| Items of the ISI | Item Response Choice* | ||||
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | |
| 1. Difficulties falling asleep | 45.1 | 25.0 | 16.4 | 11.3 | 2.2 |
| 2. Difficulties staying asleep | 35.6 | 24.6 | 22.7 | 16.3 | 0.7 |
| 3. Early morning awakenings | 36.9 | 22.6 | 18.4 | 18.7 | 3.4 |
| 4. Sleep dissatisfaction | 17.4 | 33.8 | 19.4 | 24.3 | 5.2 |
| 5. Interference of sleep problems with daytime functioning | 34.6 | 24.9 | 24.6 | 12.9 | 2.9 |
| 6. Noticeability of sleep difficulties by others | 45.8 | 23.8 | 21.6 | 7.6 | 1.2 |
| 7. Preoccupation and distress caused by sleep difficulties | 47.7 | 25.2 | 19.3 | 7.2 | 0.7 |
↵* For items 1 to 3, 0 = no problem, 1 = mild, 2 = moderate, 3 = severe, and 4 = very severe. For item 4, 0 = very satisfied, 1 = satisfied, 2 = neutral, 3 = dissatisfied, and 4 = very dissatisfied. For items 5 to 7, 0 = not at all, 1 = a little, 2 = somewhat, 3 = much, 4 = very much.
ISI, Insomnia Severity Index.