Subgroup | Discrimination | B2 threshold | B3 threshold | B4 threshold | B5 threshold | P-value (BH) a | P-value (DIF) b | |
---|---|---|---|---|---|---|---|---|
Factor 1: Daily Activities | ||||||||
Uniform Differential Item Functioning | ||||||||
23: Enjoy social functions less | No depression | 2.4 | 1.5 c | 2.0 | 2.3 | – | 0.008 | < 0.001 |
Depression | 2.4 | 1.3 | 1.7 | 2.0 | – | |||
25: Become a burden on others | No depression | 1.8 | 2.0 | 2.8 | 2.9 | – | 0.004 | < 0.001 |
Depression | 1.8 | 1.5 | 2.0 | 2.2 | – | |||
26: Frightened to lose remaining vision | No depression | 1.6 | 1.2 | 2.1 | 2.4 | – | < 0.001 | < 0.001 |
Depression | 1.6 | 0.8 | 1.5 | 1.9 | – | |||
27: Do you have reduced vision | No depression | 2.0 | 0.1 | 1.7 | 2.2 | – | 0.006 | < 0.001 |
Depression | 2.0 | 0.0 | 1.5 | 2.2 | – | |||
33: Do you have blurred vision | No depression | 2.0 | 0.4 | 1.7 | 2.4 | – | 0.006 | < 0.001 |
Depression | 2.0 | 0.4 | 1.5 | 2.2 | – | |||
Non-Uniform Differential Item Functioning | ||||||||
24: Ashamed that you can’t see | No depression | 2.6 | 1.9 | 2.4 | 2.7 | – | 0.01 | < 0.001 |
Depression | 1.6 | 1.5 | 2.3 | 2.9 | – | |||
Factor 2: Bright Lights | ||||||||
Uniform Differential Item Functioning | ||||||||
31: Vehicle light makes you close eyes | Male | 1.8 | −0.7 | 0.8 | 1.3 | – | 0.003 | =0.001 |
Female | 1.8 | −0.5 | 1.0 | 1.4 | – |