The Modification of Diet in Renal Disease (MDRD) study formula (current 4-factor formula) can also be used, although it requires a calculator or computer: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula provides a lower sensitivity but a higher specificity for detecting a GFR less than 60 mL / min per 1.73 m 2, and may be more useful in evaluating patients with normal or near-normal kidney function.