305 NKF-KDOQI CKD Stage Progression and Regression Among Primary Care Patients with Mild-To-Moderately Impaired Kidney Function

Abstract

NKF-KDOQI CKD STAGE PROGRESSION AND REGRESSION AMONG PRIMARY CARE PATIENTS WITH MILD-TOMODERATELY IMPAIRED KIDNEY FUNCTION Walter (Buzz) Stewart, Jennifer Sartorius, Melissa Stahl, Kathleen Fox, Ze Cong, Robert Perkins Center for Health Research, Geisinger Medical Center, Danville, PA; Strategic Healthcare Solutions, LLC, Monkton, MD; Amgen, Inc, Thousand Oaks, CA Little is known about the stability of kidney function over time in large, community-based populations. We identified predominantly Caucasian adult (>30 yrs) primary care patients from The Geisinger Clinic (central/northeastern Pennsylvania). Using electronic health records, patients (n=105,026) were followed from Jan 2004 to Dec 2009 and assigned to 1 of 7 initial CKD stages (stage 1-5, including 3A/3B, or no CKD) based on NKF-KDOQI criteria and the CKD-EPI eGFR formula. The primary outcome was the CKD stage at final follow-up for patients initially in stage 3A or 3B. Patients (n=6267) in stage 3A had a median age of 65 and were 62.7% female. Patients (n= 2891) in stage 3B had a median age of 70 and were 66.5% female. Over a median follow-up period of 5.9 years, only 1/3 of patients with stage 3 CKD changed in stage. For stage 3A patients, progression to 3B was slightly more likely than regression, though regression to a milder CKD stage was 10 times more likely than progression to CKD 4 or 5. For stage 3B patients, 13% progressed to stage 4-5 and regression (largely to stage 3A) was about as likely as progression. CKD cases by initial stage (3A or 3B) and status at final follow-up Initial Stage Final Stage n(%) 0 1-2 3A 3B 4-5 3A (n = 6267) 608 (9.7%) 295 (4.7%) 4176 (66.6%) 1100 (17.6%) 88 (1.4%) 3B (n = 2891) 24 (0.8%) 19 (0.7%) 434 (15.0%) 2030 (70.2%) 384 (13.3%) Regression to relatively milder CKD among patients with stage 3A and 3B CKD is not uncommon, and progression to stage 4-5 is relatively uncommon, particularly for those with stage 3A disease at baseline. The implications of these findings for current NKF/KDOQI screening and risk stratification guidelines should be further investigated.