THE LARGE American three-factor1 and the much smaller Norwegian two-factor2 coronary heart disease (CHD) prevention trials have come out with different results, the former ending inconclusively, the latter with a significantly reduced incidence of total cardiovascular and CHD end points, and substantial, although nonsignificant, reductions in CHD and total mortality.
The Oslo diet-smoking trial in 1,232 high-risk, normotensive, healthy men aged 40 to 49 years, representing the 20% upper risk of a screened male population of 16,200, combined lipid-lowering dietetic intervention with smoking cessation advice. The trial lasted from five to 6 1/2 years.
Differences Between the Trials
There are two main differences in study design between the two trials. The Multiple Risk Factor Intervention Trial (MRFIT) combined hygienic-dietetic intervention measures against smoking and eating habits with drug treatment of the hypertensive subjects (almost two thirds of the intervention group), while the Oslo Study management decided to exclude
Paul Leren, Anders Helgeland, Ingvar Hjermann, Ingar Holme. MRFIT and the Oslo Study. JAMA. 1983;249(7):893–894. doi:10.1001/jama.1983.03330310023019