Showing papers by "Wayne Hall published in 2007"

Trajectories of adolescent alcohol and cannabis use into young adulthood

Abstract: Background Both alcohol and cannabis use carry health risks. Both are commonly initiated in adolescence. To date little research has described trajectories of adolescent cannabis or alcohol use or compared their respective consequences in young adulthood. Methods The design was a 10-year eight-wave cohort study of a state-wide community sample of 1943 Victorians initially aged 14-15 years. Moderate- and high-risk alcohol use was defined according to total weekly alcohol consumption. Moderate- and high-risk cannabis use were defined as weekly and daily use, respectively. Results Around 90% of young adults used either alcohol or cannabis. Although an association existed between alcohol and cannabis use, there was a tendency for heavy users to use one substance predominantly at any one time. Weekly or more frequent cannabis use in the absence of moderate-risk alcohol use in teenagers predicted a sevenfold higher rate of daily cannabis use in young adults but only a twofold increase in high-risk alcohol use. Conversely, moderate-risk adolescent alcohol use in the absence of weekly cannabis predicted an approximately threefold increased rate of both high-risk drinking and daily cannabis use in young adulthood. Selective heavy cannabis use in both adolescence and young adulthood was associated with greater illicit substance use and poorer social outcomes in young adulthood than selective alcohol use. Conclusions Heavier teenage cannabis users tend to continue selectively with cannabis use. Considering their poor young adult outcomes, regular adolescent cannabis users appear to be on a problematic trajectory.

Prevalence and correlates of cannabis use in developed and developing countries.

Abstract: Purpose of review The aim of this article is to review recent research on the prevalence, antecedents and correlates of cannabis use in young adults in developed and developing countries. Recent findings Cannabis is the most widely used illicit drug globally and its use appears to be increasing in developed and developing countries. In developed countries rebelliousness, antisocial behaviour, poor school performance, and affiliation with drug-using peers are risk factors for early and regular cannabis use. Similar antecedents are now being reported in developing countries. Dependence is an underappreciated risk of cannabis that affects one in six to seven adolescents who use cannabis in developed countries. Adolescent cannabis dependence is correlated with an increased risk of using other illicit drugs, symptoms of depression, and symptoms of psychosis. The plausibility of cannabis playing a contributory causal role has increased for symptoms of psychosis in longitudinal studies but remains contentious. In the case of other illicit drug use and mood disorders common causal explanations remain difficult to exclude. Summary Early and regular cannabis use in adolescence predicts an increased risk of cannabis dependence which in turn predicts an increased risk of using other illicit drugs, and reporting symptoms of mood and psychotic disorders.

Substance use and the adolescent brain: a toxic combination?

Abstract: Early onset substance use has consistently been associated with increased risk for a range of adverse outcomes in late adolescence and early adulthood. However, the mechanisms that underlie this relationship are not fully understood. Recent advances in developmental neuro-science, together with emerging literature on early onset substance use, suggest that the adolescent brain may be more vulnerable to the effects of addictive substances because of the extensive neuromaturational processes that are occurring during this period. Such findings are suggestive of disrupted developmental trajectories in early onset users, although there is growing evidence that high-risk youths have premorbid neurobiological vulnerabilities. Prospective studies investigating neurobiological correlates and sequelae of early adolescent drug use are urgently required to inform appropriate public health responses.

Should the Health Community Promote Smokeless Tobacco (Snus) as a Harm Reduction Measure

Abstract: Background to the debate: The tobacco control community is divided on whether or not to inform the public that using oral, smokeless tobacco (Swedish snus) is less hazardous to health than smoking tobacco. Proponents of “harm reduction” point to the Swedish experience. Snus seems to be widely used as an alternative to cigarettes in Sweden, say these proponents, contributing to the low overall prevalence of smoking and smoking-related disease. Harm reduction proponents thus argue that the health community should actively inform inveterate cigarette smokers of the benefi ts of switching to snus. However, critics of harm reduction say that snus has its own risks, that no form of tobacco should ever be promoted, and that Sweden’s experience is likely to be specifi c to that culture and not transferable to other settings. Critics also remain deeply suspicious that the tobacco industry will use snus marketing as a “gateway” to promote cigarettes. In the interests of promoting debate, the authors (who are collaborators on a research project on the future of tobacco control) have agreed to outline the strongest arguments for and against promoting Swedish snus as a form of harm reduction.

The Temporal Dynamics of Relationships Between Cannabis, Psychosis and Depression Among Young Adults with Psychotic Disorders: Findings From A 10-Month Prospective Study

Abstract: Background. The aim was to examine the temporal relationships over 10 months between cannabis use and symptoms of psychosis and depression in people with schizophrenia and related disorders. The design was a prospective study of 101 patients with schizophrenia and related disorders who were assessed monthly over 10 months on medication compliance, cannabis and other drug use, symptoms of depression and symptoms of psychosis.Method. Linear regression methods to assess relationships between cannabis use and symptoms of psychosis and depression while adjusting for serial dependence, medication compliance and other demographic and clinical variables.Results. Cannabis use predicted a small but statistically significant increase in symptoms of psychosis, but not depression, after controlling for other differences between cannabis users and non-users. Symptoms of depression and psychosis did not predict cannabis use.Conclusion. Continued cannabis use by persons with schizophrenia predicts a small increase in psychotic symptom severity but not vice versa.

Why Do They Do It? A Pilot Study Towards Understanding Participant Motivation and Experience in a Large Genetic Epidemiological Study of Endometriosis

Abstract: Objective: This exploratory, pilot study aimed to investigate motivations and reflections of participants who had provided epidemiological information, blood samples and access to cl

Opioid overdose deaths can occur in patients with naltrexone implants

Abstract: From Australian coronial records, we identified five deaths involving implantable naltrexone between 2000 and 2004. One man died from acute narcotism with a naltrexone implant in place and a blood naltrexone level of 0.3 mg/L. A woman died of combined drug effect (including naltrexone) accompanied by severe pain from a naltrexone implant site. These cases indicate that patients can die from opioid overdose with a naltrexone implant and blood naltrexone levels higher than reported blockade levels.

The search for Methuselah. Should we endeavour to increase the maximum human lifespan

Abstract: One of the oldest dreams of humankind has been to find a way to evade death for as long as possible—or even entirely. Molecular biologists, geneticists and biogerontologists are actively exploring ways to extend the maximum human lifespan by slowing or stopping the ageing process. This so‐called ‘strong’ form of life extension differs from ‘weak’ forms, which focus only on the better prevention and treatment of common diseases, without seeking to alter the upper lifespan limit of about 120 years (Lucke & Hall, 2006). There is no consensus at present on whether anti‐ageing interventions will prove possible or, if such methods are developed, when they will be available and to whom. Nevertheless, the idea of expanding the maximum human lifespan has fascinated philosophers, scientists and writers for millennia—from the biblical Methuselah to the medieval Fountain of Life, and from the Philosopher's Stone to contemporary debates about increasing longevity using scientific methods. Also, given the unwavering media interest in research into slowing or preventing ageing, it is not surprising that ethicists have begun to debate whether we should attempt to increase human longevity—and whether society should finance research focused on this goal. In this article, we briefly summarize the ethical arguments raised in this debate, with a focus on the issues surrounding the more controversial form of life‐extension research that would extend the human life span beyond the current maximum of 120 years. The most fundamental opponents of increasing the maximum human lifespan in this way are conservative critics of biotechnology, who argue that this would be contrary to the ‘natural’ order of things or that it would be against ‘divine’ law. These conservatives have taken ‘pro‐life’ stances in abortion and stem‐cell debates, and are generally wary of human intervention in natural processes, such as reproduction and ageing (Horrobin, 2006 …

Assessing the impact of prescribed medicines on health outcomes.

Abstract: This paper reviews methods that can be used to assess the impact of medicine use on population health outcomes. In the absence of a gold standard, we argue that a convergence of evidence from different types of studies using multiple methods of independent imperfection provides the best bases for attributing improvements in health outcomes to the use of medicines. The major requirements are: good evidence that a safe and effective medicine is being appropriately prescribed; covariation between medicine use and improved health outcomes; and being able to discount alternative explanations of the covariation (via covariate adjustment, propensity analyses and sensitivity analyses), so that medicine use is the most plausible explanation of the improved health outcomes. The strongest possible evidence would be provided by the coherence of the following types of evidence: (1) individual linked data showing that patients are prescribed the medicine, there are reasonable levels of patient compliance, and there is a relationship between medicine use and health improvements that is not explained by other factors; (2) ecological evidence of improvements in these health outcomes in the population in which the medicine is used. Confidence in these inferences would be increased by: the replication of these results in comparable countries and consistent trends in population vital statistics in countries that have introduced the medicine; and epidemiological modelling indicating that changes observed in population health outcomes are plausible given the epidemiology of the condition being treated.

Cigarette Century: the Rise, Fall and Deadly Persistence of the Product that Defined America

Abstract: By A M Brandt, Basic Books: New York, 2007, £1699; pp 600, ISBN 13 978-0-465-07047-3 Allan Brandt, a leading US historian of medicine, provides a superb history of the century of the cigarette in the USA He explains the technological and social reasons for the victory of the cigarette over all other methods of tobacco use; the key role played by the first world war in legitimating cigarette smoking; and the success of advertising and public relations in the 1920s and 1930s in making smoking such a pervasive habit that by 1950 over half of all …

Reducing cannabis-impaired driving: is there sufficient evidence for drug testing of drivers?

Abstract: There is research evidence that marijuana use to the point of intoxication on the part of automobile drivers results in increased risk of motor vehicle crashes. Cannabis use produces dose-related cognitive and behavioral impairments in laboratory and simulation studies. The authors review the research literature on this topic, noting that cannabis users in surveys are more likely to report being involved in accidents than drivers who do not use the drug, and cannabis is the illicit drug detected most often in drivers who have been killed in motor vehicle crashes. Recent studies have provided more evidence that cannabis-affected drivers are at a higher risk of being involved in crashes, by approximately two to three times. This is, however, a much lower risk than alcohol use in automobile drivers, which increases risk of involvement in a crash six to fifteen times more than sober drivers.

A research agenda for assessing the potential contribution of genomic medicine to tobacco control

Abstract: This paper identifies research priorities in evaluating the ways in which “genomic medicine”—the use of genetic information to prevent and treat disease—may reduce tobacco‐related harm by: (1) assisting more smokers to quit; (2) preventing non‐smokers from beginning to smoke tobacco; and (3) reducing the harm caused by tobacco smoking. The method proposed to achieve the first aim is “pharmacogenetics”, the use of genetic information to optimise the selection of smoking‐cessation programmes by screening smokers for polymorphisms that predict responses to different methods of smoking cessation. This method competes with the development of more effective forms of smoking cessation that involve vaccinating smokers against the effects of nicotine and using new pharmaceuticals (such as cannabinoid antagonists and nicotine agonists). The second and third aims are more speculative. They include: screening the population for genetic susceptibility to nicotine dependence and intervening (eg, by vaccinating children and adolescents against the effects of nicotine) to prevent smoking uptake, and screening the population for genetic susceptibility to tobacco‐related diseases. A framework is described for future research on these policy options. This includes: epidemiological modelling and economic evaluation to specify the conditions under which these strategies are cost‐effective; and social psychological research into the effect of providing genetic information on smokers' preparedness to quit, and the general views of the public on tobacco smoking.

The social implications of neurobiological explanations of resistible compulsions.

Abstract: A major attraction of neuroscientific explanations of addiction is their potential to reduce community skepticism about the “reality” of addiction. By highlighting the neurophysiological changes th...

Statins down under.

Abstract: Use of statins in Australia is markedly higher than in Europe [1], although overall expenditure on cardiovascular drugs is less than that of many European countries [2]. A high rate of statin use is consistent with extensive trial evidence suggesting that the statins produce significant health gains. However, in practice, achieving those gains will require doctors to prescribe appropriately, eligible patients to receive treatment and patients to persist with treatment. In order to make international comparisons, we applied the standard international method for estimating drug use across populations, the defined daily dose (DDD), to national data on community statins dispensed, from 1990, when they were first introduced in Australia, to the end of 2004. The DDD is the assumed average maintenance dose for a drug for its main indication [3]. We do not know if Australians enjoy better health outcomes as a result of their high statin use. For example, we lack Australian studies to compare with the work of Unal & colleagues who estimated that statins contributed 6.5% to reduced coronary heart disease mortality in England and Wales from 1981 and 2000 [4]. In 2000, Australia’s use of statins was three times higher than that given by Walley & colleagues [1] for England (79.5 vs. 23.9 DDDs/1000/day). Higher use of statins in Australia might be reflected in a greater contribution of statins to reductions in mortality, although this could be modified by differences in prescribing practices, patients’ persistence with treatment and the effect of dietary and other factors. In 2003, Australian use of statins was 25% greater than the highest rates across EU countries, and in 2000 it was 40% higher [1]. Even before the marked increase in statin utilization rate in 1997/1998, which corresponded to the introduction of atorvastatin to the Australian Pharmaceutical Benefits Scheme, Australia had higher statin utilization than Finland, Italy, Norway and Sweden [5]. From 1991 to 1997, Australian utilization increased from 5.2 to 25.3 DDDs/1000/year representing a mean annual increase of 3.6 DDDs/1000/year. From 1998 to 2004, the increase was from 39.1 to 162.1 DDDs/1000/year, a mean annual increase of 19.5 DDDs/1000/year (Figure 1). Figure 1 Australian community utilization of individual statins and all statins combined, DDDs/1000 population/day, yearly from 1990 to 2004. Source: DUSC database, August 2005 The DDD has not altered since statins were introduced. Thus if, for example, some patients were prescribed twice the DDD, utilization rates would double even though no more people were taking statins. Walley & colleagues observed that apparent variation between countries might in part be explained by the rise in relative use of more potent statins, particularly atorvastatin [1]. Using commercial data sources they calculated that on average two thirds of the DDD increase in statin use, related to increases in prescribed daily dose (PDDs). In Australia there was a trend to greater strength tablets for all statins. Atorvastatin 40 mg experienced a six-fold market share increase (2–12%) from 2001 to 2004, while simvastatin 40 mg almost tripled its market share (5–14%). Over the same period, atorvastatin 10 mg market share fell from 17% to 13%, although the absolute number of prescriptions dispensed remained steady, while simvastatin 10 mg fell fourfold (26% to 6%) although the absolute number of prescriptions fell only twofold. In 2004, atorvastatin 20 mg had the highest market share (18.5%) overtaking simvastatin 20 mg in 2002 (data available on request). An objective assessment of the outcomes from the use of greater strength tablets in the population is overdue, especially in view of the IDEAL trial in which patients randomized post-myocardial infarction to atorvastatin 80 mg day−1 did not achieve a significant reduction in major coronary events compared with those taking simvastatin 20 mg day−1[6]. The Australian health care system provides universal cover for pharmaceuticals listed on the Pharmaceutical Benefits Scheme (PBS), so statins have been widely available. However, we need person-level linked data to explore fully the distribution of statin use and associated cardiovascular outcomes in Australia. These data are collected nationally but studies linking drug use prescription data to health data require ethical clearance before data custodians can release data. It is difficult to study demographic patterns of use as this requires linkage of databases: one utilization study for 7 months of 2002 has been conducted, showing differential statin utilization across age, sex and socioeconomic groups [7]. The marked increase in statin use in Australia over the past decade raises the question: how much higher are they likely to rise? Currently, the PBS listing for all statins restricts doctors to prescribing them according to cholesterol or triglyceride concentrations which differ for different patient categories. If PBS restrictions for statins were expanded to accord with clinical evidence supporting absolute risk as the basis for prescribing [8], further increases in statin utilization could reasonably be expected.

The Ethical Use of Psychosocially Assisted Pharmacological Treatments for Opioid Dependence

Abstract: The ethical delivery of psychosocially-assisted pharmacological treatment of opioid dependence is achieved by respecting the following ten basic principles: 1: Human rights of opioid dependent individuals should be respected 2: Treatment decisions should be based on the best available evidence 3: Treatment decisions should be based on standard principles of medical care ethics 4: Equitable access should be provided to treatment and psychosocial support that best meets the needs of the individual patient 5: Treatment should respect and validate the autonomy of the individual 6: Patients should be fully informed about the risks and benefits of treatment choices 7: Programs should create supportive environments and treatment relationships to facilitate treatment 8: There should be coordinated treatment of comorbid mental and physical disorders and social factors 9: Programs should include participation of community and other stakeholders 10: The use of legal coercion into treatment for opioid dependence should respect basic ethical and legal principles 3 Our analysis of the practical application of these basic principles suggests that the ethical delivery of psychosocially-assisted treatment of opioid dependence treatment should meet a series of minimum requirements. These are: 1) The provision of initial treatment aimed at the stabilisation of the client from the cycle of withdrawal and intoxication to increase their capacity to make major decisions about treatment. The provision of information and requirement of consent to treatment should be limited at this stage until the client is stabilised and their decision making capacity has improved. 2) The use of procedures to ensure the safety of individual clients, e.g. reducing their overdose risk by close monitoring during induction onto opioid agonist maintenance treatments; close supervision of dosing; and in abstinence based treatment, providing clear information about the risks of overdose if they return to drug use. 3) Provision of enough information to give an understanding of the rationale behind treatment, including the risks and benefits of treatment in the short to long term, and information on other treatment options. 4) Ensuring there is a good understanding by staff and patients of treatment aims that serve the ends of both personal and public health. 5) Education of treatment staff about the effectiveness of different treatment strategies, and emphasis on the importance of a cooperative and trusting relationship with clients. 6) Availability of a range of treatment options that best achieve goals of the client. 7) A defensible drug testing program (e.g. urinalysis) with a …

Community attitudes to the regulation of life extension.

Abstract: Technologies purported to extend human life are already being marketed widely, and are being used by community members, despite a lack of evidence on their efficacy or safety: in fact, the use of some putative anti-aging technologies (e.g., human growth hormone) is illegal. Existing regulation is proving to be ineffective, especially in the face of Internet sales. Further advances in the field of life extension are a distinct possibility, exacerbating the need for a policy response. This paper presents the preliminary results of a study of community attitudes to life extension, with a focus on attitudes to the control and availability of strong life-extending technologies.

Cost-effectiveness analysis of genetic screening for the Taq1B polymorphism in the secondary prevention of coronary heart disease.

Abstract: Coronary heart disease is a major health priority area in Australia. Cholesterol-lowering agents are generally considered to be cost effective for the secondary prevention of coronary heart disease. There is growing evidence, however, that the effectiveness of statins varies from one individual to another. The Taq1B polymorphism is an example of a genetic polymorphism that is thought to influence the effectiveness of statins. The aim of the current analysis is to estimate the cost–effectiveness of genetically screening coronary heart disease and stroke patients for the Taq1B polymorphism, and prescribing statin treatment to those with the B1B2 or B2B2 forms of the gene. A health sector perspective was adopted with a maximum acceptable cost–effectiveness ratio set at AUS$50,000/disability-adjusted life year. There is an 89% probability that screening and prescribing statins to those with the B1B2 and B2B2 alleles is more cost effective than prescribing statins to all patients. Modeling the cost–effectiveness of pharmacogenetics in major areas of medicine provides useful information to help in resource allocation and decision making. Economic evaluations similar to this one will be required in the future as the results of further clinical trials to establish the effectiveness of statins based on genotype become available.

Assessment of Swedish snus for tobacco harm reduction: an epidemiological modelling study. The Lancet 369 (9578), pp. 2010-2014

Abstract: Background Swedish snus is a smokeless tobacco product that has been suggested as a tobacco harm reduction product. Our aim was to assess the potential population health effects of snus. Methods We assessed the potential population health effects of snus in Australia with multistate life tables to estimate the difference in health-adjusted life expectancy between people who have never been smokers and various trajectories of tobacco use, including switching from smoking to snus use; and the potential for net population-level harm given different rates of snus uptake by current smokers, ex-smokers, and people who have never smoked. Findings There was little difference in health-adjusted life expectancy between smokers who quit all tobacco and smokers who switch to snus (difference of 0•1–0•3 years for men and 0•1–0•4 years for women). For net harm to occur, 14–25 ex-smokers would have to start using snus to offset the health gain from every smoker who switched to snus rather than continuing to smoke. Likewise, 14–25 people who have never smoked would need to start using snus to offset the health gain from every new tobacco user who used snus rather than smoking. Interpretation Current smokers who switch to using snus rather than continuing to smoke can realise substantial health gains. Snus could produce a net benefit to health at the population level if it is adopted in sufficient numbers by inveterate smokers. Relaxing current restrictions on the sale of snus is more likely to produce a net benefit than harm, with the size of the benefit dependent on how many inveterate smokers switch to snus.

The Australian heroin shortage six years on: what, if any, are the implications for drug policy?

Abstract: During the mid to late 1990s in Australia heroin and heroin related deaths increased steeply, peaking at over 1000 deaths in 1999. In January 2001, there was an abrupt, unpredicted and unprecedented reduction in heroin supply with nearly simultaneous onset in all Australian jurisdictions. The shortage was most marked in New South Wales, the State with the largest heroin market. There were large increases in price, dramatic decreases in purity at the street level, and marked reductions in the ease with which injecting drug users reported that they could obtain heroin. The abrupt onset of the shortage and an immediate and dramatic reduction in fatal and nonfatal overdoses prompted national (and later international) debate about the causes and policy significance of the shortage. This briefing paper summarises the results of research into the consequences of the “heroin shortage” and reviews the continuing debate about its causes and policy significance.