National External Quality Assessment follow-up: 2010–2017 Turkish experience.

Objective: Medical laboratories encounter critical obstacles in External Quality Assessment (EQA) practices that are key to assessment of the analytical period. Present study aims to unveil the challenges in nationwide inter-laboratory harmonization and suggest practical solutions. Materials and methods: EQA results of 1941 laboratories participating in 18 different EQA-programs between 2010 and 2017 were examined. Standard Deviation Index (SDI) of each program calculated using 801,028 sample data from 24 different clinical chemical tests were used to conduct a process assessment. Results: There is a significant discrepancy in unsatisfactory performance ratio among different EAQ-programs with an average of 3.4% (27,074 cases) between 2010 and 2017 and a decreasing trend (~40–50%) in 7-years. Programs with higher SDI display lower discrepancy rates. Reasons for unaccepted results appear to be data entry errors (8.27–22.2%), material dilution errors (5–11.4%), technical problems (3.76–7.9%); while random or unidentified causes account for a major of 44.9–59.5%. In 7-years, 15.7% reduction was observed in average SDI of all tests. Conclusion: With the launch of national EQA follow-up program, increased awareness of the analytical processes led to a decrease in unaccepted results and variances in the analytical period. Staff training is suggested as a significant measure. In addition, simultaneous assessment of SDI and allowable total error rates would reduce the variation between programs. [ABSTRACT FROM AUTHOR]