A Study of Pre-Analytical Errors in a Chemical Pathology Laboratory

Abstract

Clinical chemistry laboratory plays a crucial role in clinical decision-making, yet it is not immune to human errors. While scientific innovations like automation have significantly improved laboratory science, avoidable errors still happen. A major example of this is the high prevalence of errors occurring in the pre-analytical phase of the total testing phase. The objective of this study was to evaluate the pre-analytical phase of laboratory testing in a Clinical Chemistry Laboratory, identify the types of errors occurring, and determine specific steps where these errors arise to formulate corrective measures. This prospective observational study was conducted in the Chemical Pathology Laboratory of Osun State University Teaching Hospital over six months, from April to September 2024. We reviewed all samples and accompanying request forms for pre-analytical errors, systematically recording daily errors and their types. Data analysis was performed using Microsoft Excel software. Out of 10,136 forms reviewed, 5,575 forms (55%) included an identifying hospital number, while diagnosis was provided in 6,690 forms (66%). Doctors' handwriting was legible in 7,703 forms (76%), and the type of specimen was specified in 7,501 forms (74%). The date of sample collection was recorded in 2,027 forms (20%), while only 507 forms (5%) indicated the time of collection. Sample mix-ups occurred 253 times (2.5%), and wrong numbering of samples was noted in 111 instances (1.1%). Insufficient samples led to rejection in 426 cases (4.2%), and lipaemic samples were identified in 81 instances (0.8%). Haemolyzed samples were observed 314 times (3.1%), while clotted samples and incorrect times of sample collection were reported 172 (1.7%) and 111 (1.1%) times respectively. Continuous evaluation of the pre-analytical phase, along with identifying the causes of errors and implementing corrective measures, is essential to minimize these errors.