Usefulness of community surveillance for the ascertainment of coronary heart disease and stroke.

In a prospective study of coronary heart disease (CHD) and stroke in Honolulu Japanese men, two methods of case ascertainment were used. The first consisted of cyclic re-examination of the cohort, and the second was based on periodic review of hospital discharge rosters, death certificates, and obituary columns (community surveillance). When a suspected case of CHD or stroke was located by either method, pertinent medical records were sought to verify it. Re-examination resulted in more complete ascertainment of CHD because it included silent myocardial infarction and angina pectoris. Community surveillance ascertained 83 per cent of all myocardial infarctions and CHD deaths combined; it was cheaper to operate and gave estimates of disease experience both in examined and unexamined men. In the first two years of this study, CHD incidence was 12 per cent lower in the examined men than in the total community.