Types and Frequency of Errors during Different Phases of Testing At a Clinical Medical Laboratory of a Teaching Hospital in Tehran, Iran

Background: According to official data, 60-70% of clinical decisions about hospitalization and discharge are based on laboratory results. Aims: The objective of this study is to examine the frequency of errors before, during, and after analysis in a major medical laboratory. Materials and Methods: This descriptive, cross-sectional study was conducted throughout 2012 (January-December 2012). Errors are recorded by the Quality Control Committee in a specially designed record. Results: A total of 303,866 samples, 2,430,928 tests were received for analysis. The total number of errors was 153,148 (6.3%) (116,392 for inpatients and 36,756 for outpatients). Analysis of the results revealed that about 65.09% of the errors occur across preanalytical phase, whereas 23.2% and 11.68% are related to analytical and postanalytical phase, respectively. Conclusion: More than half of the laboratory errors are related to preanalytical phase; therefore, proper training and knowledge of intervening factors are essential for reducing errors and optimizing the quality.