Renal Function Underreported in Studies of Renally Affected Drugs in the Critically Ill

Introduction: Accurate and transparent reporting of renal function in clinical studies is essential to appropriately interpret their methodology and results to bedside care, yet variability in reporting methods in the critically ill may limit generalizability. The study aimed to assess the frequency and methods of renal function reporting in studies of renally affected drugs (those where renal function impacts drug dose or effect) in critically ill patients and to identify gaps in renal function reporting.


Methods: Articles published from 2019-2024 in the top 10 critical care journals by impact factor were screened using a two-phase, dual investigator process for studies that met the following criteria: conducted in critically ill adult patients; investigated drug use; designed as clinical trial, observational, and/or retrospective analyses; and English language. Non-original research/commentaries; studies involving fluids, nutrition therapies, or coagulation factors; and investigations of emergently administered drugs or drugs administered outside of the ICU were excluded. Reporting followed the PRISMA extension for scoping reviews.


Results: Of 232 studies, 107 (46%) involved renally affected drugs. Among these, only 49 (46%) reported baseline renal function, most commonly serum creatinine (36/54), eGFR (6/54), or creatinine clearance (5/54). Other rarely reported baseline metrics included acute kidney injury (AKI), renal failure, and urine output. 16 (17%) studies did not describe or include pre-planned renal dose adjustments. Among studies in which renal function was an outcome, baseline renal function was reported in 25 of 28 (66%). Renal adverse events were reported in 31 of 107 (29%), most often AKI that was most commonly defined by KDIGO criteria.


Conclusions: Less than half of studies evaluating renally affected drugs in critically ill patients report baseline renal function, even when renal outcomes are primary or secondary endpoints. This gap limits the interpretation and clinical applicability of drug studies in the ICU. Standardizing renal function assessment and reporting is urgently needed to enhance study quality and bedside relevance in critical care pharmacotherapy.