. 2020 Apr 9;12:16. doi: 10.1186/s13089-020-00163-w

Table 2.

Multivariable proportional hazards models to predict acute kidney injury in 145 patients after cardiac surgery using the Venous EXcess UltraSound (VExUS) C grading system

	Crude hazard ratio			Model 1			Model 2
	Crude hazard ratio			Adjusted hazard ratio^a			Adjusted hazard ratio^b
	HR	CI	p	HR	CI	p	HR	CI	p
VExUS C Grade 0	Reference category			Reference category			Reference category
VExUS C Grade 1	1.25	0.58–2.66	0.57	1.13	0.52–2.43	0.76	1.13	0.52–2.43	0.76
VExUS C Grade 2	2.65	1.07–6.60	0.036	2.31	0.92–5.80	0.074	2.32	0.92–5.83	0.073
VExUS C Grade 3	3.69	1.65–8.24	0.001	2.83	1.22–6.55	0.015	2.82	1.21–6.55	0.016
Pre-operative AKI risk score [30]	1.02	1.01–1.04	0.001	1.02	1.003–1.03	0.019	1.02	1.003–1.033	0.02
Vasopressor–inotrope score	1.01	0.99–1.03	0.51				1.001	0.98–1.03	0.93

Multivariable proportional hazard regression model (Cox) with the VExUS grade considered as a time-varying covariate (i.e., VExUS grade at day 0 is used to predict AKI at day 1, VExUS grade at day 1 is used for AKI at day 2 and so on). HR hazard ratio, CI 95% confidence intervals

^aVariables included in the multivariate model were the VExUS C grade (segmented time-dependant) and pre-operative AKI risk score [30]

^bVariables included in the multivariate model were the VExUS C grade (segmented time-dependant), vasopressor–inotrope score (segmented time-dependant) and pre-operative AKI risk score [30]