**3.7 Quantifying injury in a dilute environment**

Changes in GFR and water handling will change urinary biomarker concentrations independent of injury. Normalising biomarkers to urinary creatinine has been proposed to account for these effects. This process also amplifies the signal soon after a decline in function (Waikar et al. (2010)). This may be advantageous in an early intervention trial if the threshold for intervention is set high enough, but it may distort the analysis of biomarker performance in a biomarker performance study. Whilst there is no consensus on whether biomarkers should or should not be normalised to urinary creatinine we recommend reporting both normalised and non-normalised results.
