Prediction Tools for COPD Exacerbations

Patients with chronic bronchitis (CB) are more likely to experience chronic obstructive pulmonary disease (COPD) exacerbations. Previous research has established that the St. George’s Respiratory Questionnaire (SGRQ) definition of CB can identify patients who have a clinical phenotype comparable to the classic definition of CB, but it is unclear if the SGRQ CB definition can accurately predict future COPD exacerbations. This study included 7,557 smokers who had normal spirometry and Global Initiative for Chronic Obstructive Lung Disease stage 1-4 COPD in the Genetic Epidemiology of COPD study. All participants were required to have longitudinal follow-up data on exacerbations. Patients were categorized into classic CB+ or classic CB–, per the classic definition, as well as SGRQ CB+ or SGRQ CB–. A total of 1,434 classic CB+ and 2,290 SGRQ CB+ patients were included in the study. Annual exacerbation frequency was greater in the classic CB+ group than the classic CB– group (0.69 ± 1.26 vs. 0.36 ± 0.90 exacerbations per patient per year; P<0.0001), as was annual severe exacerbation frequency (0.26 ± 0.74 vs. 0.13 ± 0.46 severe exacerbations per patient per year; P<0.0001). Between-group differences were similar in the SGRQ groups. Multivariable analysis observed SGRQ CB and classic CB to both be independently predictive of exacerbation frequency, but the regression coefficient was higher in the SGRQ CB group. SGRQ CB also independently predicted severe exacerbation frequency, while classic CB did not. Read more