Method comparison and accuracy of 15 commercial serum total protein assays / 中华检验医学杂志

ABSTRACT

Objective To evaluate the difference of Doumas′method and 15 commercial serum total protein ( TP ) methods based on EP9-A3.Methods Serum panels were quantified for TP with Doumas′method and measured in parallel with 15 commercial methods.The linear regression analyses were performed, followed by calculating relative deviation and 95%CI between commercial method and Doumas′method at three different medical decision levels (45 g/L, 60 g/L, 80 g/L).We also calculated relative deviation, 95% limit of agreement ( LoA ) and 95% CI based on classical and improved Bland-Altman method at three different medical decision levels.If both the relative deviation and 95%CI were within 5%, we conside red the commercial serum total protein method was comparable to Doumas′method.Results (1) All assays presented high correlation ( r>0.975, P<0.001) with the Doumas′method.All assays showed that the relative deviations and 95%CIs were within the biological total error goal (5%) at medical decision levels based on regression analysis.(2) Based on classical and improved Bland-Altman method, fourteen of 15 commercial methods showed that the relative deviations and 95%CIs were within +/-5%. Conclusions All commercial assays are comparable to Doumas′method at medical deviation levels.There is no difference between regression analysis and Bland-Altman method for comparison study.