Abstract
Investigations on sick absence, the summer data (1964) of which had been reported in part one of the studies, was continued for one year. The winter data thus obtained are compared in this report with those of the summer. Observations in Hokkaido were analysed from the viewpoint of frequent absence, classification of diseases, and the difference of occupations, in comparison with those of all Japan. The following results were obtained. 1) Incidence rates per 100 persons per year in the factory (scale 1) and mine (scale 2) were almost the same as those of all Japan in both scales (scale 1: less 500 employees, scale 2: 500-1, 000 employees), while in the transportation industry (scale 3: more than 1, 000 employees) showed a very low rate of about one third of that of all Japan. (Fig. 5) 2) Incidence rate per month was higher in winter than that in summer in all Japan, while in Hokkaido there was no difference in the factory (scale 1) and it was lower in winter than in summer in mines (scale 2) and transportation (scale 3). Considering the severe winters of Hokkaido, this observation is very interesting. (Fig. 6) 3) According to the distribution (%) of diseases as a cause of absence, VIIIa (common cold) and XIb (gastro-intestinal diseases) were the most frequent, approximately one third of all diseases were common colds. These tendencies were almost the same as those of all Japan. (Fig. 7) 4) Attention shold be put on the fact that XVII (occupational accident) especially XIII (diseases of the bones and organs of movement) was high in incidence in the mine. Health and safety management must be promoted further. (Fig. 7) 5) In the distribution of absentees by number of absence per year, those of six times or more were as high as 10% in the factory. When the incidence and severity rates are taken into consideration, it is recognized that there were many persons of frequent absence of short duration in the factory. The highest was absence of once a year, being 55% in the mine and 70% in the transportation. The rate decreased in inverse proportion with the increase of absence frequency. (Fig. 8)
