Study Procedures
Pilot study: After providing written informed consent, participants
completed a self-administered CSOC questionnaire. After filling out the
CSOC, each patient was asked how well they had understood each item.
Content validity: We sent an e-mail to the experts alongside an
explanatory cover letter, reviewer instructions, definitions of terms,
and a content-review questionnaire. The members of the panel responded
by e-mail. In the content-review questionnaire, experts were asked to
judge how representative the questionnaire items are of QOL in COS using
a 4-point scale: 1 = not representative, 2 = somewhat representative, 3
= quite representative and 4 = highly representative. Experts were
prompted to evaluate the clarity of item construction and wording.
Finally, suggestions for addition or deletion of items were requested.
Validation process: After providing written informed consent,
participants completed a self-administered CSOC questionnaire at the
following time points:within45 days before sialendoscopy, in the
preoperative area before sialendoscopy and 90-120 days after
sialendoscopy. SF-36 and visual analogue scale (VAS)fordiscomfort were
completed at the first and third time points. The CSOC filled out during
the validation process comprised 18 items according to the results of
the pilot study and the content validityassessment (Supplementary Table
3).