Reduced COPD Exacerbation Risk Correlates With Improved FEV1: A Meta-Regression Analysis.

BackgroundThe mechanism by which various classes of medication reduce COPD exacerbation risk remains unknown. We hypothesized a correlation between reduced exacerbation risk and improvement in airway patency as measured according to FEV1.MethodsBy systematic review, COPD trials were identified that reported therapeutic changes in predose FEV1 (dFEV1) and occurrence of moderate to severe exacerbations. Using meta-regression analysis, a model was generated with dFEV1 as the moderator variable and the absolute difference in exacerbation rate (RD), ratio of exacerbation rates (RRs), or hazard ratio (HR) as dependent variables.ResultsThe analysis of RD and RR included 119,227 patients, and the HR analysis included 73,475 patients. For every 100-mL change in predose FEV1, the HR decreased by 21% (95% CI, 17-26; P < .001; R2 = 0.85) and the absolute exacerbation rate decreased by 0.06 per patient per year (95% CI, 0.02-0.11; P = .009; R2 = 0.05), which corresponded to an RR of 0.86 (95% CI, 0.81-0.91; P < .001; R2 = 0.20). The relationship with exacerbation risk remained statistically significant across multiple subgroup analyses.ConclusionsA significant correlation between increased FEV1 and lower COPD exacerbation risk suggests that airway patency is an important mechanism responsible for this effect

Remote Patient Monitoring for the Detection of COPD Exacerbations

BackgroundCOPD exacerbations occur more frequently with disease progression and are associated with worse prognosis and higher healthcare expenditure.PurposeTo utilize a networked system, optimized with statistical process control (SPC), for remote patient monitoring (RPM) and to identify potential predictors of COPD exacerbations.MethodsSeventeen subjects, mean (SD) age of 69.7 (7.2) years, with moderate to severe COPD received RPM. Over 2618 patient-days (7.17 patient-years) of monitoring, we obtained daily symptom scores, treatment adherence, self-reported activity levels, daily spirometry (SVC, FEV1, FVC, PEF), inspiratory capacity (IC), and oxygenation (SpO2). These data were used to identify predictors of exacerbations defined using Anthonisen and other criteria.ResultsAfter implementation of SPC, concordance analysis showed substantial agreement between FVC (decrease below the 7-day rolling average minus 1.645 SD) and self-reported healthcare utilization events (κ=0.747, P<0.001) as well as between increased use of inhaled short-acting bronchodilators and exacerbations defined by two Anthonisen criteria (κ=0.611, P<0.001) or modified Anthonisen criteria (κ=0.622, P<0.001). There was a moderate agreement between FEV1 (decrease >1.645 SD below the 7-day rolling average) and self-reported healthcare utilization events (κ=0.475, P<0.001) and between SpO2 less than 90% and exacerbations defined by two Anthonisen criteria (κ=0.474, P<0.001) or modified Anthonisen criteria (κ=0.564, P<0.001).ConclusionExacerbations were best predicted by FVC and FEV1 below the one-sided 95% confidence interval derived from SPC but also by increased use of inhaled short-acting bronchodilators and fall in oxygen saturation. An RPM program that captures these parameters may be used to guide appropriate interventions aimed at reducing healthcare utilization in COPD patients