Comparison of disease-severity measures within severe and very severe COPD patients: results from a nationally representative chart review and patient survey.

This study aimed to compare spirometry- and risk + symptom-based classification systems to physician-based severity assessment and find which system is most predictive of patient-reported health status, as measured by the St George's Respiratory Questionnaire for COPD (chronic obstructive pulmonary disease; SGRQ-C).