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^ |