EDITOR—We agree with Ebrahim and Davey Smith that contamination of the “control” area in the Heartbeat Wales programme seems likely. 1 2 The aetiological evidence for coronary heart disease is now well established—principally smoking, poor diet, raised cholesterol concentrations, hypertension, and poverty.3 This risk factor model helps to explain the trends within countries and the large differences between countries. 3 4 But how can we achieve the 10-fold lower mortality from coronary disease that is seen in Japan and France?

Ebrahim and Davey Smith suggest that, in isolation, the effectiveness of all community based interventions is low.2 Might it therefore be useful to examine the bigger picture? In Finland mortality from coronary heart disease has dropped by 73% in North Karelia and by 65% elsewhere.5 Why is this more than twice the fall in Britain, a country with similar cardiovascular epidemiology?

In Finland a comprehensive, integrated programme of prevention and treatment started in 1972 in North Karelia and extended to the rest of Finland five years later. …