. Author manuscript; available in PMC: 2015 Jul 31.

Published in final edited form as: Chronic Obstr Pulm Dis. 2015;2(2):103–121. doi: 10.15326/jcopdf.2.2.2014.0152

Table 4. Variables Used to Identify Cases of COPD by Study Type.

Theme	Variables Used in Screening Tools	Variables Tested in Epidemiologic Studies
Exposure	Smoking status	Smoking status
	Pack years	Passive smoke, exposure to smoke^a, second hand smoke
	Pack years	Exposure to dust, biomass fuel, or other inhalant
Personal and Family History	Allergies	Allergies
	Prior diagnosis of asthma	Prior diagnosis of asthma, bronchitis, or chronic expectoration
	Breathing-related hospitalizations	Chest infections^a
		Childhood illness^a
		Family history of lung disease
		Frequency of primary care visits^a
		Breathing medication or antibiotics
		Cardiac co-morbidity
Symptoms	Cough	Cough
	Phlegm	Phlegm
	SOB	SOB
	Wheeze	Wheeze
		Respiratory symptoms (combination)^a
		Fatigue/tiredness
Impact	Activity limitation (Breathing-related)	Self-rated health status^a
Demographics	Age	Age
	BMI	BMI
		Gender^a
		Race
		Education/occupation^a
		Income

Significant independent predictor of COPD status

Variables in italics are unique to that study type.