# Table 1 The difference between non-invasive cuff and invasive arterial blood pressure measurements

Difference NIBP–IABP SBP DBP MAP
For the 66 flush-tested arterial lines*
Optimal damping (n = 30) 0.8 (12.2); 0.5 (−9, 8.5) −5.2 (8.7); −5.5 (−10.5, 0.3) −4.9 (7.6); −6.5 (−10, −2)
Over damping (n = 25) −1.5 (11.2); −1 (−7, 6) 2 (12.5); 1 (−5.5, 6.5) −1.3 (8.5); −1.3 (−7, 2)
Under damping (n = 11) −2.7 (12.5); −3 (−11, 6) 1.9 (8.4); 1 (−2, 7) −1.4 (9.6); −4 (−10, 6)
For all the n = 148 arterial lines
Combined results −1.7 (11.6); −2 (−8, +5) −2.1 (11.4); −3 (−8, +3) −5.0 (9.2); −5 (−10, −1)
Combined results r = 0.87 r = 0.78 r = 0.87
For the 42 flush tested arterial lines in the d1–3 category
Optimal damping (n = 19) −3.1 (12.2); −4 (−12, 6) −5.4 (7.4); −6 (−10, 0) −6.5 (5.6); −8 (−10, −3)
Over damping (n = 16) −2.0 (12.7); −0.5 (−7.5, 5.5) −1.9 (9.7); −1 (−6.8, 3) −3.5 (7.8); −2.5 (−8, 0.5)
Under damping (n = 7) −2.9 (13.8); −4 (−9, 1) 1.4 (10.4); −3 (−8, 5.5) −2.0 (10.4); −6 (−14, −1)
For all the 83 arterial lines in the d1–3 category
Combined results −1.5 (11.6); −2.0 (−8, 6) −3.5 (8.4); −4.0 (−8, 1) −5.5 (7.0); −6.0 (−10, −1)
Combined results r = 0.83 r = 0.84 r = 0.89
1. Given as mean (SD); median (IQR). *Analysis of variance, diastolic blood pressure (DBP) values are different by damping category (p = 0.024). NIBP non-invasive blood pressure, IABP invasive arterial blood pressure, SBP systolic blood pressure, DBP diastolic blood pressure, MAP mean arterial pressure, r correlation coefficient, d day