Table 3.
Cognitive Domain (3 items) - Overview of final SF-HDQ item level and domain model fit statistics
| Item # | Final SF-HDQ items | Item level statistics | ||||
|---|---|---|---|---|---|---|
| Cognitive domain | Location | SE | Residual | ChiSq χ 2 | p value | |
| 21 | Trouble remembering like appointments and when to take medication | − 0.072 | 0.058 | 2.764* | 20.271 | 0.005* |
| 22 | Trouble thinking clearly | 0.498 | 0.061 | − 1.078 | 34.33 | < 0.001a |
| 23 | Trouble concentrating | − 0.427 | 0.060 | − 0.918 | 21.292 | 0.003a |
| Final model: cognitive domain—3 items (raw score range: 0–12) | ||||||
| Mean | − 1.813 | |||||
| Standard deviation | 1.764 | |||||
| Sample size | 730 | |||||
| Chi-square statistic (df) p value | 75.8970 (df: 21); p < 0.001 | |||||
| Cronbach’s alpha | 0.77602 | |||||
| Person Separation Index | 0.70994 | |||||
| Unidimensionality t-test (% significant) | 1.23% | |||||
| Differential Item Functioning (DIF) | None | |||||
*Item fit residual for HDQ21 (2.764) significant (p < 0.017; Bonferroni: 0.05/3) but retained due to clinical importance and need for minimum of 3 items in domain
aSignificant residual (p < 0.017; Bonferroni: 0.05/3) but fit residual F value < ± 2.5