Environmental health

The absence of information on immunisation after the age of 7 years leaves a public health void The Australian Government currently funds the Australian Childhood Immunisation Register, including financial incentives for vaccine providers and parents, to update and record vaccinations given to children up to 7 years of age.1 The register provides information enabling appropriate updating of vaccination status for young Australian children. It also provides invaluable data on immunisation coverage, allowing ongoing evaluation, at a population level, of implementation, impact on disease, and vaccine safety for current childhood vaccination programs. However, this information is not available for vaccines administered after 7 years of age, the number of which is steadily increasing with the availability and funding of new vaccines as part of the National Immunisation Program. In 2007, a separate register was developed for human papillomavirus vaccine. But, in the absence of a register for other vaccines administered after age 7, providers, clinical researchers and assessors of program implementation must rely on self-reported vaccination status or on locating vaccination records. In some other countries there are alternatives for accessing data on vaccination status at a population level (eg, the records of health maintenance organisations providing private health cover for sub-populations in the United States,2 or population-based linked databases such as a government-run initiative in Catalonia, Spain3), but none exist at present in Australia. In 2006, the Australian Government Department of Health and Ageing announced a scoping exercise to examine the need for a “whole-of-life” immunisation register.4 It is illuminating to consider some key points informing this important debate relating to vaccination of elderly Australians. These have included the potential impact of relying on self-report to vaccinate elderly Australians, as well as improvements in program evaluation and opportunistic vaccination that might occur with the introduction of an expanded immunisation register. Influenza vaccine and 23-valent pneumococcal polysaccharide vaccine (23vPPV) have been funded in Australia for people aged ≥ 65 years since 1998 and 2005, respectively. They have proven benefit against confirmed influenza and invasive pneumococcal disease in this age group. Yet current assessment of coverage achieved by the program is limited to annual telephone surveys based on self-reported data from about 1000 people from each jurisdiction, and excludes residents from institutions such as aged-care facilities.5 Adverse events are reported via passive surveillance to the Therapeutic Goods Administration. Such an approach is likely to provide much poorer population estimates than accessing an effective register for the entire population. In addition, providers vaccinating individuals must continue to rely on self-report or location of vaccination records, and there is no facility for evaluating program implementation in other recommended at-risk groups such as Indigenous adults. The most recent of two Australian studies examining the validity of self-reported 23vPPV and/or influenza vaccination status in elderly people, which included almost 3000 Victorians, confirmed that self-report is problematic.6 Compared with provider-confirmed dates of influenza vaccination in the previous year, self-report had low specificity (56%) and over-estimated true coverage by 10% (86% versus 76%) — estimates that fall within the range provided by earlier studies.7-10 Estimates for validity of self-reported 23vPPV status in the previous 5 years (76%–85%)7 are also consistent with these earlier studies. Further improvements in vaccination coverage for elderly Australians with 23vPPV and influenza vaccine are warranted, given recent population coverage estimates of 71%–79% (influenza vaccine)5,7,11 and 51%–53% (23vPPV).5,7,11 A study of opportunistic vaccination among 4772 elderly hospital inpatients11 revealed a zero in-hospital opportunistic vaccination rate, despite virtually all unvaccinated subjects having had multiple visits (an average of 12) to vaccine providers in the community or the same hospital in the year before admission. Furthermore, only 2% of the inpatients had had their 23vPPV or influenza vaccination status recorded during admission — an omission previously cited as the single most important factor impeding opportunistic vaccination.12 Providers clearly have competing priorities and are failing to fully implement vaccination policy. Given the difficulties inherent in relying on self-reported vaccination status or written records, a register would greatly improve ascertainment of vaccination status among elderly people and potentially contribute to delivery of more vaccinations. Influenza vaccine and 23vPPV for the elderly are just two examples. It is highly likely that a national vaccination register would also improve the delivery and assessment of other vaccines received after age 7. An expanded register with the facility to include current and new National Immunisation Program vaccines beyond the 0–7-year age group could improve vaccination status and prevent over-vaccination. It would also allow evaluation of programs and monitoring of adverse events, and would be a valuable addition to any future national data linkage system that included health care records and drug prescription data, for which Australia has the potential to be a world leader.13 How Australia chooses to record vaccination status for all of its citizens will require careful consideration of costs and will no doubt be examined by the current scoping exercise. Assessment of the issue should include the potential human costs of incomplete vaccination and suboptimal monitoring of adverse events related to vaccination.

Susan A Skull FAFPHM, FRACP, MAppEpid · Terence M Nolan FAFPHM, FRACP, PhD

Objective: To describe tumour characteristics and clinical management of melanomas newly diagnosed in 1996 and in 2000 — before and after publication of the clinical practice Guidelines for the management of cutaneous melanoma by the Australian Cancer Network (1997), and their endorsement by the National Health and Medical Research Council (NHMRC) and republication (1999).Design and setting: Survey of clinicians involved in the management of patients with melanoma sampled from the Victorian Cancer Registry. The Registry is notified of all cases of cancer diagnosed by pathology laboratories and hospitals in both the public and private health sectors in the state of Victoria.Patients: People with a cutaneous melanoma newly diagnosed in 1996 and 2000. All invasive melanomas > 1.50 mm in thickness were included, and for each year random samples were selected of 100 each of invasive melanomas 0.76–1.50 mm in thickness, invasive melanomas ≤ 0.75 mm, and in-situ melanomas, plus 50 melanomas of unknown thickness.Main outcome measures: Biopsy method, adequacy of pathology reporting, adequacy of definitive excision (compared with margins recommended by the Guidelines), and follow-up procedures.Results: The use of partial biopsies increased between 1996 and 2000. Recommended margins of definitive excision were used in only 33.6% of cases. Margins were smaller than recommended for 36% of in-situ melanomas, risking recurrence of primary melanoma. Documented follow-up examinations for subsequent primary skin malignancy were uncommon (6%).Conclusions: Many aspects of the management of primary cutaneous melanoma appear not to meet the recommendations of the published Guidelines. Further studies to explore the reasons for failure to meet the Guideline recommendations are needed.

John W Kelly MD, FACD · Michael A Henderson MD, FRACS · Vicky J Thursfield BSc, GradDip(Applied Stats) · John Slavin FRCPA · Jill Ainslie FRANZCR · Graham G Giles PhD

New technologies are often widely available to drivers before their safety can be evaluated In recent years, the availability of technological devices that can potentially be used while driving has expanded rapidly. One device that has received particular attention due to concern about driver distraction is the mobile phone. In this issue of the Journal, Taylor et al report on the use of handheld mobile phones by drivers in metropolitan Melbourne (→ Handheld mobile telephone use among Melbourne drivers).1 This observational study, which follows up research conducted by the same investigators in 2002, indicates that drivers continued to use handheld phones 4 years later, despite legislative and enforcement practices that prohibit their use and evidence that such use increases the risk of having a crash. On the other hand, the rate of use has remained steady even though mobile phone ownership has increased. Mobile phones are just one of a number of devices that may distract a driver. These technologies may be driving-related (eg, satellite navigation and intelligent speed adaptation [ISA] systems), or non-driving-related (eg, iPods, personal digital assistants and wireless email). Driving-related technologies seek to enhance drivers’ mobility and/or safety while non-driving related technologies do not. However, if poorly designed or used inappropriately, both types of technologies have the potential to compromise road safety. Aside from distraction, safety issues include: poor understanding of system operation; negative behavioural adaptation (drivers potentially taking more risks because their cars are fitted with additional safety equipment); system misuse; and increased driver workload. Thus, research is required to evaluate the safety implications of any device that can be used while driving. Apart from mobile phones, little is known about the proportion of Australian drivers who use driving-related and non-driving-related technologies and how frequently the technologies are used while driving. One survey conducted in late 2003 found that use of personal organisers and email was very low (0.3%) during a specified driving trip,2 but did not collect information on the availability and use of novel driving-related technologies. How the use of non-driving-related technologies affects driving performance is under investigation. To date, most research has involved the use of driving simulators. Studies have examined the use of mobile phones, stereo equipment and speech-based email systems, and have shown driving impairment.3-5 Epidemiological studies of the risk of crash relating to the use of devices other than mobile phones are currently lacking. Indeed, the rapid change in non-driving-related technologies means that road safety research can lag behind uptake of these devices by the driving public. In relation to driving-related technologies, early research is showing promise in enhancing safety, though much work remains to be done. A large field trial of ISA systems in Sweden involving over 10 000 drivers using about 5000 fitted vehicles demonstrated reductions in the mean speeds travelled.6 In Australia, the Transport Accident Commission (TAC) SafeCar project, which evaluated four driving-related technologies (ISA, following distance warning [FDW], seatbelt reminder [SR], and reverse collision warning) among 15 drivers using specially equipped vehicles, found positive effects for the ISA, FDW and SR systems.7 Recently, a naturalistic driving method has been developed in which drivers are videorecorded during their everyday driving.8 Multiple views are taken, including the driver, console, and the vehicle’s forward, rear and lateral views. The data can then be used to quantify drivers’ exposure to and interaction with technological devices while driving, and to estimate the risk (or benefit) associated with the use of these technologies. In addition to current research, a large naturalistic driving study to evaluate the safety of technological devices used in vehicles should be conducted in Australia. This will provide locally relevant data to inform the design of these technologies. Periodic surveys to monitor trends in the use of technological devices while driving are also indicated. The impact of driver distraction in all its forms (technological and non-technological) is considerable. Australian studies have shown that drivers commonly engage in distracting activities while driving, and that distraction is a contributing factor in 14%–21% of crashes;2,9 these figures are even higher among inexperienced drivers. In response, passenger restrictions and a ban on all mobile phone use (including hands-free) were introduced for novice drivers in New South Wales and Queensland in July 2007 as part of their graduated driver licensing systems. In Victoria, the TAC has recently launched a driver distraction media campaign to raise awareness,10 and a complete ban on mobile phone use while driving for novice drivers will be enacted in July 2008. Considerable gains have been made in the area of road safety in Australia in the past 30 years. If we are to maintain and improve on these gains, then managing the risks and benefits of technologies that can be used while driving will be critical. If certain driving-related devices are found to benefit road safety, then their uptake should be facilitated. Means to achieve this include regulatory requirements to ensure that new vehicles are fitted with the technology, that drivers are educated about the correct use and benefits of the technology, and that the technology is installed in vehicle fleets. Conversely, any technologies found to be unsafe will require measures to limit their use while driving. Car manufacturers and portable device developers will need to consider the potential for design improvements or the use of appropriate warnings.

Suzanne P McEvoy FAFPHM, MAppEpid, PhD

Objective: To evaluate change in handheld mobile telephone (mobile) use among motor vehicle drivers between 2002 and 2006.Design and setting: Observational study of motor vehicle drivers at three times (10:00–11:00; 14:00–15:00; 17:00–18:00) on three consecutive Tuesdays in October 2006 at 12 highway sites in metropolitan Melbourne.Main outcome measures: Rates of handheld mobile use overall and by the sex and age of drivers, highway site (major metropolitan road, central business district, freeway exit ramp) and time of day.Results: In 2002, 315 of 17 023, and in 2006, 331 of 20 207 drivers were observed using handheld mobiles. This represented a non-significant rate decrease from 18.5 to 16.3 users/1000 drivers (rate difference, 2.1 users/1000 drivers; 95% CI, − 0.6 to 4.8; P = 0.07). Unlike 2002, the rate of handheld mobile use among men in 2006 was significantly higher than for women (rate difference, 3.7 mobiles/1000 drivers; 95% CI, 0.1–7.3; P = 0.03). In both 2002 and 2006, mobile use was most common in the central business district. In 2002, there was significantly more mobile use in the evening, while in 2006, the evening rate was significantly lower than the morning rate (rate difference, 4.3; 95% CI, − 0.1 to 8.7; P = 0.03) and slightly lower than the afternoon rate (rate difference, 3.0; 95% CI, − 1.1 to 7.1; P = 0.08). The effect of age remained unchanged between 2002 and 2006, with older drivers using mobiles least (P < 0.001).Conclusion: The number of drivers at risk from handheld mobile phone use remains almost unchanged. However, a slight reduction in the rate of use overall and variations in use among driver subgroups are apparent. Policing and public awareness campaigns need to further address this preventable risk of injury.

David McD Taylor MD, MPH, FACEM · Catherine E MacBean BA(Hons) · Atandrila Das · Reizal Mohd Rosli

Objective: To highlight recent reductions in mortality rates in Australia and identify conditions and population groups with the greatest potential for further reduction in mortality rates.Design: International benchmarking and intranational comparisons of mortality rates were used to identify areas with the greatest potential for improvement.Results: Latest data from Organisation for Economic Cooperation and Development (OECD) countries confirm that, while Japan’s death rates remain the lowest in the world, Australia’s are decreasing rapidly and we now rival Switzerland for second overall ranking. When the contributions of specific conditions are compared, the areas with the greatest potential for reductions are circulatory diseases (especially ischaemic heart disease); suicide; injury and violence; smoking-related conditions; and cancers amenable to prevention/early detection. Intranational comparisons show considerable scope for reduction in inequalities, especially those between Aboriginal and Torres Strait Islander peoples and other Australians, between males and females, and between low and high socioeconomic groups. These conditions and inequalities are highly interrelated, as differentials in health status are often mediated through broader societal inequalities.Conclusions: Australia should aim to become the country with the lowest mortality rate in the world. This could realistically be achieved by benchmarking performance nationally and internationally, applying current knowledge and available interventions, matching policies with funding, and implementing systemic national programs and activities to promote health and prevent “illth”.

Ian T Ring MB BS, MSc(Stats/Epid), FAFPHM · John F O’Brien MHSc

To the Editor: The recent editorial by Ring and Wenitong1 about interventions to prevent child abuse in the Northern Territory highlights the importance of treating the causes as well as the symptoms. This is true not only for children in remote Aboriginal communities, but for all children across Australia. Child abuse and neglect is not a “new” national emergency. In 1966, Bialestock2 wrote in the Journal: This situation should be considered as a national emergency as lethal to the lives of potential Australians as is a war. Immediate allocations of revenue to prevent this situation should be made if the[se children] . . . are to be allowed to grow into adults able to live in dignity and to work to contribute to our economy. We must not sentence these children to a lifelong need for State support. There are no reliable prevalence data, but Australian Institute of Health and Welfare data indicate that there were 266 745 notifications of suspected child abuse and neglect in Australia last year, double the number 6 years ago. About one in five of these notifications were “substantiated”. Over 25 000 children are in state care at any one time, an 82% increase in the past decade.3 Our child protection systems are at risk of imploding under the strain. These systems are also potentially dangerous, with high levels of multiple placements contributing to the very high prevalence of mental health problems among children in care.4 The contributory factors are well known. Children with disabilities, chronic health problems, difficult temperaments and externalising behaviours, families where there is domestic violence and parental mental health or substance misuse, and communities characterised by poverty, unemployment, higher residential mobility, and a low adult to child ratio are at much greater risk. We must close the gap between what we know and what we do. A public health approach is needed to reduce the risk factors, using population-based measures of child abuse and neglect, and tapping the potential of universal health, welfare and education services as platforms for primary and secondary prevention. In relation to health services, the adequate provision of universal maternal and child health services, including sustained nurse home-visiting programs, is vital. General practitioners and mental health and drug treatment services using child-sensitive and family-centred approaches also have a major role to play. These interventions have also been shown to improve overall outcomes for children in education, health, and social and economic participation. Hence, economists have suggested that they are the most cost-effective intervention for a nation.5 Now is the time to ask whether governments are really serious about preventing child abuse and neglect.

Fiona J Stanley · Dorothy A Scott · Melissa O’Donnell

Three cases of cholera in women aged 71, 72 and 84 years were notified in November 2006 in Sydney, New South Wales. This is the first reported cluster of cholera in Australia for over 30 years, and was an unusual outbreak in patients with no history of recent travel to cholera-endemic areas. A food trace-back investigation found that the only exposure common to all cases was consumption of raw whitebait imported from Indonesia. This outbreak demonstrates that the practice of eating raw whitebait does occur in Australia, albeit in the process of taste-testing uncooked fritter batter. All three patients were undergoing long-term therapy with proton-pump inhibitors, which may have contributed to their susceptibility to the disease. A review of importation practices of food from cholera-endemic regions may be required to prevent future transmission.

Bradley Forssman MB BS, MPHTM, FAFPHM · Trish Mannes BAppSci, MPH · Jennie Musto MPH · Thomas Gottlieb MB BS, FRACP, FRCPA · Graham Robertson MSc · Jonathan D Natoli BSc · Craig Shadbolt PhD · Brian Biffin · Leena Gupta MB BS, MPH, FAFPHM

Re: “Influenza outbreak related to air travel”, by Andrew G Marsden, in the 4 August 2003 issue of the Journal (Med J Aust 2003; 179: 172-173). The title should have been “Outbreak of influenza-like illness related to air travel”, consistent with the text.

Andrew G Marsden

To the Editor: The introduction of indoor smoking restrictions in Western Australian pubs, clubs and nightclubs1 has been championed as a public health success and an advance in tobacco control. But how well is it being observed, and is the current legislation adequate? Although smoking in Australia is declining, a report showed that one in seven 16–17-year-olds had smoked cigarettes in the previous month.2 Peer pressure has an important influence on smoking uptake,3 and alfresco hospitality settings, being exempt from the smoke-free restrictions, constitute important risk environments for young people. Moreover, 85% of adults in WA do not smoke, but continue to be affected by second-hand smoke drifting from alfresco balconies, beer gardens and street cafes. Indeed, the legislation risks turning these popular and highly visible entertainment areas into nicotine classrooms4 for the young, and “no-go” zones for health-conscious non-smokers. We set out to evaluate compliance with the smoke-free legislation, and its impact on smoking in licensed premises. Twenty medical students were recruited to monitor smoking in 93 Perth hotels and nightclubs on two Friday evenings during November 2006. Entertainment areas were classified as indoor (smoke-free), semi-outdoor (smoke-free, failing to meet exemption criteria) and alfresco (smoking allowed), in accordance with the new legislation. Average observation times were 20 minutes, 17 minutes and 15 minutes respectively. Indoor compliance with the legislation was high, with smoking noted in only five (5%) of the 93 premises. Whether by default or design, 58 premises (62%) had alfresco areas and there was smoking activity in those areas in 56 (97%) of these premises. Forty premises (43%) also had semi-outdoor areas where, contrary to the legislation, smoking remained prevalent (23 premises; 57.5%). Overall, smoking was observed in 69 of the 93 premises (74%). In 35 of these premises (51%), smoking was visible to the passing public. These results demonstrate the inadequacy of the new smoke-free legislation in restricting smoking, protecting the health of non-smokers and strengthening tobacco control. The legislation has been well accepted, but smoking (legal and illegal) remains prevalent in licensed premises. This presents a serious challenge to tobacco control and efforts to reduce smoking by young people. A key lesson from the history of tobacco control is that partial bans achieve partial results.5 A complete ban on smoking, both inside and outside licensed premises and restaurants, is urgently required.

William J Patterson · Michael M Daube · Stephen L G Hall · Denitza Moronova

In Australia, many deaths and significant cardiac disability result from delayed response to symptoms of heart attack. Although delays due to transport and initiation of reperfusion therapy in hospital may contribute to late treatment, the major component of delay is the time patients take in deciding to seek help. A critical examination of campaigns to shorten patient delay concludes that they were based on a factual, short-term, non-targeted approach that included education and mass media strategies. They achieved equivocal results. One randomised controlled trial has been conducted. Although this showed an improved understanding of heart attack symptoms, it did not shorten pre-hospital delays. The implications of these findings are that future campaigns to shorten patient delay are likely to be more effective if they address the psychosocial and behavioural blocks to action, are ongoing rather than short term, and focus on people at highest risk, including those with known or high risk of coronary heart disease, those in rural locations, and Indigenous Australians. The National Heart Foundation of Australia proposes a comprehensive strategy to incorporate this approach into its future campaigns to reduce patient delay for suspected heart attack.

on behalf of the National Heart Foundation of Australia Chest Pain Every Minute Counts Working Group

Measles is now rare in Australia, and cases can usually be linked to its importation from endemic countries. To prevent measles outbreaks in Australia, high vaccination coverage with two doses of vaccine must be sustained. All medical practitioners should consider a diagnosis of measles in a patient of any age who presents with fever and a non-vesiculating, non-itchy rash. If measles is suspected clinically, public health authorities should be immediately notified, so that testing and management of patients can be discussed and contact tracing initiated. When a patient is suspected of having measles, testing of a serum sample for measles-specific IgM and IgG antibodies should be requested urgently. Pathology laboratories should have effective protocols for immediately reporting positive measles-specific IgM antibody tests, or other results indicative of measles, to public health authorities.

David N Durrheim DrPH, MB ChB, FAFPHM · Heath Kelly MB BS, MPH, FAFPHM · Mark J Ferson MD, FRACP, FAFPHM · David Featherstone BSc

About a thousand Australian children are seriously injured in motor vehicle accidents each year, despite 92% using seatbelts or child restraints. Premature graduation of children to adult seatbelts, misuse of seatbelts and use of lap-only belts increase the risk of injury or death. In Australia, use of a child restraint or booster seat is not mandatory for children aged > 1 year, while other countries mandate their use for children up to 5–12 years old. Australian parents are confused about the safest restraint and seating position, particularly for children aged > 2 years. Australian child restraint legislation needs to be reviewed to increase the rate of optimal restraint use.

Katie N Reeve MB BS(Hons), MRCPCH, MRCP · Yvonne A Zurynski BAppSc, MAppSc, PhD · Elizabeth J Elliott MD, FRACP, FRCPCH · Lynne Bilston BE(Mech)(Hons), MSE, PhD

To the Editor: In 2000, the United Nations Millennium Summit produced an agenda for reducing global poverty. It listed eight Millennium Development Goals (MDGs) and was signed by 189 countries. Improving maternal health (with the aim of reducing the maternal mortality ratio by three-quarters between 1990 and 2015) is the fifth and perhaps the core health-related MDG if we consider the centrality of mothers in social development and health.1,2 Globally, the number of maternal deaths remains high at 529 000 per annum.2 Ensuring maternal survival demands functional health care systems with skilled health care workers. However, migration of health care workers (mostly to wealthier English-speaking countries) is a major threat to achieving the MDGs.3-5 Here, I estimate the associations between maternal health and physician migration and human resources for health. I used recently updated physician migration3 and global health workforce data4 to look at correlations between physician migration and two core maternal health indicators — the maternal mortality ratio, and the percentage of births attended by skilled personnel.1,2 I also explored the associations between these maternal health indicators and human health care resources. Migration was measured as the number of physician émigrés working in Australia, the United Kingdom, Canada, and the United States during 1999–2002, per 1000 population of their source countries.5 Physician migration density values for all four countries combined, and for each country individually, were determined (Box). Human health care resources included current densities of health care workers remaining in the source countries (Box). I calculated the Pearson’s correlation coefficients between these variables and the two core maternal MDG indicators. The Box shows that countries with better maternal health are likely to have higher physician migration and more human resources for health care. For example, higher migration to Australia is seen from countries with lower maternal mortality (r = − 0.29; P = 0.011) and more births attended by skilled staff (r = 0.25; P = 0.037). I acknowledge that, like most health system and global health analyses, these correlations are based on an ecological (cross-country) design which does not lend itself to causal inference. These findings are therefore descriptive and require further exploration. Furthermore, the two maternal health indicators used here (which are the core maternal health MDG indicators used by the United Nations) could be viewed as indicators of health system and population health progress. Although physicians and other health care workers play major roles in maternal survival, especially in pregnancy, they cannot be seen as the only requirements for better maternal health. Physicians’ roles can also be substituted by other health care workers in many situations in resource-poor settings. However, less-poor source countries often have higher capacities than poor nations to turn out skilled workers who subsequently migrate. Contrary to conventional wisdom, Australia, the UK, Canada, and the US draw substantially more migrant physicians from countries with higher health care worker capacities. Many countries may be losing physicians just when they should be reaping the benefits of their improving fortune. Given the patchy progress towards achieving the MDGs,1 health care worker shortages may impede many countries’ progress in improving health standards if migration rates exceed workforce replacement in the face of changing but increasingly complex health care needs.1,2,4 Physician migration must be taken seriously if the global target of reducing maternal mortality by three-quarters between 1990 and 2015 is to be realised and sustained. Australia and other Western countries must partner with source countries to develop strong political commitment and scaled-up investments in human resources for health. Correlations between source countries’ core maternal Millennium Development Goal indicators and (A) physician migration to Australia, the United Kingdom, Canada and the United States and (B) human health care resources* Maternal Millennium Development Goal indicators in source countries (A) Physician migration to Australia, the UK, Canada and the US No. of source countries† Mean physician migration density‡ (SD) Maternal mortality ratio¶ P Births attended by skilled health care staff** P Total migration 141 0.094 (0.224) − 0.45 < 0.001 0.34 < 0.001 Migration to Australia 75 0.007 (0.040) − 0.29 0.011 0.25 0.037 Migration to the UK 117 0.017 (0.072) − 0.27 0.003 0.17 0.072 Migration to Canada 116 0.008 (0.027) − 0.47 < 0.001 0.45 < 0.001 Migration to the US 124 0.061 (0.158) − 0.55 < 0.001 0.43 < 0.001 (B) Human health care resources Mean density of health care workers§ (SD) Physicians 141 1.655 (1.426) − 0.84 < 0.001 0.67 < 0.001 Nurses 141 3.636 (3.544) − 0.81 < 0.001 0.72 < 0.001 Public and environmental health care workers 64 0.114 (0.169) − 0.56 < 0.001 0.54 < 0.001 Health management and support workers 71 1.488 (2.222) − 0.73 < 0.001 0.51 < 0.001 * Data are those available for 1999–2002, and each variable was transformed into its natural logarithmic form for analysis. † Top 10 source countries losing physicians (per 1000 population) to the four destinations combined (in decreasing order): Ireland, Saint Lucia, Lebanon, New Zealand, Jamaica, Iceland, Malta, Dominican Republic, Israel, and Cook Islands. Top 10 source countries for Australia: New Zealand, Ireland, Singapore, Fiji, Malta, Sri Lanka, South Africa, Slovakia, Bahrain, and Hungary. Top 10 source countries for the UK: Ireland, Malta, Barbados, Jamaica, New Zealand, Sri Lanka, Libya, Greece, Iraq, and Iceland. Top 10 source countries for Canada: Ireland, Jamaica, Kuwait, Lebanon, South Africa, New Zealand, Barbados, Bahrain, Saudi Arabia, and Iceland. Top 10 source countries for the US: Saint Lucia, Lebanon, Ireland, Iceland, Dominican Republic, Jamaica, Cook Islands, Israel, Belize, and the Philippines. ‡ Number of source country’s physicians working in Australia, the UK, Canada and the US per 1000 source country’s population (based on average year-2000 population). § Number of health care workers remaining in home/source country per 1000 population. ¶ Correlations between the number of maternal deaths per 100 000 live births and (A) physician migration density and (B) human health care resources. ** Correlations between the percentage of births attended by skilled health care staff and (A) physician migration density and (B) human health care resources.

Onyebuchi A Arah

Despite advances in treatment, the greatest gains in cancer control are achieved through prevention The translation of basic cancer research on cell growth to the clinic has resulted in a paradigm shift in cancer treatment by providing new therapeutic targets. The initial successes — the monoclonal antibodies trastuzumab and rituximab — have improved the survival of patients with breast cancer and lymphoma, as has the small molecule imatinib mesylate in chronic myeloid leukaemia; all have less toxicity than conventional cytotoxics.1 The challenge is to fund these new high-cost drugs. Although targeted drugs can be limited to the specific patient populations expressing the appropriate target, further funding is then required to screen patients for those targets. New models of cost- and risk-sharing between governments and industry must evolve to pay for these developments. A similar evolution in the diagnosis of cancer will see genomics and proteomics become a more important guide to treatment selection and prognosis than traditional pathology tests.2,3 These research technologies will need to be developed in such a way that they can provide guidance to clinicians as quickly as conventional techniques, and will also require upskilling of current clinicians, pathologists and their trainees. Investment in cancer research pays considerable dividends.4 There is a need for more funding of translational research — it has been an ongoing concern that Australia lacks the infrastructure to take promising new drug discoveries all the way from the laboratory into clinical practice. Newer fields, such as health services research, with its potential to address the pressing issue of inequities in access to treatment and cancer outcomes in rural and remote Australia, and psychosocial research, require new sources of funding. The challenge in Australia is to make research less fragmented and better targeted to questions of international importance, which we have the capability to competitively pursue. Although breakthroughs in cancer treatment generate significant media coverage, the greatest gains in cancer control in Australia are to be made in prevention strategies based on established science. Evidence-based health promotion campaigns have provided strong economic returns, yet governments invest only 1.7% of the overall health care budget in primary prevention.5 More than 21% of cancer deaths in Australia are attributed to tobacco use. Add smoking to excessive sun exposure, inadequate fruit and vegetable intake, alcohol, inactivity and obesity, and more than 34% of cancer deaths in Australia can be attributed to modifiable behaviour.6 Currently, 17.4% of Australians smoke.7 Australia has a smoking prevalence among the world’s lowest, but from a public health perspective it remains unacceptable that almost one in five Australians incurs a significant yet avoidable cancer risk by continuing to smoke. The prohibition of broadcast tobacco advertising in the mid 1970s was the first key policy step in a series of tobacco control reforms that have since been shown to have saved 17 000 Australians from premature death.8 This government initiative required no taxpayer funding, but a cultural shift. Where funds have been invested, the returns have been enormous, with the $176 million spent on antismoking campaigns over the past 30 years delivering $8.6 billion in benefits.9 There remains no more effective cancer control measure than reducing smoking, but there is a risk that the incremental reduction in smoking prevalence achieved over the past 30 years will stall unless the tobacco control effort is sustained. Smoking also contributes significantly to social inequities in health outcomes. For example, a smoking prevalence of 50% among Indigenous Australians10 is believed to be a major cause of the significantly poorer cancer survival rates among Aboriginal and Torres Strait Islander peoples. Targeted approaches are needed to break the cycle of social disadvantage, smoking, and cancer evident in specific population groups. Moreover, studies on tobacco control achievements over recent decades strongly suggest that a more sustained, whole-of-government commitment, built around integrated policy, social marketing, and research, could bring smoking prevalence down in Australia by a further 1% annually. Estimates based on recent trends indicate that reducing smoking prevalence by 5% in 5 years would save more than $1.15 billion in health care costs over the next 30 years.8 Yet some major political parties continue to accept donations from tobacco companies,11 and governments delay legislation to ban smoking in enclosed public spaces, and invest taxpayer funds in tobacco companies on the basis of sound economic management — despite having to spend more taxpayer funds on treating tobacco-related diseases (at least until patients die of them). While public policy has been gradually reducing the tobacco burden, obesity is escalating as a community health crisis. Obesity is linked to colorectal cancer, postmenopausal breast cancer, and kidney, oesophageal, gall bladder and endometrial cancers.12 Obesity control includes encouraging and facilitating physical activity and communicating dietary advice. The tobacco experience suggests that restricting junk-food advertising to children is likely to have an important impact, as supported by early Canadian data.13 This measure is not about restricting choice, as well targeted multimillion-dollar advertising campaigns already create an imbalance in the choices that uninformed and often disadvantaged families see as being available to them. Other lifestyle messages require more subtle public education. Advice from the SunSmart skin cancer prevention program must balance the need to avoid excessive sun exposure with the importance of low-level sunlight for vitamin D production. Similarly, while any alcohol consumption carries some cancer risk, the more you drink, the higher the risk — a factor that should be balanced against the benefits of very low alcohol intake in preventing cardiovascular disease. Cancer screening is another area that is presenting new opportunities and challenges. The benefits of breast cancer screening need to be continually reinforced to ensure high participation rates by eligible women. A new challenge for cervical cancer screening is ensuring continued high participation despite the introduction of the human papillomavirus immunisation program. The new National Bowel Cancer Screening Program requires community and professional education, a patient registry to ensure follow-up, and extra resources and minimum standards to meet increased colonoscopy demand. This will test the shared responsibilities for health care between national and state/territory governments — a potential barrier to efficient health policy implementation. The community must also understand that an ineffective screening test — one that evidence shows lacks the specificity and sensitivity to reduce cancer mortality on a population basis — is worse than no test at all, as the false positives and negatives can lead to poorer health outcomes than would surveillance on a case-by-case basis. The key is ensuring that evidence guides the implementation of government-funded measures aimed at cancer prevention and early detection — at a time when we could prevent well over a third of all cancer deaths in Australia using existing prevention and early detection technology. By investing more taxpayer funds in the high proven returns of cancer prevention and early detection, we could make resources available to better support the significantly increasing numbers of new cancer patients associated with population ageing over the coming years. Savings generated through improved prevention could also fund targeted cancer research to help further reduce the impact of cancer in the future. Increasing the cancer workforce, and improving workforce training and support through a more integrated approach across jurisdictions, is also pivotal to ensuring we can provide optimal multidisciplinary cancer care to meet the challenges of the future.

Ian N Olver MD, PhD, FRACP

Objective: To assess the impact of iodine fortification of bread on the iodine status of pregnant women, and to determine if studies of iodine levels in school-age children were indicative of women’s gestational iodine status.Design: Urinary iodine surveys of pregnant Tasmanian women before and after bread was fortified with iodine in October 2001.Participants and setting: 285 women attending the Royal Hobart Hospital (RHH) antenatal clinic from 1 October 2000 to 30 September 2001 and 517 women attending the RHH antenatal clinic or primary health care centres in 2003–2006.Main outcome measures: Median urinary iodine concentration (UIC) for comparison against the World Health Organization recommendation of of 150–249 μg/L for pregnant women.Results: Before supplementation, the median UIC of the 285 women attending the RHH antenatal clinic was 76 μg/L. After supplementation, median UICs were 81 μg/L for 288 women attending primary health care centres and 86 μg/L for 229 women attending the RHH antenatal clinic. Differences in mean UIC were not significant for either the antenatal clinic group (P = 0.237) or the primary health care group (P = 0.809) compared with the pre-supplementation group.Conclusions: Iodine deficiency in pregnancy persists despite being corrected in Tasmanian children. Successful iodine supplementation must target reproductive-age and pregnant women and be substantiated by ongoing monitoring during pregnancy and lactation. A robust national program for correcting iodine deficiency is urgently needed. Mandatory universal salt iodisation has international endorsement, and should be considered the preferred strategy for eliminating iodine deficiency in Australia.

John R Burgess BMedSc, MD, FRACP · Judy A Seal MPH, AdvAPD · Georgina M Stilwell MB BS · Peter J Reynolds MB BS, FRACOG · E Roscoe Taylor GradDipEpid, MRNZCGP, FAFPHM · Venkat Parameswaran PhD

Objective: To determine whether remoteness category of residence of Indigenous women affects the perinatal outcomes of their newborn infants.Design and participants: A population-based study of 35 240 mothers identified as Indigenous and their 35 658 babies included in the National Perinatal Data Collection in 2001–2004.Main outcome measures: Australian Standard Geographical Classification remoteness category, birthweight, Apgar score at 5 minutes, stillbirth, gestational age and a constructed measure of perinatal outcomes of babies called “healthy baby” (live birth, singleton, 37–41 completed weeks’ gestation, 2500–4499 g birthweight, and an Apgar score at 5 minutes ≥ 7).Results: The proportion of healthy babies in remote, regional and city areas was 74.9%, 77.7% and 77.6%, respectively. After adjusting for age, parity, smoking and diabetes or hypertension, babies born to mothers in remote areas were less likely to satisfy the study criteria of being a healthy baby (adjusted odds ratio [AOR], 0.87; 95% CI, 0.81–0.93) compared with those born in cities. Babies born to mothers living in remote areas had higher odds of being of low birthweight (AOR, 1.09; 95% CI, 1.01–1.19) and being born with an Apgar score < 7 at 5 minutes (AOR, 1.63; 95% CI, 1.39–1.92).Conclusions: Only three in four babies born to Indigenous mothers fell into the “healthy baby” category, and those born in more remote areas were particularly disadvantaged. These findings demonstrate the continuing need for urgent and concerted action to address the persistent perinatal inequity in the Indigenous population.

Simon Graham BIS · Lisa R Jackson Pulver PhD, MPH, GradDipAppEpi · Yueping Alex Wang MB BS; MPH · Paul M Kelly DTM · Paula J Laws BA(Hons) · Narelle Grayson BA(Hons) · Elizabeth A Sullivan MB BS, MPH, MMed(Sexual Health)

Objective: To examine overweight and obesity in Australian children followed through to adulthood.Design and participants: A cohort study of 8498 children aged 7–15 years who participated in the 1985 Australian Schools Health and Fitness Survey; of these, 2208 men and 2363 women completed a follow-up questionnaire at age 24–34 years in 2001–2005.Main outcome measures: Height and weight were measured in 1985, and self-reported at follow-up. The accuracy of self-reported data was checked in 1185 participants. Overweight and obesity in childhood were defined according to international standard definitions for body mass index (BMI), and, in adulthood, as a BMI of 25–29.9 and ≥ 30 kg/m2, respectively, after correcting for self-report error.Results: In those with baseline and follow-up data, the prevalence of overweight and obesity in childhood was 8.3% and 1.5% in boys and 9.7% and 1.4% in girls, respectively. At follow-up, the prevalence was 40.1% and 13.0% in men and 19.7% and 11.7% in women. The relative risk (RR) of becoming an obese adult was significantly greater for those who had been obese as children compared with those who had been a healthy weight (RR = 4.7; 95% CI, 3.0–7.2 for boys and RR = 9.2; 95% CI, 6.9–12.3 for girls). The proportion of adult obesity attributable to childhood obesity was 6.4% in males and 12.6% in females.Conclusion: Obesity in childhood was strongly predictive of obesity in early adulthood, but most obese young adults were a healthy weight as children.

Alison J Venn BSc(Hons), PhD · Russell J Thomson BSc(Hons), PhD · Michael D Schmidt BS, MS, PhD · Verity J Cleland BAppSci(Hons) · Beverley A Curry BSc, MSc · Hanni C Gennat BSc, PhD · Terence Dwyer MB BS, MPH, MD

It is well accepted that heavy alcohol consumption during pregnancy is a risk factor for fetal alcohol spectrum disorder, but research findings for exposure to low to moderate alcohol levels during pregnancy are equivocal, allowing a range of interpretations. The 2001 guideline from the National Health and Medical Research Council (NHMRC) for low-risk drinking for “women who are pregnant or might soon become pregnant” recommends fewer than seven standard drinks per week, and no more than two standard drinks on any one day. This position has polarised health professional and consumer opinion in Australia. The NHMRC guidelines on alcohol are scheduled for review in 2007. We surveyed the alcohol and pregnancy policies and clinical practice guidelines of Australia and six other English-speaking countries to identify current policy. Documents were obtained through Internet searches and direct contact with the relevant organisations. The policies and guidelines varied both across and within countries, and the NHMRC guideline, while not universally supported in Australia, is in step with the policies of the United Kingdom and Canada. Research is needed to elucidate the true association between low to moderate alcohol consumption and fetal harm, the impact of different policies on rates of maternal alcohol consumption during pregnancy, and any untoward outcomes of an abstinence message, to inform and underpin future policy development in Australia.

Colleen M O'Leary BSc, MPH · Louise Heuzenroeder BN, MBA, MPH, MHlthSc · Elizabeth J Elliott MD, FRACP, FRCP, FRCPCH · Carol Bower PhD, FAFPHM, DLSHTM

A roadmap based on initiatives such as producing healthier foods and modifying the built environment may help to tame the beast Unlike the altruistic lion in the famous C S Lewis story, the obesity lion is roaring louder than ever before as it relentlessly expands its territory. The villagers (us) are frankly terrified. Where will it stop? What will it cost? Will it maim and destroy our children? How can we save ourselves? There is much confusion among the villagers. We find that not only are fat people dying earlier and suffering more damage to their body parts and functions, but they are not the jolly souls we were formerly led to believe. On the contrary, they suffer depression if very obese,1,2 and, whether children or adults, experience widespread prejudice, teasing and discrimination on the basis of their size.3-7 As a group, they are less productive than their non-obese counterparts — accounting in Australia for some 4 million days away from work in 2001.8 We know there is a genetic component to obesity, but genes have always been with us and obesity on its current scale is a relatively new phenomenon. We are not sure who or what unleashed the lion. Was it too much food, too little exercise, or the changed combinations and composition of the food we eat? Was it our ever more sedentary workplaces, our passion for cars, our obsession with automatic just-about-everything, or our thoughtless urban design that spelt the death knell for incidental physical activity? Perhaps it was television and e-games. Or should we just blame parents — working mothers are always fair game — and leave it at that? Whatever the vector, or combination of vectors, there is no doubt we are fatter than ever before, but the evidence can be puzzling and we have much to learn. Some suggest our children are more physically active than their counterparts of 20 years ago,9 and the scientific jury is still out on the relative contributions of diet and physical activity to obesity. Intensive lifestyle interventions have been shown to achieve modest but therapeutic weight loss to avert or delay progression to type 2 diabetes by 58% in high-risk individuals,10-11 but we haven’t yet figured out how best to translate this knowledge from a clinical trial setting to the whole population. And, even if we manage to do this, how do we ensure that such programs penetrate beyond the “worried well” to socially disadvantaged people living in areas where fast-food outlets are much more common than in our more affluent communities? We know that our social and physical environment is not conducive to health and slimness, but the political, structural and ideological barriers to changing it seem insurmountable. So, driven by the innate human propensity to do “something rather than nothing” in the face of a crisis, we go to the wardrobe. Will it help if we dress the lion in different clothes? Should we call it a disease? Maybe cloak it under the mantle of a Medicare item or give it a National Health Priority hat? Raising the status of the problem to this level has some compellingly appealing elements, such as attracting attention and funding to resolve it, but there are potential drawbacks. The resultant obesity industry may serve to perpetuate rather than resolve the problem. Pills may moderate the magnitude of the effects of obesity in individuals, but may prove an expensive population option and, even if affordable, will not address its determinants. Physical activity is a natural human function. Will reifying it into something that must be prescribed and supervised enhance or inhibit it? Will the medicalisation of obesity further cloud the issue of whose responsibility it is? Could it absolve individuals from exercising restraint — and perhaps from exercising at all? Could it localise the problem to the health sector and let the all-important transport, agriculture, public works, education and local government sectors off the hook? Perhaps a witch hunt would help. But how far should we go? Everyone would agree that removing so-called “junk food” and sweet drinks from school canteens is a good move, but curtailing the odd sausage sizzle seems puerile in the face of the magnitude of the problem. Banning junk-food advertising to children appears all but inevitable, but, while this may have symbolic merit, there is little evidence that it makes a measurable difference. Moreover, defining junk food is highly complex and may depend on portion sizes, frequency of consumption and relative contribution to total dietary composition and energy intake as much as the nature of the food itself. Advertising, in itself, is neither good nor bad — just a means of communicating a message — but the issues around it are equally convoluted. From a quick check of the Australian Children’s Television Standards,12 anyone can figure out that kids’ prime viewing time (technically termed “C and P [children’s and preschool] classifications”) seems to be a moveable feast, with no explicit nationally standardised real time. And a personal perusal of a few TV guides suggests that there is no mandatory requirement for identifying C and P time on the programming notices from which average parents choose what to let their kids watch. Further, in a rare insight into the real-world nutrition of very young children, Webb et al13 report that toddlers, although too young to be influenced by TV ads, are getting 27% of their caloric intake from hot chips, sweet drinks and other energy forms that one could easily be forgiven for defining as junk food. To top it all off, food manufacturers who wish to opt for responsible advertising to children may be thwarted by the lack of an agreed definition of what constitutes “responsible”. The world has changed. We will never return to the 50s or even the 80s, when sturdy but slim Aussie kids played touch footy and cricket in expansive backyards or on generously proportioned nature strips until their irate mothers menaced them inside to bathe, eat home-cooked “meat and three veg” and do their homework. Healthy school food policies are to be applauded but do not go far enough. There is a lot of time left over outside school hours when our kids frequent shopping mall food halls and local independent fast-food outlets. If we are to truly tame the lion, we need to address the broader environment. Pills, sporting facilities, bans, community education or awareness programs will not be enough. The food manufacturing and advertising industry is an obvious and important vector for obesity and needs substantial re-engineering. We can ban their products appearing on TV, as we did with cigarette ads — which, in tandem with a raft of other strategies, worked brilliantly. But have you noticed lately how many Hollywood productions are peopled with our kids’ idols smoking incessantly? Bans, if applied at all, need to be embedded in a much more comprehensive multi-pronged approach that makes healthy food available and affordable and contemporary forms of incidental physical activity possible and appealing. In a passionate call for a considered and logic-driven response to obesity, Yach et al14 tell us “there is a crucial need to develop a roadmap that defines appropriate interventions based on the causes of obesity at the macro- and microscopic levels from which a coherent prevention plan can be constructed”. What might such a roadmap look like? We could start with a priority-driven research program to fill in our knowledge gaps and guide our interventions. With appropriate emphasis on prevention, health services and social policy research, this might also serve to reinvigorate the public health sector to deal more effectively with the problem. Funding acute care and community care from the same budget stream could encourage greater emphasis on primary and secondary prevention. Maybe we could increase spending on getting more people moving more often if we spent a little less on our elite athletes. And why not provide incentives and disincentives aimed at convincing the food industry to reduce the salt, fat and sugar content of manufactured and processed foods? Or take it a step further and require them to provide health-promoting workplaces for their employees. Speaking of which, why is it that we have occupational health and safety rules to prevent injuries but happily let people sit hunched over computers — barely moving — day after day after day? As part of our roadmap, employers would provide amenities and incentives for people to cycle to work rather than drive, and both employers and trade union representatives would engage in promoting health and protecting our human capital. Consigning the lion out of the village will not be easy. If bans and Medicare items will help, let’s use them. But let’s not throw out with the bathwater the notion of producing healthy fast food and drinks or intelligent design for healthy urbanisation to ensure our towns and cities are walkable, have a health-promoting land-mix use, and encourage active forms of transport. The law could be used, not only for prescriptive legislation and consumer protection, but as a tool for redesigning the policies that shape social determinants of obesity and chronic diseases. This could underpin a cross-sectoral approach addressing food supply, trade, health taxes, incentives and much more. We have a convincing enough economic argument detailing the current and prospective cost of obesity. Let’s concentrate now on what can be saved.

Ruth Colagiuri BEd, Grad Cert Health Policy Management

To the Editor: The recent viewpoint by Kamien1 and letter by Gunasekera2 rightly highlight the benefits of folate fortification and the unlikely occurrence of masking pernicious anaemia. Food Standards Australia New Zealand recently submitted a proposal supporting the mandatory fortification of bread-making flour to increase folate intakes in women of child-bearing age, with the aim of reducing the risk of children being born with neural tube defects.3 This proposal has had extensive public comment and will be considered by the Australia and New Zealand Food Regulation Ministerial Council. Several public groups and individuals continue to raise concerns that higher dietary folate levels could increase B12 deficiency. Our data, collected from a population-based sample of 2596 older people in the Blue Mountains region, from 1997 to 2000, do not suggest that this is a likely outcome. We recently reported the prevalence of low serum vitamin B12 levels in the Blue Mountains Eye Study cohort of people aged 50 years and older. We found that 22.9% had low serum B12 levels (< 185 pmol/L).4 New data from this study show that higher intakes of folate (from diet and supplements) did not increase the likelihood of low serum B12 levels; in fact, people whose diets included folate in the highest quintile of intake had significantly higher serum B12 levels than those consuming lower dietary folate (Box), after accounting for age and sex (P < 0.001). After also adjusting for vitamin B12 from diet and supplements, there was no significant difference in mean serum B12 levels for the various quintiles of folate intake. We also investigated older people who reported consuming high amounts of folate (> 500 μg dietary folate equivalents [DFE] [n = 645] and > 1000 μg DFE [n = 123]) and found higher mean serum B12 levels in these groups than in people who consumed < 500 μg DFE, after adjusting for age and sex (P for trend < 0.001). After further adjustment for vitamin B12 intake, there were no significant differences in mean serum B12 levels for these high dietary folate intakes (Box). We also examined the frequency of macrocytic anaemia in our cohort (n = 6; 0.2%); two of these had low serum B12 levels (0.3% of subjects with low serum B12 levels). In the United States, where mandatory folate fortification began a decade ago, a study of the presence of anaemia in people with B12 deficiency found no significant change in the proportion with anaemia before and after the introduction of mandatory fortification.5 Although many older Australians have low serum levels of vitamin B12, our data show that higher intakes of folate do not increase the likelihood of low serum B12 levels. Given the relatively high prevalence of low serum B12 levels among older people, it would seem reasonable for this to be monitored more frequently in this age group. We suggest that this is not a valid concern that should prevent moves to proceed with mandatory folate fortification of key foods in Australia. Mean serum vitamin B12 levels in a population of older Australians, for various folate intakes (from diet and supplements) (n = 2596) Folate intake Mean serum B12 (95% CI) adjusted for age and sex Mean serum B12 (95% CI) adjusted for age, sex and B12 intake (diet and supplements) Folate (μg DFE) Quintile 1–4 (< 571.8) (n = 2077) 273 (263–289) 278 (267–289) Quintile 5 (> 571.8) (n = 519) 316 (295–337) 297 (275–319) P < 0.001 0.132 Folate cut-points < 500 μg DFE (n = 1828) 273 (261–284) 278 (267–290) 500–1000 μg DFE (n = 645) 294 (276–314) 289 (270–308) > 1000 μg DFE (n = 123) 346 (303–389) 300 (253–348) P for trend < 0.001 0.239 DFE = dietary folate equivalents.

Victoria Flood · Paul Mitchell

To the Editor: The adverse health effects of environmental tobacco smoke (ETS) are well documented. Workplaces are increasingly smoke-free, and restrictions on smoking in restaurants, pubs and clubs are increasing. Paediatricians counsel parents to make their children’s home smoke-free and to smoke outside if they can not quit. In Australia, attention is turning to ETS exposure in cars, in the belief that the confined space may result in increased exposure, even if the windows are wound down. However, few, if any, objective data on the health effects of ETS exposure in cars have been published. We report here the risks of current wheeze at the age of 14 years in children exposed to ETS in their parents’ car. Questionnaire data were available from parents of 1427 children taking part in the 14-year assessment of a longitudinal birth cohort in Perth. Characteristics of the cohort have been described elsewhere.1 Information about current wheeze (defined as the occurrence of wheeze in the previous 12 months) and asthma risk factors, including ETS exposure in the house and car, was obtained. Standard spirometry, methacholine challenge and skin prick tests to local aeroallergens were performed in 1400, 1334 and 1308 children, respectively. Current wheeze was reported in 191 children (14.0%) at the age of 14 years, compared with 537 (38.2%) when they were seen at 6 years of age. Persistent wheeze, at both 6 and 14 years of age, was reported in 145 children (10.2%). ETS exposure in the parents’ car was common. The 14.6% of children who were exposed at 14 years had increased risk of both current wheeze (odds ratio [OR], 1.55; 95% CI, 1.02–2.35; P = 0.038) and persistent wheeze (OR, 2.14; 95% CI, 1.34–3.42; P = 0.001). These risks were higher than those for ETS in the home: for the 8.9% of children exposed in the home, the OR for current wheeze was 1.33 (95% CI, 0.80–2.22; P = 0.27) and the OR for persistent wheeze was 1.98 (95% CI, 1.12–3.50; P = 0.016). Those with current wheeze and ETS exposure in the car had increased methacholine responsiveness: PC20 (provocative concentration required to produce a 20% fall in forced expiratory volume in 1 second) was 5.9 mg/mL in children with ETS exposure compared with 15.2 mg/mL in those not exposed (P = 0.004). These effects were independent of sex and atopic status. These data provide evidence that the community needs to be educated about the adverse health consequences of ETS exposure in cars and suggest that health care professionals should include such education in counselling sessions for families of children with asthma. Teenagers can escape ETS exposure in the home, either by removing themselves or by their parents smoking outside. However, children of this age and younger have no choice but to travel with their parents in the car, especially given the phenomenon of “mum’s taxi” transporting children to school and extracurricular activities. Smoke-free cars are important for all children.

Peter D Sly · Marie Deverell · Merci M Kusel · Patrick G Holt

To the Editor: Refugees are a particularly marginalised group, often originating from countries where immunisation coverage is low.1 As vaccine-preventable diseases such as hepatitis B and measles are endemic in both their countries of origin and the countries in which they spend time in displaced persons camps, the potential burden of disease for refugees is greater than for Australians.2 It is important to determine whether our health systems provide refugees with access to optimal health care, including vaccines. From May 2004, refugee families arriving in Newcastle, New South Wales, have attended the Newcastle Refugee Clinic, where, with the assistance of interpreters, health screening is provided and catch-up vaccination regimens are commenced according to the Australian Standard Vaccination Schedule.3 Vaccines administered are documented in an appropriate personal health record. All age-appropriate vaccines are registered with the Australian Childhood Immunisation Register (ACIR). Families are provided with a copy of the catch-up schedule and, through interpreters, are advised to complete their vaccination schedule through a general practitioner. In NSW, general practices can obtain free vaccines for refugees through public health units. In March and April 2006, there was an outbreak of measles in NSW. A review of ACIR records of refugee children seen over the previous 12 months (May 2005 to April 2006) at our clinic showed that, of the 35 children aged under 7 years, all were overdue for subsequent vaccinations, and only two children had received any additional vaccines after their Refugee Clinic visit. By contrast, vaccination coverage for all children in the Greater Newcastle area is high, and exceeds 90% for scheduled vaccines. Older members of refugee families also required additional vaccines, highlighting concerns that refugee families are not attending general practices for this basic preventive health care measure. While the reasons for this are unclear and need further research, it is likely that multiple factors, including lack of knowledge of the health system, lack of transport, no local government or community vaccination services, and lack of bulk billing by general practices, all play a role. Further, a number of local general practices have closed their books and do not accept new patients. Consequently, catch-up vaccination sessions were conducted at the Refugee Clinic, and transport was provided. Home visits were conducted for families unable to attend these clinics. Seventy-seven people were vaccinated and 209 vaccine doses administered. A thorough assessment of refugees for important medical and psychological conditions is merited soon after they arrive in Australia.4 It is also essential that early access to general practice is secured for continuity of care and completion of vaccination. It is the responsibility of all — the Department of Immigration and Citizenship, contracted resettlement organisations, proposers, public health services and general practitioners — to ensure that vaccinations are accessible to newly arrived refugees. We believe they deserve the same protection against vaccine-preventable diseases as other Australians.

Kylee J Parsons · Maggi Osbourn · David N Durrheim · Murray T Webber

Objective: To characterise a pulmonary tuberculosis (TB) cluster in the Hunter Area of New South Wales using a combination of traditional epidemiological methods and molecular typing.Design, setting and participants: Review of all notifications of TB in the Hunter Area between January 1994 and June 2005, with a detailed analysis of cases among people born in Australia or New Zealand.Main outcome measures: Comparison of genotypes of Mycobacterium tuberculosis isolates; extent of TB cluster.Results: Over the period studied, there were 72 TB notifications among people born in Australia or New Zealand. Genotypic testing was available for 20 of these cases, of which nine were confirmed to be part of a cluster. Two further cases for which genotyping was not available were epidemiologically linked to the cluster and regarded as probable cluster cases. Members of the cluster were relatively young (median age at diagnosis, 35 years; range, 21–57 years), and eight were women. Over the same period, there were 83 TB notifications among people born overseas, the majority being from Asia (47%) or central and eastern Europe (24%) (median age, 54 years; range, 9–63 years).Conclusion: Clinicians should maintain a high index of suspicion for pulmonary TB in a person presenting with a productive cough lasting more than 3 weeks, weight loss, haemoptysis, night sweats and chest pain, even if the person is not overseas-born or elderly. A comprehensive tuberculosis genotyping network at regional and national level in Australia could help identify clusters resulting from recent transmission.

Tony D Merritt MB BS, MPH · Vitali Sintchenko MB BS, FRCPA, PhD · Peter Jelfs BSc · Margaret Worthing RN · Brian Robinson RN, MMSc · David N Durrheim MB ChB, DrPH, FAFPHM · Gwendolyn L Gilbert MD, FRCPA, FRACP

Objective: To assess the evidence of an association between periconceptional folic acid (FA) supplementation or fortification of foods with FA and the risk of twinning, using the Food Standards Australia New Zealand (FSANZ) framework for assessing evidence when substantiating nutrition, health and related claims on foods.Data sources: The Cochrane Library Database, MEDLINE, MEDLINE in Process, EMBASE, PubMed National Library of Medicine, and CINAHL were searched to identify systematic reviews and primary intervention and observational studies published from 1 July 1994 to 7 July 2006.Study selection: One prospective and five retrospective cohort studies that assessed the rate of twinning in populations exposed to FA through supplementation, and six retrospective registry-based cohort studies examining twinning rates after fortification of foods with FA.Data extraction: Two reviewers appraised eligible studies and evaluated data independently.Data synthesis: The best maximal risk estimates of twinning after FA supplementation were an adjusted odds ratio (adjOR) of 1.26 (95% CI, 0.91–1.73) for preconceptional supplementation and dizygotic twinning and an adjOR of 1.02 (95% CI, 0.85–1.24) for overall twinning. Data from four FA fortification studies in the United States that allowed for calculation of an annual percentage increase showed a maximal annual increase in twinning rates of 4.6%.Conclusions: Overall, under the FSANZ framework, there is possible evidence for a relationship between periconceptional FA intake and increased twinning. To support this tentative relationship, more well designed, long-term follow-up studies are needed in places where fortification with FA has been introduced, focusing on dose–response and obtaining accurate data on infertility treatments.

Evelyne E Muggli MPH · Jane L Halliday PhD

Nanomaterials — a wide variety of materials with a diameter of less than 100 nm — have unique properties. Nanotechnology is being promoted as the technology that will drive the next industrial revolution. Nanomaterials may have unique biological activities, but little research has been undertaken to investigate their potential effects on human health and the environment. Many seminal reports have identified gaps in our knowledge, and a large multidisciplinary effort will be required to undertake the necessary research to assist the framing of regulatory models to deal with any novel risks.

Brian G Priestly MPharm, PhD · Andrew J Harford BAppSc, PhD · Malcolm R Sim PhD, FFOM