To establish the clinical reportable range (CRR) of Sysmex CS-5100 automatic coagulation analyzer for the detection of D-dimer.

According to the EP6-A document issued by the Clinical and Laboratory Standard Institute (CLSI), the polynomial regression analysis method was used to carry out the D-dimer analysis measurement range (AMR) experiment on the Sysmex CS-5100 automatic coagulation analyzer. The statistical analysis of the nonlinear coefficient was used to determine whether there was non-linearity, and the optimal polynomial method was determined by calculating the regression standard error. This study determine the upper limit of the AMR by calculating whether the linear deviation of each concentration point meets the industrial standard, and establish its CRR in combination with the functional sensitivity (FS) and the maximum dilution ratio.

According to FS test, the concentration of D-dimer is 0.065 7 mg/L when CV is close to 20%, so FS is 0.065 7 mg/L. No outliers were found in the experimental data of AMR. The relative error of repeated measurement of experimental samples was 1.89%, which was lower than the in batch imprecision target (2.5%). After the highest two groups of data were discarded in polynomial regression analysis, the best fitting curve was determined to be cubic polynomial after reanalysis of the first to ninth experimental data, and the linear deviation was not beyond the allowable deviation range (7.5%). The determined AMR of D-dimer is 0.065 7~5.26 mg/L; The maximum allowable dilution is 1∶32, and the CRR of D-dimer is 0.065 7~168.32 mg/L.

The CRR was established, which was significant for clinical diagnosis with the high test value.