- For predicting COPD exacerbations, the Saint George's Respiratory Questionnaire (SGRQ) definition of chronic bronchitis (CB) might be better than the classic CB definition.
- In this comparison, only CB by SGRQ was independently linked to severe exacerbations.
Why this matters
- CB affects about 10 million people in the United States.
- People with COPD who also have CB tend to fare worse.
- How well SGRQ captures CB and predicts COPD exacerbation has not been established.
- CB by either definition was linked to increased risk for more and severe exacerbations during the 5.16-year follow-up.
- SGRQ bested the classic definition on multivariate analysis as an independent predictor for frequency:
- Classic: β coefficient, 0.083; P=.006; and
- SGRQ: β, 0.166; P<.0001.>
- It also was the only 1 of the 2 to be independently associated with severe exacerbation frequency:
- Classic: β coefficient, 0.032 (P=.054); and
- SGRQ: β, 0.065 (P<.0001>
- Study included 7557 smokers with COPD, normal spirometry, all part of the COPDGene study.
- Classic definition: chronic cough, sputum for 3 months/year, at least 2 consecutive years.
- SBRQ: uses answers to questions about cough and phlegm.
- Funding: National Heart, Lung, and Blood Institute; some industry funding for the COPDGene study.
- Exacerbations self-reported.