A health-related quality-of-life instrument for symptomatic patients with endometriosis: A validation study

OBJECTIVE: This study was designed to evaluate the reliability, validity, and responsiveness of a newly developed, health-related quality-of-life measure. STUDY DESIGN: A total of 137 women (122 from a Phase III clinical trial and 15 from a private practice setting) with endometriosis completed the questionnaire several times. RESULTS: Reproducibility and internal-consistency reliability were acceptable with intraclass correlation coefficients ranging from 0.94 to 1.00 and Cronbach's alpha coefficients ranging from 0.84 to 0.97. Construct validity was demonstrated on the basis of correlations between items and scales. Health-related quality of life varied in a consistent manner according to clinician-rated measures of pelvic pain and dysmenorrhea and patient-reported levels of endometriosis pain, but no relationship emerged according to the revised American Fertility Society classification. In general, the questionnaire was moderately to highly responsive to change. CONCLUSION: This is the first comprehensive health-related quality-of-life questionnaire available for use with endometriosis patients that has demonstrated reliability, validity, and responsiveness.