Table 2.
Overused items (expressed in %) for θ-values ranging between −2 and +2
| θ | Total bank | Fatigue | Physical function | Social roles | COPD-SIB |
|---|---|---|---|---|---|
| −2 | 15 | 10 | 13 | 17 | 22 |
| −1.8 | 14 | 8 | 13 | 17 | 20 |
| −1.6 | 12 | 6 | 11 | 17 | 17 |
| −1.4 | 11 | 6 | 8 | 17 | 17 |
| −1.2 | 9 | 6 | 8 | 9 | 15 |
| −1 | 8 | 6 | 6 | 6 | 15 |
| −0.8 | 8 | 6 | 6 | 6 | 13 |
| −0.6 | 7 | 6 | 5 | 6 | 13 |
| −0.4 | 7 | 6 | 5 | 6 | 11 |
| −0.2 | 7 | 6 | 5 | 6 | 11 |
| 0 | 7 | 6 | 5 | 6 | 11 |
| 0.2 | 7 | 6 | 3 | 9 | 13 |
| 0.4 | 8 | 6 | 3 | 9 | 15 |
| 0.6 | 7 | 6 | 3 | 6 | 15 |
| 0.8 | 7 | 6 | 3 | 6 | 15 |
| 1 | 8 | 8 | 3 | 6 | 17 |
| 1.2 | 9 | 10 | 3 | 6 | 17 |
| 1.4 | 10 | 12 | 3 | 9 | 17 |
| 1.6 | 11 | 12 | 6 | 11 | 17 |
| 1.8 | 13 | 12 | 8 | 20 | 15 |
| 2 | 14 | 14 | 8 | 17 | 20 |
Overused items are defined as items whose usage rate exceeded the expected usage rate (average test length for a given θ-value divided by the total bank size)