Fig. 3From: A comparison of prognostic significance of strong ion gap (SIG) with other acid-base markers in the critically ill: a cohort studyVariability in hospital mortality explained by each acid-base marker in a multivariate model including all acid-base markers and allowing each to have a U-shape relationship with mortality by a 3-knot restricted cubic spline function. SIG strong ion gap. SIDe effective strong ion difference, CO 2 carbon dioxide, HCO 3 actual bicarbonateBack to article page