A New Self-Administered Questionnaire to Monitor Health-Related Quality of Life in Patients With COPD

Abstract

To develop and validate a brief, computer-scannable, self-administered questionnaire to monitor health-related quality of life in patients with COPD. The Seattle Obstructive Lung Disease Questionnaire (SOLQ) consists of 29 items measuring four health dimensions: physical function, emotional function, coping skills, and treatment satisfaction. A series of studies was performed to assess reliability, validity, and responsiveness. Internal consistency was measured using a cross-sectional survey of 203 COPD patients. Reproducibility was tested over a 4-month interval among 97 patients with self-reported stable conditions. To assess construct validity, SOLQ scales were correlated with corresponding Chronic Respiratory Disease Questionnaire (CRDQ) scales, the COPD Self-Efficacy Scale (CSES), percent predicted FEV1, and 6-min walk test. Treatment satisfaction scores of 920 subjects were correlated with a general measure of patient satisfaction. Baseline and follow-up scores of subjects were compared to assess treatment responsiveness. SOLQ scales were reliable (Cronbach's alpha 0.79 to 0.93, and intraclass correlation coefficients 0.64 to 0.87). Change in SOLQ scores correlated with corresponding CRDQ scales: dyspnea, r=0.42; emotional burden, r=0.49; mastery, r=0.36. Coping skills correlated highly with CSES, r=0.93. Treatment satisfaction correlation was r=0.54. Significant changes occurred in all three scales postintervention. The SOLQ is a reliable, valid, and responsive measure of physical and emotional function, coping skills, and treatment satisfaction. Brief, self-administered, and computer scannable, it is useful in monitoring long-term outcomes among large groups of COPD patients.