Table 2 Fit of the items in the subscales of the precontemplation (A), contemplation (B), action (C) and maintenance (D) subscale according to the Rasch analysis (n = 231)

A. Precontemplation

I 11

I have tried everything that people recommended…

-0.39

0.07

1.47

2.54

0.47

I 16

Everyone I speak with tells me I have to learn..

0.06

0.07

0.35

3.93

0.27

I 25

Why can’t someone just do something..

-0.35

0.06

-0.66

6.60

0.09

I 29

I have been wondering if there is something I..

0.68

0.08

1.44

3.41

0.33

Bonferroni corrected significance level 0.01

B. Contemplation

I 1

I have been thinking that the way I cope with my pain..

0.26

0.09

0.99

2.61

0.46

I 7

I have recently realised that there is no medical cure…

0.29

0.09

1.06

0.38

0.94

I 8

Even though my pain is not going away…,

-0.80

0.09

-1.47

7.06

0.07

I 14

I am beginning to wonder if I need some help..

0.38

0.09

1.12

0.73

0.87

I 19

All this talk about how to cope better..

0.51

0.09

0.54

0.09

0.99

I 28

I have been wondering if there is something I..

-0.65

0.10

0.06

1.28

0.73

Bonferroni corrected significance level 0.008

C. Action

I 2

I am developing new ways to cope with my pain

-0.52

0.09

-1.11

4.74

0.19

I 6

I have started to come up with some strategies..

-0.40

0.09

-0.10

3.54

0.32

I 20

I am getting help learning some strategies for..

0.82

0.09

2.19

2.41

0.49

I 26

I am learning to help myself controlling my pain without..

0.16

0.08

1.32

1.43

0.70

I 27

I am testing out some coping skills to manage..

0.05

0.08

-0.40

6.06

0.11

I 30

I am learning ways to control my pain without..,

-0.03

0.07

0.55

1.71

0.63

Bonferroni corrected significance level 0.008

D. Maintenance

I 3

I have learned some good ways to keep my pain

0.30

0.09

1.27

0.24

0.97

I 4

When my pain flares up I find myself automatically..

0.16

0.08

0.73

1.09

0.78

I 5

I use some strategies that help me better deal with..

-0.36

0.10

-1.13

6.20

0.10

I 10

I use what I have learned to keep my pain..

-0.56

0.10

0.64

0.43

0.93

I 17

I have incorporated techniques..

-0.28

0.10

-1.87

1.35

0.72

I 18

I have made a lot of progress in coping with my pain

0.74

0.09

1.05

1.09

0.78

Bonferroni corrected significance level 0.008