Preanalytical Errors in Clinical Biochemistry Laboratory
Keywords:preanalytical errors, rejection, biochemistry laboratory
Introduction: In an era of evidence-based medicine, accuracy of test reports is mandatory. Automation of
laboratories has drastically reduced the errors in the analytical phase of testing but errors in the preanalytical
and postanalytical phases are largely responsible for the decrease in quality of clinical laboratory results.
Objective of this study is to evaluate the leading causes of preanalytical errors in a clinical chemistry
Method: The study was carried out in clinical biochemistry laboratory of Mahavir Cancer Sansthan, Patna.
A prospective analysis of 3 months duration 1st October to 31st December has been carried out to evaluate
errors in the preanalytical phase. samples from ward as well as out-patient samples were collected in the
laboratory. Rejections of the samples as well as their causes for rejection were registered.
Results: 14,832 samples received during the data collection period. Out of these 639 samples were found
unsuitable for further processing. This accounted for 4.18% of all samples collected. Reasons for the rejection
were mentioned: hemolysis - 2.1%; specimens with inappropriate or no patient i.d - 0.81%; samples in
inappropriate vacutainers -0.62%, inappropriate sample time - 0.31 % (for fasting and postprandial plasma
glucose, and lipid profile) and insufficient sample quantity - 0.33%.
Conclusion: The overall percentage of rejection found is 4.18%. Most Quality control programs at laboratory
focuses only on the analytical phase, and the pre-analytical errors are neglected. Therefore, monitoring of
pre and postanalytical phases for finding errors and corrective actions for the same are needed to achieve
better test reporting.