Table 2.
Diagnostic statistics for the original item set of DEMQOL (28 items)
| Item | Location | Fit Residual | ChiSq | p | DIF | Item residual correlations | |
|---|---|---|---|---|---|---|---|
| r | Correlation with item | ||||||
| 1. Cheerful | 0.480 | 0.452 | 2.08 | 0.99 | ns | 0.36, 0.27, 0.21, 0.20, 0.07, 0.04 | 3, 5, 10, 6, 12, 7 |
| 2. Worried or anxious | 0.160 | 0.413 | 6.07 | 0.73 | ns | 0.22, 0.18, 0.10, 0.08, 0.01, 0.01 | 9, 4, 7, 14, 11, 12 |
| 3. Enjoying life | 0.322 | 1.340 | 4.46 | 0.88 | ns | 0.36, 0.30, 0.25, 0.21, 0.06, 0.05, 0.04 | 1, 10, 6, 5, 12, 8, 7 |
| 4. Frustrated | 0.352 | −0.645 | 2.86 | 0.97 | ns | 0.18, 0.17, 0.15, 0.14, 0.07, 0.07 | 2, 11, 12, 9, 7, 13 |
| 5. Confident | 0.578 | 1.129 | 5.46 | 0.79 | ns | 0.27, 0.21, 0.18, 0.18, 0.02 | 1, 3, 6, 10, 9 |
| 6. Full of energy | 1.244 | 4.014 | 11.68 | 0.23 | ns | 0.53, 0.25, 0.20, 0.18, 0.07, 0.01 | 10, 3, 1, 5, 13, 12 |
| 7. Sad | −0.108 | −1.561 | 6.79 | 0.66 | ns | 0.17, 0.15, 0.15, 0.10, 0.07, 0.04, 0.04, 0.01 | 12, 8, 9, 2, 4, 1, 3, 11 |
| 8. Lonely | −0.380 | 0.916 | 3.25 | 0.95 | ns | 0.39, 0.15, 0.14, 0.05, 0.04 | 20, 7, 12, 3, 9 |
| 9. Distressed | −0.563 | −3.047 | 9.83 | 0.36 | ns | 0.22, 0.15, 0.14, 0.10, 0.07, 0.04, 0.02 | 2, 7, 4, 12, 11, 8, 5 |
| 10. Lively | 1.340 | 5.076 | 17.35 | 0.04 | ns | 0.53, 0.30, 0.21, 0.18, 0.02, 0.01 | 6, 3, 1, 5, 12, 13 |
| 11. Irritable | −0.177 | −0.343 | 2.89 | 0.97 | ns | 0.17, 0.15, 0.07, 0.04, 0.01, 0.01 | 4, 12, 9, 13, 2, 7 |
| 12. Fed-up | 0.227 | −2.171 | 6.69 | 0.67 | ns | 0.17, 0.15, 0.15, 0.14, 0.10, 0.07, 0.06, 0.04, 0.02, 0.01, 0.01 | 7, 4, 11, 8, 9, 1, 3, 13, 10, 2, 6 |
| 13. Things you wanted but couldn’t | 0.633 | 1.526 | 7.15 | 0.62 | ns | 0.07, 0.07, 0.04, 0.04, 0.01, 0.01 | 4, 6, 11, 12, 10, 26 |
| 14. Forgetting happened recently | 0.454 | −0.907 | 3.93 | 0.92 | ns | 0.21, 0.18, 0.12, 0.12, 0.11, 0.08, 0.04, 0.04 | 17, 19, 15, 18, 2, 24, 27 |
| 15. Forgetting who people are | −0.197 | 3.299 | 8.56 | 0.48 | ns | 0.17, 0.15, 0.13, 0.13, 0.12, 0.08, 0.06 | 17, 16, 18, 19, 14, 24, 26 |
| 16. Forgetting what day it is | −0.034 | 3.399 | 7.23 | 0.61 | ns | 0.18, 0.15, 0.11, 0.07, 0.05, 0.03 | 17, 15, 14, 19, 18, 26 |
| 17. Thoughts being muddled | −0.046 | −1.890 | 4.96 | 0.84 | ns | 0.28, 0.21, 0.18, 0.18, 0.17, 0.12, 0.07 | 19, 14, 16, 18, 15, 24, 27 |
| 18. Difficulty making decisions | −0.267 | −2.999 | 7.47 | 0.59 | ns | 0.20, 0.18, 0.13, 0.12, 0.06, 0.05, 0.02, 0.01, 0.01 | 19, 17, 15, 14, 24, 16, 21, 23, 25 |
| 19. Poor concentration | 0.117 | −1.781 | 5.91 | 0.75 | ns | 0.28, 0.20, 0.18, 0.13, 0.08, 0.07, 0.05, 0.02, 0.02, 0.01 | 17, 18, 14, 15, 24, 16, 28, 25, 27, 21 |
| 20. Not having enough company | −0.572 | −0.572 | 2.85 | 0.97 | ns | 0.39, 0.10, 0.09, 0.04, 0.03 | 8, 22, 25, 23, 21 |
| 21. Get on with people close to you | −0.567 | −0.592 | 3.87 | 0.92 | ns | 0.46, 0.15. 0.10, 0.09, 0.03, 0.02, 0.02, 0.01, 0.01 | 22, 24, 23, 25, 20, 18, 27, 19, 28 |
| 22. Getting the affection you want | −0.663 | 0.959 | 5.59 | 0.78 | ns | 0.46, 0.11, 0.10, 0.10, 0.07, 0.02, 0.02, 0.01 | 21, 25, 20, 23, 24, 26, 28, 27 |
| 23. People not listening to you | −0.630 | −1.712 | 4.10 | 0.90 | ns | 0.21, 0.10, 0.10, 0.09, 0.04, 0.02, 0.01 | 24, 21, 22, 25, 20, 28, 18 |
| 24. Making yourself understood | −0.490 | −1.645 | 4.00 | 0.91 | ns | 0.21, 0.15, 0.12, 0.09, 0.08, 0.08, 0.07, 0.06, 0.04, 0.02, 0.01 | 23, 21, 17, 25, 15, 19, 22, 18, 14, 28, 26 |
| 25. Getting help when needed | −0.663 | −3.235 | 6.27 | 0.71 | ns | 0.11, 0.09, 0.09, 0.09, 0.09, 0.06, 0.04, 0.02, 0.02, 0.01 | 22, 20, 21, 23, 24, 28, 26, 19, 27, 18 |
| 26. Getting to the toilet in time | −0.429 | 2.661 | 15.41 | 0.08 | ns | 0.06, 0.04, 0.03, 0.02, 0.02, 0.02, 0.01, 0.01 | 15, 25, 16, 6, 22, 28, 13, 24 |
| 27. How you feel in yourself | −0.170 | −5.376 | 19.98 | 0.02 | ns | 0.22, 0.07, 0.04, 0.02, 0.02, 0.02, 0.01 | 28, 17, 14, 19, 21, 25, 22 |
| 28. Overall health | 0.047 | −2.102 | 7.97 | 0.54 | ns | 0.22, 0.06, 0.05, 0.02, 0.02, 0.02, 0.02, 0.01 | 27, 25, 19, 22, 23, 24, 26, 21 |
Fit residuals in bold are outside the acceptable range of +/− 2.5. Location = average item threshold location (logit). ChiSq = chi square value; p = chi square probability. DIF = differential item functioning; ns = non-significant. None of the chi square tests is statistically significant at p < 0.01 (Bonferroni corrected)