Table 3.
Diagnostic statistics for the original item set of DEMQOL-Proxy (31 items)
| Item | Location | Fit Residual | ChiSq | p | DIF | Item residual correlations | |
|---|---|---|---|---|---|---|---|
| r | Correlation with item | ||||||
| 1. Cheerful | 0.154 | −0.545 | 6.31 | 0.71 | ns | 0.42, 0.36, 0.28, 0.27, 0.22, 0.20, 0.11, 0.07 | 8, 6, 4, 11, 5, 10, 9, 7 |
| 2. Worried or anxious | 0.469 | −0.437 | 8.04 | 0.53 | ns | 0.34, 0.32, 0.28, 0.21, 0.17, 0.12, 0.04 | 3, 7, 5, 10, 9, 12, 6 |
| 3. Frustrated | 0.410 | −1.346 | 7.24 | 0.61 | ns | 0.34, 0.34, 0.31, 0.29, 0.25, 0.08, 0.05 | 2, 9, 10, 7, 5, 12, 6 |
| 4. Full of energy | 1.439 | 3.763 | 19.31 | 0.02 | ns | 0.66, 0.28, 0.26, 0.19, 0.07, 0.06 | 8, 4, 11, 6, 31, 10 |
| 5. Sad | --0.485 | −2.889 | 15.30 | 0.08 | ns | 0.39, 0.31, 0.28, 0.25, 0.22, 0.17, 0.15, 0.09, 0.06, 0.02 | 10, 7, 2, 3, 1, 9, 6, 11, 8, 28 |
| 6. Content | 0.332 | 0.831 | 6.14 | 0.73 | ns | 0.36, 0.26, 0.23, 0.19, 0.19, 0.15, 0.07, 0.05, 0.04 | 1, 8, 11, 4, 10, 5, 9, 3, 2 |
| 7. Distressed | --0.564 | −3.147 | 14.07 | 0.12 | ns | 0.32, 0.31, 0.29, 0.25, 0.23, 0.09, 0.07, 0.01 | 2, 5, 3, 10, 9, 6, 1, 16 |
| 8. Lively | 1.299 | 4.383 | 23.41 | 0.01 | ns | 0.66, 0.42, 0.37, 0.26, 0.11, 0.06, 0.02 | 4, 1, 11, 6, 10, 5, 31 |
| 9. Irritable | --0.094 | 0.040 | 4.74 | 0.86 | PWD sex PWD age Relation |
0.34, 0.30, 0.23, 0.17, 0.17, 0.11, 0.07 | 3, 10, 7, 2, 5, 1, 6 |
| 10. Fed-up | 0.126 | −3.633 | 16.44 | 0.06 | ns | 0.39, 0.31, 0.30, 0.25, 0.21, 0.20, 0.19, 0.11, 0.10, 0.06, 0.03 | 5, 3, 9, 7, 2, 1, 6, 8, 11, 4, 28 |
| 11. Things to look forward to | 0.470 | 4.110 | 26.13 | 0.00 | ns | 0.37, 0.27, 0.26, 0.23, 0.05, 0.01 | 8, 1, 4, 6, 28, 17 |
| 12. Memory in general | 0.503 | 1.733 | 7.16 | 0.62 | ns | 0.18, 0.12, 0.09, 0.08, 0.04, 0.04, 0.02, 0.01 | 14, 2, 15, 3, 18, 31, 13, 29 |
| 13. Forgetting happened long ago | −0.587 | 4.393 | 19.07 | 0.02 | ns | 0.16, 0.06, 0.05, 0.04, 0.03, 0.02, 0.02, 0.02 | 15, 16, 27, 25, 14, 12, 20, 24 |
| 14. Forgetting happened recently | 1.257 | 0.481 | 1.98 | 0.99 | ns | 0.30, 0.26, 0.26, 0.18, 0.18, 0.06, 0.03, 0.03, 0.01 | 15, 17, 18, 12, 19, 16, 13, 27, 26 |
| 15. Forgetting people’s names | 0.523 | 2.785 | 10.10 | 0.34 | ns | 0.30, 0.17, 0.16, 0.12, 0.09, 0.09, 0.07, 0.07, 0.02, 0.01 | 14, 17, 13, 16, 12, 18, 19, 20, 27, 25 |
| 16. Forgetting where he/she is | −0.984 | −1.341 | 5.45 | 0.79 | ns | 0.24, 0.18, 0.12, 0.09, 0.06, 0.06, 0.05, 0.03, 0.01 | 17, 18, 12, 19, 13, 14, 20, 23, 7 |
| 17. Forgetting what day it is | 0.301 | 1.954 | 5.52 | 0.79 | Severity | 0.30, 0.26, 0.24, 0.17, 0.17, 0.04, 0.01 | 18, 14, 16, 15, 19, 23, 11 |
| 18. Thoughts being muddled | 0.437 | −3.998 | 23.64 | 0.00 | ns | 0.39, 0.30, 0.26, 0.18, 0.17, 0.09, 0.04, 0.03 | 19, 17, 14, 16, 20, 15, 12, 26 |
| 19. Difficulty making decisions | 0.299 | −3.794 | 16.87 | 0.05 | ns | 0.39, 0.19, 0.18, 0.17, 0.09, 0.09, 0.07, 0.03, 0.02 | 18, 20, 14, 17, 16, 26, 15, 27, 25 |
| 20. Making him/herself understood | −0.334 | 3.519 | 0.54 | 1.00 | ns | 0.19, 0.17, 0.07, 0.05, 0.05, 0.02, 0.02, 0.01, 0.01 | 19, 18, 15, 16, 27, 13, 25, 21, 24 |
| 21. Keeping him/herself clean | −0.860 | 1.746 | 7.57 | 0.58 | ns | 0.64, 0.13, 0.09, 0.05, 0.04, 0.03, 0.01, 0.01 | 22, 23, 24, 31, 29, 26, 20, 30 |
| 22. Keeping him/herself looking nice | −0.814 | 2.051 | 6.38 | 0.70 | ns | 0.64, 0.15, 0.08, 0.05, 0.05, 0.02, 0.01, 0.01 | 21, 23, 29, 24, 31, 30, 25, 27 |
| 23. Getting from the shops | −0.615 | −1.029 | 2.99 | 0.96 | ns | 0.26, 0.15, 0.13, 0.11, 0.09, 0.06, 0.04, 0.03 | 24, 22, 21, 25, 27, 26, 17, 16 |
| 24. Using money to pay | −0.688 | −0.991 | 5.64 | 0.78 | ns | 0.49, 0.26, 0.11, 0.09, 0.08, 0.05, 0.02, 0.01 | 25, 23, 27, 21, 26, 22, 13, 20 |
| 25. Looking after finances | −0.418 | 1.519 | 9.45 | 0.40 | ns | 0.49, 0.17, 0.11, 0.05, 0.04, 0.02, 0.02, 0.01, 0.01 | 24, 27, 23, 26, 13, 19, 20, 15, 22 |
| 26. Things taking longer | 0.246 | −3.239 | 12.97 | 0.16 | ns | 0.15, 0.15, 0.09, 0.09, 0.08, 0.08, 0.06, 0.05, 0.03, 0.03, 0.01 | 27, 30, 19, 29, 24, 31, 23, 25, 18, 21, 14 |
| 27. Getting in touch with people | −0.593 | −1.469 | 5.18 | 0.82 | ns | 0.17, 0.15, 0.14, 0.11, 0.10, 0.09, 0.06, 0.05, 0.05, 0.03, 0.03, 0.02, 0.01 | 25, 26, 29, 24, 28, 23, 30, 13, 20, 14, 19, 15, 22 |
| 28. Not having enough company | −0.487 | 0.784 | 5.75 | 0.76 | PWD sex Carer age Relation |
0.10, 0.05, 0.03, 0.02 | 27, 11, 10, 5 |
| 29. Not able help other people | −0.593 | 0.668 | 3.07 | 0.96 | ns | 0.41, 0.14, 0.09, 0.09, 0.08, 0.04, 0.01 | 30, 27, 26, 28, 22, 21, 12 |
| 30. Not playing useful part | −0.368 | −3.119 | 10.01 | 0.35 | ns | 0.41, 0.15, 0.11, 0.06, 0.02, 0.01 | 29, 26, 28, 27, 22, 21 |
| 31. His/her physical health | 0.218 | 0.854 | 2.33 | 0.99 | ns | 0.18, 0.14, 0.08, 0.07, 0.05, 0.05, 0.04, 0.02 | 30, 29, 26, 4, 21, 22, 12, 8 |
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)