Background: The North Karelia project, a community-based programme for prevention of cardiovascular diseases in North Karelia in 1972-1977, was successful in reducing some major cardiovascular risk factors. It was studied whether changes in the incidence of smoking- or diet-related cancers in North Karelia were different from those in a reference area without a programme.
Methods: Poisson age-period-cohort-county regression models were fitted to each cancer-sex combination. Specially designed variables were added to the best models to detect any post-programme changes in the incidence trend in North Karelia.
Results: After having been consistently higher, the incidence of lung cancer among males in North Karelia decreased below that of the reference county during 1987-1991. The programme-related risk ratio in 1987-1991 indicated a significant 20% beneficial effect. The trend in stomach cancer among males was more favourable in the reference county than in North Karelia.
Conclusion: The quicker reduction in smoking may have caused the more favourable trend of lung cancer among North Karelian males than males in the reference county.