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Table 2 Sleep timing measures, Mean (SD), Change values and Effect Sizes

From: Efficacy of a behavioral self-help treatment with or without therapist guidance for co-morbid and primary insomnia -a randomized controlled trial

  Pre Post Fu3 Change Pre to Post Change Pre to Fu3
  Mean (SD) Mean (SD) Mean (SD) Mean (95% CI) Effect size (d)a Mean (95% CI) Effect size (d)
Sleep Onset Latency, minutes        
   Bibliotherapy with support (n = 44) 60.3 (41.0) 24.9 (17.0) 33.5 (22.6) -35.4 (-46.6 to -24.2) -1.13 -26.8 (-39.0 to -14.5) -0.81
   Bibliotherapy (n = 45) 65.7 (45.1) 45.1 (32.2) 43.0 (28.4) -20.6 (-30.6 to -10.6) -0.53 -22.7 (-34.8 to -10.5) -0.60
   Wait-list control (n = 43) 66.9 (42.1) 62.2 (42.4) 62.4 (45.1) -4.6 (-10.7 to 1.5) -0.11 -4.5 (-12.0 to 3.0) -0.10
Wake After Sleep Onset, minutes        
   Bibliotherapy with support (n = 44) 53.6 (40.4) 17.0 (16.8) 26.8 (29.3) -36.5 (-47.7 to -25.4) -1.18 -26.8 (-38.9 to -14.6) -0.76
   Bibliotherapy (n = 45) 47.5 (33.6) 32.0 (27.0) 30.2 (28.7) -15.6 (-24.6 to -6.5) -0.51 -17.4 (-26.6 to -8.2) -0.55
   Wait-list control (n = 43) 36.9 (29.5) 30.4 (28.9) 25.3 (25.0) -6.5 (-12.5 to -0.4) -0.22 -11.6 (-19.4 to -3.7) -0.42
Total Sleep Time, hours        
   Bibliotherapy with support (n = 44) 5.56 (1.44) 6.07 (1.02) 6.52 (0.95) 0.51 (0.20 to 0.83) 0.41 0.97 (0.56 to 1.37) 0.79
   Bibliotherapy (n = 45) 5.73 (0.89) 6.22 (1.02) 6.46 (0.96) 0.49 (0.26 to 0.73) 0.51 0.73 (0.46 to 1.00) 0.79
   Wait-list control (n = 43) 6.40 (1.09) 6.55 (1.26) 6.74 (1.11) 0.14 (-0.14 to 0.42) 0.13 0.34 (0.09 to 0.59) 0.31
Sleep Efficiency, %        
   Bibliotherapy with support (n = 44) 67.1 (15.5) 85.4 (6.8) 83.3 (8.3) 18.3 (14.4 to 22.2) 1.53 16.2 (11.7 to 20.6) 1.30
   Bibliotherapy (n = 45) 68.3 (11.1) 76.4 (10.9) 78.4 (9.8) 8.1 (5.8 to 10.3) 0.74 10.1 (7.6 to 12.6) 0.96
   Wait-list control (n = 43) 71.5 (11.2) 74.5 (11.5) 76.1 (10.5) 3.0 (0.5 to 5.4) 0.27 4.5 (1.8 to 7.2) 0.42
  1. Abbreviations: Pre, Pre-treatment assessment; Post, Post-treatment assessment; Fu3, 3-month follow-up assessment
  2. a Effect sizes calculated within groups, pre-post, and pre-fu3, with pooled SDs. (A negative effect size represents a decrease in the measure, a positive effect size an increase.)