Table 1.

Percentage of each item endorsed on the Insomnia Severity Index

	Item response choice*
Item	0	1	2	3	4
1. Difficulty falling asleep	59.4	22.6	12.8	2.2	0.9
2. Difficulty staying asleep	38.4	34.1	19.7	5.1	1.3
3. Problems with early wakening	42.8	34.3	16.7	3.3	0.8
4. Satisfaction with sleep pattern	18.3	37.8	18.5	22.0	3.5
5. Interference with daily functioning	56.7	30.5	8.5	2.5	1.6
6. Sleep difficulty noticeable to others	78.4	15.3	3.9	1.1	0.8
7. Worried about sleep pattern	66.4	22.6	7.6	1.4	1.4

*Items 1–3: 0, no problem; 1, mild; 2, moderate; 3, severe; 4, very severe.

*Item 4: 0, very satisfied; 1, satisfied; 2, neutral; 3, dissatisfied; 4, very dissatisfied.

*Items 5–7: 0, not at all; 1, a little; 2, somewhat; 3, much; 4, very much.