Effects of Fatigue on Driving Safety: A Comparison of Brake Reaction Times in Night Float and Postcall Physicians in Training

Abstract

Background Concerns about duty hour and resident safety have fostered discussion about postshift fatigue and driving impairment. Objective We assessed how converting to a night float schedule for overnight coverage affected driving safety for trainees. Methods Brake reaction times were measured for internal medicine and orthopaedic surgery resident volunteers after a traditional 28-hour call shift and after a night float shift. We conducted matched paired t tests of preshift and postshift reaction time means. Participants also completed the Epworth Sleepiness Scale pre- and postshift. Results From June to July 2013, we enrolled 58 interns and residents (28 orthopaedic surgery, 30 internal medicine). We included 24 (41%) trainees on night float rotations and 34 (59%) trainees on traditional 28-hour call shifts. For all residents on night float rotations, there was no significant difference pre- and postshift. An increase in reaction times was noted among trainees on 28-hour call rotations. This included no effect on reaction times for internal medicine trainees pre- and postshift, and an increase in reaction times for orthopaedic trainees. For both night float and traditional call groups, there were significant increases in the Epworth Sleepiness Scale. Conclusions Trainees on traditional 28-hour call rotations had significantly worse postshift brake reaction times, whereas trainees on night float rotations had no difference. Orthopaedic trainees had significant differences in brake reaction times after a traditional call shift.

Shorter Versus Longer Shift Durations to Mitigate Fatigue and Fatigue-Related Risks in Emergency Medical Services Personnel and Related Shift Workers: A Systematic Review

“…Eight studies reported outcomes stratified by 6 versus 30-hour shifts, 8 versus 24-hour, 8.5 versus 24-hour, 9 versus 32hour, 14 versus 24-hour, and 14 versus 28-hour shifts. Three of the 15 studies grouped into the <24 versus ࣙ24-hour comparison reported findings for critical outcomes of patient and personnel safety (16,31,32). One study by Talusan et al measured the reaction time of medical residents at the start and end of shifts in a driving simulator (32).…”