Validation of a Quality of Life Questionnaire for Bronchiectasis: psychometric analyses of the Spanish QOL-B-V3.0

Abstract

Purpose: Bronchiectasis is a chronic disease, leading to worsening of health-related quality of life. This study evaluated the psychometric properties of a new patient-reported outcome for non-cystic fibrosis bronchiectasis, the Quality of Life Questionnaire Bronchiectasis, translated into Spanish (QOL-B-Sp-V3.0).

Methods: This prospective study recruited clinically stable patients with non-cystic fibrosis bronchiectasis at 4 Spanish centers. Health status was assessed with multiple indicators (dyspnea, exacerbations, bronchorrhea, etc.), microbiological, radiological, spirometric, and anthropometric parameters plus St-George Respiratory Questionnaire (SGRQ). Psychometric analyses included internal consistency, test-retest reliability, convergent validity, predictive validity, and responsivity to change.

Results: The 207 stable patients (mean age 57.2 years) had a Bhalla score of 11.53 ± 7.39 and FEV1% of 68.3 ± 22.2 %. One hundred and sixty-one stable patients repeated the test 2 weeks later, and 80 patients who had an exacerbation within 6 months of the assessment also repeated it. Internal consistency was high across all scales (Cronbach's alpha >0.70). Thirty-six of 37 items correlated more strongly with their assigned scale than a competing scale. Test-retest coefficients were strong (intraclass correlations r = 0.68-0.88). All scales, except Treatment Burden, discriminated significantly between patients with mild, moderate, and severe disease according to FEV1% and other respiratory parameters. Strong convergence was found between the QOL-B-Sp-V3.0 and SGRQ. Significant correlations were found between QOL-B-Sp-V3.0 and various clinical, spirometric, radiological, and anthropometric variables. Significant differences were found on all QOL-B-Sp-V3.0 scales, except emotional functioning, between the baseline responses and onset of an exacerbation; robust sensitivity to change was observed on the Respiratory Symptoms scale.

Conclusions: The QOL-B-Sp-V3.0 questionnaire demonstrated strong reliability and validity. Scores were reproducible after 2 weeks, and it discriminated between patients who varied in severity and was responsive to changes related to exacerbation.