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Table 4 Methods comparison (Bland-Altman statistics) for lung function measurements performed in a GP’s office and at lung function lab (N = 227)

From: Diagnostic accuracy of a pocket screening spirometer in diagnosing chronic obstructive pulmonary disease in general practice: a cross sectional validation study using tertiary care as a reference

 

COPD-6™ at GP’s office

Lung function lab measurements

 

FEV1 (L)

FEV6 (L)

FEV1/FEV6 (%)

COPD-6™

FEV1 (L)

Δ (95 % CI)

0.01 (−0.05 to 0.03)

NA

NA

FEV6 (L)

Δ (95 % CI)

NA

−0.17 (−0.24 to −0.12)*

NA

FEV1/FEV6 (%)

Δ (95 % CI)

NA

NA

4.83 (3.71 to 6.35)*

Spirometry

FEV1 (L)

Δ (95 % CI)

−0.12 (−0.15 to −0.09)*

NA

NA

FVC (L)

Δ (95 % CI)

NA

−0.66 (−0.72 to -0.59)*

NA

FEV1/FVC (%)

Δ (95 % CI)

NA

NA

10.24 (9.32 to 11.26)*

Post-bronchodilator spirometry

FEV1 (L)

Δ (95 % CI)

−0.15 (−0.19 to −0.12)*

NA

NA

FVC (L)

Δ (95 % CI)

NA

−0.60 (−0.65 to −0.54)*

NA

FEV1/FVC (%)

Δ (95 % CI)

NA

NA

8.52 (7.57 to 9.47)*

  1. GP general practitioner, FEV 1 forced expiratory volume in 1 s, FEV 6 forced expiratory volume in 6 s, FVC forced expiratory volume, FVC forced expiratory volume, Δ mean difference of the index test (COPD-6™ measurement at GP’s office) from the reference (tertiary care measurement), 95 % CI 95 % confidence interval
  2. NA not applicable
  3. *P < 0.001