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Table 3 Comparison between days for all participant's Actiwatch night sleep measures (n = 32), KSS2 (n = 29) and KSD3, (n = 32) ratings.

From: Sleep and recovery in physicians on night call: a longitudinal field study

  Night after day-time work Night call 1st post-call night 2nd post-call night Saturday night Type III F-test
  Mean 95% CI Mean 95% CI Mean 95% CI Mean 95% CI Mean 95% CI P-value
AW sleep measures            
Total sleep time (min) 364a 344-383 186 148-224 419b 385-452 399b 373-425 412b 393-431 < 0.001
Sleep efficiency1 (%) 90 88-92 86c 83-90 90 89-92 91 90-92 89d 88-91 0.045
KSS measures2            
Sleepiness (mean) 5.6 4.9-6.2 ---   6.1 5.4-6.8 5.5 4.8-6.3 5.1 4.2-6.0 0.206
Mental fatigue 6.1 5.6-6.6 ---   7.1e 6.5-7.7 6.1 5.4-6.9 5.8 5.0-6.7 0.004
KSD measures3            
SQI4 4.2 3.9-4.4 ---   4.3 4.1-4.5 4.3 4.0-4.5 4.2 3.9-4.4 0.673
Sufficient sleep 3.0 2.7-3.4 ---   2.9 2.5-3.3 3.1 2.7-3.6 3.6 3.2-4.0 0.052
Ease awakening 2.6f 2.2-3.0 ---   2.8f 2.5-3.2 3.0 2.6-3.4 3.4 3.0-3.8 0.042
Well rested 2.6f 2.2-3.0 ---   2.4g 2.0-2.8 3.0 2.6-3.4 3.3 2.9-3.7 0.013
  1. (Estimated means are presented).
  2. Note: 1. Sleep efficiency = the relative sleep time between sleep start and sleep end in %, (with awakenings during the night accounted for).
  3. 2. KSS (Karolinska sleepiness scale)-ratings are 1-10 (low-high). 3. KSD (Karolinska sleepiness diary)-ratings are scored 1-5, where 5 is the most positive. 4. SQI = (Sleep quality index) 1-5 (low quality-high quality), is the mean of 4 variables in the KSD.
  4. a Higher than night call, but lower than 1st and 2nd post-call nights and Saturday night (P's < 0.05). b Higher than night after day-time work and night call (P's < 0.05). c Lower than 1st and 2nd post-call nights. d Lower than 2nd post-call night (P's <0.05). e Higher than daytime work, 2nd post-call night, and Saturday. (P' < 0.01). f Lower than Saturday night (P's < 0.05). g Lower than Saturday night and 2nd post-call night (P's < 0.05).