This is the ValueSet that contains all the codes in CH LAB-Report Codes for eGFR in CKD-EPI (http://fhir.ch/ig/ch-lab-report/ValueSet/observation-code-cdk-epi-2009) and CH LAB-Report Codes for eGFR in CKD-EPI (http://fhir.ch/ig/ch-lab-report/ValueSet/observation-code-cdk-epi-2009). E.g. what you have to deal with if you get resources containing codes in either of them