Table 6.

Day-to-Day Activities Domain (5 items) - Overview of final SF-HDQ item level and domain model fit statistics

Item #	Final SF-HDQ items	Item level statistics
Day-to-day activities domain		Location	SE	Residual	ChiSq χ²	p value
49	Unsteady on my feet	− 0.170	0.052	0.837	8.166	0.518
50	Trouble walking	0.554	0.055	1.055	14.058	0.120
53	Trouble doing household chores such as cleaning, doing dishes, laundry, and cooking	0.407	0.052	− 1.374	27.246	0.001^a
54	Trouble taking part in leisure or recreation, such as exercise or dancing	− 0.647	0.048	− 0.982	14.090	0.119
55	Trouble getting out to do errands, such as grocery shopping, banking, or doctor’s appointments	− 0.145	0.049	− 0.069	13.207	0.153
Final model: day-to-day activities domain—5 items (raw score range: 0–20)
Mean		− 1.494
Standard deviation		1.168
Sample size		675
Chi-square statistic (df) p value		76.7660 (df: 45) p = 0.002
Cronbach’s alpha		0.79477
Person Separation Index		0.69006
Unidimensionality t-test (% significant)		0.74%
Differential Item Functioning (DIF)		None

Person Separatoin Index (PSI) approaching the threshold of ≥ 0.70

^aSignificant residual (p < 0.006; Bonferroni: 0.05/9) but fit residual F value < ± 2.5