Agreement between creatinine performed in the emergency department point-of-care test and central laboratory test

¹Department of Emergency Medicine, Jeonbuk National University Hospital, Jeonju, Korea
²Department of Emergency Medicine, Jeonbuk National University Medical School, Jeonju, Korea

Correspondence

Tae Oh Jeong ,Tel: 063-250-1075, Fax: 063-250-1075, Email: emmd@jbnu.ac.kr,

Received: October 31, 2023; Revised: November 7, 2023 Accepted: November 7, 2023. Published online: August 28, 2025.

ABSTRACT

Objective:
This study aimed to evaluate the agreement between the creatinine levels measured by a point-of-care test (POCT) in the emergency department (ED) and that measured by a central laboratory test (CLT).
Methods:
We evaluated the agreement between the results of the creatinine levels obtained with the ABL90 Flex Plus analyzer in the ED and those measured by CLT. Both analyses were performed using the same samples between January 1 and 11, 2023. The agreement between the results was assessed by Passing-Bablok regression analysis and Bland-Altman plot. We also evaluated the frequency of the POCT samples meeting the maximum allowed difference suggested by Clinical Laboratory Improvement Amendments.
Results:
A total of 813 consecutive paired sample analyses were conducted. Using the Bland-Altman method, the mean difference in the creatinine levels measured by the POCT and CLT was 0.06 mg/dL, and the range was -0.49 to 0.61 mg/dL. In these samples, the frequency of measurements not meeting the maximum allowed difference was 2.7%. In the analysis using the 363 paired samples in patients where contrast enhanced computed tomography was performed after checking creatinine levels with POCT, the mean difference in creatinine between POCT and CLT was 0.04 mg/dL, and the range was -0.01 to 0.18 mg/dL. In these, the frequency of samples not meeting the maximum allowed difference was 1.7%.
Conclusion:
The creatinine levels measured by the POCT showed good agreement with CLT measurements. The rapid measurement of creatinine through POCT could help the early detection of renal injury and screen high-risk patients for contrast-induced nephropathy in the ED.

Key words: Point-of-care testing; Creatinine; Computed tomography