Sleep and Motor Performance in On-call Internal Medicine Residents

STUDY OBJECTIVES: To compare vigilance and performance among internal medicine residents doing in-house call versus residents not doing in-house call. DESIGN: Prospective study of resident cohorts with repeated testing. SETTING: University Teaching Hospital. PARTICIPANTS: Internal medicine residents doing in-house call and residents not doing in-house call (pathology, endocrinology) (controls). MEASUREMENTS AND RESULTS: Subjective sleepiness scores (daily Stanford Sleepiness Scale and Epworth Sleepiness Scale at start and end of the test period), actigraphy, and daily sleep logs as well as regular psychomotor vigilance testing using a Palm version (Walter Reed Army Institute of Research) of the Psychomotor Vigilance Test (PVT). Subjects were enrolled for a period of 28 to 32 days, which included 4 to 6 on-call nights for the internal medicine residents. Controls took call from home. Participants were compensated for their time. RESULTS: Twenty residents were evaluated, 13 internal medicine and 7 controls. Overall median reaction time was slower in the internal medicine residents (264.7 +/- 102.9 vs 239.2 +/- 26.1 milliseconds; P < .001). Internal medicine residents showed no difference in reaction time postcall versus other periods (269.9 +/- 131.2 vs 263.6 +/- 95.6; P = .65). Actigraphic sleep time was shorter during on-call than noncall nights and in internal medicine residents as compared with controls (287.48 +/- 143.8 vs 453.49 +/- 178.5 and 476.08 +/- 71.9 minutes; P < .001). Internal medicine residents had significantly greater major and minor reaction-time lapses compared with controls (1.26 +/- 3.4 vs 0.53 +/- 1.1 & 2.4 +/- 7.4 vs 0.45 +/- 1.0; P < .001). They reported increased sleepiness on postcall days compared with the start of their call (Stanford Sleepiness Scale: 3.26 +/- 1.2 vs 2.22 +/- 0.8; P < .001) but had scores similar to those of controls by their next call (2.22 +/- 0.8 vs 2.07 +/- 0.8; P = .13). CONCLUSIONS: Internal medicine residents have impaired reaction time and reduced vigilance compared with controls. Despite subjective improvements in sleepiness postcall, there was no change in their objective performance across the study period, suggesting no recovery. Internal medicine residents did not get extra sleep on postcall nights in an attempt to recover their lost sleep time. Implications for residents' well-being and patient care remain unclear.