Epidemiological Studies of Health Effects of General Examinations

Overview

The effect of systematic health examinations and screening of the general population is under debate. Recently, a large Danish randomized study found that systematic screening of risk factors and lifestyle advice in the general population did not have a preventive effect on coronary heart disease, stroke or all-cause mortality. However, there are still very few completed randomized studies, and the effect on other diseases remains unclear. The purpose is to investigate whether repeated health examinations with screening of various risk factors in an unselected population prevent long-term incidence of ischemic heart disease, stroke, total and cause-specific mortality, diabetes, dementia, chronic obstructive pulmonary disease and various forms of cancer. A preliminary protocol was submitted and approved by the Danish Data Protection Agency before the registry-based data on primary and secondary outcomes were received by the investigator.

Introduction The effect of systematic health examinations and screening of the general population is under debate. Recently, a large Danish randomized study found that systematic screening of risk factors and lifestyle advice in the general population did not have a preventive effect on coronary heart disease, stroke or all-cause mortality. However, there are still very few completed randomized studies, and the effect on other diseases remains unclear. Purpose The purpose is to investigate whether repeated health examinations with screening of various risk factors in an unselected population prevent long-term incidence of ischemic heart disease, stroke, total and cause-specific mortality, diabetes, dementia, chronic obstructive pulmonary disease and various forms of cancer. Research question Can health examinations with screening of various risk factors prevent the long-term incidence of ischemic heart disease, stroke, total and cause-specific mortality, diabetes, dementia, chronic obstructive pulmonary disease and various forms of cancer? Data and method For the Danish Monica1 study, a random sample of the general population (adults) in Copenhagen County in 1982 and 1983 was extracted, consisting of a total of 17,845 people. These individuals were randomly divided into two groups, one group was offered a general medical examination while participating in the study, while the control group was not invited and remained unaware of the intervention. The intervention was thus an examination with measuring of e.g., blood pressure, cholesterol level and body mass index as well as subsequent conversation with a nurse. Participants were invited 3 times at 5-year intervals. Data from the intervention group (4,807 people) and the control group (13,038 persons) will be linked to register data from the Danish Civil Registration Register, the Cause of Death Register, the National Patient Register, the Diabetes Register and the Cancer Register. The effect of the intervention will be examined using Cox regression with intention-to-treat analysis.