Validity of a questionnaire-based diagnosis of chronic obstructive pulmonary disease in a general population-based study

Table 4 Diagnostic accuracy of the question “Have you been diagnosed by a physician as having COPD or emphysema?” to detect chronic obstructive pulmonary disease (COPD), in non-smokers, ex-smokers, and current smokers

		FEV₁/FVC <0.7 (GOLD)		FEV₁/FVC <1.645 SD below predicted (ATS/ERS)
		Value	95% CI	Value	95% CI
Sensitivity	Non-smokers	0.009	−0.014–0.032	0.022	−0.033–0.077
	Ex-smokers	0.070	0.017–0.124	0.138	0.025–0.251
	Current smokers	0.087	0.021–0.153	0.117	0.013–0.220
Specificity	Non-smokers	1		1
	Former smokers	0.992	0.986–0.998	0.991	0.985–0.997
	Current smokers	0.996	0.989–1.003	0.991	0.981–1.000
PPV	Non-smokers	1		1
	Former smokers	0.5	0.22–0.78	0.4	0.126–0.674
	Current smokers	0.833	0.564–1.102	0.583	0.228–0.939
NPV	Non-smokers	0.941	0.928–0.955	0.976	0.967–0.985
	Former smokers	0.906	0.886–0.925	0.964	0.951–0.976
	Current smokers	0.830	0.792–0.867	0.914	0.886–0.942

ATS = American Thoracic Society; CI = confidence interval; ERS = European Respiratory Society; FEV₁ = forced expiratory volume in 1 second; FEV₁/FVC = FEV₁/forced vital capacity ratio; Gold = Global Initiative for Chronic Obstructive Lung Disease; NPV = negative predictive value; PPV = positive predictive value.

ISSN: 1471-2466