Figure 2.

Cumulative total sleep time during the residents' intensive care unit (ICU) schedule including nocturnal sleep and diurnal naps in comparison with cumulative sleep over 14 days prior to the ICU rotation (including 7 days of projected cumulative sleep; dotted lines, open circle). Compared with daily sleep duration (7.75 h; 95% confidence interval 6.5-9.0 h) obtained when not on alternating extended duration shifts, when on a schedule including alternating 30-h shifts residents obtained 10.9 h less sleep by day 7, 20.4 h less sleep by day 14, and a projected 30.6 h less sleep by day 21, n = 34.