Evaluation of the effects of calibration modes and sample reconstitution on the analytic precision of 26 clinical chemistry analytes using system measurement procedure / 中华检验医学杂志

ABSTRACT

Objective To evaluate the system measurement procedure effects on the analytic precision of clinical chemistry analytes.Methods In June 2009, June 2010 and September 2010 respectively,the National Center for Clinical Laboratories of China and the Organization of Five Hospitals in Fukuoka Japan organized comparison activities of 26 clinical chemistry analytes which were ALT,AST,GGT, ALP,CK,LDH,AMY,ChE,TG,TC,HDL-C,LDL-C,Glu,Cr,BUN,UA,K,Na,Cl,Ca,TP,Alb,TBil,DBil, P,Fe.In this paper, we investigated 26 analytes of three sets in Beijing Aerospace General Hospital as follows.(1)The precision of different reconstitution methods was observed by using three kinds of pipetting tools, such as measuring pipette, pipette and dispenser.(2)The experiments were carried out in three stages by testing the dried powder control samples of two concentration levels(101-Ⅰ,101-Ⅱ)provided by Hitachi Japan.They were measured on 28 consecutive days at each stage in order to observe the precision of 26 clinical chemistry analytes.In the first stage,we used the former measurement procedure to measure the control samples;in the second stage we added three conditions of the measurement procedure.The first was two calibration modes,which were once-a--day calibration and twice-a--day calibration.The second was the calibration standard and the last was the conditions of the freeze-thaw samples.In the third stage, we used the twice-a-day calibration only for GGT,ALP,ChE,TG,Cr,Na,K,CL,ALB.(3)JSCC and Health Industry Standard quality objectives were implemented to evaluate whether the precision of the improved measurement procedure met the requirements.(4)Paired T test were used to compare the precision of measurement between the second stage and the first stage, and between the third stage and the second stage of the measurement procedure.Results (1)The precision of three kinds of pipetting tools were 0.56%,0.10%, 0.01%.(2)The ranges of precision of ALT,AST,GGT,ALP,CK,LDH,AMY,ChE,TG,TC,HDL-C,LDL-C,Glu,Cr,BUN,UA,K,Na,Cl,Ca,TP,Alb,TBil,DBil,P,Fe were 0.99%-10.5% about 101-Ⅰ and 0.91%-7.03%about 101-Ⅱin the first stage.The ranges of precision were 0.66%-8.81%of 101-Ⅰand 0.66%-4.28%of 101-Ⅱin the second stage.The ranges of precisions were 0.60%-3.91%of 101-Ⅰand 0.73%-3.39%of 101-Ⅱin the third stage.(3)73%/80%of the samples met the standard of JSCC about 101-Ⅰand 101-Ⅱand 80%/88%of the samples met the standard of Health Industry Standard in the first stage.88%/100% of the samples met the standard of JSCC about 101-Ⅰand 101-Ⅱ and 100%/100%samples met the standard of Health Industry Standard in the second stage.The ratio of samples meeting the standard of JSCC about 101-Ⅰand 101-Ⅱwere 96%/100% and that of Health Industry Standard were 100%/100%in the third stage.(4)Precision of 101-Ⅰand 101-Ⅱwas statistically significant between the measurement procedures of second stage and the first stage,and there was no significant difference between the third stage and the second stage.Conclusion (1)The precision of samples using dispenser to reconstitute is higher than that of the other two pipetting methods.(2)Improving the calibration mode and reconstitution of samples increase the precision of 26 clinical chemistry analytes by over 50%.