Current Practices in Estimating Kidney Function: Insights From a Cross‐Sectional Survey

ABSTRACT Background Numerous equations have been developed to estimate kidney function. Recently, Chronic Kidney Disease‐Epidemiology Collaboration (CKD‐EPI) estimated glomerular filtration rate (eGFR) equations reformulated without race have been recommended by the National Kidney Foundation (NKF)–American Society of Nephrology Taskforce and by the NKF Workgroup for Implementation of Race‐Free eGFR‐Based Medication‐Related Decisions. The objective of this survey was to examine current pharmacy practices on the implementation of these recommendations. Methods A survey was distributed primarily to specific American College of Clinical Pharmacy Practice and Research Network listservs between February and March 2024. Results There were 275 survey respondents who answered at least one question. Of pharmacists who completed the demographics section, the majority were from the United States and were female, with the most common practice sites being academic health centers and community hospitals. Regarding kidney estimation and dosing, 199 (72.4%) indicated that their institution has a kidney dose adjustment policy, with the majority (162/199, 81.4%) utilizing the Cockcroft‐Gault (C‐G) estimated creatinine clearance (eCrCL) equation within their policy and C‐G being the only equation within some policies. Additionally, 88/275 (32%) reported rounding up serum creatinine values for elderly patients when using the C‐G equation, with 47 of those 88 (53.4%) rounding it to 1 mg/dL. There was also notable variability regarding the choice of patient weight for C‐G eCrCL calculations: actual body weight was used by 137/275 (49.8%), adjusted body weight by 146/275 (53%), and ideal body weight by 113/275 (41.1%). If utilizing an eGFR equation for medication dosing, 36/275 (13.1%) reported adjusting eGFR for body surface area (BSA) in all patients, and 44/275 (16%) reported adjusting for BSA in those with extreme body weights. Conclusions There is considerable variability in kidney function assessment for drug dosing by pharmacists, highlighting the need for education and adoption of non–race‐based CKD‐EPI equations to standardize care and improve outcomes.