Tele-patient-reported outcome measures (telePROM) in follow-up of endometriosis: a validity and test-retest reliability study of an endometriosis-specific questionnaire (EQ)

Patient-Reported Outcome (PRO) measures supported by a severity algorithm may serve as a decision aid for triage and consultation in follow-up of patients with endometriosis. In a new follow-up regime, patients filled out an endometriosis-specific questionnaire (EQ) at home before outpatient consultation (tele-Patient-Reported Outcome Measures; telePROM). A severity algorithm was assigned patients’ answers using a color code thereby reflecting the need of clinical attention. Our study aimed to assess the test-retest reliability of the severity algorithm and of the single items as well as to evaluate the face- and content validity of the EQ. The study was carried out in a referral endometriosis clinic at a Danish University Hospital. The validation was based on an initial version of the EQ, which was adjusted simultaneously with its severity algorithm, to meet the purpose of this study. Reliability was assessed by a test-retest setting of the questionnaire including patients with endometriosis, ≥ 18 years and Danish speaking. Kappa statistics and interclass correlation analyses were applied to assess test-retest reliability. Face- and content validity was explored by focus group interviewing of patients. In total, 14 patients answered the questionnaire twice. Results indicate that the EQ demonstrated substantial reliability in three out of five domain indicators in the severity algorithm and 65% of items with kappa values above 0.60. Further, focus-group interview of five patients resulted in adding an open-ended question regarding important issues to discuss at the consultation. TelePROM in outpatient follow-up of endometriosis is feasible as patients viewed the questionnaire relevant for their clinical follow-up. Yet, due to the small sample size results should be interpreted with caution. Further validation of the EQ is recommended.