Characteristics and risk factors for inconsistency between the risk of exacerbations and the severity of airflow limitation in COPD based on GOLD 2017: A retrospective, cross-sectional study

BACKGROUND AND OBJECTIVES: The clinical implications of the discordance between the risk of exacerbations and the level of airflow limitation in patients with chronic obstructive pulmonary disease (COPD) are still unknown. This study aimed to clarify the clinical significance of such discordance in the management of COPD by exploring its characteristics and risk factors. METHODS: In this retrospective, cross-sectional study, participating physicians completed a detailed patient record form for each participating outpatient with COPD. The data, collected by the Taiwan Obstructive Lung Disease consortium, were managed and analyzed. RESULTS: Of the enrolled participants, 316 (41.7%) had an inconsistency between the risk of exacerbations and the severity of airflow limitation. Univariate analysis showed that more severe airflow limitation (p = 0.000), higher COPD assessment test (CAT) scores (p = 0.003) and modified Medical Research Council (mMRC) scales (p = 0.008), and the presence of at least one (p = 0.000) or two (p = 0.003) co-morbidities were significantly associated with such inconsistency. More severe airflow limitation (Global Initiative for Chronic Obstructive Lung Disease (GOLD) 3 and 4 classification; odds ratio (OR) = 27.09, p = 0.000 and OR = 25.15, p = 0.000, respectively) and the presence of at least one co-morbidity (OR = 2.01, p = 0.001) were still associated with the inconsistency in multivariate logistic regression analysis. Furthermore, the presence of wheezing (OR = 3.90, p = 0.000) and at least two co-morbidities (OR = 5.43, p = 0.005) were independent risk factors for an inconsistency of a high risk of exacerbations / GOLD 1 or 2 and the CAT score≧10 (OR = 1.58, p = 0.007), mMRC scale 2–4 (OR = 1.53, p = 0.017), and the presence of at least one co-morbidity (OR = 2.55, p = 0.000) for an inconsistency of a low risk of exacerbations / GOLD 3 or 4. CONCLUSIONS: The patients with COPD and an inconsistency between the risk of exacerbations and level of airflow limitation had unique clinical characteristics and risk factors for this inconsistency. Management of these patients should include more detailed evaluations.