A self-administered questionnaire to measure the painful symptoms of endometriosis: Results of a modified DELPHI survey of patients and physicians.

Purpose: To develop a questionnaire based on patients' verbal descriptors, to measure the painful symptoms of endometriosis.

Methods: We performed a two-round modified DELPHI procedure mixing endometriosis patients and physicians to select a set of statements to describe the painful symptoms of endometriosis. Each panelist rated each statement based on diagnosis validity and clarity. The clinicians were experts in endometriosis management selected from various geographic regions in France. Patients were women with surgically confirmed endometriosis who volunteered from a patient association and from the recruitment of the participating physicians. The first round questions were derived from words and phrases in narratives of pain by endometriosis patients.

Results: Overall, 76 experts were invited, and of these 56 (74%), comprising 33 patients and 23 gynecologists, responded to the first round questionnaire, and 40 (71.4%) to the second round. Among the 48 statements assessed in the first-round questionnaire, 11 were selected after completion of the two round DELPHI procedure. After discussion and rewording of some items, a total of 21 questions were selected during a final face-to-face meeting. The content of the final questionnaire is organized according to four dimensions: (i) spontaneous pelvic pain and dysmenorrhea, (ii) dyspareunia, (iii) painful bowel symptoms, (iv) and other symptoms. We also provide an English (UK) version produced using several steps of translation and back-translation.

Conclusions: The questionnaire has content validity to measure the subjective experiences of patients with painful endometriosis and can provide a solid basis on which to develop an efficient patient-centered outcome to measure the painful symptoms in therapeutic or in diagnostic studies of endometriosis.