Aims: To assess current attitudes and clinical practice of New Zealand doctors in the management of dyslipidaemia.
Methods: Questionnaires were sent to all New Zealand general practitioners, fellows of the Royal Australasian College of Physicians and members of the Cardiac Society. Questions were asked about the present status of plasma lipids as risk factors for coronary heart disease, screening practices, thresholds for dietary and drug intervention and the cost-effectiveness of interventions.
Results: A total of 1798 replies were analysed, an effective response rate of 64%. Eighty-six percent were from general practitioners. Cholesterol is regarded as an independent risk factor for coronary heart disease by 88% (95% CI 86-89) of general practitioners, 94% (86-98) of general physicians and 98% (88-100) of cardiologists. High-density lipoprotein cholesterol is regarded as an independent risk factor less by general practitioners (68% (66-70)) than general physicians (87% (76-94)) or cardiologists (89% (76-96)), p < 0.001. Over 80% of doctors believe that reducing cholesterol levels will reduce cardiac death, myocardial infarction and the progression of coronary heart disease. However, in practice only 25% measure lipids in all their adult patients, 92% measure lipids in patients with symptomatic coronary heart disease, 86% in patients with hypertension and 60% in smokers, while 73% percent of doctors have measured their own cholesterol. Whereas 86% thought the population diet should be modified, 71% of doctors would not give dietary advice to asymptomatic patients unless the fasting cholesterol was > 6.5 mmol/L. The reduction in cholesterol achieved by a low fat diet was thought to be < 10% by 68% of responders. Fifty percent of doctors refer less than a quarter of their patients to dietitians although 83% stated that they had ready access to a publicly-funded dietitian. There is wide variation in thresholds for intervention in patients with symptomatic coronary heart disease. The median threshold for dietary intervention was 5.2-6.5 mmol/L, and for drug therapy, 6.6-7 mmol/L among physicians. Eight percent of doctors believe patients > 75 years of age should be treated for dyslipidaemia with drugs. Over half could not answer questions about the relative cost-effectiveness of lipid-modifying drug therapy.
Conclusions: Most New Zealand doctors believe there is an independent relationship between plasma lipid levels and coronary heart disease. In practice, screening is selective and there is wide variation in thresholds for dietary and drug intervention.