{"id":"egfr-creatinine-cystatin-c","name":"eGFR (Creatinine + Cystatin C, CKD-EPI 2021)","shortName":"eGFR (cr-cys)","aliases":["eGFRcr-cys","eGFR Creat-Cys","eGFR Creatinine and Cystatin C","eGFR (CKD-EPI 2021 Cr-CysC)","eGFR Creatinine-Cystatin C","eGFR (creatinine + cystatin C)","eGFR cr-cys","eGFRcr-cys (CKD-EPI 2021)","eGFR (CKD-EPI Creatinine-Cystatin C 2021)","Estimated GFR (Creatinine and Cystatin C)","GFR Estimated, Creatinine and Cystatin C","Creatinine-Cystatin C eGFR","eGFR (Cr-CysC)"],"abbreviations":["eGFRcr-cys","eGFRcr-cysC","eGFR cr-cys"],"loinc":[{"code":"98980-6","primary":true},{"code":"94677-2","primary":false}],"specimen":"calculated","units":[{"ucum":"mL/min/{1.73_m2}","display":"mL/min/1.73 m²"},{"ucum":"mL/s/{1.73_m2}","display":"mL/s/1.73 m²"}],"referenceRanges":[{"population":"18+","low":60,"high":null,"unit":"mL/min/{1.73_m2}","unitDisplay":"mL/min/1.73 m²","note":"KDIGO 2024 asks labs to report eGFR as a whole number and to flag values below 60 as low, and ARUP prints 60 or higher as its reference for the CKD-EPI 2021 creatinine–cystatin C result. This is a flagging cutoff, not the middle 95% of healthy people. Averages are much higher in younger adults and decline with age. KDIGO notes there are not enough externally validated data to judge whether combining creatinine and cystatin C improves pediatric equations, so this row is for ages 18 and older.","sources":[{"title":"KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease","url":"https://kdigo.org/wp-content/uploads/2024/03/KDIGO-2024-CKD-Guideline.pdf","publisher":"Kidney International 105(4S):S117-S314","year":2024},{"title":"Cystatin and Creatinine With eGFR (test 3018316)","url":"https://ltd.aruplab.com/Tests/Pub/3018316","publisher":"ARUP Laboratories"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"An estimate of how well your kidneys filter blood, worked out from both your creatinine and cystatin C levels plus your age and sex.","url":"https://bloodtesttracker.com/markers/egfr-creatinine-cystatin-c","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}