The comparative study and the bias estimation on the result of serum enzymes with different biochemical detecting system

Objective The comparability of serum enzyme results of different biochemical detecting system were studied through bias estimation and method comparison. Method Following NCCLS document EP9-A2, different biochemical detecting system, detecting system 1-4(laboratory method) and detecting system 5 (comparison method, which includes Hitachi 7170 biochemical analyzer, reagent of Roche, C.f.a.s. calibrator and controller of Roche, and have accredited by ISO/IEC 17025), were used respectively to 5 serum enzyme items including ALT, AST, ALP, LDH and CK to obtain the correlation coefficient and the linear equation. Then the coefficient and the equation were used to evaluate the system bias between laboratory method and comparison method. We judge the comparability of different investigate systems according to the half of CLIA′88 standard. Results The system bias of ALT(system 4), ALP at higher value (system 1), AST(systems 3 and 4) were not acceptable, the rest could be accepted. ConclusionIf the same test are determined by more than two systems, it is necessary to do method comparison and Bias estimation for judge clinical acceptability in order to insure the comparability.