Table 3

Fit statistics for PHQ-9 items (collapsed across sample size) for the Rating Scale Model



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


Smith et al. BMC Medical Research Methodology 2008 8:33   doi:10.1186/1471-2288-8-33