Gender, ageing, and shiftwork intolerance.

The study investigated the hypothetical differences between male and female shiftworkers in their susceptibility to shiftwork-related health and social problems, with the special reference to the role of the age factor. The comparison concerned two matched-for-age-and-occupation groups of men and women, each of 83 persons, selected from the larger studied population of more than 700 workers in a Polish steel plant. The subjects were crane-operators employed in the same forward-rotated, three-shift, four-team shift system, 4:4:4 with shift changes at 06:00, 14:00, 22:00; and 48 h off following each shift block. The investigation comprised a battery of questionnaires on demographic characteristics, sleep quantity and quality, subjective health complaints, and opinions on shiftwork. The analysis of data revealed that men slept more than women, especially when working on the afternoon and night shifts. The differences became more striking and significant for all work shifts and days-off when related to declared individual sleep requirements. Women experienced more sleep disturbances than men and suffered more frequently from drowsiness during work, especially when working the morning shift. The ratings of subjective health were lower in women, with exception of respiratory complaints. Women generally suffered more than men from symptoms considered as specific to the 'intolerance syndrome', i.e. psychoneurotic, digestive, circulatory, and those of chronic fatigue. However, after passing the 'critical decade' of 40-50 years their subjective health generally improved, whereas in males one observed the consequent deterioration of health with advancing age. Women more often complained about their health and went to see the doctor, but on the other hand, they did not tend to quit shiftwork as often as did their male counterparts.