Letters

Mai Maddisson General Practitioner, Mitcham North Clinic, 188 Mitcham Road, Mitcham, VIC 3132. mmaddisson.nmcATwdgp.com.au To the Editor: I read with interest McFarlane’s article on post-traumatic stress disorder and debriefing,1 which reminded me of a long-term patient. Over a decade ago, I discovered that this patient was a Vietnam veteran, and expressed concern that he had not told me previously. His reply came thus (although, of course, I no longer remember the exact words): “How would you know what it feels like to be, by sheer chance, the only man left alive in a group of soldiers?” I acknowledged that he was correct, that I had no idea. With that poignant remark in mind, I planned his care. He is doing OK. Can we really address an abstraction that we cannot conceptualise, or predict the resulting obstacles in a person’s journey through life? This is equally valid at the beginning of the journey or anywhere along its course. Perhaps the notion of debriefing at an appropriate time is not the problem; perhaps it is the formula we use.

Mai Maddisson

Peter J Collignon*, Dianne E Dreimanis† and Wendy D Beckingham† *Director, Infectious Diseases Unit and Microbiology Department; †Clinical Nurse Consultants, Infection Control; The Canberra Hospital, PO Box 11, Woden, ACT 2606. peter.collignonATact.gov.au To the Editor: Single-use devices (SUDs) are in common use, and many are reprocessed.1-7 When examined, these devices are frequently not clean and have residual biological material on or within them.2-4,6 This material may contain viruses or other infectious agents. SUDs are usually made from plastics or other heat-sensitive materials resulting in less effective means being used for sterilisation than can be used for more robust materials — chemical disinfectants can be ineffective in the presence of organic material, and have poor penetration compared with heat (eg, an autoclave). In 1994 we found that, of 168 Australian hospitals reviewed, 68% were reprocessing SUDs used in sterile sites.1 We repeated this survey (using a similar questionnaire) in 2001, in acute-care hospitals with more than 45 beds. The questionnaire was sent to 461 hospitals — 181 private hospitals (117 with fewer than 100 beds, 59 with 100–300 beds, and five with more than 300 beds) and 286 public hospitals (115 with fewer than 100 beds, 116 with 100–300 beds and 55 with more than 300 beds). Responses were received from 189 (see Box 1). Not all respondents answered all questions and many responded anonymously. Reuse of SUDs still occurred in all states and territories, but compared with 1994 the rate had dropped to 15% (28 hospitals). Large hospitals reused more often than smaller hospitals (see Box 1). Reuse was slightly lower in private hospitals than in public hospitals (13% v 16%). Rural hospitals reused SUDs less often than metropolitan hospitals (12% v 16%). The commonest SUDs reused were diathermy pencils. Given their low cost ($5), the labour costs of reprocessing would exceed the cost of replacement. Diathermy pencils (Box 2) have spring-loaded buttons, which inevitably become contaminated with blood during surgical procedures. Thus, the potential exists to contaminate the surgeon's fingers during subsequent procedures. We believe that reusing such relatively inexpensive items is inappropriate from both financial and infection control perspectives. An Australian National Health and Medical Research Council (NHMRC) report stated that, after reprocessing and packaging in hospitals, almost all SUDs were contaminated with foreign material (including blood), and several pacing electrodes had damaged insulation.6 Other studies have shown that blood persists on cardiac ablation catheters when structural abnormalities (which occurr frequently and early) are present.3 The reuse of these devices has been reviewed by the NHMRC and important changes have been recommended.6 Reuse of SUDs has been common in many countries. In the United States, reprocessing is frequent (eg, 2.5 million devices by one commercial reprocesser).5 In 2000, the US Food and Drug Administration issued a policy that, for practical purposes, should abolish the practice of reprocessing SUDs in hospitals.4 In Australia, the Therapeutic Goods Administration recently announced that reprocessing of SUDs will be regulated.7 This should have a similar effect. As the methods and response rates of our two surveys were similar, we believe that the reuse rate has decreased. However, proportionately, fewer large public hospitals responded (only 13 of 55, or 24%, compared with 41% overall), even though they have the highest reuse rate (54%). Therefore, we are likely to have underestimated the actual rate of reuse. Also, those who are reusing may be less likely to admit to this practice, and thus less likely to respond. Reuse of SUDs in sterile sites remains common practice in Australian hospitals (although the rate is lower than it was in 1994). Most SUDs appear to be unsuitable for reuse as they cannot be adequately cleaned and sterilised. We strongly advise against further reuse of these items. 1: Number and types of hospitals reusing single-use medical devices Number reusing devices / Number respondents Bed numbers Type of hospital Unknown < 100 100–300 > 300 Total respondents Unknown 0/1 0/2 1/4 1/1 2/8 (25%) Public 0/1 5/41 4/44 7/13 16/99 (16%) Private 4/40 6/36 0/2 10/78 (13%) Combined public and private 0/2 0/2 0/4 Total respondents 0/2 9/85 (11%) 11/86 (13%) 8/16 (50%) 28/189 (15%) 2: A diathermy pencil

Peter J Collignon · Dianne E Dreimanis · Wendy D Beckingham

Clifford F Hughes Head, Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Suite 304, 100 Carillon Avenue, Newtown, NSW 2042 clifford.hughesATemail.cs.nsw.gov.au Comment: The letter by Collignon, Dreimanis and Beckingham about reuse of single-use medical devices (SUDs) in Australian hospitals again brings in to stark contrast the issue of safety and quality of medical devices and the pressing need to provide affordable services to the Australian public. Seven years ago, Collignon and colleagues showed an unacceptably high reuse of SUDs in Australia, especially in public healthcare institutions.1 Since then, the National Health and Medical Research Council (NHMRC) has produced an expert panel report on these devices2 and the Therapeutic Goods Administration has promulgated detailed device regulations.3 There has been continued debate in both the scientific literature and lay press, and the United States Food and Drug Administration has had extensive comments published on this matter.4,5 Given the intensity of this debate, it is surprising that so few hospitals completed the questionnaire. It is also surprising that, despite the overall reduction in the reuse of SUDs, there has been no apparent reduction in their use in large public institutions, 50% of which continue the practice. Collignon and colleagues have not investigated the quality control mechanisms in place in these hospitals. That could well be a subject for further research. Not so obvious to the casual user is the effect of resterilisation on the materials of the device. The authors allude to the potential for degradation during sterilisation. There is inevitable pressure to use less effective (chemical) means for re-sterilisation. On the other hand, the waste of an enormous resource that, if safe, could be readily reused must be recognised. The costs of devices are easy to quantify. The costs of resterilisation, not to mention quality control, less so. Collignon et al suggest one example of false economy in the reuse of a low budget but commonly used item — diathermy pencils. They make a strong case for mandated reporting of resterilisation protocols for all single-use items. Informed consent must be a prerequisite. Tracking systems could well provide beneficial information on the safety and efficacy of procedures for particular devices. Furthermore, clinical audit would provide an early warning mechanism should resterilisation prove inadequate. These are among the main recommendations of the Report of the NHMRC Panel.2 Extensive regulations and controls have been applied to the use of biological products such as dura mater, heterograft and cardiac valves, among others. There is, however, reluctance to apply similar stringent controls to devices which may be contaminated by more pervasive but less obvious biological hazards. There are only three options: cease this practice wherever a viable alternative is available until there is incontrovertible proof of the safety of reuse; mandate detailed protocols which include audit and surveillance mechanisms coupled with appropriate informed consent whenever SUDs are reused;2 and develop a research and evidence base for improvements in design and materi-al technology so that the "cost efficiencies" of single-use devices could be translated to "nondisposable items". All three must be adopted.

Clifford F Hughes

Graeme H Johnson*, Donna B Mak†; *Acting Public Health Medical Officer; †Former Public Health Medical Officer, Kimberley Population Health Unit, Derby, WA 6728. graeme.johnson@health.wa.gov.au To the Editor: In their study of a SAFE-style trachoma control program (which included Antibiotic treatment, Facial cleanliness, and Environmental improvement, but not Surgery) in a remote Australian community, Ewald et al suggest that no systematic SAFE trachoma control program exists in Australia.1 In the Kimberley region of Western Australia, the Kimberley Public Health Unit (KPHU) has coordinated a trachoma control program since 1989. The World Health Organization SAFE strategy has been implemented since 1996, as described in the Kimberley regional trachoma control guidelines and a peer-reviewed publication.2,3 The trachoma control program in the Kimberley has been delivered by a variety of environmental health, health promotion, community and clinical health professionals employed by State and local governments, and by community-controlled and other non-government organisations. We believe a coordinated regional approach is mandatory, because of the numerous organisations involved in program delivery. The trachoma control program in the Kimberley continues to achieve good results. The prevalences of follicular trachoma during annual screening of school-aged children in the Kimberley have been published annually in the KPHU Bulletin.4 Since 1996, in accordance with the WHO SAFE strategy, communities with trachoma prevalences of less than 5% were not screened in subsequent years and did not contribute to regional prevalence data. Thus, the observed decrease in trachoma prevalence between 1996 and 2001 is likely to be greater than that shown in the Box. We believe the Kimberley region is well placed to achieve the WHO aim of eradicating blinding trachoma by 2020.5 However, it is a concern that other regions of Australia with endemic trachoma infection may not conduct disease control activities in a coordinated manner because of lack of leadership in trachoma control or insufficient resources, or both. The community described by Ewald et al borders the Kimberley region and has strong cultural links with several Kimberley groups. The achievements in trachoma control in the Kimberley cannot be sustained in the long term without a nationally coordinated approach. We believe that it falls within the statutory responsibilities of State and Territory departments of health to ensure that environmental and clinical health services are coordinated to achieve trachoma control in Australia. Trachoma in Kimberley children Point prevalence of follicular trachoma among children in the Kimberley region aged 5–15 years at annual trachoma screening, 1991–2002

Graeme H Johnson · Donna B Mak

Andrew C Laming,* Bart J Currie† * Advisor, Federal Minister for Health and Ageing, Parliament House, MG 48, Canberra, ACT 2600; † Professor in Medicine, Northern Territory Clinical School and Menzies School of Health Research, Darwin, NT. andrew.lamingAThealth.gov.au To the Editor: The important article by Ewald et al shows that offering azithromycin treatment to 70% of a remote community may be inadequate to control hyperendemic trachoma, even when combined with a health promotion campaign.1 Yet, significant short-term gains in similar locations have been achieved with as little as 20% of the population receiving azithromycin, where administration to children with trachoma and their household contacts was directly observed by health staff.2 In that study,2 we reported a 6-month follicle resolution rate in schoolchildren of 72%, followed, however, by a return of trachoma prevalence towards baseline levels over 12 months. The critical factors for short-term success with azithromycin appear to be appropriate selection of cases and contacts, plus, where possible, directly observed therapy to minimise reinfection from untreated cases. Sustainability of initial reduction in trachoma prevalence is problematic, and issues of how extensively and how often to screen and/or treat need to be determined in the Australian context. Similar sustainability considerations have arisen in community scabies programs.3 Ewald et al are correct to identify population mobility as a major issue, with trachoma likely to be reintroduced by untreated children entering a community where a treatment program has occurred. Hence the need for a coordinated regional approach. However, a regional approach to trachoma control does not necessarily mean a uniform approach, and it is vital to tailor programs to suit the capacity of communities and their degree of commitment to labour-intensive treatment and health promotion. Our study suggested that directly observed twice-yearly azithromycin therapy, with a health promotional component, is likely to be preferable to an annual program.2 Mathematical modelling supports this more frequent dosing and, unlike in Africa, the cost of azithromycin should not be a constraining factor in Australia.4 Regardless of the strategy selected, if, after treatment, the prevalence remains hyperendemic (> 20%), then the outcomes from concurrent health promotion are compromised. Appropriately targeted and directly observed azithromycin therapy can help create conditions favourable for health promotion campaigns, which in turn prolong those gains by reducing trachoma transmission.5 Major issues for trachoma control in Australia are (i) who to screen and treat (with directly observed azithromycin therapy); (ii) how often to screen and treat; (iii) how to plan trachoma programs as regional initiatives; and (iv) who will fund, coordinate and implement trachoma programs.

Andrew C Laming · Bart J Currie

Dan P Ewald,* Gillian V Hall,† Christine C Franks‡ * Senior Research Fellow, Centre for Remote Health, Flinders University, PO Box 4066, Alice Springs, NT; † Lecturer, National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT; ‡ Educator, Health Development, Health and Community Services, Alice Springs, NT. dan.ewaldATflinders.edu.au In reply: These letters reinforce a number of important points about control of trachoma (and other endemic infections) in Australia. The questions of whom and how often to treat need refining through Australian experience. Long-term control needs multifaceted, intersectoral collaboration to alter environmental and behavioural conditions against disease transmission. Strategies should be sustained, regional (large as practicable); acknowledging, and guided by, Aboriginal kinship networks; and recommend observed drug treatment (which was negotiated for the final treatment in our study). A non-uniform approach could include more frequent treatment in hyperendemic communities, probably leading to less net use of antibiotic treatment. Reports from the Kimberley Population Health Unit show a very mixed picture, with wide year-to-year fluctuations in prevalence in many communities. While hyperendemic communities remain in a region, the prevalence of trachoma may increase unnoticed in communities no longer screened because their prevalence has dropped below 5%. If not looked for, it is unlikely to be noticed. Further analysis, such as the graph provided by Johnson and Mak, is to be applauded in the context of a thorough analysis. When this happens, it will greatly strengthen the case for active trachoma control in other regions. For trachoma prevention, and for many other reasons, we believe environmental health interventions are critical. These remain difficult to evaluate given the high mobility of people in Aboriginal communities. Reliable, long-term, regional environmental health and mobility data are needed as part of this broad issue.

Dan P Ewald · Gillian V Hall · Christine C Franks

Richard X Davey Chemical Pathologist, Melbourne Health Shared Pathology Service, Pathology Department, Western Hospital, Footscray, VIC, 3011. richard.daveyATwh.org.au To the Editor: Stone and colleagues must be complimented for their study of gestational diabetes mellitus (GDM) published recently in the Journal.1 Although the study was comprehensive, in that it linked two pertinent records for 99.3% of the women delivering in Victoria in 1996, their analysis was necessarily limited to the parameters recorded in those two data sets. Stone et al do not refer to relevant recent work from Toronto, Ontario,2 and Sunshine, Victoria,3 which has already determined the maternal risk factors for GDM: increasing age, racial origin, family history of diabetes mellitus, and pre-pregnancy body mass index. Data on the latter two of these four factors were specifically noted as not available to Stone's group, but could have been mentioned as established risk factors to consider in patient management. The findings of Stone et al regarding age are similar to those previously reported. However, the relative risk for GDM in the Sunshine cohort increased from 25 years of age (odds ratio, 1.9; 95% CI, 1.3–2.7).3 Recasting the all-Victorian data1 with "< 25 years" as the reference datum would most likely produce a similarly significant result to that found in the Sunshine study. Again, the Victorian data on racial origin are but the Sunshine data writ large. Stone and colleagues had to choose a reference datum for this parameter, but have not avoided a problem that bedevils all such work in the "New World": there is as yet no definitive Australian reference datum available for racial origin. For example, the designation "Australian" may be used, but parents who are themselves second or third generation Australian-born may have, say, pure Maltese ancestry, giving them a high risk of GDM and thus distorting the reference datum. I have argued this case in more detail elsewhere,4 and took measures to circumvent the problem in the Sunshine study.3 Among their findings, Stone et al confirm that there is a significantly increased incidence of macrosomia in GDM-affected infants. I agree. Their work is unquestionably the definitive statement of Victoria's GDM-related macrosomia status (as at 1996), but it lacks one vital ingredient: it defines macrosomia, but does not cite the source of the data used as the study's benchmark. To enable comparisons with their work in future years, could we please have that benchmark referenced so that others may use it too?

Richard X Davey

Christine A Stone,* Kylie A McLachlan,† Jane L Halliday,‡ Peter Wein,§ Christine Tippett¶ * Epidemiologist, Prevention and National Health Priorities, ‡ Epidemiologist, Birth Defect Registry, Perinatal Data Collection Unit, Public Health Division, Department of Human Services, 17th Floor, 120 Spencer Street, Melbourne, VIC 3001; † Research Fellow in Endocrinology, Department of Endocrinology and Diabetes, St Vincent's Hospital, Fitzroy, VIC; § Senior Lecturer, Department of Obstetrics and Gynaecology, University of Melbourne, East Melbourne, VIC; ¶ Director, Maternal Fetal Medicine, Monash Medical Centre, Clayton, VIC. christine.stoneATdhs.vic.gov.au In reply: We thank Davey for his comments, which provide us with the opportunity to highlight the benefits and limitations of reports using population-based data. The value of population-based data is that the reported incidence, risk factors and outcomes reflect current practice in the whole of Victoria and are not subject to bias introduced by local referral patterns or clinical practice. Our study1 shows that, in addition to established risk factors for gestational diabetes mellitus (GDM), the reported incidence varies according to hospital size and geographic location, demonstrating the type of bias that can occur. In addition, the large number of subjects in our study (over 60 000) enables more accurate analysis of subgroups. A limitation, already highlighted in our discussion, is that we are restricted to the parameters available within the data sources used. Davey and Hamblin's article2 demonstrates the difficulty of obtaining individual patient data on body mass index, racial grouping, and family history of diabetes. Even working at the hospital level, they had to extrapolate from population-level data to derive an estimate of these risk factors among the control subjects.2 Given that their study population is a subgroup of ours,1 it is no surprise that the two studies showed similar results. An important implication for providers of health services is that, with increases in the age at which mothers give birth and in the number of births to Asian-born mothers,3 we predict that the prevalence of GDM in Victoria will rise. Davey correctly points out that our article does not refer to a relevant 1997 study by the Toronto group.4 However, we do actually refer to a later publication by the same group.5 The problem of ethnicity and migration arises in studies of conditions that are not only polygenic but also a result of complex interactions between a person's genes and his or her environment. Lastly, the source of information on macrosomia was 1996 population data. We have since produced a percentile chart of weight (g) for gestational age (weeks) based on 15 years of Victorian data.6

Christine A Stone · Kylie A McLachlan · Jane L Halliday · Peter Wein · Christine Tippett

Michael Copeman Paediatrician, Department of Paediatrics, Manly and Mona Vale Hospitals, Darley Road, Manly, NSW 2095. mcopeman@bigpond.net.au To the Editor: Law and Batey1 rely on a flawed study for their conclusion that needle/syringe programs (NSPs) have saved lives and money. The study in question2 compared the incidence of HIV and hepatitis C virus (HCV) infections in cities round the world and concluded that cities with NSPs had achieved reductions in HIV incidence that were not seen in cities without NSPs. However, interestingly, no similar reduction in HCV incidence was reported. Detailed reading of the study shows that a third of the cities (22/67) without NSPs were in Thailand — a country in which, unfortunately, there are many other reasons why HIV incidence is increasing rapidly. Given the large proportion of Thai cities included in the study, it is plausible that the rapid rise in HIV incidence in these cities biased the overall results of the study, leading to an erroneous conclusion that NSPs themselves were associated with a reduction in HIV incidence in cities worldwide. Further reading of the study shows that HCV incidence was not measured in any studies in Thailand. So, the reported lack of effect of NSPs on HCV incidence depends on comparisons between cities with and without NSPs from other parts of the world, perhaps less affected by some of the problems in Thailand. In conclusion, if Thai cities had been excluded from the study, it seems likely that no change in the incidence of either HCV or HIV might have been found in association with NSPs. The original study needs urgent re-analysis to see if this is in fact the case.

Michael Copeman

Matthew G Law,* Robert G Batey† Statistician, National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, 376 Victoria Street, Darlinghurst, NSW 2010; † Clinical Chair, Division of Medicine, John Hunter Hospital, Newcastle, NSW. mlawATnchecr.unsw.edu.au In reply: Copeman's criticism of the report Return on investment in needle and syringe programs in Australia1 is essentially that the comparison of the effectiveness of needle/syringe programs (NSPs) is confounded by other factors. This point, and its implications for the results, was extensively discussed in that report. Copeman suggests that the estimated reduction in HIV due to NSPs might largely be attributable to the inclusion of data from many cities in Thailand that do not have NSPs. This criticism is not supported by the data. A sensitivity analysis including only cities from developed countries was performed at the time of the report (see Methods, Section 3.1.2, page 131), but was not included among the report's results because of space constraints and because it didn't alter the main findings. The analysis of cities in developed countries showed an overall mean reduction in the annual rate of change in HIV seroprevalence of –30.0%, compared with –24.7% based on all cities, albeit with lower statistical significance (P = 0.105 v P = 0.057), reflecting the loss in power through exclusion of cities. Copeman's assertion that the report indicated that NSPs had no effect on rates of hepatitis C virus (HCV) infection is incorrect. The report estimated that, following the introduction of NSPs, HCV prevalence among injecting drug users declined by 2% per annum, compared with no introduction of NSPs (P < 0.001). The report is freely available on the Internet,1 and we encourage readers to look at it for themselves.

Matthew G Law · Robert G Batey

Peter J Goadsby Professor of Clinical Neurology, Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen's Square, London, WC 1N 3BG, United Kingdom To the Editor: Gebski and Keech describe with clarity and accuracy the important basic concepts of statistical analysis for physicians.1 I would like to draw attention to two issues. Firstly, the authors refer to common measurement scales that are used in medicine. It is crucial to understand the limits of a measurement to begin to appreciate results from any study. They describe the continuous scale and offer blood pressure and temperature measurements as examples. This scale refers to data determined such that the distance between any two points is known and measureable. Siegel used the term "ratio scale" if there was a true zero point to the measurement.2 This contrasts to an ordinal categorical scale, in which the intervals are not constant. The scale referred to can be transformed, and is anchored with respect to the measurements to some reproducible point. The term "ratio" for this scale seems preferable, as the world is, in essence, discrete when measured, in the quantum sense. Certainly, the measured world is not continuous, at least as far as we can determine it. Secondly, the authors do not mention resampling methods.3 These can be very powerful and are attractive in biomedical research when the distribution may not be defined. While I realise these methods are relatively new, they do seem unreasonably ignored in undergraduate medical education.

Peter J Goadsby

Val J Gebski,* Anthony C Keech† * Principal Research Fellow, † Deputy Director, NHMRC Clinical Trials Centre, University of Sydney, Locked Bag 77, Camperdown, NSW 1450. valATctc.usyd.edu.au In reply: While one can view the world as being "discrete", the assumptions underpinning most common statistical methods in analysis of clinical studies are "continuous" distributions. In fact, statisticians go to enormous lengths to approximate discrete systems as continuous ones (lifetime analysis, normal approximations, etc). The measurement scale by which study outcomes are assessed needs careful consideration (to ensure consistent precision and units of measurement). However, both practical and statistical considerations allow for the more common definitions of continuous and discrete measurements to be just as effective for statistical comparisons. Indeed, there is frequently little loss of statistical efficiency when "continuous" variables are appropriately categorised into ordinal groups.1 Resampling methods randomly sample the data repeatedly to estimate the underlying population distribution parameters (eg, mean, standard deviation, etc). They can be very useful in solving specific problems in which the underlying properties of the data used to make treatment comparisons are unknown and using other statistical approximations is deemed to be inappropriate. However, these are specialised computer-intensive techniques for use by trained biostatisticians, rather than commonly used analysis methods. Problems arise with resampling techniques (eg, obtaining confidence intervals), which require specialised statistical expertise.

Val J Gebski · Anthony C Keech

John H T Ellard Psychiatrist, Medical Specialist Centre, 710 Military Road, Mosman, NSW. To the Editor: I read with interest the article in the Journal on ranking medical journals and the fallacies to be found therein.1 I have a simpler method. I subscribe to two classes of journals: those specialising in psychiatry, and more general journals. The psychiatry journals I keep entire. However, as my house is of modest size I cannot do that with the general journals, so I tear out and file the articles that I find interesting and informative. You will be interested to know that in the past month I have filed away one article from the Lancet, one from the New England Journal of Medicine and three from the Medical Journal of Australia. What better measure of merit could there be?

John H T Ellard

William Lancashire*, Craig Hore† and Jennifer A Law‡ *Conjoint Senior Lecturer, †Senior Lecturer, ‡Lecturer, School of Rural Health, University of New South Wales, PO Box 2466, Port Macquarie, NSW 2444. Bill.lancashireATmaynegroup.com To the Editor: We read with interest Hillman's editorial on the hospitalist movement.1 As our group includes a couple of recent expatriates from the Canadian healthcare system,* we can give some historical perspective on the evolution of the hospitalist in Canada, some of which parallels what is happening in Australia. Traditionally, family physicians (general practitioners) in Canada were able to manage their patients in hospital, either as the primary care doctor or in consultation with a specialist. Not infrequently, the specialist would assume primary care and consult with the family doctor. Continuity of care was assured, and both the family doctor and the specialist benefited socially and professionally from the interaction. The "corridor consultation" thrived and the doctor's lounge was a source of medical education and social interaction as GPs and specialists met over a morning coffee before rounds. Around 10 years ago, the family doctor became increasingly unwelcome in the hospital, particularly in teaching centres. As there was never a financial incentive to be involved in hospital practice, this atmosphere persuaded most family doctors to resign their hospital privileges. However, it soon became apparent that a visiting-consultant-based service could not cope with the numbers of patients being admitted to hospitals. Patients with no apparent "teaching value" were becoming difficult to admit into teaching units. Consequently, those few GPs who had retained hospital privileges were increasingly being asked to accept patients primarily under their care. As the system became more stressed, they found that they were managing more and more acutely ill patients. These experienced GPs evolved to become hospitalists — essentially, primary care doctors who were prepared to look after acutely ill inpatients, often in consultation with a specialist. Unfortunately, attempts to encourage GPs back into the hospital system have generally proved unsuccessful. The College of Family Physicians of Canada, recognising that there may no longer be ready access to specialist services or hospital beds, is starting to train its residents accordingly. We agree with Hillman that the complexities of acute medicine require specialists (such as emergency physicians, intensive care specialists and general physicians) with training and skills in acute medicine, resuscitation and multisystem problems. Indeed, our experience in rural Australia suggests that hospital-based multidisciplinary critical care physicians are already undertaking some of the hospitalist roles that Hillman describes. Perhaps we are witnessing the emergence of hospitalists in Australia.

William Lancashire · Craig Hore · Jennifer A Law

F Frank Pyefinch Director of MD Development, Health Communication Network, 2 Santa Fe Drive, Bundaberg, QLD 4670 frank.pyefinchAThcn.com.au To the Editor: I would like to comment on the recent article by Newby et al.1 They conclude that the default settings in computerised prescription packages result in a significant increase in the use of antibiotics. I do not believe this is a valid conclusion. As the authors state that 85% of general practitioners generating computerised prescriptions are using Medical Director (MD), it is reasonable to assume that the default settings in MD would contribute significantly to this effect if their conclusion is correct. I have installed and tested MD v.2.3 from February 2000, MDW v.1.85 from February 2000 and MD v.2.4 from May 2000. These were the versions that would have been in use at the time of this study. All versions default to printing "once-only" prescriptions without repeats. In fact, when a "once-only" prescription has been selected, MD's default behaviour is to display a prompt for the quantity and repeats with the default repeats field set to "0". This is very easy to verify simply by installing a copy of MD onto a "clean" computer and printing some scripts. As this was evidently not done, it casts doubt on the quality of the whole study. How can the authors reach a conclusion about the effect of the default settings in computerised prescription packages without first ascertaining what those default settings are? They appear to have assumed that the default behaviour of all computer prescription packages is to print the maximum number of repeats allowed by the Pharmaceutical Benefits Scheme. No attempt appears to have been made to verify whether this is the case. Whatever the reason for the observed increase in repeat antibiotic prescriptions, it is incorrect to conclude that it is due to the default settings in computerised prescribing packages. No discussion of other possible explanations for the observed increase is presented and it appears as though the data have been used to support a conclusion that had been decided before the study was commenced.

F Frank Pyefinch

David A Newby,* Jayne L Fryer,† David A Henry‡ * Lecturer, † Statistical Analyst, ‡ Professor, Department of Clinical Pharmacology, University of Newcastle, Newcastle Mater Misericordiae Hospital, Newcastle, NSW 2298 mddanATalinga.newcastle.edu.au In reply: As Pyefinch notes, if the "once only" option in Medical Director (MD) is chosen during prescribing, the doctor must enter the quantity and number of repeats that he or she wishes to order. However, if the doctor chooses the "regular" medicine option (both options are offered during prescribing), then the maximum Pharmaceutical Benefits Schedule quantities and repeats are inserted. There are various reasons why doctors may be using the "regular" option rather than the "once only" option when prescribing antibiotics using MD. Some of these have been discussed on the General Practice Computing Group Listserv,1 and include factors such as confusion regarding the terms "regular" and "once only" and difficulties recalling patient medication histories if the "once only" option is used. Another explanation is that doctors commonly prescribe chronic medications, and therefore use of the "regular" option may become a habit. Whatever the cause, there is no obvious explanation for the differences observed, except for the use of prescribing software. Our recommendation that prescribing software be altered to avoid these shortcuts was made because it represents the most immediate way of resolving the problem.

David A Newby · Jayne L Fryer · David A Henry

Jennifer A O'Dea Senior Lecturer, Faculty of Education, University of Sydney, Building A35, Sydney, NSW 2006. j.o'deaATedfac.usyd.edu.au To the Editor: As part of a large, national nutrition study, height and weight were measured among 4441 students from 38 schools randomly selected from lists of all state and territory schools in Australia in 2000. Public, private and Catholic schools, in both rural and urban areas, were represented. Schools were categorised as being of low or middle/high socioeconomic status (SES),1 based on direct measurement of parental income. Parental consent was obtained, and the study was approved by the University of Sydney Ethics Committee and all state departments of education. Overweight and obesity, as defined by an international standard definition,2 were identified in 17.3% and 6.4% of participants, respectively. These characteristics showed a trend towards greater prevalence among students from low-SES backgrounds compared with those from middle/high-SES backgrounds for the total group (19% v 16.8% overweight [P = 0.09]; 8.9% v 5.8% obese [P = 0.02]), females (19.7% v 17.2% overweight [P = 0.2]; 6.9% v 6.2% obese [P = 0.56]), and males (18.5% v 16.3% overweight [P = 0.23]; 9% v 5.5% obese [P = 0.003]), although not all differences were statistically significant. After controlling for SES differences in age and height, mean body mass index (BMI) was significantly higher among low-SES than middle/high-SES participants for the total group (20.3 kg/m2 [95% CI, 20.1–20.5 kg/m2] v 19.7 kg/m2 [95% CI, 19.6–19.9 kg/m2]; P < 0.001), females (20.4 kg/m2 [95% CI, 20.1–20.7 kg/m2] v 19.8 kg/m2 [95% CI, 19.6–19.9 kg/m2]; P < 0.001), and males (20.2 kg/m2 [95% CI, 20.0–20.5 kg/m2] v 19.6 kg/m2 [95% CI, 19.5–19.8 kg/m2]; P < 0.001). A breakdown of results by SES, sex and school level is shown in the Box. Low-SES primary school children were also 1–2 cm shorter, on average, than middle/high-SES primary school children (boys: mean 141.5 cm [95% CI, 140.6–142.5 cm] v 143.5 cm [95% CI, 143.0–144.0], P < 0.001; girls: mean 141.0 cm [95% CI, 140.8–142.6 cm] v 143.3 cm [95% CI, 142.5–143.6 cm], P = 0.01). The average proportions of overweight and obese children and adolescents in the study were similar to those found in other Australian studies.3-5 The results suggest that SES is a factor in the development of overweight and obesity among Australian school children. This may be a relatively recent trend, as these data were obtained in late 2000. Low SES in children may also be associated with nutritional deprivation and height retardation. Further research should clarify these relationships among children from low, middle and high SES backgrounds, as well as examining the combined impact of both SES and ethnicity. School students classified as overweight or obese* according to socioeconomic status (SES), school level and sex Males (n = 2232) Females (n = 2209) Low SES (n = 574) Middle/high SES (n = 1658) Low SES (n = 508) Middle/high SES (n = 1701) Primary school students (grades 1–6; ages 6–13 years) Overweight students 19.4% (42/216) 16.2% (110/680) 23.2% (51/220) 17.8% (136/766) Obese students 6.9% (15/216) 5.3% (36/680) 6.4% (14/220) 5.7% (44/766) High school students (grades 7–12; ages 13–18 years) Overweight students 17.6% (63/358) 16.4% (160/978) 17.0% (49/288) 16.8% (157/935) Obese students 10.1% (36/358) 5.6% (55/978) 7.3% (21/288) 6.5% (61/935) * Overweight and obesity are classified according to the international standard definition.2

Jennifer A O'Dea

Tony D Merritt,* Carolyn Herlihy† * Epidemiologist/Biostatistitian, † Environmental Health Officer, Hunter Public Health Unit, Hunter Area Health Service, LMB 119, Wallsend, NSW 2287. tmerrittATdoh.health.nsw.gov.au To the Editor: Travelling animal shows, with animals such as young poultry, rabbits and reptiles, commonly visit childcare centres in Australia. Transmission of Salmonella infection to children from ducklings and chickens is well documented in the United States1,2 and United Kingdom,3 but not in Australia. We investigated a cluster of Salmonella agona cases in children, identified through routine laboratory surveillance. Initial investigations identified a potential association with visits to childcare centres by a single local hatchery. At each show, children saw an egg hatching, watched day-old ducklings swim and had the opportunity to hold a day-old chick or duckling, and to touch an adult chicken. Details of gastrointestinal illness were sought from childcare centres that had hosted visits from the hatchery. This identified laboratory-confirmed cases with onsets between 14 April and 6 May 2002 in seven people. All attended one of four childcare centres; six were children and one was a staff member. Onset of illness occurred 2–12 days after the hatchery visit. A total of 316 children attended shows by the hatchery between 9 April and 8 May. Environmental sampling at the hatchery recovered Salmonella agona from multiple sites over repeated visits. These included the egg incubator, faeces from day-old hatchlings returning from a show with children, faeces from young chicks and ducklings in the brooder cage, duck faeces from their yard, corn meal used in the preparation of feed for all poultry, and rat droppings in the feed preparation and storage areas. No Salmonella were detected in samples collected from the corn meal supplier. New procedures based on guidelines from South Australia4 and the Centers for Disease Control and Prevention5 were introduced for all shows from 8 May. These included supervised handwashing after handling animals, avoiding carpeted areas for the show, adequate cleaning of macroscopic faecal contamination and disposal of the water used by swimming ducklings into the sewerage system. No further cases were identified among the 251 children who attended shows over the subsequent two weeks until the hatchery cancelled all further visits. We conclude that infection was acquired through contact with chicks and ducklings from a single hatchery, and that the outbreak was halted by the introduction of measures emphasising handwashing after animal contact. Contact between young children and young animals, both of whom have naïve immune systems, represents a special ecological niche. Young poultry are particularly vulnerable to salmonella infection and subsequent high level excretion, and young children are similarly vulnerable. As animal visits to childcare centres are highly valued by children and carers, appropriate guidelines should be widely promoted to the childcare sector and the petting zoo industry to reduce the risks these visits pose. The petting zoo guidelines developed in South Australia4 are an excellent resource and NSW Health is currently developing a fact sheet on the topic.

Tony D Merritt · Carolyn Herlihy

To the Editor: Metformin is a commonly prescribed oral hypoglycaemic agent used to treat type 2 diabetes mellitus. Its major effect is on hepatic glucose production and thereby fasting blood glucose level (f-BGL). Metformin does not commonly cause weight gain, and may be associated with significant weight loss.1 Over the past year, we have prescribed metformin as adjunctive therapy for five patients with type 1 diabetes (T1DM). ...

Jenny E Gunton · Stephen M Twigg

To the Editor: I concluded my recent article with a hope that the "recommendations of the Dawson Committee will provide much needed amendment to the Trade Practices Act".1 In the article, I argued that medical rosters ran the risk of illegality as exclusionary provisions under the Trade Practices Act 1974 (Cwlth) because of either a drafting deficiency in the Act or a policy non-appreciation of ...

Warren Pengilley

To the Editor: Chlamydial infection is the most common bacterial sexually transmitted infection in Victoria and Australia, and notifications are increasing significantly. Most chlamydial infections are asymptomatic and, if untreated, lead to significant morbidity.1 The direct costs of these infections to the Australian healthcare system have been estimated at $90–$160 million annually.2 Chlamydial infection has been implicated in as many as 50% of cases of infertility.3 Widespread screening is cost effective and reduces both the prevalence of infection and the rate of complications.4 Screening is recommended in a number of countries and in the recently released Victorian Chlamydia Strategy.2 To determine if there has been an increase in the proportion of women tested for chlamydial infection who are asymptomatic in Victoria, we analysed notification and enhanced surveillance data. Since 1997, the Department of Human Services has collected enhanced surveillance data using a standard questionnaire distributed by laboratories to clinicians. The forms record information on risk factors and the reason for testing. Data from the Health Insurance Commission were obtained to provide an indication of trends in testing through Medicare. The number of notifications almost doubled between 1997 and 2001, from 2059 to 3977 notifications (Box). In 2001, enhanced surveillance data were available on 2300 notifications (58%). Symptomatic presentation remained the major reason for testing (53%), with no significant change in the proportion tested for this reason since 1997. However, when data for the two sexes were analysed separately, the proportion of men who were symptomatic fell significantly between 1997 and 2001, from 77% to 65% (P = 0.02), while there was no change in the proportion of women who were symptomatic — 42% in 1997 and 41% in 2001 (P = 0.35) (Box). From 1997 to 2001, the number of positive chlamydial tests notified relative to the number of tests conducted has remained constant (9.7%, 8.8%, 11.8%, 11.5% and 9.8% in consecutive years, respectively), despite the increase in number of tests performed. However, even if all tests had been performed in the 20–30-year-old age group, they would represent only 10% of the population in that age group tested each year. Our data suggest that the reasons for testing over the past 5 years have not changed, and, in particular, that there has been no change in the proportion of women tested who are asymptomatic. Chlamydial infection meets the World Health Organization criteria for a screening program,5 and screening for this infection is cost effective.4 Although chlamydial infections are a significant public health concern for women, targeted screening is not occurring widely. Chlamydia notifications and enhanced surveillance data for Victoria, 1997–2001 1997 1998 1999 2000 2001 Male Female Male Female Male Female Male Female Male Female Number of notifications 788 1271 948 1542 1181 1761 1328 1915 1631 2346 Number with enhanced surveillance data 484 782 619 954 735 968 858 1037 992 1308 Reasons for testing* Symptomatic 76.9% 42.3% 75.8% 46.0% 73.9% 44.1% 68.6% 39.4% 64.9% 41.1% STI Screen 7.2% 25.4% 6.5% 25.6% 9.0% 26.3% 9.8% 27.2% 12.3% 27.2% Asymptomatic contact 13.8% 15.5% 16.2% 17.5% 15.8% 18.7% 18.1% 16.9% 18.9% 17.4% Abnormal examination 0.2% 3.2% 0.6% 3.8% 0.7% 4.0% 0.2% 1.6% 0.8% 2.3% Pre-termination screen 0 9.3% 0 5.5% 0 5.6% 0 5.6% 0 3.7% Other/not stated 1.9% 4.3% 0.9% 1.7% 0.6% 1.2% 3.2% 9.3% 3.1% 8.4% Total notifications 2059 2490 2942 3243 3977 STI = sexually transmitted infection. * Mutually exclusive choices presented to clinicians in the surveillance questionnaire.

Megan L Counahan · Jane S Hocking · Christopher K Fairley

To the Editor: We describe six cases of amoebic appendicitis, encountered during a 15-month period in the Pathology Department of the Royal Darwin Hospital. The patients were all Indigenous Australians and four of them came from remote communities. The average age was 24 years and five of the six were men. They all presented with abdominal pain, fever and right iliac fossa tenderness for up to 6 days. The clinical notes did not indicate the presence of pre-existing dysentery, and no faecal examination was undertaken. Recovery following appendicectomy was uneventful in all the cases. No further follow-up is available. The aetiology was established histo-logically, as no distinctive clinical or macroscopic features were noted. The appendices showed extensive coagulative necrosis of the mucosa, submucosa and muscularis propria and invasion of the wall by variable numbers of amoebae with ingested blood cells. Inflammation secondary to perforation was evident in the serosa and the mesoappendix, but no significant inflammation was seen in the inner layers of the wall (Box). Coagulative necrosis of the appendiceal wall was seen in all the cases. In fact, in some of the cases the diagnosis was suspected on seeing this distinctive coagulative necrosis and the amoebae were only found later. Thus, we believe this type of necrosis, which has not been previously emphasised in the literature, to be characteristic of the condition. Amoebiasis is rare in a developed country like Australia. The infection is generally acquired during travel to endemic parts of the world. However, case reports of invasive amoebiasis in Indigenous Australians who have not travelled outside Australia have been previously reported.1,2 Immigration, immunosuppression and poor sanitation are other settings in which amoebiasis can be seen.3 The finding of six cases of amoebic appendicitis in Indigenous Australians in the Northern Territory in a 15-month period is significant, as appendicitis is a very rare manifestation of the disease. McCarthy et al, in a recent MJA article,2 highlight the potential public health significance of endemic invasive amoebiasis because of its high transmissibility in settings where hygiene may be suboptimal. We agree with this and believe in selective screening and appropriate treatment of at-risk contacts of the patients, as prolonged latency between infection and disease is well documented.3 Cross-section of appendix Cross-section of appendix with coagulative mural necrosis and secondary serosal inflammation (haematoxylin and eosin [H&E] original 1×). Numerous amoebae in clear spaces, some with ingested blood cells, are seen in the insert (H&E original 40×).

Ibrahim M Zardawi · Joseph S Kattampallil · Jurgen W Rode

To the Editor: Murray et al recently suggested that after an initial screening urinalysis, routine urinalysis could be eliminated from antenatal care without adverse outcomes for women.1 Their conclusions are based on a prospective observational study of 1000 women, 26 of whom developed pre-eclampsia, with 6/24 (25%) developing new proteinuria before the onset of hypertension. We have concerns about the authors' claims, which, we believe, are not justified by their findings. Pre-eclampsia remains a major cause of maternal and perinatal mortality.2 A study of 26 cases of pre-eclampsia is clearly underpowered to evaluate important morbidity and mortality outcomes. Therefore, one must place great emphasis on potentially undetected cases of pre-eclampsia, such as those that repeatedly appear as examples of substandard care in the Report on confidential inquiries into maternal deaths in the United Kingdom.3 That the initial screening urinalysis detected only 2/26 (8%) women who subsequently developed pre-eclampsia is no surprise. In contrast, routine urinalysis at antenatal visits detected 25% of cases of pre-eclampsia before the onset of hypertension. In the UK, this would amount to 4500 women per annum. The detection of proteinuria provokes further antenatal visits earlier than would normally be planned, facilitating early detection and management of pre-eclampsia. Intervals of 2–4 weeks between visits are usual in the early part of the third trimester when the risks to mother and fetus of severe early onset pre-eclampsia are greatest.4 By eliminating routine urinalysis from antenatal care, a quarter of affected women are potentially exposed to the risk of ongoing undetected pre-eclampsia for up to four weeks. Murray et al suggest that most women would be detected by risk assessment at the initial visit. While there are known risk factors for pre-eclampsia, the largest group who develop pre-eclampsia are primigravid women with no previous history of note. In addition, there are no reliable studies to justify this claim of Murray et al. Recent randomised controlled trials have suggested that the frequency of antenatal visits could be reduced without demonstrating harmful effects.5 None of these trials, however, have the power to demonstrate safety. Even the recent large World Health Organization trial involving 24 526 women6 would have required 490 000 women for 80% power, and 649 910 women for 90% power, to exclude the 40% increase in maternal mortality actually observed with reduced antenatal care. Changes in well-tried methods of antenatal care need to be assessed with more stringency before it is concluded that they are safe.

Deirdre J Murphy · Christopher W Redman

In reply: We agree with Murphy and Redman that pre-eclampsia remains an important disorder and a major cause of maternal and perinatal mortality. However, we disagree with their interpretation of our data. Murphy and Redman allege that, by eliminating routine urinalysis, a quarter of cases of pre-eclampsia may remain undetected for up to four weeks. As we pointed out in our article,1 three of the six women who developed dipstick proteinuria before they developed pre-eclampsia were already considered "at risk" for pre-eclampsia — two because of multiple pregnancies and one with a history of prior pre-eclampsia. These women would, in our practice, continue to have routine urine tests during their pregnancies. The argument is then whether it is justifiable to undertake repeated urinalysis in almost 1000 women to detect three who have dipstick proteinuria, but no other warning signs before the onset of their hypertension. In practice, we would have had to increase antenatal clinic visits for 338 women with dipstick proteinuria (most of whom will have had false-positive results2) to detect these three women with proteinuria before they developed pre-eclampsia. It is already our normal practice for women to have antenatal visits every second week in their third trimester. Therefore, it is just as likely that their blood pressure changes would have been detected by our routine surveillance as by the knowledge that they had dipstick proteinuria. We did acknowledge clearly in our discussion that our study had a potential for type II error and that the best approach is a randomised controlled trial of outcomes between those who do and do not have continued urinalyses during pregnancy. None of this belittles the importance of pre-eclampsia, nor the need for us to separate women considered at "low risk" from those considered "at risk" for pre-eclampsia on the basis of well recognised risk factors. The latter group should never be considered among those in whom routine urinalysis can be omitted.

Mark A Brown · Caroline S E Homer · Gregory K Davis · George Mangos

To the Editor: As practitioners in a community-controlled Aboriginal and Torres Strait Islander primary healthcare centre, striving to better meet the healthcare needs of our community, we would like to offer some thoughts on a recent article by Coory et al.1 In reporting on cervical cancer screening participation rates in Indigenous communities in Queensland, Coory et al identified the communities but did not inform them that the study was being conducted. We feel that such an approach is unhelpful and reflects a paternalistic attitude. The accompanying editorial2 rightly drew attention to the lack of direct consultation with the communities involved and the consequences of this in terms of future interventions. Without a true partnership with the women and their communities, the authors were unable to do more than imply that participation rates were better in centres with a primary-healthcare approach to screening. Information about the types of services and choice of Pap smear providers available in each community, in addition to the Pap smear screening participation rate, would be of great interest. It would, in part, answer the question the authors themselves posed about the role of primary healthcare in improving Pap smear participation rates. Already scarce funds could then be committed to improving access to quality primary healthcare rather than to conducting further trials. A further factor, which was not explored in either the study or the editorial, was health promotion. The cornerstone of health promotion in the Indigenous community remains the "kit-video" model, comprising posters, leaflets and a video. In contrast, mainstream health promotion often involves expensive multimedia campaigns promoted by national celebrities. Such campaigns have been shown to increase Pap smear screening in the wider community.3,4 To date, these campaigns have rarely had an Indigenous focus, and it might be argued that a consequence of this is the low Pap smear participation rate documented by Coory et al. In our experience,5 the Indigenous community does respond to culturally appropriate holistic primary healthcare. The study by Coory et al demonstrates a lack of commitment, collaboration and innovation — essential features for the delivery of quality primary healthcare — that is all too common in the current approach to Indigenous health.

Katie S Panaretto · Sarah Larkins · Vivienne Manessis