Objective: To assess the psychometric properties of the short-form chronic respiratory disease questionnaire (SF-CRQ) as a quality-of-life (QOL) instrument in chronic obstructive pulmonary disease (COPD) exacerbations.
Study design and setting: In a prospective multicenter cohort study, consecutive emergency department (ED) patients with COPD exacerbation were interviewed using the SF-CRQ and other instruments. Baseline information was collected in the ED and from follow-up data 2 weeks later. The results of the SF-CRQ were compared with the results of the other instruments and clinical variables by correlation and factor analyses.
Results: Of the 301 enrolled patients, 80% reported improvements across each of the domains of the SF-CRQ over the 2-week post-ED period. Overall median changes for the dyspnea, fatigue, emotional function, and mastery domains were 2, 1, 1, and 1.5, respectively (P<0.001 for each domain). Correlation and factor analyses support their convergent/divergent validity and construct validity. The reliability for the change score of the SF-CRQ was high (Cronbach's alpha coefficient, 0.82). Overall minimal clinically important difference for improvement in the SF-CRQ was 1.01 (95% confidence interval, 0.72-1.31).
Conclusion: SF-CRQ is a valid, reliable, and responsive instrument for the assessment of short-term QOL change in patients with COPD exacerbations.