Validity of physician-diagnosed COPD in relation to spirometric definitions of COPD in a general population aged 50–64 years – the SCAPIS pilot study

Figures & data

Table 1 Age, gender, smoking habits, symptoms and lung function values in 1,050 subjects according to different definitions of airways obstruction and COPD

Variables	Airways obstruction (N=212)	COPDGOLD (N=105)	COPDLLN (N=100)
All (n=1,050)	20.2% (N=212)	10.0% (N=105)	9.5% (N=100)
Males (n=525)	18.3% (N=96)	11.4% (N=60)	10.9% (N=57)
Females (n=525)	22.1% (N=116)	8.6% (N=45)	8.2% (N=43)
Age (years)	58.1	58.7	58.1
Never-smokers (n=448)	13.2% (N=59)	4.7% (N=21)	7.1% (N=32)
Ever-smokers (n=602)	25.4% (N=153)	14.0% (N=84)	11.3% (N=68)
Physician-diagnosed asthma (n=97)	38.1% (N=37)	23.7% (N=23)	21.7% (N=21)
FEV1 (% pred)	90.2	83.1	86.3
FVC (% pred)	101.7	100.6	104.7
Current wheeze (n=87)	17.5% (N=37)	26.7% (N=28)	27.0% (N=27)
Physician-diagnosed COPD/emphysema (n=25)	48.0% (N=12)	44.0% (N=11)	48.0% (N=12)
Physician-diagnosed chronic bronchitis (n=46)	41.3% (N=19)	19.6% (N=9)	21.7% (N=10)
Physician-diagnosed COPD/emphysema or chronic bronchitis (n=60)	40.0% (N=24)	23.3% (N=14)	25.0% (N=15)

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; _LLN, lower limit of normal.

Table 2 Validity of items about physician-diagnosed COPD and chronic bronchitis

	Airways obstruction (n=212)		COPDGOLD (n=105)		COPDLLN (n=100)
	Value	95% CI	Value	95% CI	Value	95% CI
Physician-diagnosed COPD (n=21)
Sensitivity	0.057	0.030–0.098	0.106	0.054–0.181	0.111	0.056–0.188
Specificity	0.989	0.980–0.995	0.989	0.981–0.995	0.989	0.981–0.995
PPV	0.571	0.340–0.782	0.524	0.298–0.743	0.524	0.299–0.743
NPV	0.806	0.780–0.830	0.909	0.890–0.926	0.914	0.895–0.930
Physician-diagnosed COPD/emphysema (n=25)
Sensitivity	0.057	0.030–0.097	0.105	0.054–0.180	0.110	0.056–0.188
Specificity	0.985	0.974–0.992	0.985	0.975–0.992	0.985	0.975–0.992
PPV	0.480	0.278–0.687	0.440	0.244–0.651	0.440	0.244–0.651
NPV	0.805	0.779–0.829	0.908	0.889–0.925	0.913	0.894–0.930
Physician-diagnosed chronic bronchitis (n=46)
Sensitivity	0.090	0.055–0.136	0.086	0.040–0.157	0.100	0.049–0.176
Specificity	0.968	0.954–0.979	0.961	0.946–0.972	0.962	0.948–0.973
PPV	0.413	0.270–0.568	0.196	0.094–0.339	0.217	0.110–0.364
NPV	0.808	0.782–0.832	0.904	0.885–0.922	0.910	0.891–0.927
Physician-diagnosed COPD, emphysema and chronic bronchitis (n=60)
Sensitivity	0.113	0.074–0.164	0.133	0.075–0.214	0.15	0.087–0.235
Specificity	0.957	0.941–0.970	0.951	0.936–0.964	0.953	0.937–0.965
PPV	0.400	0.276–0.535	0.233	0.134–0.360	0.250	0.147–0.379
NPV	0.810	0.784–0.834	0.908	0.888–0.926	0.914	0.895–0.931

Abbreviations: NPV, negative predictive value; PPV, positive predictive value; _LLN, lower limit of normal.

Table 3 Validity of items about physician-diagnosed COPD and emphysema among men, women and ever-smokers in relation with different spirometry definitions of airway obstruction and COPD

	Airways obstruction (n=212)		COPDGOLD (n=105)		COPDLLN (n=100)
	Value	95% CI	Value	95% CI	Value	95% CI
Physician-diagnosed COPD/emphysema (n=25)
Males (n=14)
Sensitivity	0.063	0.023–0.131	0.100	0.038–0.205	0.105	0.040–0.215
Specificity	0.981	0.964–0.992	0.983	0.967–0.993	0.983	0.967–0.993
PPV	0.429	0.177–0.711	0.429	0.177–0.711	0.455	0.168–0.767
NPV	0.824	0.789–0.856	0.894	0.864–0.920	0.900	0.871–0.925
Females (n=11)
Sensitivity	0.052	0.019–0.109	0.111	0.037–0.241	0.116	0.039–0.251
Specificity	0.988	0.972–0.996	0.988	0.973–0.995	0.988	0.973–0.995
PPV	0.546	0.234–0.833	0.455	0.168–0.766	0.429	0.177–0.711
NPV	0.786	0.748–0.821	0.922	0.900–0.944	0.926	0.900–0.947
Ever-smokers (n=20)
Sensitivity	0.072	0.036–0.125	0.119	0.059–0.208	0.125	0.062–0.218
Specificity	0.980	0.962–0.991	0.981	0.965–0.991	0.981	0.965–0.991
PPV	0.550	0.315–0.770	0.500	0.272–0.728	0.500	0.272–0.728
NPV	0.756	0.719–0.790	0.873	0.843–0.899	0.880	0.851–0.905

Abbreviations: NPV, negative predictive value; PPV, positive predictive value; _LLN, lower limit of normal.

Table 4 Different wordings in questionnaire items about chronic obstructive pulmonary disease

References	Wording	Additional comments
Lebowitz and Burrows^Citation21	During the past year, have you seen a doctor for: a. Emphysema? b. Chronic bronchitis?
Whittemore et al^Citation22	Has a doctor ever told you that you had chronic bronchitis? Has a doctor ever told you that you had emphysema?	Positive response to either item and negative response to current asthma was defined as physician-diagnosed COPD
Schnell et al^Citation23	Has a doctor or other health professional ever told you that you had chronic bronchitis? Has a doctor or other health professional ever told you that you had emphysema?	Positive response to any was defined as physician-diagnosed COPD
Ford et al^Citation24	Have you ever been told by a doctor or other health professional that you have COPD, emphysema or bronchitis?	From the Behavioral Risk factor Surveillance System
Ford et al^Citation24	Have you been told by a doctor or other health professional that you had emphysema? During the past 12 months, have you been told by a doctor or other health professional that you have chronic bronchitis?	From the National Health Interview Survey An affirmative response to one or both questions was defined as physician-diagnosed COPD
Murgia et al^Citation12	Have you been diagnosed by a physician as having COPD or emphysema	One item
Mirabelli et al^Citation25	Have you ever been told by a doctor or other health professional that you have COPD? Have you been told by a doctor or other health professional that you have emphysema? Have you been told by a doctor or other health professional that you have chronic bronchitis?	Positive response to any of the three items was defined as physician-diagnosed COPD
Present study	Have you ever been diagnosed by a physician as having COPD? Have you been diagnosed by a physician as having emphysema?	Positive response to any of two items was defined as physician-diagnosed COPD
Present study	Have you ever been diagnosed by a physician as having COPD?	Single item

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