To select the appropriate quality control (QC) strategy for the detection of urine forming components through the application of Westgard Sigma analysis batch length rules to reduce the risk of missed and false detection.

The internal quality control (IQC) data of urine forming components analyzer and the data of bias of IQC relative to the group mean values in SNCS (Sysmex Network Communication System) were collected from January to August 2020 in our laboratory. The total allowable error (TEa) of urine visible components stipulated in "Quality Management Standard for Clinical Laboratories of Medical Institutions in Shanghai" was adopted as the quality objective in this study.

The quality control strategy for white blood cell and red blood cell analysis appears "World class", σ=8.19 for WBC and σ=8.00 for RBC, Selected 1_3s (N=2). The analysis batch length of 200 patients were used as the quality control strategy for bacterial detection, and its performance was good (BACT, σ=4.71), Selected1_3s/2_2s/R_4s/4_1s(N=4). The analysis batch length of 45 patients were used as the quality control strategy for epithelial cells tesing, whose results was "critical", σ=3.29, selected 1_3S/2_2S/R_4S/4_1S/6_x(N=6). However, the quality control strategy of CAST, σ＜3, needs to be improved. By the way, the QGI of EC and BACT is less than 0.8 in the detection items with σ＜6, and the precision should be improved as priority.

The Westgard Sigma analysis batch length rule help us to optimize and improve the urine forming components analysis easily. In addition, QGI can be used to identify specific reasons for poor performance and formulate effective and prioritized improvement strategies.