Finally, we evaluated the cost implications of implementing NICE guidance to confirm a diagnosis of CKD G3aA1 based on creatinine eGFR (eGFRcreat) by checking cystatin C eGFR (eGFRcys) and also considered the use of creatinine and cystatin C eGFR (eGFRcreat-cys) as an alternative strategy. Here, CST3 is linked to chronic kidney disease.