Table 4 STAR-MH item difficulty estimates, chi-squared test, outfit, and infit statistics, and standardised outfit and infit statistics
Item | Difficulty | SE | χ2 | df | p | Outfit | Infit | Outfit-t | Infit-t |
|---|---|---|---|---|---|---|---|---|---|
Have you felt very restless, like you can’t keep still? | 0.06 | 0.20 | 98.6 | 94 | 1 | 1.05 | 1.06 | 0.41 | 1.06 |
Have you lost interest in things? | 0.06 | 0.20 | 99.4 | 94 | 0.269 | 1.06 | 1.02 | 0.47 | 1.02 |
Have you worried about going crazy or ‘losing your mind’? | 0.40 | 0.21 | 80.2 | 94 | 1 | 0.85 | 0.95 | −0.99 | 0.95 |
Have you felt very fearful? | −0.27 | 0.20 | 81.8 | 94 | 1 | 0.87 | 0.91 | −0.99 | 0.91 |
Have you felt very trapped or caught? | − 0.13 | 0.20 | 90.5 | 94 | 1 | 0.96 | 0.97 | −0.24 | 0.97 |
Have you had a lot of pain in your body? | −0.22 | 0.20 | 119.6 | 94 | 1 | 1.27 | 1.20 | 1.97 | 1.20 |
Have you felt very worthless? | 0.11 | 0.20 | 80.5 | 94 | 1 | 0.86 | 0.89 | −1.09 | 0.89 |