Table 6 Fit statistics of Rasch model for Items

Subscale of Depression

3. couldn’t experience positive feeling

-0.243

0.801

1.203

1.207

-0.788

0.787

1.149

1.155

-0.727

0.810

1.268

1.277

5. difficult to work up the initiative to do things

-0.130

0.811

1.148

1.133

-0.103

0.741

1.214

1.220

-0.115

0.798

1.136

1.131

10. had nothing to look forward to

-0.309

0.835

0.963

0.952

-0.688

0.792

1.015

1.010

-0.704

0.831

1.011

1.006

13. felt down-hearted and blue

-0.516

0.843

0.990

1.016

-0.558

0.815

0.878

0.873

-0.539

0.844

0.935

0.927

16. unable to become enthusiastic

-0.017

0.843

0.856

0.836

-0.055

0.777

0.879

0.875

0.187

0.838

0.807

0.777

17. not worth much as a person

0.750

0.740

0.890

0.774

1.249

0.609

0.959

0.899

1.159

0.682

0.907

0.526

21. life was meaningless

0.465

0.780

0.910

0.903

0.943

0.689

0.860

0.729

0.739

0.732

0.881

0.954

Subscale of Anxiety

2. dryness of my mouth

-0.576

0.753

1.424

1.436

-1.276

0.678

1.545

1.571

-1.455

0.727

1.660

1.707

4. experienced breathing difficulty

0.252

0.789

0.921

0.881

0.293

0.730

0.889

0.810

0.049

0.764

0.902

0.849

7. experienced trembling

0.447

0.762

0.828

0.739

0.898

0.635

0.929

0.846

1.056

0.673

0.965

0.809

9. worried about situations of panic and making a fool of myself

-0.680

0.804

1.144

1.175

-1.041

0.756

1.151

1.142

-0.738

0.795

1.059

1.081

15. feeling of close to panic

0.256

0.804

0.816

0.774

0.308

0.749

0.769

0.710

0.407

0.770

0.692

0.581

19. aware of the action of my heart

0.053

0.801

0.915

0.907

0.326

0.737

0.820

0.823

0.196

0.761

0.859

0.809

20. felt scared without any good reason

0.248

0.799

0.828

0.774

0.492

0.724

0.735

0.598

0.487

0.743

0.726

0.621

Subscale of Stress

1. hard to wind down

-0.125

0.724

1.450

1.419

-0.144

0.709

1.446

1.459

-0.144

0.709

1.446

1.459

6. tended to over-react

0.425

0.774

0.861

0.817

0.605

0.723

0.990

0.947

0.605

0.723

0.947

0.947

8. using a lot of nervous energy

-0.370

0.805

1.027

1.011

-1.059

0.807

1.123

1.138

-1.059

0.807

1.138

1.138

11. getting agitated

0.272

0.807

0.769

0.738

0.312

0.794

0.682

0.607

0.312

0.794

0.607

0.607

12. difficult to relax

-0.157

0.831

0.772

0.736

-0.008

0.818

0.706

0.647

-0.008

0.818

0.647

0.647

14. intolerant of anything

-0.047

0.791

1.018

0.996

0.295

0.763

1.019

1.019

0.294

0.763

1.019

1.019

18. felt rather touchy

0.002

0.780

1.059

1.050

-0.001

0.770

1.004

0.981

-0.001

0.770

0.981

0.981