Physiological Responses to Unvarying (Steady) and 2-2-1 Shifts: Miami International Flight Service Station

摘要

Two types of shift rotation in the same air traffic facility were investigated in order to determine the relative advantages and disadvantages of nonrotating shift work (steady shift) and rotating shift work. The rotating shift work chosen for comparison was a 2-2-1 pattern often preferred by air traffic controllers, and which consists of a schedule of progressively earlier work periods throughout the workweek, with 9 to 14 hours off duty between 8-hour work periods, and an extended off-duty period of 80 hours between workweeks. Objective differences, as judged by urine biochemistry, between workers on the two shift patterns are minimal and insignificant statistically. Generally, however, greater fatigue was reported in connection with the 2-2-1 rotation than with the steady shift, both preshift and postshift. When prework to postwork changes in subjective fatigue were compared for the two shift patterns, no statistically significant differences were noted. Within the 2-2-1 schedule, there was (i) significantly greater excretion of catecholamines on the day watch as compared to the evening watch; and (ii) significantly greater preshift fatigue reported on day shift than evening shift. Despite the observed differences between and within the steady and rotating shift patterns, employee participation in shift pattern choice may have contributed greatly to worker contentment and willingness to accept the observed stressors.