Table 3.

Sleep results for simplified sleep restriction versus control at baseline and 6 months. Data presented as mean (SD)

Intervention (Simplified sleep restriction)ControlDifference between the groups,b,d (95% CI) P-value
Baseline scorea n= 466-month scorea n= 43Mean change (95% CI)b,cBaseline scorea n= 516-month scorea n= 50Mean change (95% CI)b,c
Primary outcomes
Sleep efficiency % (sleep diary)73.32 (11.80)80.46 (10.66)e6.72 (3.90 to 9.54)74.15 (11.05)78.24 (10.52)f4.28 (−6.70 to 1.86)2.44 (−0.96 to 5.84) 0.200
Sleep efficiency % (actigraphy)82.68 (4.66)83.74 (4.94)g1.75 (0.42 to 3.09)82.37 (4.67)81.96 (5.38)f−0.46 (−1.58 to 0.65)2.22 (0.65 to 3.79) 0.006
Secondary outcomes
Epworth Sleepiness Scale5.17 (3.70)3.70 (2.93)−1.62 (−2.72 to −0.53)6.45 (3.29)4.86 (3.28)−1.55 (−2.50 to −0.61)−0.07 (−1.40 to 1.27) 0.900
Flinders Fatigue Scale12.74 (6.83)7.30 (5.49)−5.39 (−7.16 to −3.63)12.53 (5.11)9.08 (4.96)−3.12 (−4.65 to −1.59)−2.27 (−4.42 to −0.13) 0.040
Sleep onset latency, minutes
  Sleep diary31.50 (23.00)22.77 (19.60)−6.29 (−12.75 to 0.16)29.55 (22.48)25.21 (19.38)e−2.84 (−8.38 to 2.70)−3.45 (−11.23 to 4.32) 0.400
  Actigraphy16.10 (14.47)13.37(7.91)f−5.08 (−9.90 to −0.26)14.66 (12.42)15.61 (12.74)e1.06 (−2.97 to 5.08)−6.13 (−11.82 to −0.44) 0.040
Wake after sleep onset, minutes
  Sleep diary44.82 (28.92)29.47 (31.71)−13.37 (−22.69 to −4.05)47.84 (30.14)40.02 (27.00)e−7.61 (−15.60 to 0.39)−5.76 (−17.00 to 5.47) 0.300
  Actigraphy47.59 (13.88)44.33 (15.44)f−4.54 (−8.99 to −0.08)51.81(19.51)51.59 (17.50)e−1.46 (−5.18 to 2.27)−3.08 (−8.35 to 2.18) 0.200
Total sleep time, minutes
  Sleep diary369.59 (65.27)397.30 (63.29)23.71 (9.51 to 37.90)376.93 (61.08)398.17 (64.91)e18.99 (6.81 to 31.67)4.72 (−12.39 to 21.83) 0.600
  Actigraphy415.68 (34.17)407.20 (36.92)f−7.00 (−15.94 to 1.95)418.36 (39.36)415.05 (38.45)e−7.10 (−14.58 to 0.38)0.10 (−10.47 to 10.67) 0.990
  • Statistically significant results are in bold.

  • a Observed (raw) data.

  • b Multiple linear regression adjusted for age, sex, and baseline insomnia severity (using Insomnia Severity Index score26).

  • c Least square mean for change from baseline to 6-month score.

  • d Least square mean difference for change from baseline to 6-month score between sleep restriction and control group.

  • e n = 43.

  • f n = 49.

  • g n = 42.