Table 3 Summary of Deming regression and Bland–Altman analyses comparing the hemoglobin concentration values between the BD FACSPresto system and the reference standard (Sysmex XT-4000i analyzer).
BD FACSPresto using venous blood sample vs Sysmex XT-4000i using venous blood sample | BD FACSPresto using capillary blood sample vs Sysmex XT-4000i using capillary blood sample | ||||||
|---|---|---|---|---|---|---|---|
All N = 1069 | HIV-positive group N = 426 | HIV-negative group N = 643 | All N = 1048 | HIV-positive group N = 416 | HIV-negative group N = 632 | ||
Deming regression (linear regression) | |||||||
Intercept | 1.35 | 1.69 | 1.08 | 1.26 | 1.12 | 1.23 | |
Slope | 0.89 | 0.86 | 0.91 | 0.92 | 0.92 | 0.93 | |
97.5% CI of slope | 0.87–0.90 | 0.83–0.88 | 0.90–0.93 | 0.90–0.94 | 0.87–0.97 | 0.90–0.95 | |
R2 | 0.962 | 0.953 | 0.969 | 0.938 | 0.917 | 0.951 | |
P value | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | < 0.001 | |
Absolute deviation | |||||||
Mean ± SD | − 0.24 ± 0.66 | − 0.46 ± 0.72 | − 0.09 ± 0.58 | 0.11 ± 0.77 | − 0.07 ± 0.87 | 0.23 ± 0.68 | |
95%CI | − 0.28 to − 0.20 | − 0.53 to − 0.39 | − 0.14 to − 0.05 | 0.06 to 0.16 | − 0.16 to 0.01 | 0.18 to 0.28 | |
Within mean ± 1.96 SD | 1016 (95.0%) | 408 (95.8%) | 609 (94.7%) | 1002 (95.6%) | 398 (95.7%) | 597 (94.5%) | |
Relative deviation | |||||||
Mean ± SD | − 1.19 ± 5.15 | − 2.57 ± 5.57 | − 0.28 ± 4.64 | 1.31 ± 6.38 | 0.02 ± 6.74 | 2.18 ± 5.98 | |
95% CI | − 1.50 to − 0.88 | − 3.10 to − 2.04 | − 0.64 to 0.08 | 0.92 to 1.69 | − 0.67 to 0.63 | 1.71 to 2.65 | |
Within mean ± 1.96 SD | 1024 (95.8%) | 410 (96.2%) | 616 (95.8%) | 1003 (95.7%) | 394 (94.7%) | 606 (95.9%) | |
