Table 3.
Summary of preliminary PU-QOL instrument psychometric analysis, field test 1
| Scale (No. of items) |
Rasch analysis |
Traditional psychometric analysis |
||||||
|---|---|---|---|---|---|---|---|---|
| Items with disordered thresholds | Item locations logits range | Fit statistics fit residuals outside +/−2.5 | Items with Chi square probability significance ≥0.001 | Person separation index | Cronbach alpha | Range IIC | Scaling assumptions corrected ITC | |
| Pain (8) |
5 |
-0.94 − 0.80 |
0 |
4 |
0.78 |
0.89 |
0.24 – 0.66 |
0.53 – 0.70^ |
| Exudate (8) |
4 |
-0.51 − 0.48 |
0 |
0 |
0.59 |
0.92 |
0.40 – 0.86 |
0.56 – 0.84^ |
| Odour (6) |
2 |
-1.47 − 0.60 |
0 |
0 |
0.62 |
0.96 |
0.74 – 0.91 |
0.83 – 0.92^ |
| Sleep (6) |
3 |
-0.54 − 0.31 |
0 |
0 |
0.62 |
0.92 |
0.48 – 0.84 |
0.67 – 0.86^ |
| Vitality (3) |
0 |
-0.48 − 0.44 |
0 |
0 |
0.03 |
n/a |
n/a |
n/a |
| Movement/mobility (11) |
4 |
-0.33 − 0.48 |
0 |
0 |
0.58 |
0.93 |
0.23 – 0.91 |
0.67 – 0.80^ |
| ADL (9) |
8 |
-0.54 − 0.57 |
0 |
0 |
0.29 |
0.95 |
0.41 – 0.90 |
0.58 – 0.90^ |
| Emotional well-being (17) |
4 |
-1.15 − 1.46 |
1 |
0 |
0.82 |
0.93 |
0.24 – 0.79 |
0.54 – 0.76^ |
| Appearance & self- consciousness (7) |
4 |
-0.83 − 0.65 |
0 |
0 |
0.56 |
0.90 |
0.41 – 0.75 |
0.60 – 0.79^ |
| Participation (9) | 4 | -0.56 − 0.54 | 0 | 0 | 0.65 | 0.96 | 0.53 – 0.89 | 0.73 – 0.90^ |
IIC inter-item correlation; ^Range item-total correlation (ITC).