This is the ValueSet that contains all the codes in CH LAB-Report Codes for eGFR (MDRD) (http://fhir.ch/ig/ch-lab-report/ValueSet/observation-code-mdrd-male-female) and CH LAB-Report Codes for eGFR (MDRD) (http://fhir.ch/ig/ch-lab-report/ValueSet/observation-code-mdrd-male-female). E.g. what you have to deal with if you get resources containing codes in either of them