The invention relates to a method for determine the adequacy parameters that are achieved during a kidney substitution treatment, wherein the kidney substitution treatment is provided by a machine, which has an extracorporeal blood system pumping the patient blood at a set blood flow rate through the blood chamber of a dialyzer, divided by a semi-permeable membrane into the blood chamber and a dialyzing fluid chamber. The dialyzing fluid flows at a preset flow rate through the dialyzing fluid system of the machine and collects the waste products from the patient after flowing through the dialyzing fluid chamber of the dialyzer, wherein a device able to measure continuously any kidney substitution treatment related waste product is coupled with the dialyzing fluid system of the kidney substitution treatment machine, wherein the data provided by the kidney substitution treatment machine is used to measure the adequacy parameters at the end of the kidney substitution treatment, wherein the data provided by the device able to measure continuously any kidney substitution treatment waste product is used to determined the adequacy parameters achieved during the kidney substitution treatment with an algorithm, wherein the measuring algorithm is based in any kind of non linear fitting procedure with or without considering any kind of event happening on the dialysis machine.
