Bronchodilator reversibility testing in XXXX .

@entity1 @entity13265 @entity3045 @entity1514 @entity1576 @entity1030
BACKGROUND: A limited or absent bronchodilator response is used to classify @entity1030 ( @entity1030 ) and can determine the treatment offered. The reliability of the recommended response criteria and their relationship to disease progression has not been established. METHODS: 660 @entity1 meeting @entity1576 ( @entity1576 ) diagnostic criteria for irreversible @entity1030 were studied. Spirometric parameters were measured on three occasions before and after @entity3045 and @entity13265 sequentially or in combination over 2 months. Responses were classified using the American @entity1514 (ATS) and @entity1576 criteria. @entity1 were followed for 3 years with post-bronchodilator FEV(1) and exacerbation history recorded 3 monthly and health status 6 monthly. RESULTS: FEV(1) increased significantly with each bronchodilator, a response that was normally distributed. Mean post-bronchodilator FEV(1) was reproducible between visits (intraclass correlation 0.93). The absolute change in FEV(1) was independent of the pre-bronchodilator value but the percentage change correlated with pre-bronchodilator FEV(1) (r=-0.44; p<0.0001). Using ATS criteria, 52.1% of @entity1 changed responder status between visits compared with 38.2% using @entity1576 criteria. Smoking status, atopy, and withdrawing inhaled corticosteroids were unrelated to bronchodilator response, as was the rate of decline in FEV(1), decline in health status, and exacerbation rate. CONCLUSION: In moderate to severe @entity1030 bronchodilator responsiveness is a continuous variable. Classifying @entity1 as "responders" and "non-responders" can be misleading and does not predict disease progression.
