Estimation of Sex- and Age-Specific Reference Values for Serum Creatinine Using Three Indirect Methods in a Multicenter Setting

The use of indirect methods to establish RIs may capture population-specific differences that are not fully reflected by manufacturer-provided intervals. However, their results depend on rigorous preprocessing. Our results highlight that, while overall agreement exists among the TML and refineR approaches, careful consideration is needed for older patient groups where variability is higher. Ultimately, integrating locally derived RIs into clinical practice may improve patient care.