Extended Workdays: Effects of 8-Hour and 12-Hour Rotating Shift Schedules on Test Performance,Subjective Alertness,Sleep Patterns,and Psychosocial Variables

A newly instituted 3–4 day/12-hr rotating shift schedule was compared to the previous 5–7 day/8-hr schedule using standard laboratory-type measures of performance and alertness, and a questionnaire on sleep patterns and other personal habits. After seven months adaptation to the new schedule, a preliminary analysis indicated that there were some decrements alertness, reductions in sleep, and disruptions of other personal activities during 12-hr workdays. Gastro-intestinal state improved during night shift, however, and increases in self-reported stress were reduced by the shortened workweek. These results are discussed in terms of trade-offs between longer workdays and shorter workweeks. It is emphasized that, at this time, no determination can be made of the extent of risk associated with these changes in alertness.