Table 5.

Measurement invariance of item parameters of the GAD-7 across subgroups.

Subgroups	Item	TotalΔχ2*	df	P	$\Delta {\chi }_{\text{a}}^2$†	df	p	Δχ2b§	df	p-value
Age	1	4.2	4	0.386	1.4	1	0.233	2.7	3	0.437
	2	2.7	4	0.607	2.0	1	0.158	0.7	3	0.869
	3	4.6	4	0.327	1.3	1	0.260	3.4	3	0.339
	4	0.8	4	0.933	0.1	1	0.808	0.8	3	0.855
	5	5.3	4	0.262	2.5	1	0.134	0.8	3	0.851
	6	5.7	4	0.227	2.7	1	0.130	1.0	3	0.811
	7	2.1	4	0.724	0.7	1	0.397	1.3	3	0.719
Gender	1	4.5	4	0.338	0.8	1	0.361	3.7	3	0.296
	2	1.7	4	0.799	0.4	1	0.526	1.3	3	0.741
	3	0.4	4	0.979	0.2	1	0.648	0.2	3	0.972
	4	1.5	4	0.830	0.2	1	0.679	1.3	3	0.726
	5	2.1	4	0.716	0.0	1	0.915	2.1	3	0.552
	6	1.5	4	0.828	0.5	1	0.490	1.0	3	0.798
	7	2.8	4	0.587	0.7	1	0.414	2.2	3	0.540
Education	1	4.4	4	0.360	0.3	1	0.610	4.1	3	0.252
	2	2.8	4	0.593	0.1	1	0.726	2.7	3	0.445
	3	3.4	4	0.489	0.2	1	0.637	3.2	3	0.362
	4	4.1	4	0.391	0.0	1	0.907	4.1	3	0.251
	5	0.5	4	0.976	0.0	1	0.909	0.5	3	0.926
	6	0.5	4	0.970	0.0	1	0.958	0.5	3	0.912
	7	7.0	4	0.134	3.6	1	0.091	2.4	3	0.495
Residence	1	4.5	4	0.348	1.2	1	0.271	3.3	3	0.356
	2	3.4	4	0.497	2.1	1	0.145	1.3	3	0.741
	3	4.6	4	0.337	3.1	1	0.077	1.4	3	0.696
	4	5.8	4	0.218	2.7	1	0.101	3.1	3	0.381
	5	2.7	4	0.608	0.3	1	0.616	2.5	3	0.484
	6	1.1	4	0.896	0.8	1	0.387	0.3	3	0.953
	7	2.3	4	0.672	0.3	1	0.568	2.0	3	0.569

^*Δχ² statistic for the specific item.

^†Δχ² statistic for discrimination parameter(a) of the specific item.

^§Δχ² statistic for difficulty parameter(b) of the specific item.