COPD
-
Minimum clinically important change of 5 points in the University of California, San Diego Shortness of Breath Questionnaire (SOBQ) is established, but cutoff values between a small, a moderate, and a large change are still unknown. We used the data set of National Emphysema Treatment Trial consisting of severe and very severe chronic obstructive pulmonary disease patients, whose mean age was 64 years. Changes from baseline to post-surgical 6-month follow-up were evaluated. ⋯ In a cohort of surgically treated patients (N = 484), we propose value of 5 (range 5-6), 11 (range 9-15), and 16 (range 14-20) for the cutoff values between a meaningless and a small change (minimum clinically important difference), a small and a moderate change, and a moderate and a large change, respectively. In a cohort of medically treated patients, numbers of patients categorized according to ∆SOBQ scores were similar to those of the patients categorizes according to the ∆SGRQ (N = 480) or ∆Forced expiratory volume in 1 second (N = 425). We propose group-level cutoff values and range between a small, a moderate, and a large changes.
-
Oxidative stress is implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Analysis of the expired breath condensate (EBC) has been suggested to provide non-invasive inflammatory markers that reflect oxidative stress in the airways. ⋯ These findings suggest that oxidative stress is involved in the pathogenesis of asthma and COPD and that the H2O2 levels in EBC might reflect the health status in COPD.
-
Progressive decline in lung function has been widely accepted as the hallmark of chronic obstructive pulmonary disease (COPD); however, recent evidence indicates that the rate of decline measured as decline in forced expiratory volume in one second (FEV1) is higher in mild to moderate COPD than in severe COPD. Usually changes in FEV1 are measured in ml that is "absolute"; however, changes can also be measured "relative" as a percentage of the actual FEV1. We hypothesize that relative measurements could be more appropriate than absolute measurements for describing changes in lung function. ⋯ Measuring changes in relative terms could have important implications for the interpretation of results from clinical trials where FEV1 is the primary outcome. DLCST; www. ClinicalTrials.org , registration number: NCT00496977.