Abstract
BACKGROUND: Serum transaminase activity is a common measure of liver injury used in clinical trials. The use of a point of care device to monitor serum transaminases would allow immediate evaluation of this safety endpoint and may be less expensive than standard laboratory testing. PURPOSE: The objective of this study was to compare a point of care transaminase test to a standard laboratory measurement. METHODS: Subjects were healthy adults participating in a clinical trial measuring the effects of therapeutic doses of acetaminophen on serum transaminase activity. For this study, serum transaminase activity was determined every 3days for 14days. At each measurement, a sample was sent to the clinical laboratory for measurement and also analyzed using a point of care device (Cholestech LDX, Hayward CA). The results were compared using a Bland-Altman plot to identify bias and we also measured the agreement between the techniques for categorizing samples as "low", "normal" or "elevated". RESULTS: One hundred thirty three samples from 35 subjects were compared. The 95% confidence interval for the limits of agreement between the LDX and the clinical laboratory was -8.46 to 27.09IU/L. Agreement for classification as low, normal or elevated was moderate between the two methods (Kappa=0.37). CONCLUSION: The point of care device provided moderate agreement with the laboratory transaminase measurement. However, use of the device would have resulted in misclassification of approximately 1/3 of samples. We do not recommend this point of care device for the measurement of serum transaminases in clinical trials.