Doctors' opinions on the prevention of myocardial infarction.

In 1979, 1981 and 1983 random samples of approximately 200 general practitioners, 200 members of the Royal College of General Practitioners and 200 hospital physicians were asked to list, in order of effectiveness, measures which they considered useful in the prevention of myocardial infarction and reinfarction. The overall response rate was 67% and of the responses 77% were eligible for inclusion in the analysis.There was a high degree of concordance between the opinions of the nine doctor-year groups (Kendall's W = 0.89, P < 0.001). Behavioural measures, such as diet, weight control, exercise and cessation of smoking, were mentioned frequently and were ranked above most drug therapies. Overall, opinions concerning the relative utility of different measures did not change between 1979 and 1983 yet there were significant changes in the frequency with which specific therapies were mentioned as useful preventive measures. Beta-blockers, calcium channel blockers, and arteriograms/coronary artery bypass grafting were mentioned more frequently in 1983 than in 1979 while lowering the lipid levels (with drugs) and sulphinpyrazone were mentioned less frequently. The changes in the opinions of doctors are discussed in the context of new therapeutic information published between 1979 and 1983.