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The new Australian Lipid Management Guidelines 2001, published as a supplement with this issue of the Journal, provide an excellent overview of the current evidence on the cardiovascular disease (CVD) benefits of cholesterol lowering. They also signal the acceptance by Australian experts that treatment decisions should be driven primarily by a patient's estimated "absolute CVD risk" — the probability of developing CVD over a specified time period — rather than primarily by his or her blood lipid level.

The Guidelines comprehensively summarise the extensive evidence showing the benefits of cholesterol-lowering interventions in people with low-density lipoprotein (LDL) levels above about 2.5-3.0 mmol/L (equivalent to a total cholesterol level above about 4.5-5.0 mmol/L). But they don't tell us that over 90% of Australians aged 45-75 years have a total cholesterol level above 4.5 mmol/L (Dr Danny Liew, Department of Epidemiology and Preventive Medicine, Monash University, VIC, unpublished analysis). The Guidelines correctly emphasise the need to base treatment decisions primarily on absolute CVD risk rather than on lipid levels, as the benefits of cholesterol lowering are determined far more by individual absolute risk than by pre-treatment level of LDL cholesterol. But the advice provided on how to identify patients at high absolute risk, particularly those without previous symptomatic disease, is rather loose, as discussed below. Moreover, the potential size of the target group for drug-based primary prevention is not mentioned.

The authors of the Guidelines endorse the CVD risk charts used in New Zealand for estimating absolute CVD risk.¹ This brings Australian lipid management recommendations more in line with those of the international community. Similar charts or risk calculators, all based on data from the Framingham Heart Study, are now included in most major national and international CVD management guidelines.^2-6 The Guidelines state that people with an estimated five-year absolute CVD risk of 10%-15% or above (identified using risk charts) are the "at-risk" group who should be targeted for treatment. Alternatively, for doctors who don't use risk charts, the at-risk group includes everyone over 45 years of age with at least one of seven listed risk factors, some of which are ill-defined in the Guidelines (ie, "hypertension" and "overweight"), yet are very prevalent using some common definitions. For people less than 45 years of age, having two listed risk factors also places them in the at-risk group. This "count the risk factors" definition of at-risk is an unnecessarily crude approach and will identify some people with only a 5% five-year CVD risk and exclude others with a five-year risk above 15%. It is also difficult to find a clear statement in the Guidelines about when to initiate drug treatment in this "at-risk" group, and no mention is made of the potential size of the group. I estimate it will include at least another 20% of Australians aged 45-75 years if the cut-off for drug treatment is an LDL cholesterol level of 4 mmol/L or a total cholesterol level of 6 mmol/L (Professor Michael Hobbs, Department of Public Health, University of Western Australia, personal communication).

The authors of the Australian guidelines are to be congratulated for their high quality review of the evidence of effectiveness of both population- and individual-level interventions, and for explicitly linking the level of evidence with their recommendations. However, they are remiss in not considering the implications of implementing the recommendations. For example, it is estimated that this year statins will account for almost a fifth of the total Australian Pharmaceutical Benefits Scheme budget.⁷ While this may or may not be good value for money, it is increasingly accepted that clinical leaders, as well as taking responsibility for individual patients, must also consider the wider resource implications of their recommendations. The practical implications and potential alternative uses of the substantial dollar and people resources required to implement these recommendations should have been considered. For example, it may (or may not) be better value to fund more coronary angioplasties, or to develop more comprehensive rehabilitation programs for patients who have had a myocardial infarction, than to give statins to hundreds of thousands of Australians with a modestly raised risk of CVD. It would also be illuminating to estimate the implications of these recommendations for health professionals, particularly general practitioners and dietitians.

It may be that the implementation costs of the new Lipid Management Guidelines 2001 are justified by the magnitude of the benefits. But recommendations that could result in the long-term treatment of perhaps one million Australians, require a substantial amount of general practitioner and dietitian time and consume a significant proportion of the national pharmaceutical budget will require a serious cost-benefit analysis if they are to be endorsed by healthcare funders. Healthcare costs will be cut by insiders with a scalpel or by outsiders with a meat axe.⁷ In their current form, these Guidelines unfortunately present an exposed neck to a large axe.

Rodney T Jackson
Professor; and Head, Division of Community Health and Effective Practice
Institute, Faculty of Medical and Health Sciences, University of Auckland, NZ
 

1. Jackson R. Updated New Zealand cardiovascular disease risk-benefit prediction guide. BMJ 2000; 320: 709-710.
2. Dyslipidaemia Advisory Group. 1996 National Heart Foundation clinical guidelines for the assessment and management of dyslipidaemia. N Z Med J 1996; 109: 224-232.
3. Wood D, Durrington P, Poulter N, et al. Joint British recommendations on prevention of coronary heart disease in clinical practice. Heart 1998; 80 (Suppl 2):S1-S29.
4. Wood D, De Backer G, Faergeman O, et al. Prevention of coronary heart disease in clinical practice: recommendations of the Second Joint Task Force of European and other Societies on Coronary Prevention. Atherosclerosis 1998; 140: 199-270.
5. Guidelines Subcommittee. 1999 World Health Organization - International Society of Hypertension Guidelines for the Management of Hypertension. J Hypertens 1999; 17: 151-183.
6. Expert Panel on Detection Evaluation and Treatment of High Blood Cholesterol in Adults. Executive Summary of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults. JAMA 2001; 285: 2486-2497.
7. Health Insurance Commission. Annual Report 1999-2000. <www.hic.gov.au/statistics/dyn_pbs/forms/pbs_tab1.shtml>
8. Eddy D. What do we do about costs? JAMA 1990; 264: 1161-1170.

©MJA 2001
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