Table 1 Internal consistency – Cronbach’s alpha, intraclass correlation coefficient (ICC) 95% Confidence Interval (Lower-Upper Bound) of test-retest reliability

1

I feel tired and unrefreshed when I wake from sleeping.

0.745

0.643–0.821

2

My muscles feel stiff and achy.

0.725

0.617–0.806

3

I have anxiety attacks.

0.794

0.708–0.856

4

I grind or clench my teeth.

0.895

0.848–0.928

5

I have problems with diarrhea and/or constipation.

0.759

0.661–0.831

6

I need help in performing my daily activities.

0.518

0.358–0.648

7

I am sensitive to bright lights.

0.739

0.635–0.817

8

I get tired very easily when I am physically active.

0.821

0.745–0.876

9

I feel pain all over my body.

0.761

0.664–0.832

10

I have headaches.

0.756

0.658–0.829

11

I feel discomfort in my bladder and/or burning when I urinate.

0.783

0.693–0.848

12

I do not sleep well.

0.795

0.709–0.857

13

I have difficulty concentrating.

0.723

0.614–0.805

14

I have skin problems such as dryness, itchiness or rashes.

0.849

0.784–0.896

15

Stress makes my physical symptoms get worse.

0.723

0.615–0.805

16

I feel sad or depressed.

0.763

0.667–0.834

17

I have low energy.

0.695

0.579–0.784

18

I have muscle tension in my neck and shoulders.

0.813

0.735–0.871

19

I have pain in my jaw.

0.868

0.810–0.909

20

Certain smells, such as perfumes, make me feel dizzy and nauseated.

0.860

0.799–0.904

21

I have to urinate frequently.

0.844

0.875–0.943

22

My legs feel uncomfortable and restless when I am trying to go to sleep at night.

0.819

0.743–0.875

23

I have difficulty remembering things.

0.815

0.736–0.871

24

I suffered trauma as a child.

0.897

0.851–0.929

25

I have pain in my pelvic area.

0.828

0.754–0.881