Table 5.

Differential Item Functioning (DIF) by gender

Test all items, anchor all items. DIF Statistics for Graded Items
Item numbers and description in:	Group 1	Group 2	Total X2	d.f	p	X2a	d.f	p	X2c|a	d.f	p
1. I feel worried	1	1	1.3	3	0.7370	0.9	1	0.3349	0.3	2	0.8455
2. I feel angry	2	2	2.8	3	0.4297	0.4	1	0.5332	2.4	2	0.3054
3. I feel sad	3	3	4.5	3	0.2100	1.5	1	0.2230	3	2	0.2187
4. I feel frustrated	4	4	1.1	3	0.7806	0.1	1	0.7755	1	2	0.6054
5. It is difficult to find someone to talk to	5	5	1.1	3	0.7715	0.3	1	0.5634	0.8	2	0.6742
6. Caring for my family member is difficult	6	6	0.7	3	0.8768	0.7	1	0.4138	0	2	0.9920
7. It is hard to find time for myself	7	7	1.1	3	0.7810	0.1	1	0.8194	1	2	0.5971
8. My every day travel is affected	8	8	1.7	3	0.6403	0.4	1	0.5501	1.3	2	0.5151
9. My eating habits are affected	9	9	4.1	3	0.2515	0.1	1	0.8035	4	2	0.1322
10. My family activities are affected	10	10	2	3	0.5747	1.3	1	0.2592	0.7	2	0.6998
11. I experience problems with going on holiday	11	11	2.5	3	0.4713	1.6	1	0.2082	0.9	2	0.6264
12. My sex life is affected	12	12	4.2	3	0.2435	0	1	0.8998	4.2	2	0.1242
13. My work or study is affected	13	13	4.4	3	0.2195	2.5	1	0.1177	2	2	0.3736
14. My relationships with other family members are affected	14	14	0.3	2	0.8460	0.1	1	0.7198	0.2	1	0.6503
15. My family expenses are increased	15	15	1.5	3	0.6919	0.5	1	0.4871	1	2	0.6143
16. My sleep is affected	16	16	2.7	3	0.4495	1.5	1	0.2142	1.1	2	0.5768

p values are for the Wald χ²-statistic that tests the difference between reference and focal group item parameters

χ²_a for slope (discrimination)

χ²_c/a for location

Significant DIF = p < 0.05