Table 3 Fit statistics for PHQ-9 items (collapsed across sample size) for the Rating Scale Model
From: Rasch fit statistics and sample size considerations for polytomous data
Infit MNSQ | SE | Infit t | SE | Outfit MNSQ | SE | Outfit t | SE | ||
|---|---|---|---|---|---|---|---|---|---|
PHQ1 | 1.01 | 0.01 | 0.33 | 0.09 | 1.02 | 0.02 | 0.30 | 0.13 | |
PHQ2 | 0.72 | 0.01 | -4.04 | 0.08 | 0.71 | 0.01 | -3.36 | 0.07 | |
PHQ3 | 1.14 | 0.01 | 2.39 | 0.09 | 1.15 | 0.02 | 2.25 | 0.11 | |
PHQ4 | 0.87 | 0.01 | -2.09 | 0.09 | 0.93 | 0.01 | -0.82 | 0.09 | |
PHQ5 | 1.37 | 0.01 | 4.19 | 0.08 | 1.28 | 0.02 | 2.46 | 0.08 | |
PHQ6 | 1.10 | 0.01 | 1.27 | 0.08 | 0.95 | 0.02 | -0.42 | 0.07 | |
PHQ7 | 1.04 | 0.01 | 0.60 | 0.08 | 0.86 | 0.01 | -1.16 | 0.06 | |
PHQ8 | 1.25 | 0.02 | 2.46 | 0.08 | 0.97 | 0.02 | -0.08 | 0.07 | |
PHQ9 | 1.17 | 0.03 | 1.48 | 0.10 | 0.84 | 0.05 | -0.87 | 0.08 | |
Underfit | >1.30 | 1.00 | >2 | 3.00 | >1.30 | 0 | >2 | 2.00 | |
Overfit | <0.70 | 0 | <-2 | 2.00 | <0.70 | 0 | <-2 | 1.00 |