NIOSHTIC-2 Publications Search
Extended workdays: effects of 8-hour and 12-hour rotating shift schedules on performance, subjective alertness, sleep patterns, and psychosocial variables.
Rosa-RR; Colligan-MJ; Lewis-P
Work Stress 1989 Jan; 3(1):21-32
This study evaluated potential changes in a range of variables associated with a switch from a 5 to 7 day/8 hour (hr) shift schedule with three rotations to a 3 to 4 day/12hr shift schedule with two rotations. The workers experiencing these schedules were control room operators at a continuous processing facility; 52 subjects were tested during the 8hr and 55 during the 12hr shift. Standard laboratory type measures of performance and alertness were used along with a questionnaire of sleep patterns and other personal habits. Decrements in the laboratory type tests of performance/alertness, attributable to the extra 4hr of work per day, were observed after 7 months on the new schedule. Reductions in sleep and disruptions of other personal activities were also associated with the 12hr workdays. Increases in self reported stress, however, were attenuated by the shortened work week. The extra work time per day was a major factor in producing poorer performance/alertness scores on the 12hr shift. Some of the disadvantages of the longer workday may be offset by the shorter workweek. The results of the study indicated that sufficient decrements in alertness and disruptions of sleep occurred to warrant 3 year followup testing which is currently under way.
NIOSH-Author; Job-stress; Sleep-disorders; Shift-work; Task-performance; Mental-stress; Psychological-effects; Author Keywords: Shift work; Compressed work week; Performance stress; Alertness; Sleep
Issue of Publication
Work and Stress
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division