ABSTRACT
Objective To discuss the value in quality improvement and continuous improvement through the way for determina-tion of target uncertainty in chemical quantitative detection project and regular evaluation of measurement uncertainty in different phase.Methods Based on the biological variability of quality specification and CNAS-TRL-001:CNAS technical report,to compare the five kinds of determination of target uncertainty.Method 1:the fundamental way(calculate the different levels of target impre-cision and bias);Method 2:biological variation of different grades of total allowable error;Method 3:the relative expanded uncer-tainty evaluation value based on target imprecision and bias;Method 4:the target relative expanded uncertainty based on biological variation of different grades;Method 5:the target relative expanded uncertainty based on the quality index of analysis.We used un-certainty evaluate index(UEI)to review the changes of uncertainty in different phase.Results The 14 conventional chemistry tests in 2013 with metrological traceability and participate in the Ministry of health EQA were as the target.There was no significant difference among the 2,3,4 method,the ratio of which reached the ideal value of uncertaninty target were not significantly different. In method 5,9 projects achieved the target of uncertainty requirements,accounted for 64.3%.TP,ALT,BUN,UA,CK,these5 pro-jects′UEI were less than 0,accounted for 35.7%;other 9 projects′UEI were more than 2.0%.Conclusion Method 5:the target relative expanded uncertainty based on the quality index of analysis which is based on WS/T403-2012 can give consideration to the quality standard of repeatability precision and bias in the laboratory at the same time,and is easy to be accepted for laboratory;method 4:the target relative expanded uncertainty based on biological variation of different grades is in the same way with the eval-uation of test results uncertainty,is better than method 2 and 3;method 1 is the fundamental way,can give the specific reasons when the test results cannot get the target uncertainty.Use UEI to assess the changes of uncertainty in different phase is more sensitive to changes of the test results′accuracy and its usefulness needs to be confirmed in practice.