Skip to main content

Table 2 Central tendency and variability of the ISI scale

From: The Moroccan dialect version of the Insomnia Severity Index

ESS items Mean (SD) Median (min-max) Floor effecta (%) Ceiling effectb (%)
Item 1 1.33 (1.02) 1 (0–4) 22.5 1.7
Item 2 0.92 (0.91) 1 (0–4) 39.2 0.8
Item 3 2.06 (1.34) 2 (0–4) 15.8 18.3
Item 4 1.93 (1.01) 2 (0–4) 5.0 6.7
Item 5 1.01 (0.96) 1 (0–4) 35.8 1.7
Item 6 1.33 (1.05) 1 (0–4) 25.0 1.7
Item 7 1.64 (0.99) 2 (0–4) 10.0 4.2
Total score 10.15 (5.02) 10.5 (0–28) 2.5 0.8
  1. SD standard deviation
  2. aPercentage of the lowest modality
  3. bPercentage of the highest modality