COPD severity score as a predictor of failure in exacerbations of COPD. The ESFERA study

Background: Exacerbations are a frequent cause of morbidity and mortality in COPD. It is crucial to identify risk factors for failure after treatment of exacerbations of COPD. This study evaluates the COPD severity score (COPDSS) as a predictor of clinical failure, together with other severity, activity and quality of life measurements, in patients with exacerbated COPD.

Method: Multicenter, prospective, observational study in ambulatory patients with exacerbation of COPD. The patients completed the COPDSS, the London Chest Activities of Daily Living (LCADL) and the EuroQol 5D (EQ-5D). A follow-up visit was scheduled one month after presentation with the exacerbation to assess the clinical evolution.

Results: A total of 346 patients were included (mean age 68.5 years (SD=9.5 years and 90.7% male) and mean FEV(1)(% predicted) 46.9% (SD=17)). After one month, 28.2% of episodes were classified as failures, with half of them requiring hospital admission. Patients who failed were more frequently active smokers, with more severe dyspnoea at presentation and worse lung function. They had significantly worse scores of COPDSS, LCADL, EQ-5D index and EQ-5D visual analogue score (VAS) and shorter mean time walking per day. ROC analysis of relationship between COPDSS and failure gave AUC 0.72, which improved only to 0.77 when the other significant variables in univariate analysis were considered.

Conclusions: Clinical failure after ambulatory treatment of exacerbation of COPD is frequent. Usual markers of severity (impaired lung function, active smoking and severe dyspnoea) are associated with failure; however, a short severity questionnaire (COPDSS) provides better predictive value than the usual variables.