Reliability of questionnaire information on cardiovascular disease and diabetes: cardiovascular disease study in Finnmark county

In a cardiovascular disease study in Finnmark county, Norway, which was repeated after three years (1977), 12 694 men and women twice answered a questionnaire on myocardial infarction, angina pectoris, other heart diseases, atherosclerosis obliterans, stroke, and diabetes. The reliability of these data is studied by using different indicators. These indicators suggest that questionnaire information on myocardial infarction is reliable and more reliable than such information on stroke or on diabetes. For stroke the study showed an underreporting. The information from the question on other heart diseases and atherosclerosis obliterans seems so unreliable that an interpretation of such data may be difficult.