Table 5.

Detection of uniform and non-uniform differential item functioning for sex in Hospital Anxiety and Depression Scale - Anxiety (HADS-A), based on ordinal regression

		Block I			Block II			Block III
Items	Predictors	OR	p-value	R2	OR	p-value	R2	OR	p-value	R2	Model comparisonsa
1	HADS-A	2.17	< 0.001	0.412	2.17	< 0.001	0.414	2.53	< 0.001	0.415	A
	Sex (male)				1.30	< 0.001		0.94	< 0.001		B
	Sex x HADS-A							0.91	< 0.001		C
3	HADS-A	2.01	< 0.001	0. 418	1.99	< 0.001	0.425	2.22	< 0.001	0. 425	A
	Sex (male)				0.56	< 0.001		0.41	< 0.001		B
	Sex x HADS-A							0.94	< 0.001		C
5	HADS-A	2.25	< 0.001	0.438	2.24	< 0.001	0.443	2.46	< 0.001	0.444	A
	Sex (male)				0.60	< 0.001		0.46	< 0.001		B
	Sex x HADS-A							0.94	< 0.001		C
7	HADS-A	1.90	< 0.001	.333	1.92	< 0.001	0.335	2.12	< 0.001	0.336	A
	Sex (male)				1.35	< 0.001		1.11	< 0.001		B
	Sex x HADS-A							0.94	< 0.001		C
9	HADS-A	2.14	< 0.001	.432	2.13	< 0.001	0.442	2.24	< 0.001	0.442	A
	Sex (male)				0.51	< 0.001		0.45	< 0.001		B
	Sex x HADS-A							0.97	< 0.001		C
11	HADS-A	1.90	< 0.001	0.334	1.96	< 0.001	0.342	2.16	< 0.001	0.343	A
	Sex (male)				1.84	< 0.001		1.47	< 0.001		B
	Sex x HADS-A							0.94	< 0.001		C
13	HADS-A	2.00	< 0.001	0.435	2.00	< 0.001	0.435	2.29	< 0.001	0.436	A
	Sex (male)				1.05	< 0.001		0.67	< 0.001		B
	Sex x HADS-A							0.92	< 0.001		C

^aModel comparison is based on the χ² difference test between the models, with Bonferroni corrected p-values (p < 0.017). Significant differences are reported as: A = Block I & II, B = Block I & III, C = Block II & III