The differences between countries in the incidence of coronary heart disease reported in the WHO MONICA register study (mid-1990s)24 were confirmed in PRIME. The crude incidence of hard coronary events in the entire PRIME cohort was twice as high in Belfast as in the French centres. Different drinking habits could play a substantial role in the disparity between Belfast and the French centres. A residual differential risk for hard coronary events between Belfast and the French centres persisted in non-drinkers after multivariate adjustment.
