Factors in medical insurance records of two groups classified as participants and nonparticipants in a multiphasic health examination (MHE) conducted in a rural town in Kyoto prefecture were compared. The purpose of this study was to clarify how the conditions of medical care influenced the participation in the MHE. The factors were days of consultation, total insurance points and days of consultation classified by specific disease and the area of the medical facility. Participants were examined at least once in 1987-1988 and nonparticipants were never examined in the corresponding period. The data were obtained from the medical insurance records of outpatients for the period from April 1986 thru March 1987. The medical care bills of 170 males and 201 females aged 30-69 were randomly sampled from National Health Insurance records (unit=family), and those of 55 males and 88 females aged 70 and over were from the Medical Service for the Aged (unit=person). These samples were about one forth of target population respectively.
Both older participants and older nonparticipants of both sexes had more consultation days and more total insurance points than the corresponding younger subjects. Nonparticipants of both sexes aged 70 and over had more consultation days and more total insurance points than participants; female nonparticipants aged 50-69 had slightly more consultation days and those aged 30-49 also had more insurance points. Nonparticipants tended to have previous medical care for hypertension or ischemic heart disease, which the MHE is responsible for discovering. In contrast, participants had gastroduodenal ulcer, musculo-skeletal disease, cataract or diabetes mellitus, all of which the MHE is less responsible for detecting, except for diabetes mellitus. This indicates that participants perceived the importance of the MHE because of previous contact with diseases, and also that patients with diseases that could be detected by the MHE did not participate in the MHE because they were visiting clinics for the same diseases.
Participants of both sexes had more chance to visit a clinic in the town than nonparticipants, and especially those in large cities. However, older nonparticipants of both sexes had more days of consultation at medical facilities not in the town. This indicates that participants consisted of those who readily visited clinics with slight sicknesses or for further examinations after the MHE, and that nonparticipants consisted of two groups, those who never visited clinics because they were healthy and those who visited for long periods because of serious illness.
