Table 2. Estimated correlation coefficients^† of ROS, TBARS and TAC with ONSD, SpO₂ and LLS.

Time included in the model	Covariate/factor	Absolute values						Relative increase from previous time-point
		ln(ROS)		TBARS		TAC		ROS		TBARS		TAC
		correlation	p-value	correlation	p-value	correlation	p-value	correlation	p-value	correlation	p-value	correlation	p-value
no	ONSD	0.713	<0.001	0.606	<0.001	0.741	<0.001	0.444	0.065	0.462	0.054	0.382	0.177
yes	time	0.693	<0.001	0.621	0.001	0.488	0.036	0.618	0.035	0.681	0.013	0.521	0.205
	ONSD	0.101	0.559	0.075	0.662	0.193	0.281	0.235	0.381	0.106	0.695	0.133	0.680
no	SpO2	0.671	<0.001	0.556	<0.001	0.630	<0.001	0.457	0.057	0.406	0.095	0.327	0.254
yes	time	0.756	<0.001	0.676	<0.001	0.647	0.001	0.580	0.057	0.708	0.008	0.540	0.179
	SpO2	0.295	0.081	0.203	0.235	0.132	0.465	0.018	0.946	0.149	0.581	0.023	0.942
no	LLS#	0.430	0.010	0.332	0.052	0.286	0.113	0.103	0.686	0.183	0.468	0.044	0.882
yes	time	0.823	<0.001	0.728	<0.001	0.800	<0.001	0.687	0.011	0.748	0.003	0.609	0.098
	LLS#	0.107	0.560	0.031	0.868	0.229	0.231	0.080	0.768	0.003	0.990	0.096	0.767

LLS, Lake Louise Score; ONSD, optic nerve sheath diameter; ROS, reactive oxygen species; SpO₂, oxygen saturation; TAC, total antioxidant capacity; TBARS, thiobarbituric acid-reactive substances.

^†Correlation coefficients are given as sqrt (sum of squares) formula from ANOVA with subject as random effect, ONSD, SpO₂ or LLS as covariate and respective parameter as dependent variable.

^#In groups: 0, ≥1.