PRE-ANALYTICAL ERRORS IN SAMPLE COLLECTION AND THEIR IMPACT ON LABORATORY RESULTS

Clinical laboratory investigations are an essential component of modern medical practice. It is estimated that approximately 60-70% of clinical decisions related to diagnosis, treatment, and patient monitoring are influenced by laboratory test results. The laboratory testing process is broadly divided into three phases: pre-analytical, analytical, and post-analytical. Among these, the pre-analytical phase is considered the most error-prone. The pre-analytical phase includes all procedures performed before the actual analysis of the specimen, such as patient identification, test request, patient preparation, sample collection, labeling, transportation, and storage. Errors occurring during this phase may significantly affect the accuracy of laboratory results, even if the analytical process is performed correctly. Pre-analytical errors may result in falsely increased or decreased values, sample rejection, repeated sampling, delayed diagnosis, unnecessary treatment, increased workload for laboratory staff, and compromised patient safety. Therefore, identification and control of pre-analytical errors are crucial for ensuring laboratory quality and reliability of test results.