Environmental health

To the Editor: In bicycle accidents, direct impact with the bicycle handlebar can cause serious abdominal injuries. These injuries occur not only in high-speed collisions, where the rider is thrown from the bicycle, but also in low-speed crashes, where the bicycle handlebar strikes the rider in the abdomen or pelvic region.1 We retrospectively reviewed all children who presented to Princess Margaret Hospital for Children with abdominal bicycle handlebar injuries from January 2002 to July 2007. The patients were identified from the emergency department trauma database; 60 boys and 10 girls were identified, aged 5–15 years. Significant injuries (defined as injuries to the liver, spleen, kidney, pancreas, small bowel, stomach or urinary bladder) were noted in 25 of the 70 patients (36%), and 15 of the 70 patients (21%) required surgery. Twenty-one patients (30%) had handlebar imprints on the abdomen (Box, A), and 17 of them (81%) had significant injuries. Traumatic abdominal wall hernia (TAWH) was present in three patients (Box, B). The odds of a significant injury were 21.8 times higher (95% CI, 5.8–82.1) for patients with handlebar imprints than for those with no handlebar imprints. Computed tomography (CT) was the main method of diagnosis of significant injury, and there was a statistically significant association between handlebar imprints and a positive CT scan result, defined as evidence of a solid or hollow viscus injury (2-sided Fisher’s exact test, P = 0.01). Of those patients who underwent CT scanning, 89% of those with handlebar imprints (16/18) had a positive CT scan, compared with 36% of those with no handlebar imprints (4/11). The odds of a positive CT scan were 14 times higher (95% CI, 2.1–95.1) for patients with handlebar imprints than for those with no handlebar imprints. Similar rates of significant injury resulting from impact with handlebars have been reported previously.2 TAWH was first described in 1906,3 and 31 cases of handlebar-related TAWH in children have been reported to date, excluding our cases.4,5 TAWH is produced by sudden application of blunt force to the abdomen that does not penetrate the skin, but is strong enough to disrupt muscle and fascia. Surgical repair is usually required to prevent complications.5 Children with handlebar imprints should be observed closely, and assessed by CT scan and treated surgically as indicated. They should be encouraged to use protective gear, such as handlebar padding, helmets and protective clothing, when riding bicycles. Injuries caused by bicycle handlebars in children A: Handlebar imprint on abdomen. B: Traumatic abdominal wall hernia, caused by handlebar injury, with omentum protruding through the defect.

Parshotam K Gera · Andrew P Barker · Ian Gollow · Jillian Orford · Sue Wicks · Liz Whan

Volunteers and the Internet can provide education in public health where it is most needed The multiple health problems faced by low-income countries require urgent solutions. One solution, as articulated in the United Nations Millennium Development Goals, is to increase the health workforce.1 An editorial (and accompanying articles) in the Lancet highlighted the need for global health capacity building,2 and the first Global Forum on Human Resources for Health (in March 2008) produced the Kampala Declaration, which urged “. . . immediate action to resolve the accelerating crisis in the global health workforce . . .”.3 Part of this solution will involve boosting in-country public health capacity,4 and an educational initiative to do this was launched recently — the People’s Open Access Education Initiative, better known as the Peoples-uni (http://peoples-uni.org).5 The “open-source” movement describes collaborative software development, where products are shared and improved upon among developers and made freely available to others. It has transformed computer software. The movement to make open-source educational materials freely available on the Internet6 promises a mechanism to provide public health education at low cost. An ever-expanding range of high-quality open educational resources is freely available on the Internet, and a number of universities are providing open access to online educational material, but do not offer tuition or accreditation. The Peoples-uni aims to provide an educational context around these materials, using a competence-based approach and volunteers to develop and deliver an educational program. Through the Internet, health professionals can learn while they work, and local workforce is not depleted. Previous experience shows that distance and online learning in public health is feasible.7 The open-source approach is a new way for individuals and organisations to collaboratively develop and share the products of their work. The Peoples-uni offers involvement in the exciting and evolving field of the application of the open-source philosophy to education. A number of national and international partners have agreed to be part of the Peoples-uni, and momentum is building. A pilot of a course module on maternal mortality, run between October and December 2007, attracted a large interest and was well received. The draft of this module is available at <http://moodle.cawd.net/course/view.php?id=2>, and student evaluation is available on the Peoples-uni website. This draft is now being modified as part of the process of developing a set of new course modules covering some of the foundation sciences of public health and some major health problems facing low- to middle-income populations. The United Kingdom Royal Society for Public Health has agreed to oversee the assessment process and offer awards at certificate and diploma levels, and teams are currently being established for course development and online facilitation. Access to educational resources and teachers of high international quality will provide highly credible education at low cost. While Australia is committed to its responsibilities towards overseas development through its official development assistance, only 12% of this budget goes to health, and even this is not focused on the areas of greatest global health need.8 Australian universities, including their medical schools,9 contribute to global educational activities, but are constrained by the need to charge fees, which cannot be met by most people who would benefit from university education. In 2005, full-fee-paying students provided 15% of income within the higher-education sector, and education services were the third highest export-earnings generator for Australia.10 For these reasons, which are not confined to Australia, the Peoples-uni has been established outside the more traditional educational sector and will rely on volunteers to meet its goals. Is the volunteer approach sustainable? Will busy health professionals be willing to add to their activities, and in a way that may not help meet the goals of their employing institutions? To date, more than 80 people have agreed to take part in the development of course modules, and are working in 12 teams. Volunteers come from 24 different countries and range from established academics in senior positions to trainees and students. Some students from the pilot have joined the teams. The difficulties of maintaining a large volunteer workforce should not be underestimated, and it is a priority to develop a system that provides rewards, such as the opportunity to work with a diverse and interesting group of colleagues, and to keep up to date with advances in international public health issues and developments in information and educational technology, in addition to appealing to the altruism of those involved. Although the workload will vary according to the level of commitment of the volunteers, we have divided it into feasible amounts for busy people, such that even a small and short-term commitment of 2–3 hours a week for a 3-week period can be a valuable contribution. A similar approach to level of commitment has also been taken by the Clinical Toxicology Teaching Resource Project (http://wikitox.org), with which the Peoples-uni shares a number of philosophical ideals. The Peoples-uni provides a novel opportunity to contribute to-wards meeting global health workforce and public health needs. Australian health care professionals and academics have made, and continue to make, major contributions to international health. I hope that the Australian health professional community will be involved in contributing to and helping shape this initiative.

Richard F Heller FRCP, FRACP, FAFPHM

To the Editor: The recent call by Robotin and colleagues for a national strategy to respond to the increasing incidence of hepatitis B and hepatocellular carcinoma (HCC) in Australia1 is timely. I would like to add the following comments. First, a comprehensive Australian hepatitis B strategy should include prisoners and Indigenous Australians. Among Australian prisoners, hepatitis B carrier prevalence is 3%–5% — more than three times the national average — and prevalence of hepatitis C, which independently and synergistically increases the risk of severe liver disease, exceeds 30%.2 In addition, of 526 acute hepatitis B notifications in Australia in 2000–2002, 57 were in Indigenous Australians, a notification rate more than four times that in non-Indigenous Australians. Indigenous people are 12 times more likely to die of liver cancer than the general Australian population.3 Second, in New South Wales, the median age of diagnosis of HCC was found to vary significantly by country of birth;4 it was 5 years younger in the Asian-born group than the Australian-born group overall (64 v 69 years), and 9 years younger in those who were hepatitis B carriers (57 v 66 years) (P < 0.001 for both differences). Early onset of HCC among Asian-born Australians may be a result of hepatitis B infection in the perinatal and early childhood period. However, other factors that promote progression to HCC, such as diabetes, alcoholism, and inadequate health care access, are amenable to targeted public health interventions. Third, hepatitis B e antigen (HbeAg) positivity is strongly associated with high hepatitis B virus DNA counts (≥ 100 000 copies/mL), which are in turn highly predictive of cirrhosis and HCC risk. It is thus counterintuitive that — as implied by Robotin et al — hepatitis B carriers who are positive for HbeAg are less likely to progress to cirrhosis and HCC than those who have undergone seroconversion and are positive for hepatitis B e antibody. In fact, HBeAg positivity is associated with increased risk of HCC and liver-related mortality.5,6 Finally, the omission of hepatitis B vaccine — the world’s first anticancer vaccine — from Robotin et al’s list of elements of a public health response to hepatitis B and liver cancer is unfortunate. Hepatitis B vaccination is essential to any credible medium- and long-term strategy to prevent hepatitis B infection and, by extension, HCC, both in Australia and globally.

Niyi Awofeso

In reply: We agree with Awofeso that prisoners and Indigenous people have an increased risk of developing chronic hepatitis B. However, as no large-scale population-based studies of hepatitis B prevalence have been published in Australia, estimates of the risk vary widely.1 A national hepatitis B strategy may provide additional impetus for obtaining high-quality data. We also concur that modifiable behavioural factors may play a role in the age of hepatocellular carcinoma diagnosis, but differences in clinical course between Asian and white Australians,2 and the specific viral genotypes prevalent in Asia,3 are likely to be more important. Although white populations who undergo hepatitis B e antigen (HbeAg) seroconversion and develop hepatitis B e antibodies have a good prognosis, this is not so for Asian populations,2 or for other populations who are mostly infected in childhood, such as Indigenous Australians and Māori in New Zealand. The median age of HBeAg seroconversion in Asian patients with chronic hepatitis B is 34.5 years,4 while the median age at diagnosis of hepatocellular carcinoma of Asian patients quoted by Awofeso is 57 years, by which age most would have seroconverted. Australia has been successful in primary prevention of hepatitis B through vaccination (albeit less so in migrants, some Indigenous communities and catch-up vaccination), and hence the omission of vaccination from our “wish list” for a public health response. However, Australia has been less successful in secondary and tertiary prevention. We hope that a national strategy would be a catalyst for these interventions to be given the priority they deserve.

Monica C Robotin · Jacob George · Rajah Supramaniam · Freddy Sitas · Andrew G Penman

Objectives: To test the hypothesis that television news coverage of different cancers reflects their incidence and burden, and to examine the journalistic approaches used in reporting cancer.Design and setting: Content analysis of all news, current affairs and infotainment reports on cancer broadcast on five free-to-air television channels in Sydney, New South Wales, 2 May 2005 – 6 January 2008.Main outcome measures: Number of items on specific cancers, relationship with burden of that cancer (disability-adjusted life-years [DALYs]), and category of “story lead” used for the item.Results: Cancer was the fifth most reported health issue, with 1319 items; 25 different cancers received news coverage. The most reported cancers were breast cancer (42.5% of all items on specific cancers), melanoma (11.9%) and cervical cancer (11.6%). Some cancers were significantly over-reported in relation to their DALYs (eg, cervical cancer was over-reported by a factor of 10.2 compared with the number of reports predicted on the basis of DALYs) while others were under-reported, including colorectal, lung and pancreatic cancers. The most common story leads used in cancer reports were treatment (32% of items) and celebrities with cancer (21%), particularly breast cancer.Conclusions: The current predominance of reports on breast and cervical cancer and on young women with cancer may be distorting public and political perceptions of the burden of cancer. The success of advocates in raising the news profile of breast cancer may hold lessons for agencies wishing to improve the newsworthiness of other cancers.

Ross MacKenzie MA · Simon Chapman PhD · Natalie Johnson MIPH · Kevin McGeechan MBiostat · Simon Holding BA

To the Editor: Walters recently suggested that Australia should implement population control strategies as part of an approach to reduce global warming.1 As a father of four, I found his assertion that my decision to father more than two children is “arrogant” to be offensive. Walters’ arguments are, at best, poorly reasoned. As a “citizen of this world”, he clearly rejects the rights of other citizens to live on an equal footing and follow their religious, cultural or social beliefs if those beliefs oppose contraception. I would argue this is contrary to law.2,3 His mathematical calculations ignore all costs required to achieve his objective, such as those associated with “contraceptives, intrauterine devices, diaphragms, condoms and sterilisation procedures”. Further, he fails to consider costs associated with the supporting bureaucracies required to effect his policy, including material amendments to the Australian taxation system. Rather, and in my opinion strangely, he advocates issuing carbon credits for the additional consumption of contraceptive products. According to Walters, people should be judged by their anticipated rather than actual emissions. A logical extension would be to punish those who exceed a predetermined mean acceptable level of emissions. No doubt, meeting the medical and ancillary needs of many sick, older and disabled people often generates excess emissions. Perhaps we should adopt some of the practices used in China and India, including abandonment and neglect of disabled children and older people.4,5 How would we deter and punish those who cannot pay? Walters addresses the issue of overpopulation by comparing Australia to India and China. This is notwithstanding that Australia has one of the lowest population growth rates in the world6 and, with its ageing population and labour shortages,7,8 has significantly different population and social concerns to these countries. There are no grounds to support the comparison made. Environmental issues are among the greatest challenges facing society. As a father, I am deeply concerned for the world my children will inherit. We must deploy our limited resources efficiently and effectively to maximise their impact. To demand social controls in the manner Walters suggests, within a society heavily burdened with laws and struggling to meet labour and health system demands, would defeat this objective. Reading Walters’ views, which I consider fundamentally flawed, in a publication such as the Journal imparts to them a validity I believe is unjustified. I do not consider that Walters’ social engineering policies could benefit anyone in Australia, while his “moral” concerns are ill conceived.

Cathal A Smith

In reply: I thank Smith for the opportunity to clarify some scientific points. The science behind climate change is undeniable and was reviewed in February this year. Moreover, “there is a greater than 90 per cent probability that the warming observed since the 1950s is due to human activities”. Therefore, attempts to prevent environmental calamity will not succeed with boundless population growth. In this sense, the more people there are, the worse it is for our earth. In particular, no nation should encourage population growth. I do not argue for compulsory sterilisation. I do argue that we recognise the cost of every extra human being to our overburdened earth. Smith labelled my note of caution about limitless procreation as “offensive”. I believe such disparagement is founded on personal and cultural beliefs, not on science, which informs and guides medicine. There is only one atmosphere. Australians occupy this planet with no more rights than others do. Racism is anathema to us. If others must observe population restraint, then so must we. Contrary to Smith’s assertion, I plead that all should be able to “live on an equal footing”. Is this not the laudable basis of law? I share his concern for the world that his “children will inherit”; my concern embraces the children of others as well.

Barry N J Walters

To the Editor: On 25 January 2008, the Australian Transport Council approved the National Transport Commission’s seventh amendment to the Australian Road Rules. This amendment provides for the mandatory use of forward-facing child restraints for children aged 6 months to 4 years, and the use of Australian Standards-approved booster seats for children aged 4–7 years and weighing up to 26 kg. It also recommends that children aged less than 7 years should not travel in the front passenger seat. These changes are welcome. They bring Australian rules on child restraints and seating position closer to (but still not on par with) restraint laws already implemented in the United Kingdom and other countries in the European Union, where booster seats are mandatory for all children aged under 12 years or less than 145 cm tall. Implementation of the amendment poses several challenges. A small proportion of children will exceed the 26 kg weight limit for booster seats by their seventh birthday; however, there is no evidence that these seats are not safe for slightly heavier children. In addition, the Australian Standard (AS 1754) is currently being revised and is likely to move towards recommending restraint selection based on seated height rather than weight, as well as developing new standards for booster seats for older children. Height is the most important determinant of adequate seatbelt fit, and children need to be about 145 cm tall before the lap portion of an adult seatbelt sits correctly over the iliac crests rather than on the soft abdomen. Community education campaigns will be pivotal in successfully implementing these new road rules. As misuse of restraints is high, education campaigns must emphasise correct use of recommended restraints.-4 Furthermore, the new recommendations may contribute to financial hardship, particularly for low-income families with several children under the age of 7 years. Subsidies or loan schemes may be required to assist such families. Fitting three restraints across the rear seat of small cars may also be difficult. Adequate enforcement will be required to maximise compliance. Research studies and injury surveillance will play an important part in maximising the effectiveness of these rule changes. Finally, the seventh amendment to the Australian Road Rules does not constitute law, and legislative changes will need to be enacted by each state and territory before these changes become law. We hope that the state and territory governments will take swift action to enact these laws, to prevent injuries and deaths in Australian children due to motor vehicle crashes.

Yvonne A Zurynski · Lynne Bilston · Elizabeth J Elliott

Cervical cancer screening needs to take into account a partially vaccinated population and new technologies A national, well funded and organised program of screening using the conventional Pap smear has significantly reduced the incidence of and mortality from cervical cancer in Australia.1 While the program has been in place, there has been a great increase in knowledge of the pathogenesis of cervical cancer, with certain oncogenic subtypes of human papillomavirus (HPV) shown to be a necessary cause for development of this disease.2 In addition, a national program of vaccination against two of the 15 oncogenic viruses began in April 2007, and tests to detect HPV are now available. Furthermore, research showing that new technologies for screening cervical samples are superior to conventional cytology has also been published.3,4 How is the cervical screening program responding to the presence of a partially vaccinated population and these newly available tests? When the Pharmaceutical Benefits Advisory Committee assessed the value of funding HPV vaccination, it noted that the current cumulative lifetime risk of cervical cancer in Australia’s screened population is 0.78% — a substantial reduction from the estimated 2.4% risk in an unscreened population, reflecting the success of the screening program. With continued screening, this risk was predicted to further decrease to 0.38% following vaccination of 12-year-old girls, 0.43% for 14-year-old girls and 0.59% for 26-year-old women.5 The Committee further commented that there would be cost savings if vaccination were to completely replace cervical screening, but the cervical cancer lifetime risk would increase to 1.173%.5 The recommendation therefore is that screening must continue after vaccination. The screening interval and screening test for vaccinated women should be different to those for unvaccinated women and should be determined by population-based research over the next 5–10 years, as the vaccinated cohort reaches maturity. A national HPV vaccination register is being established, which will be critical for determining the appropriate screening regimen. HPV testing is already recommended and funded as a “test of cure” for follow-up of high-grade cervical disease after treatment. The Digene HPV test is used in Australia and detects any one of 13 high-risk HPV subtypes but does not identify the specific subtypes. Although some individual HPV subtyping assays are available, these are expensive and not widely used, and no serological tests for HPV are available in routine practice. Use of the HPV test is therefore limited but, given its importance, should its use be expanded for screening and management of cervical disease? There has been much discussion overseas about replacing cervical cytology tests with HPV testing for primary screening.6 Currently, there is no justification for this as HPV testing is highly sensitive but not specific. It has a limited role in women under the age of 30 years, as large studies have shown that about 25% of women in this age group test positive for the oncogenic viruses.7 The great majority of these women clear the virus naturally, usually via a cell-mediated immune response or, less often, through an antibody response. Such infected women may not show any sign of disease. It is when the virus persists that women are at greater risk of both high-grade cervical intraepithelial disease and invasive cancer. HPV testing is also not recommended before vaccination8 in women who request it but are already sexually active as the decision to proceed with vaccination will not be altered by the results of the test. HPV testing may have a greater role in the management of indeterminate abnormalities detected by cervical cytology tests. Data from large United States studies are fairly compelling in assigning a true risk of significant disease based on cervical cytology and HPV testing. The latter is more accurate than colposcopy in determining the significance of low-grade squamous intraepithelial lesions detected by cervical cytology. So-called “reflex” HPV testing in women with these findings is recommended in the US.9 Another major question for cervical cancer screening in the short term is whether image-guided liquid-based cytology samples should be used as the preferred screening test. The use of liquid-based cytology in this country has long been controversial.10 However, there is now good evidence that one of the techniques — the ThinPrep Imaging System (Hologic, Marlborough, Mass, USA) — is superior to conventional cytology.4 This technique decreases the number of unsatisfactory samples and detects more true abnormalities. There are also substantial laboratory efficiencies when using this technology, which could potentially overcome the chronic shortage of trained scientists. The increased sensitivity might allow the screening interval to be lengthened. This technique also provides a sample for HPV and other microbiological testing, and is ideal for a vaccinated population in which the number of screen-detected abnormalities will decrease. Although Australia has an enviable record in the control of cervical cancer, new knowledge and associated technologies should be incorporated into screening and management of cervical disease, as they offer real benefits. Both HPV testing and ThinPrep imaging are more expensive than conventional cytology, but they could be cost-effective if used appropriately in conjunction with a comprehensive review of the cervical screening program.

Annabelle Farnsworth FRCPA, FIAC, DipCytopath(RCPA)

To the Editor: In recent years, solaria have multiplied across Australia. Solaria can emit higher concentrations of ultraviolet radiation than the midday summer sun.1 As exposure to ultraviolet radiation is a risk factor for skin cancer, including melanoma,2 it is not surprising that there is mounting evidence that solarium use increases melanoma risk.1,3-4 Public attention to this issue increased following coverage of Clare Oliver’s story in August 2007.5 Clare was dying from melanoma, which she attributed to her use of solaria. In the last weeks before her death, Clare publicly warned of the dangers of solaria. She featured in a television advertisement promoting the message “No tan is worth dying for”, launched nationally in February 2008. There is evidence that public awareness of the cancer risk of solaria increased after this media coverage. We surveyed adult Western Australians in September 2006, and again in 2007, about their perceptions of cancer risk factors. The survey was conducted by computer-assisted telephone interviewing using random-digit dialling from the Perth White Pages (2006, n = 196; 2007, n = 250). Ethical approval was granted by the Curtin University of Technology Human Research Ethics Committee. Participants were read a list of 16 factors (including solaria) and asked how each factor affected cancer risk (response categories: increase a lot; increase a little; decrease a little; decrease a lot; no effect). While risk perceptions for the other 15 factors remained constant, there was a substantial increase in the proportion of “increase a lot” responses for solaria (40% in 2006 v 72% in 2007; P = 0.001). Total “increase” responses were 71% in 2006 and 92% in 2007 (P < 0.001). In addition, Clare’s advocacy may have been a factor in increased regulation of the solarium industry. Until recently, the Australian solarium industry was unregulated, but operated under a voluntary code of practice. There is evidence that compliance with this code was lacking.6 The Australian Government has explored making the code of practice mandatory. As of 1 February 2008, the Victorian Government enacted regulations to tighten the control of solaria under the Radiation Act 2005 (Vic). Similar regulations were introduced in South Australia on 14 March 2008 and in Western Australia on 4 April 2008. There have been no campaigns about the dangers of solarium use in the general population, so it is very likely that this increase is due to the media coverage of Clare’s story. This and responses to other individuals’ personal stories7 provide evidence of how such stories can increase the community’s awareness of a health issue and gain support for legislative change.

Geoffrey Jalleh · Robert J Donovan · Chad Lin · Terry Slevin

Objective: To determine if the recent rapid fall in use of hormone replacement therapy (HRT) in Australia has been followed by a reduction in breast cancer incidence among women aged 50 years or older, but not among younger women.Design and setting: Analysis of trends in annual prescribing of HRT, using Pharmaceutical Benefits Scheme data, and in annual age-standardised breast cancer incidence rates in Australian women for the period 1996–2003.Results: In Australia, prescribing of HRT increased from 1996 to 2001, but dropped by 40% from 2001 to 2003. Age-standardised breast cancer incidence rates in women aged ≥ 50 years also increased to 2001 but declined thereafter. The incidence rates in this age group were lower by 6.7% (95% CI, 3.9%–9.3%; P < 0.001) in 2003 compared with 2001, equivalent to 600 (95% CI, 350–830) fewer breast cancers (out of about 9000 incident breast cancers annually for women this age). There was no significant change in breast cancer incidence for women aged < 50 years.Conclusions: While other factors may have contributed to a recent reduction in breast cancer incidence among Australian women aged ≥ 50 years, the available evidence suggests that much of the decrease is due to the recent fall in use of HRT. This is consistent with other evidence that the HRT-associated increase in risk of breast cancer is reversible after ceasing use of HRT.

Karen Canfell DPhil · Emily Banks MB BS(Hons), PhD, FAFPHM · Aye M Moa MPH · Valerie Beral FRS

To the Editor: Australians are fatter than they have ever been before. The prevalence of overweight and obesity (body mass index ≥ 25.0 kg/m2, or waist circumference > 80 cm for women or > 94 cm for men) in Australian adults is approaching 60% for both sexes and has more than doubled in the past 25 years.1 A prudent public health policy to fight the growing obesity epidemic would undoubtedly be to target strategies that avert this condition in the first place. So we were perplexed by the Australian Medical Association’s recent proposal to the Victorian Government to fund five public hospitals to provide 3000 obesity-related operations (ie, bariatric surgery) over the next 3 years.2 It appears the blueprint for the new millennium is to invest taxpayers’ money in modern technologies in an attempt to arrest overt clinical disease states. To attack the growing burden of obesity by investing in strategies that target secondary and tertiary treatment is an admission that we may win battles on a few fronts, but lose the war. We propose placing greater emphasis on implementing and enforcing primary prevention strategies to fight obesity. Primary defence mechanisms can decrease obesity prevalence by preventing the condition in the first place! Indeed, the health care industry is paradoxical in that its principal goal is to end health problems and human suffering, and by so doing put itself out of business.3 We need to attack the environmental roots of obesity, namely our sedentary lifestyles and caloric excess. Emphasis on secondary and tertiary prevention is too little, too late and will not reverse the growth of obesity — the funds to treat obese individuals are finite, while the number of Australians with the potential to become overweight or obese is not! In a letter to President Roosevelt voicing concerns about the Manhattan Project (the project to develop the atomic bomb during World War II),4 Niels Bohr wrote: A weapon of an unparalleled power is being created which will completely change all future conditions of warfare. Unless some agreement about the control of the use of the new active materials can be obtained in due time, any temporary advantage, however great, may be outweighed by a perpetual menace to human security. Obesity-related disorders impact on daily living. While bariatric surgery may provide a “magic bullet” for a few individuals, the time has come to legislate for minimum health standards, and to provide support for people to effect lifestyle changes to meet these requirements. Otherwise, obesity will remain a permanent threat to Australian society.

John A Hawley · David W Dunstan

Comment: Obesity is a complex public policy issue. There are no easy solutions, and the medical profession needs to work with communities, governments, researchers, teachers, parents, industry and others to help all Australians achieve and maintain a healthy weight. The Australian Medical Association (AMA) Victoria has six priority action areas to promote healthy weight: Ban food advertising to children; Simplify food labels; Promote physical activity every day; Improve clinical tools; Improve treatment options; and Evaluate and educate. Bariatric surgery is one of the treatment options that needs to be further explored. Among many other items, AMA Victoria’s state budget submission for the 2008–09 financial year1 calls for a trial of 3000 bariatric surgical procedures to be performed in public hospitals, as part of a comprehensive approach to weight loss. The evidence before AMA Victoria indicates that bariatric surgery is a safe and cost-effective treatment for a proportion of morbidly obese Victorians.2-5 However, bariatric surgery is an extreme response that should only be explored in extreme circumstances. There are many morbidly obese people who find themselves in these extreme circumstances and may benefit from the surgery if other approaches have failed. Further, bariatric surgery is cost-effective, as the costs are lower than the ongoing costs of treating chronic conditions associated with obesity. Bariatric surgery is not the only policy approach to obesity being pursued by AMA Victoria. We see it as a small part of the solution, although it has been a larger part of recent media attention on the issue. I am pleased that the AMA has been able to highlight obesity as an important public policy issue, and I look forward to working with a range of partners to explore possible solutions.

Douglas G Travis

Objective: To quantify the impact on the Western Australian health care system of hospitalisations due to interpersonal violence, and to identify risk factors for a repeat hospital admission for interpersonal violence.Design and setting: A population-based, retrospective study of interpersonal violence in WA using linked data (1990–2004) from the Western Australian Mortality Database, the Hospital Morbidity Data System and the Mental Health Information System.Main outcome measures: Number of hospitalisations and associated length of stay; risk factors for repeat hospitalisation.Results: Over the period 1990–2004, there were 36 934 hospital admissions due to interpersonal violence, with 11 507 of these hospitalisations due to a subsequent episode of interpersonal violence. The average length of stay was 2.6 days (SD, 4.9 days). People who were more likely to be readmitted for interpersonal violence included women (adjusted hazard ratio [AHR], 1.31; 95% CI, 1.23–1.39), Indigenous people (AHR, 1.37; 95% CI, 1.28–1.46) and patients with a mental illness (AHR, 1.46; 95% CI, 1.37–1.54). People with more affluent backgrounds tended to have a lower risk of being readmitted than people in the most disadvantaged socioeconomic group.Conclusion: Greater priority should be directed towards the primary prevention of violence. Groups at high risk, such as women, Indigenous people and those with a mental illness, should be targeted for special attention.

Lynn B Meuleners PhD · Delia Hendrie MSc · Andy H Lee PhD

To the Editor: The proposal by Bowden and Fethers1 to abandon “screen, treat and contact trace” methods of managing endemic sexually transmissible infections (STIs) in remote Indigenous communities and replace them with mass treatment programs in groups with defined threshold prevalence levels is flawed. Primacy must go to the question of why some STIs are so prevalent. Why deal only with the consequences rather than the causes of STIs? Without resolving these questions, the problems will persist. Bowden and Fethers’ approach has serious shortcomings. A major one is sweeping aside the concepts of one-on-one advice, counselling, opportunities to cooperate with health staff, avoidance of hazardous behaviours, and maintenance of effective follow-up. These cornerstones of public health strategies to control STIs depend on the ability of health professionals to establish meaningful relationships with Indigenous people. Transient populations move frequently between towns and remote communities. Therefore, the authors’ strategy neglects the serious risk to remote communities from inadequately controlled reservoirs of STIs that allow the diseases to be repeatedly reintroduced from rural or remote towns. The authors say, ironically, “Let’s not talk about sex”, but an essential part of the public health response to STIs must be to talk about sex. It is our observation that many Indigenous people are more comfortable talking about this subject than other Australians. Another risk in the authors’ approach is to overlook detection of HIV infection. Their proposal could also be interpreted by many Indigenous people as suggesting that they no longer need worry about STIs because the new blanket approach from their health carers will protect them from all such infections. Our long experience working in remote northern Western Australia suggests to us that a mass treatment approach would not resolve the problem of STIs. Control of many of the main chronic diseases of Indigenous people living in remote areas can be significantly enhanced by increased Indigenous community involvement, decision making, and trusting collaboration with health professionals.2 Crucially, additional government commitment is urgently needed to provide enough locally stable and adequately trained staff, facilities, and related resources to control these persisting problems in remote Australia.

Michael S Gracey · Randolph M Spargo

To the Editor: It was pleasing to see Bowden and Fethers raising the issue of public health approaches to sexually transmissible infection (STI) control in remote Indigenous communities.1 However, their suggestion that mass treatment programs would be more effective than screening programs is flawed. They note that screening programs have had some success in reducing the prevalence of STIs, but that an unacceptable prevalence persists. Rather than rejecting screening as an appropriate strategy, it would be more useful to investigate the reasons why screening programs have had limited success. It is likely that the main drawback has been inadequate coverage, and one of the main reasons for this is that there are hard-to-reach groups who are not being included in screening programs. In particular, this would include people with alcohol problems or other addictions, whose lifestyle makes them more at risk for STIs. People in this group, who often live a transient or homeless lifestyle in regional centres, have problems of access to health care and health programs. A mass STI treatment program would not overcome this difficulty and would be just as likely as current screening programs to miss this crucial target group. What is needed is better support for comprehensive primary health care programs, to allow an extension of current health programs to reach out to these groups. Bowden and Fethers suggest that screening programs are inadequate because of problems with current levels of staffing and health infrastructure. This is what needs to be addressed. Greater support for community-controlled comprehensive primary health care, to ensure adequate levels of staffing and infrastructure for STI screening (including outreach programs for hard-to-reach populations), would produce better results from STI screening and would also allow better control programs for other health problems. Furthermore, it would help reduce the problem of increasing antibiotic resistance that is likely to result from mass treatment programs.

David J Scrimgeour

To the Editor: With their radical population-based approach, Bowden and Fethers1 bring a refreshing perspective to the management of sexually transmissible infections (STIs) in Indigenous communities — normally a taboo subject with those at risk and their families. I recently participated in the federal government’s Northern Territory Emergency Response, and was told, both centrally and locally, that looking for STIs was off limits, as it might destroy the trust of Aboriginal communities. This meant that I could neither enquire about nor examine children or adolescents below the umbilicus. I noted that most teenage girls had contraceptive implants (a good public health measure), but no STI prophylaxis. I think this is a failure of the Response.

Bryan G Walpole

Cervical cancer prevention relies on two different age-specific technologies, and consumers should not be misled about the role of HPV vaccines The introduction of human papillomavirus (HPV) vaccines to clinical practice is the end result of a remarkable distillation of basic science, new technology, epidemiological understanding, clinical research and commercial development. It has brought together stakeholders from a variety of backgrounds to consider these developments, and Australia is now the first country to implement a population-based mass vaccination program against HPV. The Australian HPV vaccination program was commenced after cost-effectiveness of the quadrivalent vaccine was demonstrated,1 anticipating that the expected reduction in the cost of treating HPV-related disease in Australian women would compensate for the cost of the vaccine. This program, an Australian Government initiative,2 appears to have been very successful in terms of coverage, and offers young Australian women the opportunity to be among the first national cohort to be vaccinated against the virus types that cause most cervical cancers and a variety of other HPV-related diseases. The natural history of HPV infection and the consequent risk of developing cervical cancer are well documented. HPV infection, replication and particle maturation occurs in the stratified squamous epithelia of skin and mucous membranes, with virus spread occurring by skin-to-skin contact. Most people encounter genital HPV soon after the onset of sexual activity,3 with the highest risk of contracting the infection in the first 5–10 years after commencing sexual activity. The clinical consequences of infection will vary according to the type of HPV encountered, and most infections resolve spontaneously, presumably relying on the host’s immune system to clear the infection. For whatever reason, some individuals do not clear their infections, and if these infections are caused by some oncogenic or high-risk varieties of HPV, this persistence will lead to activation of oncogenic viral proteins, the loss of cellular control mechanisms and the potential for malignant transformation. Screening programs based on cytology have had significant impacts on the incidence and mortality of cervical cancer by detecting these potential cancer precursors, but HPV vaccines allow the opportunity to enlist the vaccinee’s own immune system to develop neutralising antibodies before exposure, and to primarily prevent the infection. The two currently available vaccines (a quadrivalent vaccine against HPV types 6, 11, 16 and 18, and a bivalent vaccine against types 16 and 18) have both been developed by recombinant genetic technology that allows expression of the major structural protein of HPV, the L1 protein, that spontaneously assembles into virus-like particles (VLPs) which are both type-specific and highly immunogenic. Both available vaccines contain VLPs, but the products differ in the types of HPV L1 proteins included as antigens, substrates used for production, adjuvant properties and in the final formulation. Antibodies raised to the VLPs provide protection against HPV infection, probably by transudation of IgG from serum to local mucosal/epithelial areas, especially at sites of trauma where HPV can otherwise gain access to basal epithelial cells.4 Published efficacy studies suggest subtle but probably insignificant differences between the two vaccines in preventing type-specific HPV infections and disease.5,6 It seems unlikely that cell-mediated immunity is involved as a direct effector mechanism of vaccine protection.7 Clearly, this mode of action highlights that the current vaccines will only be effective if administered before exposure. These vaccines have shown no therapeutic efficacy for pre-existing infections.8 Trials of both commercially available vaccines, while demonstrating very high efficacy (approaching 100%) in HPV-naïve populations, have shown diminished efficacy in populations with high rates of previous exposure.4,5 The results so far have indicated that women already infected with one of HPV types 16 or 18 can be protected against development of cervical intraepithelial neoplasia grade 2/3 or cervical adenocarcinoma in situ associated with the other type by vaccination. Both trials were conducted in young populations (generally in women aged between 16 and 25 years). Preliminary results indicating significant efficacy (greater than 90%) of the quadrivalent vaccine in an older population aged between 24 and 45 years have been presented, and these data form the basis of the vaccine sponsor’s application to regulatory authorities in both Australia and the United States for expansion of their age indication for this formulation.9 Doctors are used to being exposed to marketing from drug companies, and are susceptible to commercial persuasion with competing claims of superiority and product distinction. The quadrivalent vaccine, Gardasil (Merck), is available at no cost to Australian girls and women between the ages of 12 and 26 as part of the National Immunisation Program. The bivalent vaccine, Cervarix (GlaxoSmithKline), has to date not been included in the program, having initially been rejected by the Pharmaceutical Benefits Advisory Committee (PBAC) on the basis of uncertain cost-effectiveness,10 but subsequently recommended for inclusion.11 This recommendation has not yet been endorsed by the Australian Government. The sponsoring company appears to have decided to promote Cervarix specifically to older women,12 despite the absence of efficacy data and the uncertain population benefits in this age group. Indeed, the decision by the Australian Therapeutic Goods Administration (TGA) to register Cervarix for use in this population, in which no efficacy has been shown, is not easily understood. Under the Therapeutic Goods Act 1989 (Cwlth), the TGA is responsible for evaluating the quality, safety and efficacy of medicines.13 The World Health Organization has issued guidelines for the evaluation of HPV vaccines, indicating that studies that use immunogenicity data to bridge efficacy from younger to older women are not appropriate.14 In Australia, these guidelines have not been adhered to, and Cervarix has been licensed for use in women up to 45 years of age, despite lack of demonstrated efficacy in women over 26 years. To suggest that the vaccine will offer patients some theoretical potential benefit if they are prepared to pay for it does not reflect sound evidence-based, equitable health care provision. The promotion and media coverage of HPV vaccines in Australia have been extensive, and with this has come an increased awareness of HPV, its relation to cervical cancer, and the national HPV vaccination program. The promise of a cancer vaccine is alluring to women who perceive a risk of cervical cancer. Principles of consumer protection, however, demand that expectations should not be raised unduly, and that the available vaccine does not promise to deliver beyond its capacity. Excessive promotion in the older age group, when the vaccine is likely to be of substantially reduced efficacy because of either previous exposure or reduced risk of future exposure, potentially diverts attention and compliance with established methods of cervical cancer prevention based on cervical cytology. HPV vaccines are about preventing future infections. Cervical cytology detects cytological abnormalities from previous infections. It is important that the benefits of these two approaches to cervical cancer prevention are not confused, and that all women receive the best and most appropriate combination of two effective technologies.

Gerard V Wain FRANZCOG, CGO

Objective: To describe the influenza-related morbidity and mortality in healthy children aged under 5 years in South Australia, in order to further understand the potential role of influenza vaccination.Design and setting: We undertook a descriptive analysis of SA hospital separations data and Australian Bureau of Statistics death data for children aged under 5 years admitted to hospital for influenza. All diagnoses related to an influenza admission were examined to determine whether children were at risk of complications from influenza, according to the criteria of the National Health and Medical Research Council.Main outcome measures: Mean influenza admission rates per 100 000 population per year in children aged under 5 years between 1996 and 2006, and the proportion of children admitted to hospital who did not have a secondary diagnosis putting them at higher risk of influenza-related complications.Results: From 1996 to 2006, 649 children aged under 5 years were admitted to hospital for influenza. Mean annual admission rates per 100 000 were highest in children aged under 1 year (151.0), and decreased with age. Aboriginal and Torres Strait Islander children aged under 5 years had a mean admission rate of 161.8 per 100 000. Most children under 5 years (81%) admitted to hospital did not have an underlying illness that would put them at risk of influenza-related morbidity.Conclusion: Healthy children aged under 2 years and Aboriginal and Torres Strait Islander children under 5 years old have high rates of hospital admission, which may have implications for the target group recommendations for influenza immunisation. Currently, vaccination is recommended only for children with specified chronic diseases.

Katina D’Onise MPHTM, FRACGP · Jane C A Raupach MPH, FAFPHM, FRACGP

Objective: To examine the risk of tuberculosis (TB) in migrants a decade after their arrival in Australia.Design, setting and patients: Retrospective review of laboratory-confirmed cases of TB in migrants diagnosed between 1990 and 2004 by the state TB reference laboratory in Victoria, analysed by a multivariate model comparing migrants diagnosed 10 or more years after arrival with those diagnosed within 10 years of arrival.Main outcome measures: Time to diagnosis; characteristics of migrants diagnosed with TB, including age, sex, region of birth, site of infection, and drug resistance.Results: A third of migrants (734/1924) were diagnosed with TB 10 or more years after arrival in Australia. This group was more likely to be European-born (adjusted odds ratio [AOR], 3.4; 95% CI, 2.4–5.0) and older than 34 years (35–49 years: AOR, 3.8; 95% CI, 2.0–7.0), reflecting the longer time European migrants have been in Australia. There were two distinct European groups: European Union (EU)/Western and Central/Eastern. The Central/Eastern group were from countries with current high TB rates and, compared with the EU/Western group, were younger (mean age, 50 v 64 years) and more likely to be diagnosed within 10 years of arrival (47% v 14%; P < 0.001).Conclusion: European migrants were more likely to be diagnosed a decade or more after arrival in Australia. Once migrants from the currently high TB incidence areas of Asia and Africa have been in Australia for a similar period of time, their timing of diagnosis may resemble that for migrants from Europe. The current screening policy should be complemented with more sensitive techniques to detect latent TB.

Michelle E McPherson BSc/BA, MPH, MAppEpi · Heath Kelly MB BS, MPH, FAFPHM · Mahomed S Patel MB BCh, FRACP, FAFPHM · David Leslie MB BS, FRCPA

To the Editor: With the World Health Organization’s annual World No Tobacco Day to be held on 31 May, it is timely to encourage all patients who smoke to reconsider their actions. During my registrar training in the 1970s, I developed a simple and effective method of helping smokers consider some consequences of their tobacco habit. I offer this in the hope that others may find it useful too, as a more meaningful exercise than the concept of “pack-years”.1-3 First, enquire when the patient began to smoke regularly. I call this the “tobacco-arche” (analogous to menarche and coitarche). Next, determine how many years the patient has smoked regularly, remembering to subtract any years he or she may have suspended the habit. Then, have the patient estimate overall daily usage, relying, if possible, on prompting from an accompanying person to determine a realistic rather than idealised figure. Finally, multiply the number of years by the daily usage and by the number of days in a year. A reasonable approximation is to multiply by 400 rather than the more cumbersome 365.25. For example: a 65-year-old person who has smoked 20 cigarettes per day since his or her mid teens (ie, for 50 years) yields 20 × 50 × 400 = 400 000 — approaching half a million cigarettes lifelong. In my three decades of experience as a general physician, I have noted that an accumulated intake of a quarter of a million cigarettes usually results in at least some cough, breathlessness and end-expiratory wheeze on forced expiration, and decreased exercise tolerance; half a million cigarettes generally causes chronic smoker’s bronchitis, with or without some degree of emphysema, and other harmful effects on the body; while three-quarters of a million cigarettes makes cancer a distinct possibility.4 A further inducement for patients to confront the effects of their harmful habit is to calculate the amount of their lifetime tobacco intake in terms of the dollar cost. In the case of cigarettes, 500 000 at 60 cents each yields the impressive figure of $300 000. This usually comes as a sobering revelation to the smoker and their “significant others”. The above method can thus contribute to the desirable effect of reducing or eliminating tobacco consumption, with flow-on benefits to patients’ health, finances, and personal and occupational relationships.

C Ross Philpot

Social marketing. Why should the devil have all the best tunes? Gerard Hastings. Oxford: Butterworth-Heinemann, 2007 (xvii + 367 pp). ISBN 978 0 7506 83500. Not so long ago, it seemed businesses couldn’t swap their products for our money fast enough before disappearing. Now we can’t even have a haircut without surrendering our name, address, phone number and date of birth. Welcome to relationship marketing. Today’s companies really do care about our satisfaction because customer satisfaction underpins repeat business, explains Gerard Hastings in Social marketing. Why should the devil have all the best tunes? Hastings, the United Kingdom’s first professor of social marketing, argues that public health needs to expand the use of these successful marketing strategies to make health promotion more powerful. By examining commercial practices and dissecting case studies of public health interventions, he demonstrates how health promotion is moving beyond fear campaigns and short-term interventions to building relationships with people and providing practical, ongoing assistance to encourage risk reduction and healthier living. Hastings clearly and succinctly explains the theories underlying social marketing: stages of change, social cognitive theory and exchange theory. He argues that social marketing requires strategic analysis of the problem, of the competing forces and of the target population to underpin solutions that work. Hastings and his colleagues at the University of Stirling, Scotland, recently demonstrated the power of analysing a problem by systematically reviewing the impact of junk food advertising and finding there are adverse effects on children’s food preferences, purchases and consumption. Understanding competing forces is crucial, he argues, because one of the reasons we have binge-drinkers, smokers and people who eat and drink unhealthily is that companies have been better at marketing than have health professionals. Hastings’ well structured and clearly written book equips readers with a valuable tool of public health that can be used to counteract the “hazard merchants”, who market death and disease through products (such as tobacco), and to promote healthier living.

Catriona M F Bonfiglioli

Objectives: To identify key barriers to effective engagement of primary health care (PHC) providers and families in promoting healthy weight among children aged 2–6 years, and to examine promising interventions to identify policy goals to overcome these barriers.Methods: We conducted a literature review of published and unpublished articles from January 1990 to February 2006 using keywords relating to childhood obesity, risk factors, prevention, populations and primary care provider interventions, constraints and models. We identified barriers to engagement by PHC providers. Appraisal of “promise” was based on best available evidence and consideration of strengths and weaknesses of interventions in specific contexts and settings.Results: Of 982 interventions aimed at the primary prevention of overweight and obesity among children, few related to 2–6-year-olds, with only 45 interventions meeting the inclusion criteria and 11 ranking highly on key criteria. Areas of weakness were low-level engagement by PHC providers, focus on single risk factors rather than a multidimensional approach, and lack of a population focus. A range of administrative, attitudinal, knowledge, skills and training issues were identified as barriers to effective engagement of different PHC providers with parents and other early childhood service providers.Conclusions: Engagement of PHC providers in prevention of childhood obesity requires a systematic approach involving practice protocols, assessment tools, client support material and referral pathways, as well as adequate training and sufficient staff for implementation. A more comprehensive approach could be promoted by increased collaboration, agreed role delineation, consistent public health messages and better coordination between PHC providers and other service providers, facilitated at service policy and administration level.

Lydia A Hearn EdD, MSc, BA(Hons) · Margaret R Miller MAppSc, GradDipPubAdm, GradDipDiet · Renee Campbell-Pope BHSc

Global environmental change is threatening the health and survival of humankind — are we doing enough to ensure the environmental and social bases for health? Global warming and resultant climate change pose serious risks to human health.1-3 However, global warming is only one of a nested series of threats to the health — and even survival — of humankind. With this in mind, is our current approach to both clinical and public health sufficient? Parallel threats to the health and wellbeing of humanity arise from a myriad of anthropogenic problems (Box). All such problems, acting synergistically, stress the ecological and social foundations upon which humanity relies for air to breathe, water to drink, food to eat, and disposal of waste, and without which there can be no civilisation and no economy. Taken together, they comprise what has been described as global environmental change (GEC).4 There are many drivers of GEC. Our complex society is heavily dependent on oil to function, even though the supply of easily recoverable oil has peaked or is about to peak.5 However, the fossil fuel bonanza over the past century and a half has enabled a human population explosion that, in turn, has been driving GEC. As populations expand and encroach into new areas, destroying natural habitats and putting animals and humans into close proximity, humans are being increasingly exposed to novel animal diseases. HIV and emerging diseases such as Ebola virus, severe acute respiratory syndrome and H5N1 avian influenza may be manifestations of this.6 The rising population, ecological stress, and neoliberal-driven economic disparity all contribute to political unrest and human violence,7,8 which drive further GEC. Consequently, humanity is facing a series of serious, unprecedented ecological and social changes caused by ourselves. Of these, it is global warming that, if not the most dangerous threat, is the fulcrum about which to coordinate analysis and action. To express concern about the survival of humankind is not being alarmist. Our understanding of the threats facing humanity has moved to a point where the full range of possibilities confronting us can be appreciated. Where we end up consequent to GEC in the next two centuries will be somewhere on a continuum that extends from the extinction of Homo sapiens, through collapse or patchy disintegration of complex industrialised society, to a sustainable industrial civilisation. Exactly where we find ourselves on this continuum depends on how quickly and effectively we act environmentally, economically and socially. Our survival also depends on our ability to control weapons of mass destruction, which are more likely to be used as the consequences of GEC generate conflict over access to ever scarcer resources. As health carers, we are involved on several levels. Individually, we are both part of the cause of GEC and recipients of its effects. As health care professionals, we will need to modify both our health systems and the way we practise to meet the challenge of new health problems, and to adapt to old health problems in new guises. As health professionals, we also have a duty of care to our patients to strongly advocate for action. Serendipitously, GEC also presents unique opportunities. GEC and economic inequity have related causes. Thus, a strategic approach would enable humanity to derive a set of solutions that will make the world both environmentally sustainable and more economically just,7 with flow-on benefits for health. Indeed, Jonathan Patz proposed that “global climate change could be the greatest public health opportunity we’ve had in over a century”.9 Changes needed to mitigate and adapt to GEC present specific health opportunities; for instance, less car use means more exercise. Howard Frumkin has explained how redesigning cities and rearranging traditional work practices can enhance exercise, build social capital, and make a healthier society.10 While beneficial, such changes are not in themselves sufficient. GEC is adversely affecting our society and will continue to do so. The medical community can no longer limit its focus to hospital waiting times, fee levels, workforce shortages, obesity and diabetes. These issues all become starkly irrelevant if the ecological and social systems on which we depend for both our survival and our capacity to deliver services, save lives and care for people stop working. We need a profound shift in our paradigm. The health care sector is not only responsible for delivering health care, but must also ensure the environmental and social bases for health itself. To meet this responsibility, we can act personally — buy a hybrid car, for instance. Individually, we can join and financially support organisations that are working for change: Doctors for the Environment Australia, the Medical Association for Prevention of War, the Australian Conservation Foundation, and others. But collectively, our academic colleges and professional associations must advocate strongly and clearly to government about the gravity of our predicament and the need for urgent, wide-ranging action. Humanity needs a new vision for health for the year 2100: to make sure we have an economically equitable society on an ecologically healthy planet. The stakes are high — we must not fail. The challenge I put to all of us and to our health and political leaders is to work together to make this vision a reality. Serious current environmental problems* Destruction/loss of natural resources natural habitat (ecosystem services) wild food sources biological diversity soil (erosion, salinity, fertility) Ceilings on natural resources (soft ceiling, raising the ceiling costs) energy (fossil fuel and alternatives) fresh water photosynthetic capacity of plants Harmful things made or moved around toxic chemicals alien species atmospheric gases (greenhouse gases → climate change, ozone destruction) Increasing human population actual numbers impact per capita on the environment (resource use and waste) * Derived from Diamond J. Chapter 16. In: Collapse: how societies choose to fail or survive. London: Allen Lane, 2005.

Peter W Tait MB BS, FRACGP

Objective: To examine the relationship between child weight and vehicle booster seat usage in the context of current Australasian booster seat standards.Design, setting and participants: Questionnaire survey conducted between February and April 2005. A convenience sample of parents with children aged 4–11 years in New South Wales and Victoria completed a questionnaire, reporting on the height and weight of their children and the nature of restraint devices used in the family vehicle.Main outcome measures: Proportion of children meeting standard-specified weight and height criteria who are not restrained in booster seats; proportion of children who meet the specified height criteria but whose weight exceeds the specified weight.Results: 699 of 3959 questionnaires were returned (response rate, 18%), of which seven lacked essential details. The remaining 692 responses provided information on 1500 children. Of these children, 633 aged 4–11 years fell within the recommended height range for using booster seats, but only 29% were typically restrained in booster seats, the majority (70%) being restrained in normal seatbelts. A key finding was that 37% of the children who met the recommended height criteria exceeded the maximum weight for booster seats stipulated by the current Australasian safety standard.Conclusion: In view of increasing rates of overweight and obesity in children, it is important to reassess current Australasian standards for child restraints in vehicles. A concerted parental education campaign is also needed to raise awareness of which restraint types are appropriate for children of various heights and weights.

Michael P Fitzharris BA, BSc(Hons), PhD · Judith Charlton BEd, MSc, PhD · Megan Bohensky BA, MPH · Sjaanie Koppel BAppSc(Hons), PhD · Brian Fildes BSc(Hons), PhD