Figure 2.

Percentage of COPD-related healthcare visits by severity of airway obstruction. Percentages of COPD related healthcare visits in the mild, moderate, and severe airway obstruction cohort are presented on top of each bar of the graph. Total healthcare visits were divided into outpatient clinic visits, inpatient clinic visits, and emergency department visits. a) COPD-related total healthcare visits, b) COPD-related outpatient clinic visits, c) COPD-related inpatient clinic visits, d) COPD-related emergency department visits; mild = FEV₁/FVC < 70% and FEV₁ ≥ 80% predicted; moderate = FEV₁/FVC < 70% and 50 ≤ FEV₁ < 80% predicted; severe = FEV₁/FVC < 70% and FEV₁ < 50% predicted; normal = FEV₁/FVC ≥ 70% and FEV₁ ≥ 80% predicted; restrictive = FEV₁/FVC ≥ 70% and FEV₁ < 80% predicted.