Mediterranean Diet for Primary Prevention of Cardiovascular Disease

To the Editor: The interventional nutritional study by Estruch et al. (April 4 issue)(1) is limited by low primary composite cardiovascular outcome rates (3.8% and 3.4% in the intervention groups vs. 4.4% in the control group) with minor absolute risk differences (range, 0.6 to 1%). Given these small margins of risk, there were at least four statistically significant differences in baseline characteristics between the groups, which could contribute substantially to these minor absolute differences in risk. There were significantly higher percentages of men (+5.7%), obese persons (+4.7%), diuretic use (+3.5%), and oral hypoglycemic use (+3.2%) in the control group than ...