Abstract
Investigations on sick absence was carried out on a nation-wide scale by the committee appointed for this purpose of the Japan Association of Industrial Health, as a part of which the present studies were conducted with special attention to the locality of Hokkaido. The survey covered 4, 329 employees of two factories, four mines and one transportation company for a period of four months, from June to September of 1964 as the summer season of Hokkaido. The emphasis was laid on the relationship between sick absence and the type of work shift, sickness of occupational or private nature, frequent absence and classification of diseases, excluding absence due to other than diseases or injuries and of longer duration than 180 days. On the basis mentioned above the following points were discussed: (1) incidence rate per 100 persons, (2) average duration of absence per person under observation (disability rate), (3) average duration of absence per case (severity rate), and (4) the relation between the incidence rate and number of days elapsed from holiday to absence. The results obtained were as follows: 1) Night-shift or over-night work showed a tendency of higher incidence rate, which will be one of important keys to health administration. 2) The average duration of absence per person was about 4 days in mines, which is almost the same as shown in the report on sick absence by Enterline (U.S.A., 1964). 3) Concerning the occupational nature of sick absence, a high incidence rate was observed in mines, especially in underground work. In addition, the fact that the average duration of absence per case in mines was rather long (about 20 days) should be taken into consideration in relation to safety management. 4) Regardless of the type of the industry, the highest incidence rate was seen on the first day after a holiday.
