Psychometric assessment of the health-related productivity questionnaire (HRPQ) among women with endometriosis

Abstract

Objective: Endometriosis impacts health-related quality of life. The objective was to assess the validity and responsiveness of the Health-Related Productivity Questionnaire, version 2 (HRPQ). Methods: Outcome measures (Endometriosis Health Profile-30; pain scales; and global assessment) from Elaris Endometriosis I and II clinical trials (EM-I, EM-II) were used. Validity testing using Cohen’s conventions was assessed. Known-groups validity was evaluated using generalized linear models comparing clinical responders, assessment of change, and the endometriosis impact. The effect size (ES) and standard error of means were calculated to evaluate responsiveness. Results: 871 and 815 women participated in the EM-I and EM-II trials. The total hours of lost work among employed women were 16.5 (±11.4) hours per week for EM-I and 15.2 (±11.3) for EM-II. The total hours of lost work among the household group were 8.3 (±8.7) hours for EM-I and 8.4 (±9.0) hours for EM-II. HRPQ discriminated between all known group assessments tested. Correlations for the HRPQ compared to other measures were small to moderate. Moderate to large ES was observed and the ability of the HRPQ to detect change was strong using patient-reported impressions. Conclusion: The HRPQ is a valid and responsive tool for evaluating patient-reported productivity at work and at home among women with endometriosis.