Investigating the type and frequency of errors in the medical diagnostic laboratory in a medical center in Tehran, Iran:a medical-laboratory experience

Medical Laboratories have a great impact on patient safety and 80-90% of medical diagnoses are based on the results of laboratory tests. Medical procedures from the initial diagnostic steps such as a test or a simple injection to specialized treatment steps may be erroneous. The aim of this study was to determine the type and rate of human error, equipment, materials and procedures in all stages including before analysis, during analysis and after analysis to analyze the causes and find logical solutions to reduce of them.

This cross-sectional descriptive study was performed in a medical center in Tehran, Iran during the years 1400-1401. Data collection was considered in accordance with the instructions of the Laboratory Affairs Department of the Ministry of Health and Medical Education regarding the type of errors in the field of job description in each of the technical and non-technical sections. Data was analyzed by IBM SPSS software, version 22 (SPSS Inc., Chicago, IL, USA) software.

During the period of study, the number of  referred patients was about 45,000 and the number of tests 594,000. The total number of errors was 837. The ratio of errors to the patients was 1.9% and to the tests 0.15%. The 37 types of errors were identified and reported in this study. Of these, 11 types of errors were in the pre-analysis, 14 types during the analysis and 12 types of errors in the post-analysis stage. The frequency of errors in the three stages was 180(21.5%), 312(37.3%) and 345(41.2%), respectively that the errors rate did not have a normal distribution and a significant difference was observed (P<0.05, df=2).

Due to the variety of reported errors and the importance of their role in other stages of diagnosis and treatment, it is necessary that all human, equipment and process errors in all stages of laboratory analysis be carefully recorded and corrective and preventive measures be taken to minimize them.