Review of China national external quality assessment for neonatal screening laboratory for 5 years

Objective:To review the results of national external quality assessment (EQA) in neonatal screening laboratory for 5 years, and summarize the problems in the screening measurement.Methods:The phenylalanine (Phe) and thyrotropin (TSH) values in dried blood spot specimens on filter paper distributed by national center for clinical laboratory were measured by fluorometric method and time-resolved fluorescence immunoassay (DELFIA) respectively. The results sent by national center for clinical laboratory were analyzed.Results:Five specimens were distributed by EQA organizer each time, and 3 times each year. In the 75 specimens of 15 batches, the bias ranges of Phe and TSH measurement were wide and their average values were 11.99% and 17.09% respectively. Two quantitative results of Phe measurement and nine quantitative results of TSH measurement were out of quality control (bias≥30% or ≤-30%), accounting for 2.7%(2/75)and 12.0%(9/75) respectively. In the 75 Phe specimens, 19 were negative and 56 were positive. The qualitative analysis of specimens conformed to the expected results (75/75). In the 75 TSH specimens, 38 were negative and 37 were positive. The qualitative analysis of 74 specimens conformed to the expected results (74/75), there was one false positive (1/75). The result of every batch was up to 80%.Conclusion:It is useful to evaluate the measurement competence, find out the problems in the Phe and TSH measurement and resolve them in time through participated in the national EQA in neonatal screening laboratory. Consequently, it is useful to improve the quality of measurement, reduce the error and ensure the accuracy of results.