Int J Med Sci 2008; 5(1):9-17. doi:10.7150/ijms.5.9
Does eGFR improve the diagnostic capability of S-Creatinine concentration results? A retrospective population based study
1. Department of Clinical Chemistry, Karolinska University Hospital, SE 17176, Stockholm, Sweden
2. Department of Biochemistry, Queen's Hospital, Romford, Essex, RM70AG UK
The use of MDRD-eGFR to diagnose Chronic Kidney Disease (CKD) is based on the assumption that the algorithm will minimize the influence of age, gender and ethnicity that is observed in S-Creatinine concentration and thus allow a single cut-off at which further diagnostic and therapeutic actions should be considered. This hypothesis is tested in a retrospective analysis of outpatients (N=93,404) and hospitalised (N=35,572) patients in UK and Sweden, respectively. An algorithm based on the same model as the MDRD-eGFR algorithm was derived from simultaneously measured S-Creatinine concentrations and Iohexol GFR in a subset of 565 patients. The combined uncertainty of using this algorithm was estimated to about 15 % which is about three times that of the S-Creatinine concentration results. The diagnostic performance of S-Creatinine concentration was evaluated using the Iohexol clearance as the reference procedure. It was shown that the diagnostic capacity of MDRD-eGFR, as it stands, has no added value compared to S-Creatinine. The gender and age differences of the S-Creatinine concentrations in the dataset persist after applying the MDRD-eGFR algorithm. Thus, a general use of the MDRD-eGFR does not seem justified. Furthermore the claim that the eGFR is adjusted for body area is misleading; the algorithm does not include any body size marker. It is thus a dangerous marker for guiding drug administration.
Keywords: CKD, Diagnosis, algorithm, outpatients, inpatients
Kallner A, Ayling PA, Khatami Z. Does eGFR improve the diagnostic capability of S-Creatinine concentration results? A retrospective population based study. Int J Med Sci 2008; 5(1):9-17. doi:10.7150/ijms.5.9. Available from http://www.medsci.org/v05p0009.htm