Table 3:

Multivariable association of qualitative and quantitative EEG and mortality

Clinical factors/ EEG variables	Odds Ratio	95% confidence interval	P value
Qualitative EEG analysis (AIC* = 100.1)
Standardized age	0.46	0.25, 0.86	0.015
Brain volume score 7 or 8	9.14	2.58, 32.4	0.001
Average background voltage	0.48	0.25, 0.93	0.029
Asymmetry present	5.47	1.56, 19.2	0.008
Background attenuated or suppressed	13.8	3.14, 60.7	0.001
Quantitative EEG analysis (AIC = 91.3)
Standardized age	0.37	0.17, 0.77	0.008
Brain volume score 7 or 8	14.3	3.47, 59.1	<0.001
Low delta to total delta ratio	2.02	0.92, 4.40	0.079
Alpha Power	0.21	0.07, 0.58	0.003
Theta-plus-alpha to delta ratio	3.10	1.37, 6.98	0.006
Theta-alpha variability	0.32	0.15, 0.70	0.004

^*AIC quantifies strength of fit between a group of independent variables and the dependent variable. Models including many independent variables are penalized, thus avoiding overcomparison. When comparing models, the one with the lower AIC value has better goodness of fit.