PURPOSE: Available patient-reported outcome (PRO) measures for chronic obstructive pulmonary disease (COPD) focus primarily on impairment (symptoms) and activities (functioning). The purpose of the study was to develop a patient-based PRO measure for COPD that captures the overall everyday impact of living with COPD from the patient's perspective.
METHODS: LCOPD items (Living with COPD Questionnaire) were generated from qualitative interviews in the U.K. and focus groups in the U.S.A. The draft measure was tested for face and content validity in both countries. Item reduction and testing for reproducibility and construct validity was conducted via Rasch and traditional psychometric analyses.
RESULTS: The draft LCOPD was found to be relevant and acceptable to patients in the U.K. (N = 19) and U.S. (N = 16). Application of Rasch analysis to data collected in validation studies (n = 162 in the U.K. and 145 in U.S.) identified a 22-item scale that measured a single construct in both countries. Psychometric analyses indicated that this version was internally consistent and reproducible. Scores on the measure were related as expected to clinician ratings of disease severity and patient ratings of COPD severity and general health.
CONCLUSIONS: The LCOPD is a new measure examining the everyday impact of living with COPD. It demonstrates good scaling properties and may prove valuable in understanding treatment benefits.
