The Nordic Diltiazem Study – NORDIL is a prospective study where Swedish and Norwegian hypertensive patients were recruited. From year 1992 to 1999, 10,881 patients (aged 50–69 years) were recruited from 1032 health centers in Norway and Sweden. These patients were randomly assigned to receive either diltiazem-based (n=5410) or diuretic- and/or-blocker– based (n=5471) antihypertensive treatment to compare the 2 treatment regimens with regard to the development of cardiovascular events during a mean follow-up time of 4.5 years. Hypertension was defined as a diastolic blood pressure of ≥100 mm Hg on ≥2 occasions. The combined primary end points (PEs) in the Nordic Diltiazem Study were fatal and nonfatal stroke, fatal and nonfatal myocardial infarction, and other cardiovascular deaths.