Why isn the North Karelia approach being promoted?
Gaziano and colleagues22 are charitably disposed to the North Karelia study and suggest that as a front runner study it found a bigger effect than other, subsequent studies found—which they explain as due to the virgin field that had not been tilled by any sort of intervention. Subsequent studies would have to make their comparisons against a background of downward drift of risk factors fuelled by a general climate of health promotion messages. This is a nice idea, but ignores several important facts: (i) the North Karelia study was not a randomized experiment but many of the subsequent studies were randomized and better able to control for selection factors and confounding; (ii) the control region of Kuopio showed almost identical risk factor changes from the outset; and (iii) the mortality rates for the counties of the whole country showed parallel declines, with North Karelia showing the highest rates in the 1960s and the highest rates in the 1980s. Perhaps the most important fact i
