BACKGROUND: This study observed and analyzed the internal quality control (IQC) of cystatin C (CysC) so that we can have overall knowledge about imprecision levels in Chinese medical laboratories. METHODS: Using the software developed by the National Center for Clinical Laboratories (NCCL), we can get the IQC information of CysC from 2014 to 2017. Then the proportion of laboratories meeting five quality specifications (pass rates) were calculated and the current CVs (coefficient of variation) were also compared among subgroups and years. RESULTS: We find that the current CVs between 2014 and 2017 show significant differences (p = 0.016) and the proportion of laboratories meeting the 1/3 TEa specification distributes randomly from 2014 to 2017 but all of them exceed 80 percent. When the optimum specification is applied, the pass rates all become very low and the distributions are wide spread (from 3.63% to 6.74%). Beckman, Roche, and Hitachi are mainstream analyzers, making up as much as 78% to 85% of all. We can see a significant difference of the pass rate between Beckman and Hitachi in 2014 (p = 0.005). The primary means of detecting CysC is particle-enhanced turbidimetric immunoassay (PETIA) which makes up 30.57% - 32.64% of detection methods. The good news is that the IQC practice has improved greatly from 2014 to 2017 in laboratories in China. CONCLUSIONS: Medical laboratories have made some progress in IQC from 2014 to 2017, but it is still not satisfactory. As a result, there is a long way to go to improve detection quality of laboratories in China.
BACKGROUND: This study observed and analyzed the internal quality control (IQC) of cystatin C (CysC) so that we can have overall knowledge about imprecision levels in Chinese medical laboratories. METHODS: Using the software developed by the National Center for Clinical Laboratories (NCCL), we can get the IQC information of CysC from 2014 to 2017. Then the proportion of laboratories meeting five quality specifications (pass rates) were calculated and the current CVs (coefficient of variation) were also compared among subgroups and years. RESULTS: We find that the current CVs between 2014 and 2017 show significant differences (p = 0.016) and the proportion of laboratories meeting the 1/3 TEa specification distributes randomly from 2014 to 2017 but all of them exceed 80 percent. When the optimum specification is applied, the pass rates all become very low and the distributions are wide spread (from 3.63% to 6.74%). Beckman, Roche, and Hitachi are mainstream analyzers, making up as much as 78% to 85% of all. We can see a significant difference of the pass rate between Beckman and Hitachi in 2014 (p = 0.005). The primary means of detecting CysC is particle-enhanced turbidimetric immunoassay (PETIA) which makes up 30.57% - 32.64% of detection methods. The good news is that the IQC practice has improved greatly from 2014 to 2017 in laboratories in China. CONCLUSIONS: Medical laboratories have made some progress in IQC from 2014 to 2017, but it is still not satisfactory. As a result, there is a long way to go to improve detection quality of laboratories in China.