Retrospective study regarding absenteeism among shiftworkers.
A retrospective study on absenteeism was conducted over 24 months among 1354 shiftworkers in the heavy sheet stamping sections of three automative plants located in the Greater São Paulo area. The schedule of the shifts was organised on a semi-continuous basis as follows: 3-fixed shifts, 3-fortnightly rotating shifts, 1 evening-night and 2 months rotating shifts. During the period of the study, 29 and 58% of the workers were on the job for less than 1 and 2 years respectively). On two shift schedules (1 evening-night shift and 2 monthly rotating shifts) the time on the job appeared as an important variable inversely proportional to the frequency of the unjustified absences. Age was also related inversely with sickness and unjustified absences on two others shift schedules: 3 fixed and 3 fortnightly shifts. The 3 fixed shift schedule had the highest sickness ratio frequency compared with the other three systems. On the 1 evening-night shift the unjustified absence frequency rate was higher than on 3 fixed shifts and fortnightly rotating shifts. The analysis of all data considering only the work periods showed that unjustified absence rates were higher in the evening than in the afternoon and night. The morning and afternoon work periods showed higher sickness absence rates than evening and night. Unjustified absences (3031 spells) represented more serious problems than sickness absences (1601 spells) at the plants studied, although the number of days lost per sickness (7505) were higher than unjustified absences (4702).