Skip to main content
. 2017 Oct 10;10:497. doi: 10.1186/s13104-017-2825-0

Table 1.

Differences in measurements between different types of spirometers, spirometers of same type, and repeated measurements with a spirometer

Spirometers FVC FEV1
Mean diff. (L) Mean rel. diff. (%) Bland–Altman 95% lim. agr. Mean diff. (L) Mean rel. diff. (%) Bland–Altman 95% lim. agr.
HW–US 0.33*** 8.99 (0.09, 0.58) 0.11*** 3.59 (− 0.03, 0.24)
WB–US 0.24*** 6.56 (0.02, 0.47) 0.15*** 5.13 (− 0.06, 0.36)
HW–WB 0.09* 2.28 (− 0.14, 0.31) − 0.05 n.s. − 1.46 (− 0.25, 0.16)
HW1–US1 0.35*** 9.52 (0.01, 0.69) 0.12** 4.00 (− 0.05, 0.29)
HW1–US2 0.36*** 9.64 (− 0.004, 0.72) 0.18** 5.99 (− 0.04, 0.39)
HW2–US1 0.32*** 8.53 (0.03, 0.60) 0.04 n.s. 1.29 (− 0.21, 0.29)
HW2–US2 0.32*** 8.65 (0.06, 0.57) 0.09 n.s. 3.22 (− 0.14, 0.33)
HW3–US1 0.40*** 10.79 (− 0.02, 0.81) 0.14* 4.67 (− 0.13, 0.41)
HW3–US2 0.40*** 10.91 (0.03, 0.77) 0.20** 6.67 (− 0.07, 0.46)
HW4–US1 0.25** 6.86 (− 0.06, 0.57) 0.02 n.s. 0.53 (− 0.16, 0.19)
HW4–US2 0.26*** 6.98 (− 0.02, 0.54) 0.07 n.s. 2.45 (− 0.15, 0.30)
WB–US1 0.24*** 6.50 (− 0.002, 0.48) 0.12* 4.14 (− 0.10, 0.34)
WB–US2 0.24*** 6.62 (0.02, 0.47) 0.18** 6.13 (− 0.05, 0.40)
HW1–WB 0.11 n.s. 2.84 (− 0.19, 0.41) − 0.004 n.s. − 0.13 (− 0.24, 0.23)
HW2–WB 0.08 n.s 1.91 (− 0.18, 0.33) − 0.09 n.s. − 2.74 (− 0.37, 0.20)
HW3–WB 0.16 n.s. 4.02 (− 0.26, 0.58) 0.02 n.s. 0.51 (− 0.31, 0.33)
HW4–WB 0.01 n.s. 0.34 (− 0.21, 0.24) − 0.11* − 3.46 (− 0.30, 0.09)
HW1–HW2 0.04 n.s. 0.91 (− 0.31, 0.38) 0.08 n.s. 2.68 (− 0.25, 0.41)
HW1–HW3 − 0.05 n.s. − 1.14 (− 0.43, 0.34) − 0.02 n.s. − 0.64 (− 0.31, 0.27)
HW1–HW4 0.10 n.s. 2.49 (− 0.21, 0.41) 0.10 n.s 3.45 (− 0.14, 0.35)
HW2–HW3 − 0.08 n.s. − 2.04 (− 0.47, 0.30) − 0.10 n.s. − 3.23 (− 0.36, 0.16)
HW2–HW4 0.06 n.s. 1.56 (− 0.17, 0.29) 0.02 n.s. 0.75 (− 0.19, 0.23)
HW3–HW4 0.15 n.s. 3.67 (− 0.25, 0.54) 0.12 n.s 4.12 (− 0.14, 0.38)
US1–US2 0.004 n.s. 0.11 (− 0.1, 0.13) 0.06 n.s. 1.91 (− 0.09, 0.20)
Repeatability FVC FEV1
Mean diff. (L) Mean rel. diff. (%) ATS/ERS approved Mean diff. (L) Mean rel. diff. (%) ATS/ERS approved
HW1 0.05 1.31 Yes 0.05 1.70 Yes
HW2 0.03 0.63 Yes 0.03 1.03 Yes
HW3 0.06 1.51 Yes 0.04 1.30 Yes
HW4 0.04 1.09 Yes 0.03 1.15 Yes
US1 0.04 1.07 Yes 0.03 1.07 Yes
US2 0.05 1.35 Yes 0.05 1.62 Yes
WB 0.03 0.64 Yes 0.03 0.84 Yes

Repeatability: difference between best and second best test, Mean difference: e.g. HW–US, Mean relative difference: e.g. HW–US/US*100

diff difference, HW hot-wire, lim. agr. limits of agreement, n.s. not significant, rel relative, US ultrasonic, WB wedge-bellows

p < 0.05, ** p < 0.01,*** p < 0.001 (Bonferroni-corrected from linear mixed models, n = 12)