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

Table 2 Diagnostic accuracy of the question “Have you been diagnosed by a physician as having COPD or emphysema?” and of self-reported, questionnaire-based chronic bronchitis symptoms to detect chronic obstructive pulmonary disease (COPD)

		FEV₁/FVC <0.7 (GOLD)		FEV₁/FVC <1.645 SD below predicted (ATS/ERS)
		Value	95% CI	Value	95% CI
Physician-diagnosed COPD	Sensitivity	0.057	0.027–0.088	0.098	0.04–0.156
	Specificity	0.997	0.994–0.999	0.995	0.993–0.998
	LR+	16.859	6.894–41.228	21.532	9.226–50.25
	PPV	0.636	0.427–0.846	0.485	0.267–0.702
	NPV	0.911	0.899–0.922	0.962	0.954–0.97
Chronic bronchitis symptoms	Sensitivity	0.046	0.019–0.074	0.074	0.022–0.125
	Specificity	0.979	0.973–0.985	0.979	0.973–0.985
	LR+	2.244	1.161–4.337	3.520	1.664–7.443
	PPV	0.189	0.086–0.292	0.133	0.044–0.223
	NPV	0.908	0.896–0.920	0.960	0.952–0.968

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; LR + = positive likelihood ratio; NPV = negative predictive value; PPV = positive predictive value; SD = standard deviation.

ISSN: 1471-2466