mentioned, taking into account changes in the use and availability of these drugs in recent years.

DESIGN

Data were analysed from the Australian Bureau of Statistics and Causes of Death dataset between 1997 and 2002 on all deaths in which cocaine, amphetamines or opioids were mentioned including deaths where (a) the drugs were considered an underlying cause of death, (b) the drugs contributed to accidental drug-induced death, and (c) deaths primarily due to other causes. Data from the Australian National Drug Strategy Household Survey were also used to examine the prevalence of use of amphetamines, cocaine and opioids in Australia.

RESULTS

Thirteen deaths were attributed primarily to cocaine, 68 to amphetamines, and 4591 to opioids. An increase occurred in mentions of amphetamines, but half of these were primarily attributed to opioids. Opioid related deaths declined dramatically in 2001, consistent with a marked reduction in availability of heroin in Australia. Cocaine mentions remained relatively stable, with most cases primarily attributed to opioids. Of the other underlying causes of death, suicide was the most prevalent underlying factor, particularly for amphetamine and opioid related deaths.

CONCLUSIONS

Compared with opioid-related deaths, there are small numbers of deaths related to psychostimulants in Australia. Accidental drug induced deaths account for the majority of deaths in which these drugs are mentioned, although minorities of drug related deaths are attributed to suicide.

Evaluating explanations of the Australian 'heroin shortage'

AIMS

In this paper we outline and evaluate competing explanations for a heroin shortage that occurred in Australia during 2001 with an abrupt onset at the beginning of 2001.

METHODS

We evaluated each of the explanations offered for the shortage against evidence from a variety of sources: government reports, police and drug law enforcement documents and briefings, key informant (KI) interviews, indicator data and research data.

RESULTS

No similar shortage occurred at the same time in other markets (e.g. Vancouver, Canada or Hong Kong) whose heroin originated in the same countries as Australia's. The shortage was due most probably to a combination of factors that operated synergistically and sequentially. The heroin market had grown rapidly in the late 1990s, perhaps helped by a decline in drug law enforcement (DLE) in Australia in the early 1990s that facilitated high-level heroin suppliers in Asia to establish large-scale importation heroin networks into Australia. This led to an increase in the availability of heroin, increasingly visible street-based drug markets, increased purity and decreased price of heroin around the country. The Australian heroin market was well established by the late 1990s, but it had a low profit margin with high heroin purity, and a lower price than ever before. The surge in heroin problems led to increased funding of the Australian Federal Police and Customs as part of the National Illicit Drug Strategy in 1998-99, with the result that a number of key individuals and large seizures occurred during 1999-2000, probably increasing the risks of large-scale importation. The combination of low profits and increased success of law enforcement may have reduced the dependability of key suppliers of heroin to Australia at a time when seized heroin was becoming more difficult to replace because of reduced supplies in the Golden Triangle. These factors may have reduced the attractiveness of Australia as a destination for heroin trafficking.

CONCLUSIONS

The Australian heroin shortage in 2001 was due probably to a combination of factors that included increased effectiveness of law enforcement efforts to disrupt networks bringing large shipments of heroin from traditional source countries, and decreased capacity or willingness of major traffickers to continue large scale shipments to Australia.

Unintentional methadone-related overdose death in New Mexico (USA) and implications for surveillance, 1998-2002

AIMS

To determine death rates from methadone over time, to characterize methadone-related death and to discuss public health surveillance of methadone-related death.

DESIGN

We analyzed medical examiner data for all unintentional drug overdose deaths in New Mexico, USA, between 1998 and 2002.

MEASUREMENTS

Age-adjusted death rates for methadone-related death, logistic regression models for likelihood of methadone-related death among all unintentional drug overdose deaths and bivariate comparisons within methadone-related death.

FINDINGS

Of 1120 drug overdose deaths during this period, there were 143 (12.8%) methadone-related deaths; the death rate decreased over the time period, averaging 1.6 per 100,000. Of 143 methadone-related deaths, 22.4% were due to methadone alone, 23.8% were due to methadone/prescription drugs (no illicit drugs), 50.3% were due to methadone/illicit drugs and 3.5% were due to methadone/alcohol. These groups were significantly different in demographics, health history and circumstances of death. Of 79 decedents (55.2%) with a known source of methadone, 68 obtained methadone through a physician prescription (31 for methadone maintenance treatment (MMT), 27 for managing pain and 10 had unknown reason for prescription).

CONCLUSIONS

Methadone-related death rates and the proportion of methadone-related death among all drug overdose deaths decreased in New Mexico from 1998 to 2002. It is important for surveillance of methadone-related death to assess multiple drug causes, not just underlying cause. Also, methadone for pain management must be examined alongside MMT and when possible, methadone co-intoxication should be described in the context of other drugs causing death.

The effect of a reduction in heroin supply on fatal and non‐fatal drug overdoses in New South Wales, Australia

OBJECTIVE

To examine the impact of a sudden and dramatic decrease in heroin availability, concomitant with increases in price and decreases in purity, on fatal and non-fatal drug overdoses in New South Wales, Australia.

DESIGN AND SETTING

Time-series analysis was conducted where possible on data on overdoses collected from NSW hospital emergency departments, the NSW Ambulance Service, and all suspected drug-related deaths referred to the NSW Coroner's court.

MAIN OUTCOME MEASURES

The number of suspected drug-related deaths where heroin and other drugs were mentioned; ambulance calls to suspected opioid overdoses; and emergency department admissions for overdoses on heroin and other drugs.

RESULTS

Both fatal and non-fatal heroin overdoses decreased significantly after heroin supply reduced; the reductions were greater among younger age groups than older age groups. There were no clear increases in non-fatal overdoses with cocaine, methamphetamines or benzodiazepines recorded at hospital emergency departments after the reduction in heroin supply. Data on drug-related deaths suggested that heroin use was the predominant driver of drug-related deaths in NSW, and that when heroin supply was reduced overdose deaths were more likely to involve a wider combination of drugs.

CONCLUSION

A reduction in heroin supply reduced heroin-related deaths, and did not result in a concomitant increase, to the same degree, in deaths relating to other drugs. Younger people were more affected by the reduction in supply.

Randomised trial of intranasal versus intramuscular naloxone in prehospital treatment for suspected opioid overdose

OBJECTIVE

To determine the effectiveness of intranasal (IN) naloxone compared with intramuscular (IM) naloxone for treatment of respiratory depression due to suspected opiate overdose in the prehospital setting.

DESIGN

Prospective, randomised, unblinded trial of either 2 mg naloxone injected intramuscularly or 2 mg naloxone delivered intranasally with a mucosal atomiser.

PARTICIPANTS AND SETTING

155 patients (71 IM and 84 IN) requiring treatment for suspected opiate overdose and attended by paramedics of the Metropolitan Ambulance Service (MAS) and Rural Ambulance Victoria (RAV) in Victoria.

MAIN OUTCOME MEASURES

Response time to regain a respiratory rate greater than 10 per minute. Secondary outcome measures were proportion of patients with respiratory rate greater than 10 per minute at 8 minutes and/or a GCS score over 11 at 8 minutes; proportion requiring rescue naloxone; rate of adverse events; proportion of the IN group for whom IN naloxone alone was sufficient treatment.

RESULTS

The IM group had more rapid response than the IN group, and were more likely to have more than 10 spontaneous respirations per minute within 8 minutes (82% v 63%; P = 0.0173). There was no statistically significant difference between the IM and IN groups for needing rescue naloxone (13% [IM group] v 26% [IN group]; P = 0.0558). There were no major adverse events. For patients treated with IN naloxone, this was sufficient to reverse opiate toxicity in 74%.

CONCLUSION

IN naloxone is effective in treating opiate-induced respiratory depression, but is not as effective as IM naloxone. IN delivery of naxolone could reduce the risk of needlestick injury to ambulance officers and, being relatively safe to make more widely available, could increase access to life-saving treatment in the community.

Childhood adversity in an Australian population

BACKGROUND

The impact of adversity in childhood is well established in clinical populations, but there is little information about adversity in wider populations. The aim of this paper is to report and to explore the distribution of childhood family adversity in an Australian population.

METHOD

A total of 7485 randomly selected subjects in 20-24, 40-44 and 60-64 year age bands were interviewed at the outset of a longitudinal community study of psychological health in the Canberra region of Australia. In the initial cross-sectional interview, subjects answered 17 questions about experience of adversity in the home to age 16 years.

RESULTS

In the population, 59.5% had experienced some form of childhood adversity and 37% had experienced more than one adversity. Domestic conflict and parental psychopathology and substance use are the common adversities. Parental sexual abuse was reported by 1.1%. Adversity was highest in the 40-44 year age group and reported more in women in all age groups. The majority of subjects saw their childhood as happy or normal despite adversity, but happiness is affected most by domestic warmth and harmony, and normalcy by abuse and neglect. Severe adversities, physical and sexual abuse and neglect, were uncommon, but were related to multiple and other severe adversities.

CONCLUSION

Some form of adversity is a common experience, although the severest abuses are less common in this population. Multiple adversities are common and only a minority experience single adversities. Physical abuse, sexual abuse and neglect rarely occur alone, but indicate a context of abuse.

The contribution of research to Australian policy responses to heroin dependence 1990-2001: a personal retrospection

Periodic public concern about heroin use has been a major driver of Australian drug policy in the four decades since heroin use was first reported. The number of heroin-dependent people in Australia has increased from several hundreds in the late 1960s to around 100,000 by the end of the 1990s. In this paper I do the following: (1) describe collaborative research on heroin dependence that was undertaken between 1991 and 2001 by researchers at the National Drug and Alcohol Research Centre; (2) discuss the contribution that this research may have made to the formulation of policies towards the treatment of heroin dependence during a period when the policy debate crystallized around the issue of whether or not Australia should conduct a controlled trial of heroin prescription; and (3) reflect on the relationships between research and policy-making in the addictions field, specifically on the roles of investigator-initiated and commissioned research, the interface between researchers, funders and policy-makers; and the need to be realistic about the likely impact of research on policy and practice.

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

AIMS

This study compares the hazard of death among opiate and amphetamine using clients who accessed drug treatment with individuals who had no specialist treatment contact between 1985 and 1998.

DESIGN, SETTING, PARTICIPANTS

This was a retrospective cohort study of 4280 drug-using individuals (2887 opiate users, 1393 amphetamine users) admitted to Perth metropolitan hospitals or Perth psychiatric institutions between 1985 and 1998. Of these, 1469 attended Next Step Specialist Drug and Alcohol Services (928 received methadone and 541 attended counselling or support groups) and 2811 had no contact with this service.

METHODS

Data from two drug treatment programmes were linked with hospital morbidity, psychiatric services and the mortality database using record linkage.

FINDINGS

The results show that people who were currently in drug treatment had a lower hazard of death compared with non-clients and those who had ceased treatment. Those who had ceased treatment more than 6 months ago had 7.0 times the hazard of all-cause death and 8.4 times the hazard of drug-cause death. Opiate users were at 1.4 times the hazard of all-cause death and 2.4 times the hazard of drug-cause death compared with amphetamine users. Males were at 1.79 times the hazard of all-cause death and, unexpectedly, were found to be at 2.69 times the hazard of drug-cause death compared with females.

CONCLUSIONS

Treatment protected clients from premature death compared with people who did not receive treatment and also those who ceased treatment. While amphetamine users had a lower risk of mortality compared with opiate users, the full extent of the relationship between amphetamine use and mortality needs to be examined further.

Temporal correlation between opiate seizures in East/Southeast Asia and B.C. heroin deaths: a transoceanic model of heroin death risk

BACKGROUND

Because heroin supply changes cannot be measured directly, their impact on populations is poorly understood. British Columbia has experienced an injection drug use epidemic since the 1980s that resulted in 2,590 illicit drug deaths from 1990-1999. Since previous work indicates heroin seizures can correlate with supply and B.C. receives heroin only from Southeast Asia, this study examined B.C. heroin deaths against opiate seizures in East/Southeast Asia.

METHODS

Opiate seizures in East/Southeast Asia and data from two B.C. mortality datasets containing heroin deaths were examined. The Pearson correlation coefficient for seizures against each mortality dataset was determined.

RESULTS

Opiate seizures, all illicit drug deaths and all opiate deaths concurrently increased twice and decreased twice from 1989-1999, and all reached new peak values in 1993. Three B.C. sub-regions exhibited illicit drug deaths rate trends concurrent with the three principal datasets studied. The Pearson correlation coefficient for opiate-induced deaths against opiate seizures from 1980-1999 was R=0.915 (p<0.0001), and for illicit drug deaths against opiate seizures from 1987-1999 was R=0.896 (p<0.0001).

CONCLUSIONS

From 1980-1999, opiate seizures in East/Southeast Asia were very strongly correlated with B.C. opiate and illicit drug deaths. The number of B.C. heroin-related deaths may be strongly linked to heroin supply. Enforcement services are not effective in preventing harm caused by heroin in B.C.; therefore, Canada should examine other methods to prevent harm. The case for harm reduction is strengthened by the ineffectiveness of enforcement and the unlikelihood of imminent eradication of heroin production in Southeast Asia.

Heroin overdose: research and evidence-based intervention

Drug overdose is a major cause of premature death and morbidity among heroin users. This article examines recent research into heroin overdose to inform interventions that will reduce the rate of overdose death. The demographic characteristics of overdose cases are discussed, including factors associated with overdose: polydrug use, drug purity, drug tolerance, routes of administration, and suicide. Responses by heroin users at overdoses are also examined. Potential interventions to reduce the rate of overdose and overdose-related morbidity are examined in light of the emerging data in this field.

Hair morphine concentrations of fatal heroin overdose cases and living heroin users

AIMS

To compare heroin and other opiate use of heroin overdose fatalities, current street heroin users and drug-free therapeutic community clients.

DESIGN

Hair morphine concentrations that assess heroin use and other opiate use in the 2 months preceding interview or death were compared between heroin overdose fatalities diagnosed by forensic pathologists (FOD) (n = 42), current street heroin users (CU) (n = 100) and presumably abstinent heroin users in a drug-free therapeutic community (TC) (n = 50).

SETTING

Sydney, Australia.

FINDINGS

The mean age and gender breakdown of the three samples were 32.3 years, 83% male (FOD), 28.7 years, 58% male (CU) and 28.6 years, 60% male (TC). The median blood morphine concentration among the FOD cases was 0.35 mg/l, and 82% also had other drugs detected. There were large differences between the three groups in hair morphine concentrations, with the CU group (2.10 ng/mg) having concentration approximately four times that of the FOD group (0.53 ng/mg), which in turn had a concentration approximately six times that of the TC group (0.09 ng/mg). There were no significant differences between males and females in hair concentrations within any of the groups. Hair morphine concentrations were correlated significantly with blood morphine concentrations among FOD cases (r = 0.54), and self-reported heroin use among living participants (r = 0.57).

CONCLUSIONS

The results indicate that fatal cases had a lower degree of chronic opiate intake than the active street users, but they were not abstinent during this period.

Heroin use in New South Wales, Australia, 1996-2000: 5 year monitoring of trends in price, purity, availability and use from the Illicit Drug Reporting System (IDRS)

AIMS

To document trends in the price, purity, availability and use of heroin in New South Wales detected by the Illicit Drug Reporting System (IDRS) between 1996 and 2000, and to demonstrate the utility of the IDRS in identifying such trends.

DESIGN

The IDRS compares information derived from interviews with injecting drug users, key informants who work in the illicit drugs field, and key indicator data on illicit drug trends.

SETTING

New South Wales, Australia.

FINDINGS

The price of heroin approximately halved over this period, from a median of A$400 per gram in 1996 to A$220 per gram in 2000. While the price of heroin fell dramatically over the study period, the purity of police seizures of the drug was high across all years, ranging between 62% and 71%. In all years heroin was considered easy to obtain by both heroin users who purchased the drug, and by key informants from the law enforcement and health fields. Concurrent with the large fall in heroin prices, there appeared to have been an increase in the number of heroin users. Between 1997 and 1998 there was a sharp increase in the injecting use of cocaine by heroin users in NSW, a pattern that has persisted.

CONCLUSIONS

Regular and formal monitoring of illicit drug trends provides timely data in a systematic way to inform health and law enforcement policies towards current and emerging illicit drug problems.

Methadone maintenance programs--a two-edged sword?

Retrospective review was undertaken of all autopsies in which methadone was detected at the Forensic Science Centre, South Australia, during a 3-year period from July 1996 to June 1999. Thirty-five cases were found in which methadone had either caused or contributed to death (age range = 14-54 years; average = 31 years; M:F = 3.4:1). Ten victims were participating in a methadone maintenance program, of whom four died within a week of enrollment. Eight victims (23%) not enrolled in a methadone maintenance program were found who had died after the use of "diverted" methadone (i.e., prescribed for someone else) (age range = 14-34 years; average = 25 years; M:F = 6:2). Deaths were directly attributable to methadone toxicity in seven of the eight cases, with additional drugs or alcohol being found in seven cases. Prevention of ongoing deaths caused by methadone diversion could be achieved by allowing only daily releases of methadone, with the addict having to consume the drug under close supervision.

Trends in licit opioid use in Australia, 1984-1998: comparative analysis of international and jurisdictional data

OBJECTIVES

To examine trends from 1984 to 1998 in licit opioids used in Australia compared with nine other developed countries, and in New South Wales compared with other Australian jurisdictions.

DESIGN

Poisson regression analysis of annual rates of national and jurisdictional consumption of methadone, morphine and pethidine.

MAIN OUTCOME MEASURES

All drug data were standardised to defined daily doses per 1000 population per day.

RESULTS

Methadone consumption increased by, on average, 12% per year (RR, 1.12; 95% CI, 1.08-1.17), with Australia in the first rank of countries. Morphine use increased by 5% per year (RR, 1.05; 95% CI, 1.02-1.09), with Australia ranking equal second with three other countries behind Denmark. Consumption of pethidine in all 10 countries was unchanged (RR, 0.99; 95% CI, 0.97-1.00), with Australia equal first. In Australia, use of methadone syrup increased by 17% per year (RR, 1.17; 95% CI, 1.16-1.17) and by 11% per year for methadone tablets (RR, 1.11; 95% CI, 1.10-1.12). Consumption of methadone syrup in NSW was more than double that of any other jurisdiction. Consumption of methadone tablets was 2.4 times higher in South Australia (RR, 2.35; 95% CI, 2.09-2.65) than NSW. The Northern Territory, Tasmania and Queensland also had significantly higher consumption than NSW. From 1991 to 1998, controlled-release morphine consumption increased by 27% per year nationally (RR, 1.27; 95% CI, 1.24-1.30). The NT had 2.6 times more supply of morphine (RR, 2.63; 95% CI, 1.71-4.03) and Tasmania 58% more supply than NSW (RR, 1.58; 95% CI, 1.11-2.25).

CONCLUSIONS

Australia's consumption of licit opioids ranked high internationally. There were diverse trends in the supply of licit opioids to Australia's jurisdictions, resulting in a heterogeneous pattern throughout the country.

How many dependent heroin users are there in Australia?

OBJECTIVE

To estimate the prevalence of dependent or daily heroin users in Australia, and to compare the prevalence in Australia with that in other developed countries.

DESIGN

We applied three different methods of estimation (back-projection, capture-recapture, and multiplier) to data on national opioid overdose deaths in Australia, first-time entrants to methadone maintenance treatment, and heroin-related arrests in New South Wales. We compared our estimates with estimates derived by similar methods in countries of the European Union.

DATA SOURCES

Data on national opioid overdose deaths were obtained from the Australian Bureau of Statistics. Data on methadone entrants in NSW were extracted from a database maintained by the NSW Department of Health. Data on arrests for heroin-related offences were supplied by the NSW Police Service.

RESULTS

The best estimates of the number of dependent heroin users in Australia in 1997-1998 from the three methods of estimation were between 67 000 and 92 000 and the median estimate was 74 000. The population prevalence was 6.9 per 1000 adults aged 15-54 years. The prevalence of heroin dependence in Australia is the same as that in Britain (7 per 1000) and within the range of recently derived estimates in the European Union (3-8 per 1000 adults aged 15-54 years).

CONCLUSIONS

Although the exact figures need to be interpreted with caution, our estimates suggest that Australia has a substantial public health problem with dependent heroin use that is of a magnitude similar to that in comparable European societies.

Cohort trends in the age of initiation of drug use in Australia

AIM

To examine birth cohort trends in the prevalence of use and the age of initiation of use of: alcohol, tobacco, cannabis, amphetamines, LSD, and heroin.

METHOD

Data were taken from the 1998 National Drug Strategy Household Survey, a survey of a representative sample of Australians aged 14 years and over. Nine five-year cohorts were examined among persons born between 1940 and 1984. The weighted prevalence of use by ages 15 years, 21 years, and lifetime use, was estimated, as was the average age of first use among users. The significance of trends was tested using logistic regression (for lifetime use, use by 15 and 21 years) and linear regression (for age of first use).

RESULTS

Lifetime prevalence of alcohol and tobacco use was similar among all birth cohorts. The prevalence of illicit drug use--cannabis, amphetamines, LSD and heroin--increased with successive birth cohorts and more recent birth cohorts reported using licit and illicit drugs at a younger age.

CONCLUSIONS

More recent cohorts are more likely to use illicit drugs at some point in their lives. Greater numbers of persons from more recent birth cohorts may be at risk of developing substance-related problems.

Cohort trends in youth suicide in Australia 1964-1997

OBJECTIVE

This paper examines trends in the rate of suicide among young Australians aged 15-24 years from 1964 to 1997 and presents an age-period-cohort analysis of these trends.

METHOD

Study design consisted of an age-period-cohort analysis of suicide mortality in Australian youth aged between 15 and 24 for the years 1964-1997 inclusive. Data sources were Australian Bureau of Statistics data on: numbers of deaths due to suicide by gender and age at death; and population at risk in each of eight birth cohorts (1940-1944, 1945-1949, 1950-1954, 1955-1959, 1960-1964, 1965-1969, 1970-1974, and 1975-1979). Main outcome measures were population rates of deaths among males and females in each birth cohort attributed to suicide in each year 1964-1997.

RESULTS

The rate of suicide deaths among Australian males aged 15-24 years increased from 8.7 per 100,000 in 1964 to 30.9 per 100,000 in 1997, with the rate among females changing little over the period, from 5.2 per 100,000 in 1964 to 7.1 per 100,000 in 1997. While the rate of deaths attributed to suicide increased over the birth cohorts, analyses revealed that these increases were largely due to period effects, with suicide twice as likely among those aged 15-24 years in 1985-1997 than between 1964 and 1969.

CONCLUSIONS

The rate of youth suicide in Australia has increased since 1964, particularly among males. This increase can largely be attributed to period effects rather than to a cohort effect and has been paralleled by an increased rate of youth suicides internationally and by an increase in other psychosocial problems including psychiatric illness, criminal offending and substance use disorders.