Fig. 1
From: Creating a 13-year National Longitudinal Cohort of veterans with chronic kidney disease
CKD cohort formation based on (1) eGFR values recorded in the patient’s medical record (numbers of unique patients in blue), (2) eGFR values calculated from serum creatinine levels (numbers of unique patients in purple) using the MDRD and CKD-EPI equations, and (3) based on ICD-9-CM codes. Note that a given patient was likely identified by several methods and may appear in multiple CKD stages