Does control of risk factors prevent coronary heart disease?

principal causes of the condition, it seems illogical to use local greasy applications or haemorrhoidectomy as the mainstay of treatment. Yet throughout the world, until recent years, classical medicine has espoused these methods. Many of the enlightened now regard both treatments as refuges of the proctologically destitute. They still have a place, but only within the whole armament of stool-bulking agents, anal dilatation, sphincterotomy, and mucosal fixation by fire, oil, or frost. The seven-year American Multiple Risk Factor Intervention Trial has ended with inconclusive results-and leaving many questions unanswered.' Whether intervention to control cigarette smoking, hypertension, and hypercholesterolaemia alters mortality from coronary heart disease in men at high risk remains uncertain. And an appalling consequence of these results is that the central question is likely to remain un-resolved indefinitely, for this vast trial, costing $115 million and based on 28 institutions with 250 investigators, is unlikely ever to be repeated. The trial population was 12 866 men, selected from 361 662 men who volunteered for health screening through their employment. The 12 866 represented the upper 15% of a risk score distribution (two-thirds were in the upper 100%) based on smoking, blood pressure, and plasma cholesterol concentration. None had clinical or electrocardiographic evidence of coronary heart disease. Half the selected group was randomly allocated to an intensive intervention programme conducted by behavioural scientists, nutritionists, nurses, physicians, and health counsellors; they were seen every four months or more frequently to ensure adequate control of the risk factors. The other half received a medical examination once yearly and no specific advice about control of risk factors, other than that given by their doctors. Randomisation of characteristics associated with coronary heart disease was excellent and established that the two groups were comparable on admission to the trial. Less than 10%' of each group was lost to follow-up over the first six years. In the intervention group simultaneous intervention programmes were mounted to stop cigarette smoking, to control raised blood pressure (mostly with thiazides), and to alter the diet to reduce hypercholesterolaemia. Initially, the aim of the dietary changes was to reduce the intake of saturated fat to less than 10% of energy and the daily intake of cholesterol to less than 300 mg; later these limits were narrowed to less than 8% of energy and 250 mg of cholesterol. After six years half of the men in the intervention group had stopped smoking …