Objective: 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).
Materials and methods: In this chart review/patient survey, 99 physicians recruited patients with physician-assessed severe or very severe COPD who had recently experienced a moderate or severe exacerbation. A cross-tabulation was undertaken comparing physician report, spirometry (mild/moderate, forced expiratory volume in 1 second [FEV1] ≥50%; severe, 30% ≤ FEV1 <50%; very severe, FEV1 <30% predicted), and risk + symptom-based (A, low risk/fewer symptoms; B, low risk/more symptoms; C, high risk/fewer symptoms; D, high risk/more symptoms) severity systems. Analysis of covariance models were run for SGRQ-C, varying COPD-severity systems.
Results: Of 244 patients, 58.6% were severe and 34.8% very severe by physician report, 70% had FEV1 ≤50% at their most recent visit, and 86% fell into quadrant D. Spirometry and physician report had 57.4% agreement, with physicians often indicating higher severity. Physician report and risk + symptom agreement was high (81.2% severe/very severe and D). Physician-reported severity, risk + symptoms, exacerbations in the previous year, and symptoms were significant SGRQ-C predictors, while spirometry was not.
Conclusion: For recently exacerbating severe or very severe COPD patients, risk + symptoms more closely aligned with physician-reported severity and SGRQ-C versus spirometry.
Keywords: COPD; disease-severity measures; pharmacoepidemiology.