Vega A, et al. - Given that a relative overhydration adjusted for extracellular water (OH/ECW) measured by bioimpedance >15% has shown an increased mortality risk in haemodialysis, the impact of OH on mortality in patients with Stage 4 or 5 non-dialysis chronic kidney disease (CKD) was determined in this prospective study of 356 patients enrolled in 2011 and followed up until 2016. In this patient population, any grade of relative OH measured by OH/ECW >0% was shown to be related to long-term mortality.