Research

Objective: To provide an estimate of the morbidity and mortality resulting from abdominal overweight and obesity in the Australian population.Design and setting: Prospective, national, population-based study (the Australian Diabetes, Obesity and Lifestyle [AusDiab] study).Participants: 6072 men and women aged ≥ 25 years at study entry between May 1999 and December 2000, and aged ≤ 75 years, not pregnant and for whom there were waist circumference data at the follow-up survey between June 2004 and December 2005.Main outcome measures: Incident health outcomes (type 2 diabetes, hypertension, dyslipidaemia, the metabolic syndrome and cardiovascular diseases) at 5 years and mortality at 8 years. Comparison of outcome measures between those classified as abdominally overweight or obese and those with a normal waist circumference at baseline, and across quintiles of waist circumference, and (for mortality only) waist-to-hip ratio.Results: Abdominal obesity was associated with odds ratios of between 2 and 5 for incident type 2 diabetes, dyslipidaemia, hypertension and the metabolic syndrome. The risk of myocardial infarction among obese participants was similarly increased in men (hazard ratio [HR], 2.75; 95% CI, 1.08–7.03), but not women (HR, 1.43; 95% CI, 0.37–5.50). Abdominal obesity-related population attributable fractions for these outcomes ranged from 13% to 47%, and were highest for type 2 diabetes. No significant associations were observed between all-cause mortality and increasing quintiles of abdominal obesity.Conclusions: Our findings confirm that abdominal obesity confers a considerably heightened risk for type 2 diabetes, the metabolic syndrome (as well as its components) and cardiovascular disease, and they provide important information that enables a more precise estimate of the burden of disease attributable to obesity in Australia.

Adrian J Cameron MPH · David W Dunstan PhD · Neville Owen PhD · Paul Z Zimmet MD, PhD · Elizabeth L M Barr MPH · Andrew M Tonkin MD · Dianna J Magliano PhD · Shirley G Murray GradDipPractMan · Timothy A Welborn PhD · Jonathan E Shaw MD

Objective: To investigate the frequency, goals and outcomes of second-opinion consultations at the Sydney Cancer Centre.Design, setting and participants: A questionnaire-based study of patients who registered to see a medical oncologist at the Sydney Cancer Centre between January 2006 and January 2008 and who were seeking a second opinion.Main outcome measures: Proportion and demographic characteristics of patients who had previously seen a medical oncologist and who stated they were seeking a second opinion.Results: 123 of 1892 new patients (6.5%) stated that they were seeking a second opinion, of whom 22 declined study participation, were excluded from study participation or had been referred specifically for enrolment in a particular clinical trial. Of the remaining 101 patients, 77 completed a questionnaire; 59 were women and 26 had a university degree. Reasons for seeking second opinions included: to obtain information related to treatment (54 patients), for reassurance about diagnosis or treatment (47), and dissatisfaction with the information given by the first medical oncologist (24). Sixty-four patients reported that they received new information at the second-opinion consultation, with 45 identifying discussion of treatment options and 34 identifying discussion of future or prognosis. Fifty-one patients reported how the second-opinion consultation differed from the first, identifying it as longer (24), and indicating that the oncologist answered concerns (26). Most patients were aware of multidisciplinary teams and treatment guidelines, but fewer had read guidelines.Conclusions: Patients seeking a second opinion from a medical oncologist are typically more educated, younger and female, probably due to preferences for more detailed information. The most common reasons for seeking a second opinion were to obtain additional information or reassurance about recommended management.

Martin H N Tattersall MD, MSc, FRACP · Rachel F Dear MB BS, FRACP · Jesse Jansen MA, PhD · Heather L Shepherd PhD · Rhonda J Devine RN · Lisa G Horvath MB, FRACP, PhD · Michael J Boyer MB, FRACP, PhD

Objective: To assess the impact of introducing a publicly funded infant rotavirus vaccination program on disease notifications and on laboratory testing and results.Design and setting: Retrospective analysis of routinely collected data (rotavirus notifications [2006–2008] and laboratory rotavirus testing data from Queensland Health laboratories [2000–2008]) to monitor rotavirus trends before and after the introduction of a publicly funded infant rotavirus vaccination program in Queensland in July 2007.Main outcome measures: Age group-specific rotavirus notification trends; number of rotavirus tests performed and the proportion positive.Results: In the less than 2 years age group, rotavirus notifications declined by 53% (2007) and 65% (2008); the number of laboratory tests performed declined by 3% (2007) and 15% (2008); and the proportion of tests positive declined by 45% (2007) and 43% (2008) compared with data collected before introduction of the vaccination program. An indirect effect of infant vaccination was seen: notifications and the proportion of tests positive for rotavirus declined in older age groups as well.Conclusions: The publicly funded rotavirus vaccination program in Queensland is having an early impact, direct and indirect, on rotavirus disease as assessed using routinely collected data. Further observational studies are required to assess vaccine effectiveness. Parents and immunisation providers should ensure that all Australian children receive the recommended rotavirus vaccine doses in the required timeframe.

Stephen B Lambert MB BS, MAppEpid, FAFPHM · Cassandra E Faux MSc(ClinMicro) · Lisa Hall BTech(BiomedSc)(Hons), PhD · Frances A Birrell MPH, MAppEpid, GCSc(Stats) · Karen V Peterson DipT, BEd, MHlthSc · Christine E Selvey MB BS, MSc · Theo P Sloots BSc, GradCertMgt, PhD · Michael D Nissen BMedSc, FRACP, FRCPA · Keith Grimwood MD, FRACP

Objectives: To examine the levels and predictors of injection of buprenorphine–naloxone (BNX) — a combination of a partial opioid agonist and an opioid antagonist for treating opioid dependence — which was specifically developed to limit injecting. Comparison was made with injecting of two other opioid substitution treatment medications, methadone and buprenorphine (BPN); severe harms have been documented after injection of the latter.Design and participants: Injecting was studied in regular injecting drug users (“IDUs”) and current opioid substitution treatment clients (“clients”). Regular IDUs are interviewed annually in each Australian capital city (about 900 per year) and data for 2003–2007 were used; 399 clients were interviewed in 2007. Data on injection of opioid substitution treatment medications between 2003 and 2007 were adjusted for availability of medications (from national sales data for methadone, BPN and BNX). Predictors of injecting were analysed by multiple regression analyses.Setting: Capital cities of all Australian states and territories.Main outcome measure: Injection of opioid substitution treatment medications among individuals both in and out of treatment.Results: In the year after its introduction in Australia, BNX was injected less frequently and by fewer regular IDUs and clients compared with BPN, particularly when differences in the availability of medications were taken into account. Some individuals did nonetheless regularly inject BNX. Injection of methadone, BPN and BNX was more likely to occur among those injecting other pharmaceutical opioids.Conclusions: A partial opioid agonist–antagonist combination appears to be less commonly and less frequently injected by clients in treatment and IDUs who are not. Further studies are needed to evaluate longer-term trends in use and harms.

Louisa Degenhardt PhD, MPsych(Clinical) · Briony K Larance BSc(Psych)(Hons) · James R Bell FRACP, MD, FAChAM · Adam R Winstock MSc, MRCPsych, FAChAM · Nicholas Lintzeris MB BS, PhD, FAChAM · Robert L Ali MB BS, FFPHM, FAChAM · Nicolas Scheuer PGDipEconometrics, BAppEconometrics · Richard P Mattick PhD, MPsych(Clinical)

Objective: To examine the response of the Victorian State Trauma System to the February 2009 bushfires.Design and setting: A retrospective review of the strategic response required to treat patients with bushfire-related injury in the first 72 hours of the Victorian bushfires that began on 7 February 2009. Emergency department (ED) presentations and initial management of patients presenting to the state’s adult burns centre (The Alfred Hospital [The Alfred]) were analysed, as well as injuries and deaths associated with the fires.Results: There were 414 patients who presented to hospital EDs as a result of the bushfires. Patients were triaged at the emergency scene, at treatment centres and in hospital. National and statewide burns disaster plans were activated. Twenty-two patients with burns presented to the state’s burns referral centres, of whom 18 were adults. Adult burns patients at The Alfred spent 48.7 hours in theatre in the first 72 hours. There were a further 390 bushfire-related ED presentations across the state in the first 72 hours. Most patients with serious burns were triaged to and managed at burns referral centres. Throughout the disaster, burns referral centres continued to have substantial surge capacity.Conclusions: Most bushfire victims either died, or survived with minor injuries. As a result of good prehospital triage and planning, the small number of patients with serious burns did not overload the acute health care system.

Peter A Cameron MB BS, MD, FACEM · Biswadev Mitra MB BS, MHSM, FACEM · Mark Fitzgerald MB BS, FACEM · Carlos D Scheinkestel FRACP, FJFICM, DipDHM · Andrew Stripp BBSc(Hons), MSc · Chris Batey CCRN · Louise Niggemeyer RN, ICCert, MEd · Melinda Truesdale MB BS, FACEM, GradDipHSM · Paul Holman ASM, GradDipHealthAdmin, MACAP · Rishi Mehra MB BS, PGDipEcho, FANZCA · Jason Wasiak MPH, BN, GradDipCritCareNurs · Heather Cleland MB BS, FRACS

Objective: To understand the current organisation of services for people with transient ischaemic attack (TIA) and the processes of assessment and management across Australian hospitals.Design and setting: Cross-sectional survey in 2008 of 134 Australian hospitals, mostly urban centres that treat large numbers of stroke patients.Main outcome measures: Survey questions covered assessment, early management and follow-up practices, as well as organisation of services for TIA.Results: Seventy-four hospitals (55%) responded: 47 (64%) reported access to a stroke unit, and 19 (26%) to a specialist clinic for TIA. Initial assessment included blood tests, electrocardiogram and brain computed tomography at most sites (92%–94%), and carotid imaging at more than half (65%), but magnetic resonance imaging at only 3% of sites. A tool to stratify the risk of subsequent stroke was used at 38 sites (51%), more commonly in hospitals with a stroke unit than in those without such a unit (64% v 30%; P = 0.005). Treatment was initiated at the initial assessment at 42 sites (58%), more commonly at stroke unit than non-stroke unit sites (68% v 37%; P = 0.007). Formalised policies for management of TIA patients were used at 38 sites (54%), with clear differences between sites with a stroke unit and those without (70% v 25%; P < 0.001).Conclusion: Access to rapid assessment and management services for TIA varies considerably between Australian hospitals. The presence of organised stroke care at a hospital leads to improved processes of care for patients presenting with TIA.

Christopher J Price BSc, BSW · David J Blacker MB BS, FRACP · Rohan S Grimley MB BS, BScMed, FRACP · Helen M Dewey PhD, FRACP, FAFRM(RACP) · Richard P Gerraty MD, FRACP · Simon A Koblar BM BS, FRACP, PhD · Sonia M Denisenko BPhys, MPH · Catherine E Storey MB BS, MSc, FRACP · Christopher F Bladin MB BS, MD, FRACP · Kelvin M Hill BApplSci(Physiotherapy), GradDipBusComm

Objective: To evaluate a non-invasive molecular test using free circulating fetal DNA in maternal plasma to predict the fetal RHD type.Design: A prospective cohort study.Participants and setting: Venous blood samples were collected from 140 Rhesus (Rh) D-negative women booked for antenatal care in two tertiary maternity hospitals in Sydney and Brisbane between November 2006 and April 2008. Cell-free DNA, including free maternal and fetal DNA, was extracted from maternal plasma in the tertiary Australian Red Cross Blood Service laboratory, and three exon regions of the RHD gene were amplified.Main outcome measures: Comparison of the predicted fetal RHD status and the infant’s RhD serotype. Secondary analysis involved using SRY and RASSF1A assays as internal controls to confirm the presence of fetal DNA in RHD-negative samples.Results: Of 140 samples tested, results for RHD status were assigned for 135, and all 135 predictions were correct. A result was not assigned in five cases: three did not meet strict threshold criteria for classification, and two were due to RHD variants. Fetal SRY status was correctly predicted in 137 of 140 cases. In 16 samples typed both RHD- and SRY-negative, a positive RASSF1A result verified the presence of fetal DNA.Conclusions: Non-invasive testing of multiple exons provides a robust method of assessing fetal RHD status, and provides a safer alternative to amniocentesis for the management of RhD-negative pregnant women who are isoimmunised.

Catherine A Hyland PhD, MSc · Glenn J Gardener MB BS, DipRACOG, FRANZCOG · Helen Davies BSc, GDPH · Minna Ahvenainen BSc · Robert L Flower PhD, MSc · Darryl Irwin PhD, MIndProp, BAppSc · Jonathan M Morris MB ChB, FRANZCOG, PhD · Christopher M Ward MB ChB, PhD, FRACP · Jonathan A Hyett MB BS, MRCOG, FRANZCOG

The future of academic medicine in Australia has been identified as a significant issue, but received little mention in the interim report of the National Health and Hospitals Reform Commission. Australia is at particular risk of failing to capitalise on what is happening globally with academic medicine. New “partnerships” between health services, universities and health research institutes should be encouraged for stimulating research and learning across the health sector. Such partnerships can drive translational research, provide full costing of research, and establish national and international networks of researchers and research funding. There are many interactions between Australian state and federal jurisdictions and their hospitals and primary care organisations, but these are often loosely coordinated and with little understanding of how universities and research institutes can help to deliver better and more efficient health care. Academic health science centres, as recently designated by the National Health Service in the United Kingdom, provide a useful model for consideration in Australia.

Peter M Brooks MD, FRACP, FAFRM

Objectives: To determine whether redesign of pathology processes, including indicators of sample priority, could reduce patient length of stay (LOS) in an emergency department (ED), and assess the long-term impact of two indicators of sample priority on pathology clinical performance indicators for ED samples.Design, setting and participants: Two observational studies of de-identified data from standard databases were conducted — a single-site pilot trial of patients attending the ED of one hospital compared with historical controls, and a multisite study of 132 521 full blood count (FBC) requests for patients attending seven EDs that utilised either of two pathology process changes (coloured specimen transport bags alone, or coloured specimen bags plus blood tubes with a priority indicator).Main outcome measures: LOS in the ED was measured for the pilot trial, and collected-to-validated times for FBCs that fulfilled computer algorithm validation rules were measured for the multisite study.Results: In the pilot trial, the redesigned pathology process resulted in a 29-minute reduction (15.6%) in the median ED LOS for all patients (P < 0.001) compared with historical controls. In the multisite study, use of coloured specimen bags plus blood tubes with a priority indicator resulted in an 8-minute reduction (20.1%) in mean collected-to-validated times for FBC requests compared with FBC requests that used coloured specimen bags alone (P < 0.001).Conclusions: Our pilot trial revealed a direct relationship between pathology process design and LOS in the ED, suggesting that redesigned pathology processes can significantly reduce LOS in the ED. Our multisite study showed that collecting samples directly into blood tubes with an incorporated priority indicator reduces pathology test turnaround times. These data suggest that LOS in the ED can be significantly reduced by simple changes to pathology processes, such as collecting samples directly into specimen containers with an incorporated priority indicator.

Andrew J Francis MB BS(Hons), FRCPA · Michael J Ray PhD, BAppSc(Medical Technology) · Mary C Marshall BAppSc(Biology), GradDip Professional Communications

Objective: To characterise epidemiological, clinical and laboratory features of children in New South Wales with chronic hepatitis B (HBV) or C (HCV) infections.Design and setting: Retrospective record review of epidemiological, clinical, laboratory, liver biopsy and treatment data for children (aged < 18 years) referred to tertiary referral paediatric and refugee clinics in NSW with chronic HBV or HCV during 2000–2007; and comparison with NSW Health notification data for the same period.Main outcome measures: Numbers and characteristics of referred children with HBV and HCV, and notifications to NSW Health.Results: During 2000–2007, 79 children with chronic HBV and 29 with HCV infection were referred to specialist clinics, while 930 children with HBV and 777 with HCV infection were reported to NSW Health. Most of the referred children with HBV were born overseas, while most with HCV were born in Australia to mothers with a history of intravenous drug use. Of the 79 HBV-infected children, 56 were e-antigen positive. Most HCV-infected children (23/29) had alanine aminotransferase levels ≤ 2 times the upper limit of normal, and more than half of those who had genotype determined had type 2 or 3. Fibrosis was evident in liver biopsies performed for both HBV and HCV.Conclusions: Although advanced liver disease was uncommon in children referred with HBV or HCV infection, a large number of infected children in NSW were not referred for specialist medical care, indicating that opportunities to intervene early in the natural history of these infections, particularly HCV, are being missed.

Scott Nightingale BMed(Hons), MClinEpid, FRACP · Michael O Stormon MB BS, FRACP · Andrew S Day MD, FRACP · Murray T Webber BMed, FRACP · Kate A Ward BPhty(Hons), MPH · Edward V O’Loughlin MD, FRACP

Objective: To determine whether there is an association between compensation factors and health care utilisation following major trauma.Design and setting: Retrospective cohort study within a major metropolitan trauma centre in New South Wales.Participants: Major trauma patients aged ≥ 18 years, admitted between May 1999 and April 2004. Patients were included if they had an accidental injury and an Injury Severity Score > 15. In total, 355 of 582 potentially contactable patients returned completed questionnaires (response rate, 61%).Main outcome measure: Health care utilisation, defined as the number of times patients visited specified health care professionals (general practitioners, medical specialists, psychiatrists, physiotherapists, chiropractors and massage therapists) in the previous 3 months. For statistical analysis, health care utilisation was dichotomised into low and high (0–3 or ≥ 4 health care visits over the previous 3 months).Results: Health care utilisation was significantly higher for patients engaging the services of a lawyer (odds ratio, 3.3; 95% CI, 2.0–5.5; P < 0.001) after allowing for time since injury, chronic illness, presence of a head injury and employment status. Having a head injury and increased time since injury were significantly associated with lower health care utilisation, whereas being unemployed and having a chronic illness were associated with higher health care utilisation.Conclusion: Compensation-related factors are significant predictors of health care utilisation in a major trauma population.

Ian A Harris MB BS, MMed(ClinEpid), PhD · Darnel F Murgatroyd MScHSci(ManipPhysio), DipPhysio · Ian D Cameron MB BS, PhD, FAFRM · Jane M Young MB BS, MPH, PhD · Michael J Solomon MB ChB, MSc, FRACS

Objective: To compare the clinical effectiveness of point-of-care testing (PoCT) and that of pathology laboratory testing, as measured by therapeutic control in chronic conditions.Design: Multicentre, cluster randomised controlled trial using non-inferiority analysis.Setting: 53 Australian general practices in urban, rural and remote areas across three Australian states, September 2005 to February 2007.Participants: 4968 patients with established type 1 or type 2 diabetes, established hyperlipidaemia, or taking anticoagulant therapy.Intervention: The intervention group (3010 patients in 30 practices) had blood and urine samples tested by PoCT devices in their general practices, and the control group (1958 patients in 23 practices) had samples tested by their usual pathology laboratories. Main outcome measures: The proportion of patients and of tests with results in the target range, and change in test results from baseline.Results: For the proportion of patients with results in the target range, PoCT was found to be non-inferior to pathology laboratory testing for measuring glycated haemoglobin (HbA1c), urine albumin, albumin–creatinine ratio (ACR), total cholesterol and triglyceride levels but not for high-density lipoprotein (HDL) cholesterol level and international normalised ratio (INR). For the proportion of tests with results in the target range, PoCT was found to be non-inferior to pathology laboratory testing for measuring all variables except HDL cholesterol. For the proportion of patients showing an improvement in their test result from baseline, PoCT was non-inferior to pathology laboratory testing for HbA1c, total cholesterol and triglyceride levels, but not for HDL cholesterol level.Conclusions: This study provides important evidence for those considering the introduction of PoCT into general practice. For all tests except INR and HDL cholesterol, the PoCT approach demonstrated the same or better clinical effectiveness than pathology laboratory testing.Trial registration: Australian Clinical Trials Registry ACTRN12612607000628448.

Tanya K Bubner GradDipHlthServMg, BSocSc(HumServ) · Caroline O Laurence PhD, MHlthServMg · Angela Gialamas BHSc · Lisa N Yelland BMa, CompSc(Hons) · Philip Ryan MB BS · Kristyn J Willson BSc(Hons) · Philip Tideman FRACP · Paul Worley MB BS, PhD · Justin J Beilby MD

Integration of research and education into health care delivery leads to improved outcomes and facilitates rapid translation of results into policy and practice. Australia is at great risk of losing the important contribution of clinical research conducted in our public hospital system. This risk is increasing as research and educational training are targeted for expenditure reduction in the current business models of health service delivery, which focus only on short-term outcomes. The Centres of Clinical Research Excellence Scheme — initiated by the National Health and Medical Research Council (NHMRC) — is an excellent step towards redressing this problem, but it cannot succeed in isolation. We must improve and optimise care through promotion of attractive sustainable career pathways to provide strong clinical and translational research capabilities in hospital settings that address current health priorities and new disciplines. Targeted investment in talented people is the greatest long-term contribution that governments can make to guarantee quality in national systems of health.

Graham V Brown PhD, FRACP, MPH · Tania C Sorrell MD BS, FRACP

Objective: Design, setting and participants: A population-based study of 789 240 term singleton births in public and private hospitals in 2001–2004, using data from the National Perinatal Data Collection.Main outcome measures: Third- and fourth-degree perineal injury, requirement for high level of neonatal resuscitation, Apgar score < 7 at 5 minutes, admission to neonatal intensive care unit or special care nursery, and perinatal death.Results: 31.4% of the term singleton births occurred in private hospitals. After adjusting for maternal age, Indigenous status, parity, smoking status, diabetes, hypertension, remoteness of usual residence, and method of birth, the rates of all adverse outcomes studied were higher for public hospital births. For women, the adjusted odds ratio (AOR) for third- or fourth-degree perineal injury was 2.28 (95% CI, 2.16–2.40). For babies, the odds of a high level of resuscitation (AOR, 2.37; 95% CI, 2.17–2.59), low Apgar score (AOR, 1.75; 95% CI, 1.65–1.84), intensive care requirement (AOR, 1.48; 95% CI, 1.45–1.51) and perinatal death (AOR, 2.02; 95% CI, 1.78–2.29) were all higher in public hospitals.Conclusion: For women delivering a single baby at term in Australia, the prevalence of adverse perinatal outcomes is higher in public hospitals than in private hospitals.

Stephen J Robson MPH, MD, FRANZCOG · Paula Laws BAppPsych(Hons) · Elizabeth A Sullivan MB BS, MPH, MMed(Sexual Health)

Objective: To investigate sociodemographic variation in antidepressant utilisation.Design and setting: Cross-sectional analysis of antidepressant prescription under the Pharmaceutical Benefits Scheme in Australia, 2003–2005.Main outcome measures: Antidepressant utilisation (defined daily dose/1000/day) by sex, age, socioeconomic status (SES) and geographichal area.Results: Total antidepressant utilisation increased with age. Among those aged ≥ 15 years, female utilisation was about double that of males. About half of antidepressant utilisation was accounted for by sertraline, venlafaxine, citalopram, and paroxetine. SES differentials in antidepressant utilisation changed across age groups for males and females: among those aged ≤ 19 years, total antidepressant utilisation was significantly less in lower SES groups (P < 0.001); there was no relationship to SES among 20–29-year-olds; and among those aged ≥ 30 years, antidepressant utilisation was significantly higher in lower SES groups (P < 0.001). SES differences were attenuated after adjusting for urban or rural residence, but remained statistically significant. Antidepressant utilisation rates were highest in regional centres.Conclusion: Antidepressant utilisation in Australia partially reflects sociodemographic differences in the prevalence of affective disorder. Discrepancies between treatment provision and treatment need suggest that not all social strata in Australia have equal access to these treatments.

Andrew N Page BA(Psych)(Hons), PhD · Sarah Swannell BPsych(Hons), GradCertBiostat · Graham Martin MD, FRANZCP, DPM · Samantha Hollingworth BSc, MPH, PhD · Ian B Hickie MB BS, FRANZCP, MD · Wayne D Hall BSc, PhD

Objectives: To identify the incidence of self-reported harmful adverse events in the health care of community-dwelling adults, and to examine attitudes about safety in the health system.Design: Cross-sectional, population-based survey.Participants and setting: Analysis of data from 3522 adults participating in Stage 2 of the North West Adelaide Health Study, who were surveyed in 2004 and 2005.Main outcome measures: Self-reported adverse events causing harm in the past year; attitudes to safety in health care, including adequacy of current measures for preventing adverse events, and the effect of groups like patients themselves, doctors and governments on patient safety.Results: The annual incidence of self-reported harmful adverse events was 4.2%. The main types were medication error (45.5%) and misdiagnosis or wrong treatment (25.6%). Multiple logistic regression showed that self-reported harmful adverse events were more likely in people who had been hospitalised in the past 12 months (odds ratio [OR], 2.5; 95% CI, 1.9–3.4), those who had low annual income (< $12 000), those who completed higher education to the level of Bachelor degree or higher (OR, 3.0; 95% CI, 1.0–9.4), and those who had some level of dissatisfaction with their recent health care; and less likely in those more risk-averse rather than those with a tendency to risk-taking behaviour (OR, 0.6; 95% CI, 0.4–0.9). People were more likely to believe that individual health care professionals had a positive effect on safety than professional groups or government, and that more resources were the key to improving the safety of health care.Conclusion: We found an incidence of self-reported harmful adverse events that was significantly lower than that found by a 2002 Australian survey (4.2% v 6.5%; P = 0.009). Better communication to help patients acquire more realistic risk perception may help reduce harm. Better communication could also increase public advocacy for systems improvement in safety to counter persisting community beliefs that individual action alone can redress the situation.

Robert J Adams MD, FRACP · Graeme Tucker BSc · Kay Price RN, MA, PhD · Catherine L Hill MB BS, BS(Epid), FRACP · Sarah L Appleton BSc · David H Wilson BEd, MPH, PhD · Anne W Taylor MPH, PhD · Richard E Ruffin MB BS, MD, FRACP

Objective: To determine the rate of perinatal hepatitis B virus (HBV) transmission in an Australian setting and to identify maternal virological factors associated with highest risk of transmission.Design, participants and setting: A prospective, observational study of perinatal transmission of HBV. Participants were pregnant women attending Sydney South West Area Health Service antenatal clinics who tested positive for hepatitis B surface antigen (HBsAg), and their babies. All babies were routinely offered hepatitis B immunoglobulin (HBIG) and HBV vaccination. Babies positive for HBsAg at 9-month follow-up underwent further virological testing, including HBV DNA sequencing. The study was conducted between August 2002 and May 2008.Main outcome measures: HBV DNA levels and demographic characteristics of HBsAg-positive pregnant women; proportion of their infants with active HBV infection at 9-month follow-up; maternal characteristics affecting transmission rate; HBV DNA sequencing of infected infants and their mothers.Results: Of 313 HBsAg-positive pregnant women, 213 (68%) were HBV DNA-positive and 92 (29%) were positive for hepatitis B “e” antigen (HBeAg); 138 babies born to HBV DNA-positive mothers were tested for HBV infection (HBsAg positivity) at about 9 months of age. Four cases of transmission were identified. All four mothers had very high HBV DNA levels (> 108 copies/mL) and were HBeAg-positive. Three of the four infants were infected with wild-type HBV strains, with identical maternal/infant isolates. The fourth mother–infant pair had an S gene variant, HBV D144E, which has been previously reported in association with vaccine/HBIG escape. (Unfortunately, HBIG was inadvertently omitted from the immunisation schedule of this infant.) Transmission rates were 4/138 (3%) from HBV DNA-positive mothers overall, 4/61 (7%) from HBeAg-positive mothers, and 4/47 (9%) from mothers with very high HBV DNA levels. No transmission was seen in 91 babies of mothers with HBV DNA levels < 108 copies/mL.Conclusion: In this cohort, HBV perinatal transmission was restricted to HBeAg-positive mothers with very high viral loads.

Elke Wiseman MB BS, FRACP, PhD · Melissa A Fraser RN(Hons), GradDipInfectCont · Sally Holden · Anne Glass RN · Bronwynne L Kidson RN · Leon G Heron MB ChB, FRCPA, FAFPHM · Michael W Maley MB BS, FRCPA, FRACP · Anna Ayres BSc(Hons) · Stephen A Locarnini BSc(Hons), MB BS, PhD · Miriam T Levy MB BS, FRACP, PhD

Objective: To collect nationally representative epidemiological data on early-onset eating disorders (EOEDs) in children.Design: Prospective, active surveillance using the Australian Paediatric Surveillance Unit with key informant design.Setting: Child health specialists in Australia (July 2002 to June 2005).Patients: Incident cases of EOEDs in children aged 5–13 years.Main outcome measures: Disease rates, demographic characteristics, clinical features and complications, hospitalisation, psychological comorbidity, and concordance of clinical features with Diagnostic and statistical manual of mental disorders, fourth edition (DSM-IV) criteria.Results: We identified 101 children aged 5–13 years with EOEDs (median age, 12.2 years; range, 5.5–13.9 years), of whom one in four were boys. Most were hospitalised (78%), and the mean duration of hospitalisation was 24.7 days (range, 1–75 days). More than 70% of inpatients were admitted to specialised eating disorder units in paediatric teaching hospitals. Among inpatients, 37% met DSM-IV diagnostic criteria for anorexia nervosa; although 61% had life-threatening complications of malnutrition, only 51% met weight criteria. Psychological symptoms were similar to those in adults with anorexia nervosa: 67% of inpatients met both psychological diagnostic criteria for anorexia nervosa (fear of weight gain/fatness and misperception of body shape). Of 19 postmenarchal girls, 18 had secondary amenorrhoea. Nasogastric feeding was used in 58% of inpatients, and 34% received psychotropic medications.Conclusions: This is the first prospective national study of EOEDs. It demonstrates the limitations of applying DSM-IV diagnostic criteria for anorexia nervosa to young children; the high proportion of boys affected by EOEDs; and the significant psychological comorbidity and high frequency of hospitalisation associated with EOEDs. Potentially life-threatening medical complications are common at presentation, suggesting possible missed diagnoses and a need for education of health professionals. The study underlines the severity of EOEDs and the need for joint medical and psychiatric specialist management.

Sloane Madden MB BS(Hons), FRANZCP, CAPCert · Anne Morris MB BS, MPH, FRACP · Yvonne A Zurynski BAppSc, MAppSc, PhD · Michael Kohn MB BS, FRACP · Elizabeth J Elliot MD, FRACP, FRCPCH

Objective: To describe the pattern of perinatal HIV exposure and outcomes among children born in Australia, 1982–2006.Design and setting: National surveillance for perinatal HIV exposure.Participants: Women with HIV infection and their perinatally exposed children.Main outcome measures: Trends in the age-standardised rate of perinatal exposure, uptake of interventions by women with an antenatal HIV diagnosis, and rate of mother-to-child transmission.Results: Between 1982 and 2006, there were 354 reported cases of perinatal HIV exposure among children born in Australia. The age-standardised rate of perinatal exposure per 100 000 live births increased from 2.3 (1982–1986) to 5.1 (1991–1998), 9.9 (1999–2002) and 8.3 (2003–2006). Among children whose mother was diagnosed antenatally, the mother-to-child transmission rate declined significantly, from 25% (4/16; 95% CI, 7%–52%) in 1987–1990 to 5% (4/82; 95% CI, 1%–12%) in 2003–2006 (P < 0.001). The rate declined from 8% (4/51; 95% CI, 2%–19%) in 1987–1998 to 1% (2/151; 95% CI, 0.2%–5%) in 1999–2006 among children whose mother used at least two interventions. Mother-to-child transmission remained high among children born to women diagnosed postnatally (39/87, 45%; 95% CI, 34%–56%) and to women diagnosed antenatally who used no interventions (7/15, 47%; 95% CI, 21%–73%).Conclusion: The increasing rate of perinatal exposure and the decreasing rate of mother-to-child transmission among children whose mothers’ HIV infection was diagnosed antenatally were temporally associated with use of interventions for minimising mother-to-child transmission. Mother-to-child transmission remained high when the mother’s HIV infection was not known during pregnancy.

Ann M McDonald BSc, MPH · Yvonne A Zurynski PhD · Handan C Wand PhD · Michelle L Giles MB BS(Hons), FRACP · Elizabeth J Elliott MD, FRCP, FRCPCH · John B Ziegler MD, FRACP, FRCPCH · John M Kaldor PhD

Objective: To investigate the incidence of bicycling injuries and bicycle injury characteristics in the Victorian population.Design: Review of prospectively collected data.Setting: Bicycling injury data were extracted from four datasets for the period July 2001 to June 2006: (i) emergency department (ED) presentations from the Victorian Emergency Minimum Dataset; (ii) hospital admissions from the Victorian Admitted Episodes Data Set; (iii) major trauma cases from the Victorian State Trauma Registry (VSTR); and (iv) deaths from the National Coroners Information System.Main outcome measures: The profile and incidence of bicycling injuries across the datasets and years.Results: In the 5 years, 25 920 bicycle-related ED presentations were recorded, 10 552 bicyclists were admitted to hospital, 298 bicycling injuries were classified as major trauma (VSTR), and there were 47 bicycling fatalities. From 2001 to 2006, the incidence of bicycle-related ED presentations (incidence rate ratio [IRR] = 1.42; 95% CI, 1.37–1.48), hospital admissions (IRR = 1.16; 95% CI, 1.09–1.23) and major trauma (IRR = 1.76; 95% CI, 1.22–2.55) increased significantly. Most of those injured were males, aged < 35 years, with road-related injuries. Patients classified as having major trauma had a significantly higher incidence of trunk and head/face/neck injuries compared with those presenting to an ED or admitted to hospital.Conclusion: The incidence of serious bicycling injury has risen over recent years, highlighting the need for targeted prevention programs. Accurate data on cycling participation, use of injury prevention strategies, and injury profiles would assist in reducing bicycle-related injury.

Mirjana Sikic MB BS · Antonina A Mikocka-Walus MA(Psych), MA(Int Relations), PhD · Belinda J Gabbe BPhysio(Hons), MAppSc, PhD · Francis T McDermott MD(Monash), FRACS, FACS · Peter A Cameron MB BS, MD, FACEM

Objective: To determine the number of older Western Australians who had a gastrostomy tube (GT) placement from 1994 to 2004, to describe their characteristics, and to examine outcomes after GT placement, including rehospitalisation for complications and survival.Design and data sources: Secondary analysis of hospital (inpatient) data and linked mortality data from the WA Data Linkage System.Main outcome measures: Patient characteristics (age, sex and morbidity profile); numbers of GT closures, replacements and complications within 1 year of GT placement; age- and sex-specific survival outcomes calculated at 7, 30, 60 and 180 days, and 1 and 3 years; and mortality hazard ratios calculated for six conditions of interest, identified using all available diagnosis information on the inpatient record.Results: In Western Australia, 2023 people aged 65 years or older underwent a GT placement for the first time during the period 1994–2004, half of whom had a known history of cerebrovascular disease (50.3%). Rehospitalisation within 1 year for a GT replacement procedure, mechanical complications and incident pneumonitis occurred in 13%, 4% and 9% of patients, respectively. More than half of the patients who underwent a GT placement died within 1 year. Survival outcomes were poorest for patients with motor neurone disease and metastatic cancer.Conclusion: To better understand this complex area of health care, questions regarding decision making — by patients, families, physicians, hospitals and other caring organisations — about GT placement and maintenance need to be addressed.

Janine Calver PhD · Kieran A McCaul PhD · Melinda Burmas BCM · Barbara J Horner PhD · Leon Flicker MB BS, PhD, FRACP

Objective: To estimate the incidence and survival rates of acute myocardial infarction (AMI) for Northern Territory Indigenous and non-Indigenous populations.Design and participants: Retrospective cohort study for all new AMI cases recorded in hospital inpatient data or registered as an ischaemic heart disease (IHD) death between 1992 and 2004.Main outcome measures: Population-based incidence and survival rates by age, sex, Indigenous status, remoteness of residence and year of diagnosis.Results: Over the 13-year study period, the incidence of AMI increased 60% in the NT Indigenous population (incidence rate ratio [IRR], 1.04; 95% CI, 1.02–1.06), but decreased 20% in the non-Indigenous population (IRR, 0.98; 95% CI, 0.97–1.00). Over the same period, there was an improvement in all-cases survival (ie, survival with and without hospital admission) for the NT Indigenous population due to a reduction in deaths both pre-hospital and after hospital admission (death rates reduced by 56% and 50%, respectively). The non-Indigenous all-cases death rate was reduced by 29% as a consequence of improved survival after hospital admission; there was no significant change in pre-hospital survival in this population. Important factors that affected outcome in all people after AMI were sex (better survival for women), age (survival declined with increasing age), remoteness (worse outcomes for non-Indigenous residents of remote areas), year of diagnosis and Indigenous status (hazard ratio, 1.44; 95% CI, 1.21–1.70).Conclusions: Our results show that the increasing IHD mortality in the NT Indigenous population is a consequence of a rise in AMI incidence, while at the same time there has been some improvement in Indigenous AMI survival rates. The simultaneous decrease in IHD mortality in NT non-Indigenous people was a result of reduced AMI incidence and improved survival after AMI in those admitted to hospital. Our results inform population-specific strategies for a systemwide response to AMI management.

Jiqiong You MSc, MBA, MB · John R Condon MPH, PhD, FAFPHM · Yuejen Zhao MB BSc, MBiostats, PhD · Steven Guthridge MB BS, MTH, FAFPHM

Objective: To describe the natural history and risk of early chronic kidney disease (CKD) in Indigenous Australian populations.Design, setting and participants: A prospective cohort of 2266 Aboriginal and non-Aboriginal children enrolled from primary schools throughout New South Wales from February 2002 to June 2004 and followed for 4 years.Main outcome measures: Urinalysis, height, weight, blood pressure, birthweight and sociodemographic status at baseline and 2- and 4-year follow-up; CKD risk factors: haematuria, albuminuria, obesity, and systolic and diastolic hypertension.Results: 2266 children (55% Aboriginal; 51% male; mean age, 8.9 years [SD, 2.0 years]) were enrolled at baseline. 1432 children (63%) were retested at 2-year follow-up, and 1506 children (67%) at 4-year follow-up. Prevalence of baseline CKD risk factors was frequent (2%–7%), but most abnormalities were transient. Besides persistent obesity (5.0%), persistence of CKD risk factors at final follow-up was low: haematuria (1.9%), albuminuria (2.4%), systolic hypertension (1.5%) and diastolic hypertension (0.2%). There was no difference in prevalence of persistent CKD risk factors between Aboriginal and non-Aboriginal children.Conclusions: Over 4 years of follow-up, Indigenous Australian children had no increased risk for early evidence of CKD. More than 70% of baseline risk factors were transient, and persistent risk factors were uncommon. Our findings suggest the increased risk for end-stage kidney disease seen in Indigenous adults is not yet manifest in these schoolchildren, and may be potentially preventable.

Leigh Haysom MB BS, MClinEpi, FRACP · Rita Williams BA · Elisabeth M Hodson MB BS, FRACP · Pamela A Lopez-Vargas BN, BSc, BHSc(TCM) · Leslie P Roy MB BS, MD, FRACP · David M Lyle MB BS, PhD, FAFPHM · Jonathan C Craig MB BS, PhD, FRACP

Objective: To quantify Indigenous mortality in the Northern Territory by remoteness of residence.Design, setting and participants: Australian Bureau of Statistics mortality data were used to compare rates of death from chronic disease in the NT Indigenous population with rates in the general Australian population over the period 1998–2003. Rates were evaluated by categories of remoteness based on the Accessibility/Remoteness Index of Australia: outer regional areas (ORAs), remote areas (RAs) and very remote areas (VRAs).Main outcome measures: Mortality from cardiovascular disease, diabetes and renal disease; standardised mortality ratios (SMRs); percentage change in annual death rates; changes in mortality between 1998–2000 and 2001–2003.Results: In 1998–2000, SMRs for all-cause mortality were 285% in ORAs, 875% in RAs and 214% in VRAs. In 2001–2003, corresponding SMRs were 325%, 731% and 208%. For the period 1998–2003, percentage changes in annual all-cause mortality were 4.4% (95% CI, –2.2%, 11.5%) in ORAs, –5.3% (95% CI, –9.6%, –0.8%) in RAs, and 1.1% (95% CI, –7.2%, 11.3%) in VRAs. In 2001–2003, compared with 1998–2000, changes in the number of Indigenous deaths were +35 in ORAs, –37 in RAs and +32 in VRAs. Similar patterns were observed for cardiovascular mortality.Conclusions: Compared with mortality in the general Australian population, Indigenous mortality was up to nine times higher in RAs, three times higher in ORAs and two times higher in VRAs. The fact that rates were lowest in VRAs runs contrary to claims that increasing remoteness is associated with poorer health status. Despite the high death rate in RAs, there was a downward trend in mortality in RAs over the study period. This was partly attributable to a fall in the absolute number of deaths.

Karen Andreasyan DMD, MPH · Wendy E Hoy BSc, MB BS, FRACP

Objective: To develop national birthweight percentiles by gestational age for male and female singleton infants born in Australia, and to compare the birthweight percentiles of Indigenous and non-Indigenous infants. Design and setting: Cross-sectional study of singleton live births to Australian-born mothers from 1991 to 1994. Main outcome measures: Birthweight percentiles by gestational age. Results: During 1991–1994 Australian-born women gave birth to 769 077 live singleton infants. Of these, 28 230 (3.7%) were reported as births to Aboriginal or Torres Strait Islander women. Birthweight was missing for 581 (0.1%) births and gestational age was missing for 3014 (0.4%). An additional 3283 (0.4%) births were excluded because the recorded birthweights were extreme outliers for their recorded gestational ages. Indigenous women were more likely to be recorded as giving birth preterm (< 37 weeks’ gestation) than non-Indigenous women (11.6% v. 5.4%) and were more likely to give birth to small-for-gestational-age infants at term. After 34 weeks’ gestation, the median birthweights of Indigenous infants were consistently lower than those of non-Indigenous infants. At 40 weeks’ gestation the difference in the median birthweights between these two groups was 160 g for males and 130 g for females. Conclusions: We present recent birthweight percentiles by gestational age based on national data in Australia. These percentiles provide current Australian norms for clinicians and researchers, and can provide a baseline for monitoring Indigenous perinatal outcomes.

Christine L Roberts · Paul A L Lancaster