. Author manuscript; available in PMC: 2021 Mar 1.

Published in final edited form as: J Cardiothorac Vasc Anesth. 2019 Sep 30;34(3):616–621. doi: 10.1053/j.jvca.2019.09.035

Table 2.

Blood pressure complexity measures stratified by frailty and predictive ability from area under the receiver operating characteristic curve (C-statistic)

Complexity Measures^†	No Frailty	Frailty	P value^*	C-statistic^‡
Systolic Arterial Pressure	No Frailty	Frailty	P value^*	C-statistic^‡
MSE_Σ	9.13 [8.00; 9.72]	8.32 [7.27; 9.24]	<0.001	0.62 [0.56, 0.67]
MSE_slope	0.03 [−0.06; 0.11]	−0.03 [−0.09; 0.03]	<0.001	0.65 [0.59, 0.71]
MSE_Σ·slope	0.25 [−0.45; 1.00]	−0.25 [−0.74; 0.29]	<0.001	0.65 [0.59, 0.71]
Mean Arterial Pressure
MSE_Σ	9.18 [8.26; 9.83]	8.56 [7.56; 9.27]	<0.001	0.64 [0.58, 0.70]
MSE_slope	0.05 [−0.04; 0.11]	0.02 [−0.06; 0.08]	0.007	0.56 [0.50, 0.62]
MSE_Σ·slope	0.42 [−0.25; 1.07]	0.14 [−0.42; 0.71]	0.003	0.54 [0.48, 0.60]

Level of significance was adjusted using Hochberg sequential procedure

^†

Blood pressure complexity measures are presented as median [quartile 1; quartile 3].

MSEΣ = complexity index, the sum of entropy values from scales 1 to 5;

MSEslope = slope of linear regression line best fitting the entropy values over scales 1 to 5;

MSEΣ.slope = product of MSEΣ and MSEslope

^‡

C-statistic = Concordance statistic values and their corresponding 95% confidence intervals.