# Table 6 Detection of uniform and non-uniform differential item functioning for sex in Hospital Anxiety and Depression Scale - Depression (HADS-D), 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
2 HADS-D 1.83 < 0.001 0.313 1.84 < 0.001 0.313 1.92 < 0.001 0.313 A
Sex (male)     0.88 < 0.001   0.79 < 0.001
Sex x HADS-D        0.98 < 0.001
4 HADS-D 1.95 < 0.001 0.375 1.98 < 0.001 0.385 1.98 < 0.001 0.385 A
Sex (male)     1.96 < 0.001   0.51 < 0.001   B
Sex x HADS-D        1.00 < 0.001
6 HADS-D 2.10 < 0.001 0.411 2.11 < 0.001 0.411 1.93 < 0.001 0.412
Sex (male)     0.88 < 0.001   1.18 < 0.001
Sex x HADS-D        1.06 < 0.001
8 HADS-D 2.04 < 0.001 0.323 2.07 < 0.001 0.333 1.94 < 0.001 0.333 A
Sex (male)     0.54 < 0.001   0.62 < 0.001   B
Sex x HADS-D        1.05 < 0.001
10 HADS-D 1.73 < 0.001 0.238 1.70 < 0.001 0.248 1.68 < 0.001 0.248 A
Sex (male)     1.82 < 0.001   1.87 < 0.001   B
Sex x HADS-D        1.01 < 0.001
12 HADS-D 2.44 < 0.001 0.441 2.44 < 0.001 .441 2.32 < 0.001 0.441
Sex (male)     0.85 < 0.001   0.98 < 0.001
Sex x HADS-D        1.03 < 0.001
14 HADS-D 1.56 < 0.001 0.216 1.57 < 0.001 0.238 1.55 < 0.001 0.238 A
Sex (male)     2.52 < 0.001   2.67 < 0.001   B
Sex x HADS-D        1.01 < 0.001
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