The cognitive impact of guard shifts in physicians: a before-after study

Objective: We intend to evaluate the change of different cognitive functions after a guard shift in physicians.

Methods: A descriptive observational study was performed. The study population included Spanish physicians who were asked to complete before and immediately after their guard shift the following tests: Digit Span, TMT-A, TMT-B, Symbol Digit, Stroop, Free and Cued Selective Reminding, creep and formal fluency, Visual Orientation and Space Perception tests, and the Leeds Sleep Questionnaire.

Results: Thirty subjects were included in the study among which 43.3% were female. The mean subjective impression of the guard shift was 4.47/10 (2.57) and was correlated with the number of sleep hours during the guard shift (r = 0.72, p < 0.001). Statistically significant differences in the comparison between pre- and post-guard period results were found for the Symbol Digit test (88.27 vs. 81.47, p = 0.005), Digit Span test (7.43 vs. 7.00, p = 0.025), Free and Cued Selective Reminding Test (22.73 vs. 21.20, p = 0.002), categorical fluency (39.03 vs. 34.53, p = 0.008), and phonemic fluency (19.57 vs. 16.13, p = 0.001).

Conclusions: The realization of guard shift was associated with a lower yield in several cognitive functions, especially in tasks related to executive function and attention.