Analysis of error sources for routine chemistry external quality assessment program in China

Objective To investigate and analyze the reasons of failure in external quality assessment(EQA) for routine chemistry and provide the basis for the corrective and preventive actions. Methods Based on the network system of NCCL EQA the reasons of failure in 2013 national routine chemistry external quality assessment program were investigated, among which the reasons were classified and analyzed with seven sources of problems which were clerical errors, methodological problems, equipment problems, technical problems, EQA materials problems, EQA Evaluation problems and unable to explain after investigation. Results The return rate of this root cause investigation for each analyte ranged from 33.3% to 80.0%. The major reason for unacceptable analyte included clerical errors (6.5%)(decimal point position error: 70.1%; unit error: 20.8%; instrument or method coding error: 8.1%), methodological problems (45.1%)(calibration: 54.2%; reagent: 38.0%; EQA material: 7.8%), equipment problems (28.5%)(no regular maintenance: 98.0%; pipeline error: 2.0%), technical problems (8.2%)(do not follow SOP: 80.4%; EQA material redissolve error: 10.6%; placing order error: 9.0%) and unable to explain (11.7%)(system error: 68.2%; random error: 31.8%). There were no EQA materials problems or EQA Evaluation problems in this survey. Analysis systems' grouping statistics were implemented for seven analytes including sodium, chlorine, phosphorus, direct bilirubin, total iron binding capacity, copper, and zinc. Unsatisfied EQA proportions of mating system were lower than non-matching ones for the majority of analytes. Conclutions Further work on EQA should be undertaken by clinical laboratories. Laboratories should use reagents with high quality as well as improve the operation technology and sense of responsibility. Only in this way, can the accuracy and reliability of testing results be guaranteed.(Chin J Lab Med, 2016, 39: 376-379) Key words: Diagnostic tests, routine; Clinical chemistry tests; Laboratories; Quality control