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. 2021 Dec 4;22:873. doi: 10.1186/s13063-021-05831-3

Table 2.

What did sleep quality look like in the two groups (reading a book in bed and not reading a book in bed) at the end of the trial?

Sleep quality at the end of the trial Reading group (n=369)
n (%)
Not reading group (n=405)
n (%)
• Terrible 1 (0.27%) 4 (0.99%)
• Poor 24 (6.50%) 42 (10.4%)
• Fair 104 (28.2%) 156 (38.5%)
• Good 218 (59.1%) 186 (45.9%)
• Excellent 22 (5.9%) 17 (4.25%)
Sleep disturbance4
 Mean1 (sd)2 46.7 (7.97) 49.9 (7.94)
 Median (min, max)~ 45.5 [28.9, 70.8] 50.1 [28.9, 73.0]
Daytime sleepiness5
 Mean (sd) 6.86 (1.93) 6.15 (2.05)
 Median3 (min, max) 7 [ 0, 10] 7 [0, 10]

1Mean tells us the average sleep disturbance score indicated by people who took part in The Reading Trial

2The standard deviation (sd) tells us the amount of variability we found in the individual scores people reported for sleep disturbance compared to the mean score

3The median tell us what the ‘middle’ score was in the list of scores indicated by people when we asked them to score their daytime sleepiness after taking part in The Reading Trial

4We measured sleep disturbance using the PROMIS (Patient-Reported Outcomes Measurement Information System) Short Form Sleep Disturbance Scale (eight items each on a 5-point scale with a difference of one unit between each point on the scale)

5Daytime sleepiness’ was measured using a 10-point scale. The points on the scale increase in units of one