Table 3 Summary table of item-model fit statistics, item measure differential item functioning statistics
Item description | PCA loading | Measure (logit) | Item fit | DIF contrast | ||||
|---|---|---|---|---|---|---|---|---|
Infit MnSq | Infit ZSTD | Outfit MnSq | Outfit ZSTD | Gender | Age | |||
CUDOS | ||||||||
1.I felt sad or depressed | 0.20 | -0.40 | 0.53 | -6.91 | 0.50 | -5.99 | -0.19 | 0.11 |
2.I was not as interested in my usual activities | 0.09 | -0.53 | 0.65 | -4.84 | 0.63 | -4.20 | -0.26 | 0.00 |
3. My appetite was poor and I didn’t feel like eating | -0.07 | 0.14 | 1.21 | 2.45 | 1.29 | 2.39 | 0.22 | 0.07 |
4. My appetite was much greater than usual | -0.32 | 1.28 | 2.09 | 7.89 | 3.82 | 9.59 | 0.10 | -0.09 |
5. I had difficulty sleeping | -0.22 | -0.26 | 1.75 | 7.59 | 1.85 | 6.60 | -0.13 | 0.47 |
6. I was sleeping too much | -0.47 | 0.45 | 2.30 | 9.90 | 2.57 | 8.85 | 0.30 | -0.32 |
7. I felt very fidgety, making it difficult to sit still | -0.16 | 0.34 | 0.83 | -2.09 | 0.79 | -1.84 | -0.15 | 0.25 |
8. I felt physically slowed down, like my body was stuck in mud | -0.39 | 0.23 | 0.94 | -0.65 | 0.82 | -1.60 | 0.04 | 0.09 |
9. My energy level was low | -0.39 | -0.53 | 0.70 | -4.05 | 0.64 | -4.00 | -0.11 | 0.00 |
10. I felt guilty | 0.20 | -0.01 | 0.79 | -2.76 | 0.77 | -2.31 | 0.03 | -0.16 |
11. I thought I was a failure | 0.45 | -0.16 | 0.87 | -1.71 | 0.77 | -2.29 | -0.02 | -0.05 |
12. I had problems concentrating | -0.28 | -0.44 | 0.72 | -3.69 | 0.68 | -3.49 | 0.10 | 0.00 |
13. I had more difficulties making decisions than usual | -0.07 | -0.22 | 0.76 | -3.26 | 0.74 | -2.71 | 0.04 | -0.06 |
14. I wished I was dead | 0.75 | 0.56 | 1.15 | 1.69 | 0.92 | -0.58 | 0.55 | -0.30 |
15. I thought about killing myself | 0.71 | 0.71 | 1.13 | 0.95 | 0.60 | 0.58 | 0.42 | -0.20 |
16. I thought that the future looked hopeless | 0.67 | -0.05 | 0.89 | 0.76 | 0.74 | 0.68 | 0.04 | -0.31 |
17.Overall, how much have symptoms of depression interfered with or caused difficulties in your life during the past week? | 0.02 | -0.52 | 0.64 | 0.65 | 0.80 | 0.73 | -0.04 | 0.11 |
18.How would you rate your overall quality of life during the past week? | -0.14 | -0.59 | 0.52 | 0.84 | 0.79 | 0.74 | -0.17 | 0.22 |