Abstract:

Objective To investigate the application of patient-based real-time quality control（PBRTQC）using exponentially weighted moving average（EWMA） method on internal quality control（IQC） procedures for serum ion items. Methods The serum ion item determination results of outpatients and inpatients in Ruijin Hospital of Shanghai Jiao Tong University School of Medicine from October 2019 to May 2021 were collected. Based on PBRTQC professional intelligent software system,the normal distribution test of test data,parameter setting,procedure establishment,real-time operation and performance verification were carried out. The estimated value of EWMA for each result was included in the analysis. The cumulative coefficient of variation（CV） was calculated and was compared with the criteria of precision quality standard and the analytical IQC CV. The early-warning cases by the EWMA quality control program were recorded and analyzed for the potential reasons of analytical performace changes. Results The truncated concentration range of K（3.40-5.00 mmol/L）,Na（135-145 mmol/L）,Cl（99-110 mmol/L）,Ca（2.10-2.36 mmol/L）,Mg（0.74-0.98 mmol/L） and P（0.90-1.31 mmol/L） were shown distributed normally. The optimal weighted coefficients of K,Na and Cl were 0.02,and the optimal weighted coefficients of Ca,Mg and P were 0.05. The actual cumulative precisions（CV） of the 6 items were all smaller than the precision quality target. A total of 13 warning cases were recorded. The number of alarm cases in K,Na,Cl,Ca,Mg and P were 3,1,2,2,3 and 2,respectively. Among them,serum K,Mg and P each had 1 false positive case. Conclusions PBRTQC quality control using EWMA,as a supplementary IQC procedure,has the advantage of monitoring micro-changes in order to avoid the potential quality risks.

Key words: Patient-based real-time quality control, Serum ion item, Exponentially weighted moving average method