Table 3.
Factor loadings of DISS items
| Negative mood | Positive mood | Fatigue/sleepiness | Alert cognition* | |
|---|---|---|---|---|
| Anxious |
0.92 |
−0.01 |
−0.02 |
0.15 |
| Stressed |
0.86 |
0.04 |
0.12 |
−0.07 |
| Tense |
0.90 |
0.03 |
0.08 |
−0.14 |
| Sad |
0.86 |
−0.01 |
−0.03 |
−0.01 |
| Irritable |
0.77 |
0.07 |
0.15 |
0.00 |
| Forgetful |
0.59 |
0.01 |
0.19 |
0.19 |
| Alert |
−0.11 |
0.85 |
0.05 |
0.21 |
| Relaxed |
0.19 |
0.82 |
−0.12 |
−0.11 |
| Energetic |
−0.23 |
0.77 |
0.32 |
−0.12 |
| Calm |
0.19 |
0.84 |
−0.14 |
−0.06 |
| Happy |
0.11 |
0.86 |
−0.07 |
−0.12 |
| Efficient |
−0.08 |
0.84 |
0.14 |
−0.05 |
| Clear-headed |
0.01 |
0.86 |
−0.06 |
0.22 |
| Weary |
0.27 |
−0.05 |
0.52 |
0.14 |
| Fatigued |
0.11 |
−0.03 |
0.81 |
−0.01 |
| Sleepy |
0.04 |
0.00 |
0.85 |
−0.01 |
| Exhausted |
0.11 |
0.00 |
0.88 |
−0.01 |
| Concentrate† |
0.20 |
0.22 |
0.31 |
0.25 |
| Effort† | 0.08 | 0.23 | 0.31 | 0.12 |
†Except as noted, items are of the form, “How _____ do you feel?”.
*Lacked strong factor loadings, but was characterized based on 4 items with largest factor loadings.
Concentrate: actual wording is, “How well are you able to concentrate?”.
Effort: actual wording is, “How much of an effort is it to do anything?”.
DISS daytime symptoms in insomnia scale.
Bolded items denote primary factor loading.