Table 4 Number of items eliminated and cause for elimination
| Â | Â | Cause for elimination | Â | |||
|---|---|---|---|---|---|---|
Question set | Original # of items | Item-total correlation < 0.40 | Simple structure violation | Local dependence | DIF | Final # of items |
Cognitive | 28 | 5 | 3 | 5 | 0 | 15 |
Emotional | 28 | 5 | 1 | 0 | 2 | 20 |
Pain | 17 | 0 | 0 | 4 | 0 | 13 |
Sleep | 20 | 2 | 0 | 4 | 2 | 12 |
Social | 28 | 3 | 1 | 3 | 4 | 17 |
Stiffness | 19 | 0 | 1 | 2 | 1 | 15 |