FORM-2C (Frequency of Renal Monitoring – Creatinine and Cystatin C): An observational cohort study of primary care patients with reduced eGFR.
Monitoring is the mainstay of chronic kidney disease management in primary care. There is little evidence on how best to monitor.To compare the effectiveness of eGFR derived from creatinine or cystatin C, to predict renal function decline among those with a recent eGFR of 30-89 ml/min/1.73m².Observational cohort study in UK primary care.In 750 adult patients with a recent estimated glomerular filtration rate (eGFR) of 30-89 ml/min/1.73m² both creatinine and cystatin C were measured at seven study visits over two years. The primary outcome was change in eGFR derived from creatinine or cystatin C between 6 and 24 months.Average change in eGFR was 0.51 ml/min/1.73m²/year or -2.35 ml/min/1.73m²/year when estimated by creatinine or cystatin C respectively. The c-statistic for predicting renal decline using creatinine-derived eGFR was 0.495 (95% CI 0.47 to 0.52). The equivalent c-statistic using cystatin C-derived eGFR was 0.497 (95% CI 0.47 to 0.53). Similar results were obtained when restricting analyses to those over or under 75 years, or with eGFR above 60 ml/min/1.73m². In those with eGFR below 60 ml/min/1.73m² cystatin C-derived eGFR was more predictive than creatinine-derived eGFR for future decline.In the primary analysis neither eGFR estimated from creatinine nor cystatin C predicted future change in kidney function, partly due to small changes during two years. In some secondary analyses there was a suggestion that cystatin C to estimate eGFR was a more useful biomarker, especially in those with baseline eGFR < 60 ml/min/1.73m².
View the full article @ The British journal of general practice : the journal of the Royal College of General Practitioners
Authors: Susannah Fleming, Rafael Perera-Salazar, Kathryn Taylor, Louise Jones, Fd Richard Hobbs, Tim James, Chris O’Callaghan, Brian Shine, Jan Y Verbakel, Richard J Stevens, Clare Bankhead