The internal quality control (IQC ) information of 110 laboratories from National Center for Clinical Laboratory (NCCL) was collected. The imprecision [coefficient of variation (CV)] of Hcy was analyzed. Bias was estimated according to various detection methods in NCCL External Quality Assessment (EQA) in 2012 through online EQA platform. With current evaluation criteria for EQA(TEa=20%), sigma (σ) value of each laboratory was calculated as the formula: σ= (TEa-bias)/CV. Furthermore, the passing rates and inter-laboratory CV for each group were evaluated.

The proportions of σ>6, 3<σ≤6, 0<σ≤3 and σ≤0 by chemiluminescence, immunoturbidimetry and enzymatic cycling were 0%, 7.69%, 30.77%, 61.54%;9.09%, 0%, 63.64%, 27.27% and 11.63%, 31.40% 47.67%, 9.30%, respectively. The inter-laboratory CV by the 3 methods for 5-run quality control materials were 33.66%-43.77%, 19.54%-25.24% and 10.46%-14.21%, and the passing rates were 53.3%, 53.3%-80.0% and 85.9%-92.3%.

Laboratories in China need further efforts to improve the performance of Hcy detection.