| Factors in OTSWI | Item | Item Scale Correlation | Cronbach’s Alfa |
|---|---|---|---|
| 1. Fatigue (F) | I am physically tired | .81 | .90 |
| I have no energy | .82 | ||
| I feel lazy and listless | .83 | ||
| 2. Joint and muscle pain (JMP) | My muscles are aching | .81 | .87 |
| My joints are aching | .79 | ||
| My legs are aching | .72 | ||
| 3. Cognitive functioning (CF) | I have difficulties to remember | .89 | .84 |
| I find it hard to concentrate | .66 | ||
| 4. Basic ADL (BADL) | Due to my physical condition I can’t get dressed by myself | .98 | .92 |
| Due to my physical condition I can’t take a bath or shower | .96 | ||
| Due to my physical condition I can’t buy food by my self | .84 | ||
| 5. Sleeping problems (SP) | I have difficulties with falling asleep | .87 | .89 |
| I sleep poorly | .88 | ||
| I wake up during the night | .83 | ||
| 6. Mood (M) | I feel irritated | .74 | .82 |
| I feel angry | .86 | ||
| 7. Foot pain (FP) | There is a burning ache in my feet | .86 | .81 |
| There is a numb and stabbing feeling in my feet | .88 | ||
| 8. Economy (E) | I worry about not being able to keep my job due to my health condition | .88 | .81 |
| I worry about my economy due to my health condition | .84 |