Evaluation of pre-analytical errors using six sigma metrics towards quality of laboratory performance in an Indian tertiary care hospital

Six Sigma methodologies is one of the standard management system adopted to check the quality and improve laboratory performance continuously by assessing the laboratory process using six sigma metrics. A one-year prospective study from January 2019 to December 2019 was conducted at the laboratory of medicine department in a tertiary care hospital. A total of 162974 samples were received from both inpatient and outpatient departments and total laboratory errors were found to be 1144, with the maximum errors identified in the pre-analytical phase coming out to be 978 (0.6%). The types of errors in the pre-analytical phase after being identified and categorized were hemolyzed samples, clotted samples, phlebotomy errors, etc. The most typical error identified was clotted sample error (0.29%) followed by haemolysed sample error (0.20%). After calculating the error rate or defects per million error samples on a Sigma calculator, the value obtained was between 4 and 5 which an average class quality. Thus, we show that continuous and repeated recognition of errors and evaluating them using Six Sigma metrics can help achieve overall laboratory procedure quality and better clinical diagnosis.