# 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
1. 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