TY - JOUR T1 - Severity of airways obstruction and severity of COPD, which one? JF - European Respiratory Journal JO - Eur Respir J VL - 42 IS - Suppl 57 SP - P943 AU - Sonia Coton AU - Louisa Gnatiuc AU - Peter Burney Y1 - 2013/09/01 UR - http://erj.ersjournals.com/content/42/Suppl_57/P943.abstract N2 - BackgroundCurrent guidelines define COPD in terms of obstruction (FEV1/FVC) but most scores define severity using the FEV1 which is associated with both obstruction and restriction. We have used the BOLD data to construct a severity score based on FEV1/FVC and compared this to the equivalent score using FEV1 and tested their relative ability to predict symptoms and quality of life.MethodsSubjects with post-BD FEV1/FVC<0.70 were classified as moderate, severe and very severe COPD using the GOLD cut-offs of post-BD FEV1 % predicted <80, <50 and <30 respectively and using the BOLD alternative cut-offs of post-BD FEV1/FVC % predicted <86, <69 and <46 respectively.Agreement of the two classifications was assessed using a Kappa statistic. We estimated sensitivity and specificity of the GOLD criteria as a test for identifying severity of obstruction and we assessed how the two classifications correlate with reported dyspnoea, quality of life and exacerbations in subjects with obstruction.ResultsThe quadratic weighted Kappa displayed moderate agreement between the two classifications (kappa=0.6). The two classifications identify different individuals as moderate, severe and very severe as obstruction becomes more severe: sensitivity=0.7, specificity=0.9 for moderate; sensitivity= 0.6, specificity=0.9 for severe; sensitivity= 0.5, specificity=0.9 for very severe.The two classifications had the same ability to predict dyspnoea, MMRC score, QoL and increased frequency of exacerbations among those with obstruction.ConclusionAmong those with airway obstruction low FEV1 and low FEV1/FVC identify different groups. Both scores predict similar levels of dyspnoea, QoL and exacerbations. ER -