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Report No: DOT/FAA/AM-96/23

Title and Subtitle: Shift Work, Age, and Performance: Investigation of the 2-2-1 Shift Schedule Used in Air Traffic Control Facilities II. Laboratory Performance Measures

Report Date: September 1996

Authors: Pamela S. Della Rocco and Crystal E. Cruz

Abstract: Many Air Traffic Control Specialists (ATCSs) work a counterclockwise rotating shift schedule, called the "2-2-1," or some variation of the schedule. The 2-2-1 involves rotating from two afternoon shifts to two mornings, and finally, to a midnight shift over the course of one work week. The purpose of the present study was to investigate the effects in two different age groups of working the 2-2-1 schedule, as compared to a straight day schedule on measures of complex task performance in a laboratory-based synthetic work environment. It was hypothesized that the counterclockwise rotations would result in performance decrements over the course of the 2-2-1 week.

Four groups of five male subjects between the ages of 30 to 35 (n=10) and 50 to 55 (n=10) participated in the four-week study. Subjects were screened on medical and cognitive criteria. The Multiple Task Performance Battery (MTPB) was utilized to provide a motivating synthetic work environment. Subjects worked three 2-hour sessions on the MTPB per eight-hour day for three weeks of a four-week protocol. During the second and fourth weeks, subjects worked day shifts (0800-1630). During the third week, subjects worked the 2-2-1 schedule. Performance measures were analyzed for each of the five tasks in the MTPB. Composite scores were also computed. Significant performance decrements were observed primarily on the night shift for both age groups. The older group demonstrated decrements in accuracy of recall on the code lock task following both rapid rotations during the 2-2-1 schedule.

This study was part of a research program designed to develop fatigue countermeasures for Air Traffic Control Specialists. The hypothesis that the rapid, counterclockwise rotations would result in performance decrements was partially supported. Data suggest that initial interventions should be directed toward maintaining alertness and performance on the night shift.

Key Words: Shift Work, Performance, Multiple Task Performance Battery, Age

No. of Pages: 60