Study objective: To determine whether currently available measurement tools can be used to obtain valid measurements of short-term changes in dyspnea and disease-specific quality of life (QOL) in outpatients with an acute COPD exacerbation.
Design: Prospective cohort study.
Methods: Sixty-six patients with an acute COPD exacerbation who presented to the emergency department completed the chronic respiratory disease index questionnaire (CRQ) and the baseline dyspnea index (BDI) and were discharged home receiving 10 days of medical therapy. Reassessment with the CRQ and the transitional dyspnea index (TDI) occurred within 48 h of relapse (defined as an urgent hospital revisit within 10 days because of worsening respiratory symptoms), or 10 days later if relapse did not occur.
Results: Patients who did not relapse (n = 49) showed moderate-to-large improvements in disease-specific QOL across all four CRQ domains (improvements in each domain of 1.4 to 1.9 U; p < 0.001 for all domains) and large positive changes in the TDI (total TDI score, + 5.02 plus minus 0.55 U; p = 0.0001). In contrast, patients who had a relapse (n = 17) did not have improved CRQ or TDI scores (mean negative change in three of four CRQ domains, total TDI score - 3.06 plus minus 1.14 U; p = 0.02). Changes in the CRQ dyspnea score and TDI correlated with each other (r = 0.78; p = 0.0001) and with changes in FEV(1) (CRQ, r = 0.48 and p = 0.0001; TDI, r = 0.46 and p = 0.0002). Ten control patients with stable COPD showed no changes in the CRQ or TDI over 10 days.
Conclusion: The CRQ and BDI/TDI can be used to obtain valid, responsive measures of acute changes in QOL and dyspnea associated with a COPD exacerbation. The direction and magnitude of change in these scores was highly correlated with clinical outcome and with other health measures. Most outpatients treated for a COPD exacerbation experience significant short-term improvements in QOL and dyspnea, with the exception of patients who have a clinical relapse of symptoms.