Background
Methods
Participants
Instruments
The Hospital Anxiety & Depression Scale (HADS)
Patient Health Questionnaire (PHQ-9)
Rasch Models
Rasch Fit Statistics
Method
Results
1. Fit Statistics – Type I error rate
Infit MNSQ | SE | Infit t | SE | Outfit MNSQ | SE | Outfit t | SE | ||
---|---|---|---|---|---|---|---|---|---|
ANX1
| 0.92 | 0.04 | -1.12 | 0.26 | 0.93 | 0.04 | -1.07 | 0.26 | |
ANX2
| 1.02 | 0.02 | 0.11 | 0.17 | 0.98 | 0.02 | -0.40 | 0.18 | |
ANX3
| 0.95 | 0.04 | -1.06 | 0.25 | 0.95 | 0.04 | -1.11 | 0.27 | |
ANX4
| 0.90 | 0.03 | -1.38 | 0.28 | 0.97 | 0.04 | -0.13 | 0.28 | |
ANX5
| 0.87 | 0.03 | -1.71 | 0.23 | 0.88 | 0.04 | -1.37 | 0.22 | |
ANX6
|
1.46
| 0.03 |
5.92
| 0.20 |
1.46
| 0.03 |
5.97
| 0.2 | |
ANX7
| 0.80 | 0.03 |
-3.49
| 0.33 | 0.76 | 0.03 |
-3.71
| 0.28 | |
Underfit
|
>1.30
| 1.00 |
>2
| 1.00 |
>1.30
| 1.00 |
>2
| 1.00 | |
Overfit
|
<0.70
| 0 |
<-2
| 1.00 |
<0.70
| 0 |
<-2
| 1.00 | |
Infit MNSQ
|
SE
|
Infit t
|
SE
|
Outfit MNSQ
|
SE
|
Outfit t
|
SE
| ||
DEP1
| 1.02 | 0.04 | -0.18 | 0.25 | 0.91 | 0.03 | -1.56 | 0.21 | |
DEP2
| 1.09 | 0.06 | 1.35 | 0.31 | 0.97 | 0.07 | 0.01 | 0.25 | |
DEP3
| 0.86 | 0.06 | -1.82 | 0.33 | 0.81 | 0.05 | -1.72 | 0.27 | |
DEP4
| 1.03 | 0.03 | 0.51 | 0.22 | 1.10 | 0.04 | 1.65 | 0.32 | |
DEP5
|
1.34
| 0.07 |
3.48
| 0.29 | 1.18 | 0.09 | 1.17 | 0.22 | |
DEP6
| 0.77 | 0.03 |
-3.06
| 0.23 | 0.68 | 0.03 |
-3.83
| 0.19 | |
DEP7
|
1.37
| 0.07 |
3.78
| 0.29 |
1.33
| 0.07 |
2.24
| 0.18 | |
Underfit
|
>1.30
| 2.00 |
>2
| 2.00 |
>1.30
| 1.00 |
>2
| 1.00 | |
Overfit
|
<0.70
| 0 |
<-2
| 1.00 |
<0.70
| 1.00 |
<-2
| 1.00 |
Infit MNSQ | SE | Infit t | SE | Outfit MNSQ | SE | Outfit t | SE | ||
---|---|---|---|---|---|---|---|---|---|
ANX1
| 0.97 | 0.04 | -0.17 | 0.25 | 0.98 | 0.04 | -0.06 | 0.27 | |
ANX2
| 0.88 | 0.03 | -1.87 | 0.23 | 0.87 | 0.03 | -1.78 | 0.22 | |
ANX3
| 0.86 | 0.03 |
-2.41
| 0.26 | 0.90 | 0.04 | -1.89 | 0.28 | |
ANX4
| 1.05 | 0.03 | 0.95 | 0.23 | 1.06 | 0.04 | 1.12 | 0.24 | |
ANX5
| 0.92 | 0.03 | -0.93 | 0.20 | 0.91 | 0.04 | -0.97 | 0.22 | |
ANX6
|
1.45
| 0.04 |
5.36
| 0.22 |
1.44
| 0.05 |
5.24
| 0.24 | |
ANX7
| 0.78 | 0.03 |
-3.61
| 0.28 | 0.74 | 0.03 |
-3.48
| 0.26 | |
Underfit
|
>1.30
| 1.00 |
>2
| 1.00 |
>1.30
| 1.00 |
>2
| 1.00 | |
Overfit
|
<0.70
| 0 |
<-2
| 2.00 |
<0.70
| 0 |
<-2
| 1.00 | |
Infit MNSQ
|
SE
|
Infit t
|
SE
|
Outfit MNSQ
|
SE
|
Outfit t
|
SE
| ||
DEP1
| 0.96 | 0.04 | -0.74 | 0.20 | 0.88 | 0.04 | -1.51 | 0.19 | |
DEP2
| 0.97 | 0.04 | -0.03 | 0.25 | 0.98 | 0.08 | 0.17 | 0.23 | |
DEP3
| 0.86 | 0.04 | -1.76 | 0.28 | 0.85 | 0.06 | -0.93 | 0.29 | |
DEP4
| 1.17 | 0.03 |
2.54
| 0.21 | 1.11 | 0.03 | 1.71 | 0.19 | |
DEP5
| 1.12 | 0.06 | 1.26 | 0.27 | 1.20 | 0.11 | 1.06 | 0.21 | |
DEP6
| 0.73 | 0.03 |
-3.82
| 0.20 |
0.64
| 0.03 |
-3.20
| 0.19 | |
DEP7
| 1.17 | 0.06 | 1.41 | 0.25 |
1.68
| 0.19 |
2.74
| 0.19 | |
Underfit
|
>1.30
| 0 |
>2
| 1.00 |
>1.30
| 1.00 |
>2
| 1.00 | |
Overfit
|
<0.70
| 0 |
<-2
| 1.00 |
<0.70
| 1.00 |
<-2
| 1.00 |
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 |
Infit MNSQ | SE | Infit t | SE | Outfit MNSQ | SE | Outfit t | SE | |
---|---|---|---|---|---|---|---|---|
PHQ1
| 0.98 | 0.01 | -0.02 | 0.09 | 0.96 | 0.02 | -0.27 | 0.11 |
PHQ2
| 0.79 | 0.01 |
-2.99
| 0.07 | 0.74 | 0.01 |
-3.19
| 0.07 |
PHQ3
| 1.17 | 0.01 |
2.95
| 0.08 | 1.17 | 0.02 |
2.55
| 0.10 |
PHQ4
| 1.01 | 0.01 | 0.05 | 0.08 | 0.98 | 0.01 | -0.25 | 0.08 |
PHQ5
| 1.22 | 0.01 |
2.47
| 0.08 |
1.30
| 0.03 | 1.93 | 0.09 |
PHQ6
| 0.95 | 0.01 | -0.36 | 0.07 | 0.97 | 0.03 | -0.26 | 0.08 |
PHQ7
| 0.91 | 0.01 | -1.00 | 0.07 | 0.86 | 0.02 | -1.04 | 0.07 |
PHQ8
| 1.05 | 0.02 | 0.34 | 0.08 | 0.95 | 0.03 | -0.08 | 0.08 |
PHQ9
| 0.92 | 0.02 | -0.22 | 0.06 | 1.00 | 0.10 | -0.41 | 0.10 |
>1.30
| 0 |
>2
| 2.00 |
>1.30
| 0 |
>2
| 1.00 | |
<0.70
| 0 |
<-2
| 1.00 |
<0.70
| 0 |
<-2
| 1.00 |
2. Fit Statistics – Sample Size
HADS A | Infit t | Infit t | Infit MNSQ | Infit MNSQ | Infit MNSQ | Outfit t | Outfit t | Outfit MNSQ | Outfit MNSQ | Outfit MNSQ |
---|---|---|---|---|---|---|---|---|---|---|
<-2 | >2 | <0.7 | >1.2 | >1.3 | <-2 | >2 | <0.7 | >1.2 | >1.3 | |
25
| 0 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 |
50
| 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 |
100
| 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 |
200
| 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 |
400
| 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 |
800
| 1 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 |
1600
| 5 | 1 | 0 | 1 | 1 | 4 | 1 | 0 | 1 | 1 |
3200
| 5 | 1 | 0 | 1 | 1 | 4 | 1 | 0 | 1 | 1 |
HADS D
|
Infit t
|
Infit t
|
Infit MNSQ
|
Infit MNSQ
|
Infit MNSQ
|
Outfit t
|
Outfit t
|
Outfit MNSQ
|
Outfit MNSQ
|
Outfit MNSQ
|
<-2
|
>2
|
<0.7
|
>1.2
|
>1.3
|
<-2
|
>2
|
<0.7
|
>1.2
|
>1.3
| |
25
| 0 | 0 | 0 | 2 | 2 | 0 | 0 | 1 | 2 | 1 |
50
| 0 | 0 | 0 | 2 | 2 | 0 | 0 | 1 | 1 | 1 |
100
| 0 | 0 | 0 | 2 | 2 | 1 | 0 | 1 | 2 | 2 |
200
| 0 | 2 | 0 | 2 | 2 | 1 | 0 | 0 | 2 | 0 |
400
| 1 | 2 | 0 | 2 | 1 | 1 | 1 | 0 | 1 | 1 |
800
| 1 | 2 | 0 | 2 | 2 | 2 | 1 | 1 | 1 | 1 |
1600
| 2 | 3 | 0 | 2 | 2 | 3 | 3 | 0 | 1 | 1 |
3200
| 2 | 3 | 0 | 2 | 2 | 3 | 3 | 0 | 1 | 1 |
Infit t | Infit t | Infit MNSQ | Infit MNSQ | Infit MNSQ | Outfit t | Outfit t | Outfit MNSQ | Outfit MNSQ | Outfit MNSQ | |
---|---|---|---|---|---|---|---|---|---|---|
Sample | < -2 | > 2 | < 0.7 | > 1.2 | > 1.3 | < -2 | > 2 | < 0.7 | > 1.2 | > 1.3 |
25
| 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 2 |
50
| 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
100
| 0 | 1 | 1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 |
200
| 1 | 1 | 0 | 0 | 2 | 1 | 0 | 0 | 0 | 0 |
400
| 1 | 3 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 |
800
| 2 | 3 | 1 | 0 | 1 | 1 | 2 | 2 | 0 | 0 |
1600
| 2 | 5 | 0 | 0 | 1 | 2 | 2 | 0 | 0 | 0 |
3200
| 2 | 5 | 0 | 0 | 1 | 4 | 2 | 0 | 0 | 0 |
HADS A | Infit t | Infit t | Infit MNSQ | Infit MNSQ | Infit MNSQ | Outfit t | Outfit t | Outfit MNSQ | Outfit MNSQ | Outfit MNSQ |
---|---|---|---|---|---|---|---|---|---|---|
<-2 | >2 | <0.7 | >1.2 | >1.3 | <-2 | >2 | <0.7 | >1.2 | >1.3 | |
25
| 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 1 |
50
| 0 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 |
100
| 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 |
200
| 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 |
400
| 2 | 1 | 0 | 1 | 1 | 2 | 1 | 0 | 1 | 1 |
800
| 3 | 1 | 0 | 1 | 1 | 3 | 1 | 0 | 1 | 1 |
1600
| 3 | 2 | 0 | 1 | 1 | 3 | 2 | 0 | 1 | 1 |
3200
| 4 | 2 | 0 | 1 | 1 | 4 | 2 | 0 | 1 | 1 |
HADS D
|
Infit t
|
Infit t
|
Infit MNSQ
|
Infit MNSQ
|
Infit MNSQ
|
Outfit t
|
Outfit t
|
Outfit MNSQ
|
Outfit MNSQ
|
Outfit MNSQ
|
<-2
|
>2
|
<0.7
|
>1.2
|
>1.3
|
>2
|
<-2
|
<0.7
|
>1.2
|
>1.3
| |
25
| 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 2 | 2 |
50
| 0 | 0 | 0 | 2 | 0 | 0 | 0 | 1 | 1 | 1 |
100
| 1 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 2 | 2 |
200
| 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
400
| 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 |
800
| 1 | 1 | 0 | 0 | 0 | 2 | 1 | 1 | 1 | 1 |
1600
| 2 | 3 | 0 | 0 | 0 | 2 | 2 | 1 | 2 | 1 |
3200
| 3 | 3 | 0 | 0 | 0 | 3 | 3 | 1 | 2 | 1 |
Infit t | Infit t | Infit MNSQ | Infit MNSQ | Infit MNSQ | Outfit t | Outfit t | Outfit MNSQ | Outfit MNSQ | Outfit MNSQ | |
---|---|---|---|---|---|---|---|---|---|---|
Sample | < -2 | > 2 | < 0.7 | > 1.2 | > 1.3 | < -2 | > 2 | < 0.7 | > 1.2 | > 1.3 |
25
| 0 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 2 | 2 |
50
| 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 1 |
100
| 0 | 0 | 0 | 2 | 1 | 0 | 0 | 0 | 2 | 2 |
200
| 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
400
| 1 | 2 | 0 | 2 | 0 | 1 | 1 | 0 | 2 | 0 |
800
| 1 | 2 | 0 | 2 | 0 | 1 | 2 | 0 | 2 | 0 |
1600
| 1 | 2 | 0 | 1 | 0 | 2 | 2 | 0 | 2 | 0 |
3200
| 2 | 2 | 0 | 1 | 0 | 2 | 2 | 0 | 2 | 0 |