Development and content validation of a patient-reported endometriosis pain daily diary

Endometriosis is an inflammatory and gynaecological disorder. However, without a reliable and valid patient-reported outcome (PRO) instrument it is difficult to measure the endometriosis-related pain in clinical trials. Therefore, in this study, the author developed a PRO known as Endometriosis Pain Daily Diary (EPDD) and showed its impacts on patients’ lives.

Endometriosis is one of the frequently occurred gynaecological problems which leads to levic pain and inflammation. The patient-reported outcome (PRO) measures identified the endometriosis-associated pain significantly, however in the absence of valid and reliable PRO tool the evaluation of endometriosis-associated pain in the clinical trials is difficult. This study explains the development of an electronic PRO, the Endometriosis Pain Daily Diary (EPDD) as a survey tool to determine endometriosis-associated pain and its effect on patients’ lives.

By considering a targeted review of the suitable literature, open-ended (concept elicitation) patient interviews in the Japan and United States (US) which record patients’ experience, available Endometriosis Pain and Bleeding Diary, clinical expert interviews, and with endometriosis, an EPDD was initially developed. The evaluation of patient comprehension of the EPDD items was done using the cognitive interviews of patients with endometriosis. A conceptual model of endometriosis was invented.  A meeting with US and European regulatory authorities dispensed feedback for affirming the EPDD in the context of clinical trials. The confirmation of its appropriate elucidation and ease of completion over 17 languages was done by using the translatability assessments of the EPDD.

The three versions of the instrument progressed the iterative development. The EPDDv1 comprised 18 items associating to dyspareunia and sexual activity, hot flashes, dysmenorrhea/pelvic pain, use of rescue medication, bleeding, and daily activities. The EPDDv2 was a large-scale 43-item investigation examined in cognitive interviews and eventually revised to yield the present 11-item EPDDv3, comprising of six extension items connecting to daily activities, use of rescue medication, and sexual activity, and five core items associating to dyspareunia, non-menstrual pelvic pain, and dysmenorrhea.

The EPDD is a PRO for the determination of endometriosis-associated pain and its effects on patients’ lives. The EPDD considered as an essential step to design to assess the related pain and in dispensing a PRO.