Table 4.

Comparative specificity for individual tests

Individual test	CAPTURE (95% CI, p value)	CDQ (95% CI, p value)	C-SBQ (95% CI, p value)	COPD-SQ (95% CI, p value)	Peak flow (95% CI, p value)	Microspirometry (95% CI, p value)
CAPTURE		−8.4 (−10.7 to −6.0; <0.0001)	−3.9 (−6.2 to −1.6; 0.0008)	−7.1 (−9.3 to −4.8; <0.0001)	−12.3 (−14.8 to −9.8; <0.0001)	−19.5 (−21.8 to −17.1; <0.0001)
CDQ			4.5 (3.0 to 5.9; <0.0001)	1.3 (−0.4 to 3.0; 0.1335)	−3.9 (−6.1 to −1.8; 0.0003)	−11.1 (−13.2 to −9.0; <0.0001)
C-SBQ				−3.1 (−4.8 to −1.5; 0.0002)	−8.4 (−10.6 to −6.2; <0.0001)	−15.5 (−17.7 to −13.3; <0.0001)
COPD-SQ					−5.3 (−7.4 to −3.1; <0.0001)	−12.4 (−14.6 to −10.3; <0.0001)
Peak flow						−7.1 (−9.1 to −5.2; <0.0001)
Microspirometry

Values indicate the difference in specificity (with 95% CI and p values), comparing index tests in the column against index tests in the row. For example, specificity for CAPTURE is 8.4% lower than for CDQ (95% CI −10.7 to 6.0; <0.0001).

CAPTURE, COPD assessment in primary care to identify undiagnosed respiratory disease and exacerbation risk; CDQ, COPD Diagnostic Questionnaire; COPD, chronic obstructive pulmonary disease; C-SBQ, Chinese Symptom-Based Questionnaire.