Validation of a simplified quality-of-life questionnaire for socioeconomically deprived asthma patients

Abstract

Introduction: Quality-of-life questionnaires have been recognized as an important tool to measure the impact of asthma in the patient's life and has become a main outcome in clinical research. To be effective, questionnaires should be adapted to reflect the needs of the target population.

Objective: To assess the reliability, responsiveness, and cross-sectional validity of a simplified quality-of-life questionnaire (QQL-EPM) as a tool specially developed for a socioeconomically deprived target population of asthmatic patients.

Method: Thirty-five asthma patients were followed in a prospective open study over a period of 9 weeks. Clinical visits were performed monthly with pulmonary function assessment and the patients filled out a diary card regarding symptom scores, use of rescue medication, and PEF. At each visit, FEV1 and FVC were measured and two health-related quality-of-life questionnaires were applied: general quality of life (SF-36) and specific quality of life (QQL-EPM). The condition of patient regarding asthma control was assessed at each visit to the clinic, with treatment optimization and medication adjustment as needed. At the end of the study, each period was analyzed across the trial period and classified as stable or noncontrolled asthma.

Results: QQL-EPM was able to correlate changes in quality of life in patients with alterations in their asthma control condition (global = 0.0001) and to differentiate these patients from those whose condition remained stable (global = 0.0001). The reliability of QQL-EPM was 0.68-0.90, and correlation with other clinical measurements and generic quality of life was moderate.