Table 2 Items of evaluation questionnaire

1. How often did you visit the website? ^a

11. Did you find the links useful?^c

2. Did your HCP recommend this website to you?^b

12. How often did you use the exercises provided?^f

3. Did your HCP discuss this website with you?^b

13. Did you find the exercises useful?^c

4. Did you experience any added value from the website in addition to the treatment you received from your HCP?^c

14. Were the advices applicable to you?^c

5. Was the information on the website clear to you?^c

15. Did you find the monthly newsletter useful?^c

6. Did you find the website useful?^c

16. Did you use social media for this study, if yes, which one(s)?^g

7. How many video-messages have you watched?^d

17. Did the website contribute to your recovery?^b

8. Did you find the video-messages useful?^c

18. If the website contributed to your recovery, which component(s) was/were the most helpful to you?^h

9. On a scale from 0 (lowest) to 10 (highest), how would you rate your appreciation of the video-messages?^e

19. Would you recommend this website to others with back pain?^b

10. How often did you use the links provided?^f

20. On a scale from 0 (lowest) to 10 (highest), how would you rate your appreciation of the website?^e