Figure 4:

Age- and sex-adjusted probability of AKI by baseline creatinine (upper panels) or cystatin C (lower panels) estimates of GFR (in mL/min/1.73 m²) in logistic regression modelling treating eGFR as a non-linear covariate fitted to a restricted cubic spline. Three side-by-side panels show modelling of AKI for the 25th, 50th and 75th centiles of age (51, 65 and 76 years, respectively) For eGFR-Cr a U-shaped relationship with increasing risk at low and high eGFR is apparent, for eGFR-Cysc the relationship is J-shaped with highest risk with lower eGFR below 90.