Table 1:

Criteria for study diagnosis of obstructive airway disorders in patients with shortness of breath

Disease	Study diagnosis	Criteria4,5
Asthma	Definite asthma	Increase in FEV₁ > 200 mL and > 12% above prebronchodilator FEV₁ OR Positive response to methacholine provocation test: an airway hyperresponsiveness as defined by use of PC₂₀
Asthma	Probable asthma	Diagnosis by two-thirds consensus of the expert physician panel from review of examination, current respiratory symptoms and prior medical records
COPD	Definite COPD	Postbronchodilator FEV₁ < 80% predicted together with an FEV₁/FVC < 0.70
COPD	Probable COPD	Diagnosis by two-thirds consensus of the expert physician panel from review of examination, current respiratory symptoms and prior medical records
Non-OADs	Probable normal or with other entities	Does not fulfill criteria for definite or probable asthma or COPD diagnoses^*

Note: COPD = chronic obstructive pulmonary disease, FEV₁ = forced expiratory volume in 1 second, FVC = forced vital capacity, OAD = obstructive airway disorder, PC₂₀ = the provocative concentration of methacholine that results in a 20% drop in FEV₁.
↵* In patients with a brain natriuretic peptide measurement > 100 pg/mL, a cardiologist consultation was obtained to evaluate the patient for heart failure.