Is the EQ-5D responsive to recovery from a moderate COPD exacerbation?

Background: To correctly estimate the cost-effectiveness of treatments that reduce COPD exacerbations, the utility gains from preventing exacerbations need to be measured. This requires utility measurement during exacerbations.

Aim: To assess the ability of the EQ-5D to detect the recovery from moderate COPD exacerbations.

Methods: In the US, 65 COPD and/or chronic bronchitis patients (≥40 years old smokers or ex-smokers with a history of 10 pack-years) were enrolled within 48 h of symptom onset of the exacerbation. Patients completed the EQ-5D at enrollment and after 7, 14 and 42 days. Symptoms and medication use were recorded in diaries. Change over time and loss of quality-adjusted life years (QALYs) due to the exacerbation was estimated. Using standardized response mean (SRM) as the metric of responsiveness, we compared the responsiveness of the EQ-5D to the responsiveness of morning peak expiratory flow rate, rescue medication use and symptom scores. SRMs were also used to assess whether patients with greater improvements in peak expiratory flow rate, rescue medication use, symptom scores, clinician global impression of change, and patient global impression of change had a greater improvement in EQ-5D than patients with smaller improvement.

Results: Mean utility index scores (standard deviation) using the US value set were 0.683 (0.209), 0.726 (0.216), 0.768 (0.169) and 0.760 (0.181) at days 1, 7, 14 and 42, respectively. The mean of each patient's lowest index score, either at visit 1 or visit 2, was 0.651 (0.213). Over the course of 6 weeks there was a highly significant improvement in mean utility. The greatest improvement was seen between day 7 and day 14. Patients lost on average 0.00896 QALY (0.0086) or 3.27 (3.13) quality-adjusted life days during the exacerbation. The EQ-5D (SRM: 0.653) was more responsive to change than peak expiratory flow (0.269), rescue medication use (0.343) and sputum symptom scores (0.322) and equally responsive as cough (0.587) and dyspnea (0.638) symptom scores.

Conclusion: The EQ-5D is responsive to the recovery from a moderate COPD exacerbation.