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Table 1 Average bias (average of the differences between values measured in real time and values measured in post-processing)

From: Inferior vena cava diameters and collapsibility index reveal early volume depletion in a blood donor model

 

Mean (real time measurement)

Mean (post-processing)

Average bias

95 % limit of agreement

p value for trend

p value for variability consistence

Short axis hepatic window

Max diameter before donation

1.77

1.99

–0.04

−0.41; 0.33

0.34

0.27

Min diameter before donation

1.15

1.17

0.01

–0.32; 0.35

0.19

0.11

Max diameter after donation

1.54

1.71

0.09

−0.25; 0.42

0.98

0.5

Min diameter after donation

0.74

0.72

0.09

−0.22; 0.39

0.7

0.81

Long axis hepatic window

Max diameter before donation

1.88

1.95

–0.06

−0.47; 0.35)

0.48

0.06

Min diameter before donation

1.26

1.26

0.02

−0.34; 0.38

0.37

0.62

Max diameter after donation

1.56

1.56

0.04

−0.23; 0.32

0.59

0.07

Min diameter after donation

0.83

0.82

0

Not constant

0.99

0.03

Short axis renal window

Max diameter before donation

1.65

1.82

0.02

−0.36; 0.40

0.51

0.51

Min diameter before donation

1.15

1.16

Not constant

−0.39; 0.46

0.01

0.76

Max diameter after donation

1.34

1.3

0.02

−0.7; 0.74

0.27

0.67

Min diameter after donation

0.66

0.59

0.06

Not constant

0.34

0.04

  1. Trend was assessed by regressing differences (between methods) on averages and checking with a t test whether the slope was 0; variability consistence was assessed by regressing averages (between methods) against the absolute residuals computed from the regression model used for trend and checking with a t test whether the slope was 0