Avoiding misclassification of acute kidney injury: Timing is everything

Area of Science:

• Nephrology
• Clinical Trials
• Medical Diagnostics

Background:

• Accurate detection of acute kidney injury (AKI) is crucial in clinical trials.
• Using creatinine levels from trial enrollment as a baseline may not reflect true kidney function.
• The timing of baseline creatinine measurement can impact AKI incidence assessment.

Purpose of the Study:

• To compare pre-trial baseline creatinine with trial baseline creatinine.
• To evaluate how baseline creatinine timing affects AKI detection in the CAMERA2 trial.
• To determine the ideal timing for baseline creatinine collection in clinical trials.

Main Methods:

• Retrospective collection of pre-trial baseline creatinine (up to 1 year prior).
• Defined trial baseline creatinine as highest value within 24 hours before randomization.
• Used Wilcoxon sign rank test for comparing creatinine concentrations in 217 patients.

Main Results:

• Median pre-trial creatinine (82 μmol/L) was significantly lower than trial baseline creatinine (86 μmol/L).
• Pre-trial creatinine identified 22% of patients with AKI at enrollment, versus only 2.3% using trial baseline creatinine.
• Trial enrollment creatinine failed to detect numerous AKI cases.

Conclusions:

• Pre-trial baseline creatinine provides a more accurate assessment of kidney function than trial enrollment creatinine.
• Current trial protocols may underestimate AKI incidence due to suboptimal baseline creatinine timing.
• Consideration of pre-illness baseline creatinine is essential for accurate AKI detection in clinical trials.