Developing a short-form version of the HIV Disability Questionnaire (SF-HDQ) for use in clinical practice: a Rasch analysis

Table 5 Uncertainty Domain (5 items) - Overview of final SF-HDQ item level and domain model fit statistics

Item #	Final SF-HDQ items	Item level statistics
Uncertainty domain		Location	SE	Residual	ChiSq χ²	p value
35	Worry about future health living with HIV	− 0.114	0.041	− 1.295	25.455	0.002^a
36	Worry about lab test results such as my CD4 count and viral load	0.701	0.041	0.084	13.146	0.156
39	Worry about the side effects of HIV treatments	0.069	0.038	0.793	5.110	0.825
40	Worry about income or financial security living with HIV	− 0.608	0.035	0.900	6.796	0.658
41	Worry what might happen to my family and friends if have an episode of illness	− 0.048	0.037	0.618	7.220	0.614
Final model: uncertainty domain—5 items (raw score range: 0–20)
Mean		− 0.366
Standard deviation		1.190
Sample size		930
Chi-square statistic (df) p value		58.7265 (df: 45) p = 0.0965^b
Cronbach’s alpha		0.82314
Person Separation Index		0.78006
Unidimensionality t-test (% significant)		1.72%
Differential Item Functioning (DIF)		None

^aSignificant residual (p < 0.004; Bonferroni: 0.05/14) but fit residual F value < ± 2.5
^bChi-square statistic not significant (ideal outcome). HDQ43—removed as this item considered to be captured by HDQ35 worry about future health

ISSN: 1477-7525