Table 2 Questions used as interview guide for interviews with developers who did not involve patients

-Was involving patients in the development of the questionnaire actively considered?

-Was there anything you expected to gain from patient involvement?

-Where there any negative consequences you expected to experience regarding patient involvement?

-What were the main reasons for not involving patients?

-Would you consider the questionnaire relevant for patients?

-Could the questionnaire have been improved by involving patients?

-If you would develop a new questionnaire, would you involve patients?

-How did you make sure that patients interpreted the questions as they were intended?

-How did you make sure that patients could complete the questionnaire?