Table 3 IRT difficulty parameters for the QLQ-C30 items
From: Ethnic differential item functioning in the assessment of quality of life in cancer patients
Standardized Difficulty | |||||||
|---|---|---|---|---|---|---|---|
Item | Content | Caucasian | Japanese | Filipino | Hawaiian | χ2(3) | p |
01 | Physical | 1.09 | 1.64 | 1.11 | 0.74 | 27.7 | * |
02 | Physical | 0.72 | 0.83 | 0.19 | 1.11 | 15.2 | * |
03 | Physical | -1.51 | -1.29 | -2.35 | -0.61 | 11.1 | .01 |
04 | Physical | -1.12 | -0.78 | -1.24 | -0.88 | 2.3 | .51 |
05 | Physical | -2.15 | -2.39 | -2.97 | -2.29 | 2.5 | .47 |
06 | Role | 0.81 | 0.51 | 0.51 | 0.61 | 7.3 | .06 |
07 | Role | -1.79 | -0.80 | -0.73 | -0.38 | 22.2 | * |
08 | Dyspnea | -0.15 | -0.01 | -0.06 | 0.17 | 4.2 | .24 |
09 | Pain | 0.90 | 0.89 | 0.67 | 0.68 | 5.3 | .15 |
10 | Fatigue | 1.50 | 0.94 | 1.25 | 1.02 | 28.8 | * |
11 | Insomnia | 1.05 | 0.68 | 0.93 | 1.02 | 11.0 | .01 |
12 | Fatigue | 0.23 | 0.35 | 0.51 | 0.43 | 5.2 | .15 |
13 | Appetite Loss | -0.11 | -0.39 | 0.00 | -0.34 | 5.2 | .16 |
14 | Nausea | -0.96 | -1.25 | -0.30 | -0.61 | 19.4 | * |
15 | Nausea | -2.23 | -2.89 | -1.35 | -3.43 | 19.5 | * |
16 | Constipation | -0.34 | 0.01 | 0.16 | 0.16 | 27.2 | * |
17 | Diarrhea | -0.44 | -0.55 | -0.73 | -1.04 | 12.1 | .01 |
18 | Fatigue | 1.26 | 1.20 | 1.08 | 1.41 | 1.3 | .72 |
19 | Pain | -0.35 | -0.14 | -0.13 | 0.11 | 9.0 | .03 |
20 | Cognitive | -0.42 | -0.35 | -0.42 | -0.24 | 1.0 | .80 |
21 | Emotional | 0.44 | 0.18 | 0.42 | 0.01 | 11.1 | .01 |
22 | Emotional | 1.18 | 0.91 | 1.27 | 0.56 | 21.7 | * |
23 | Emotional | 0.49 | 0.51 | 0.58 | 0.72 | 2.5 | .47 |
24 | Emotional | 0.47 | 0.30 | 0.54 | -0.03 | 11.0 | .01 |
25 | Cognitive | 0.54 | 0.89 | 0.13 | 0.92 | 30.2 | * |
26 | Social | 0.07 | 0.23 | 0.21 | -0.24 | 4.7 | .19 |
27 | Social | 0.71 | 0.57 | 0.28 | 0.23 | 15.2 | * |
28 | Financial | 0.26 | 0.30 | 1.12 | 0.49 | 47.0 | * |
29 | Physical | 0.08 | 0.14 | -0.33 | -0.01 | 15.1 | * |
30 | Overall | -0.22 | -0.22 | -0.37 | -0.31 | 2.0 | .56 |