Diagnostic accuracy of cystatin C compared to serum creatinine for the estimation of renal dysfunction in adults and children—A meta-analysis

Objectives: To perform a systematic review comparing the diagnostic accuracy of CysC with SCr. Methods: MEDLINE and EMBASE (January 1984–February 2006) were searched. Studies included i) evaluated CysC against a recognised ‘gold standard’ method for determining GFR using a receiver operating characteristics (ROC) curve analysis and ii) included data that could be extracted into a 2 × 2 table. Results: The search identified 27 population groups in 24 studies (n = 2007) that compared the diagnostic accuracy of CysC with SCr. The diagnostic odds ratios (DORs) (95% CI) of predicting renal dysfunction derived from a Moses–Littenberg linear regression model were 3.99 (3.41–4.57) for CysC and 2.79 (2.12–3.46) for SCr. Conclusion: The diagnostic accuracy for impaired renal function favours CysC. However, the confidence intervals for the pooled DORs for the biomarkers overlap. The ability of CysC (cut-off values between 0.9 and 1.4 mg/L) to rule in renal impairment (as measured by inulin-determined GFR of 60–79 mL/min/1.73 m2) in persons in whom this is suspected is large and conclusive.