A retrospective analysis of the assessment results of external quality control of fluoride testing laboratories in national endemic disease prevention and control institutions / 中华地方病学杂志

ABSTRACT

Objective:To analyze the external quality control assessment results of fluoride testing laboratories in endemic disease prevention and control institutions nationwide from 2006 to 2023, investigate the quality control capabilities of these laboratories in various provinces, prefectures, cities, and counties nationwide, and ensure the accuracy and reliability of surveillance data on endemic fluorosis nationwide.Methods:Using retrospective analysis, the external quality control assessment results of all participating fluoride testing laboratories of national endemic disease prevention and control institutions from 2006 to 2023 were summarized and analyzed. The assessment results from 2006 to 2008 were tested for outliers using Grubbs method, homogeneity of variance using Cochran method, excluding the assessment data of unqualified laboratories, calculating the total mean and total standard deviation, Z-score method was used to test the assessment of laboratories, and statistical analysis and judgment were done when the result of │Z│ < 3. The assessment results from 2009 - 2023 were obtained from all laboratories. In 2010, two tests were conducted in the first and second half of the year, and the Z-ratio scores of each laboratory were calculated using robust statistics. When │Z│≤2, the assessment was qualified; when 2 < │Z│ < 3, the assessment was basically qualified; when│Z│≥3, the assessment was unqualified, and the consensus value came from all participating laboratories in the assessment.Results:From the beginning of quality control operation in 2006 to 2023, the number of laboratories participated in external quality control assessments had significantly increased. The number of laboratories participated in water fluoride assessment increased from 30 in 2006 to 1 277 in 2023, and the number of laboratories participated in urine fluoride assessment increased from 29 to 497. The number of laboratories participated in the brick tea fluorine assessment had increased from 43 in 2014 to 193 in 2023. The assessment results showed that when │Z│ < 3, the total qualified rate of fluoride external quality control in fluoride testing laboratories of national endemic disease control institutions was 95.2%, with the lowest being 87.1% (27/31) in 2008 and the highest being 100.0% (394/394) in 2014. When │Z│≤2, the total feedback pass rate was 88.4%, with the lowest being 79.3% (288/363) in the first half of 2010 and the highest being 99.5% (392/394) in 2014. The assessment results showed that when │Z│ < 3, the total pass rate of urine fluoride external quality control in fluoride testing laboratories of national endemic disease control institutions was 98.0%, with the lowest being 86.2% (25/29) in 2006 and 2007, respectively, and the highest being 100.0% (68/68) in 2014. When │Z│≤2, the total qualification rate was 93.7%, with the lowest being 86.5% (64/74) in the second half of 2010 and the highest being 100.0% (68/68) in 2014. The assessment results showed that when│Z│ < 3, the total pass rate of extra-fluoride quality control of brick tea in fluoride testing laboratories of national endemic disease control institutions was 95.4%, with the lowest being 85.0% (164/193) in 2023, and the highest being 100.0% (43/43, 51/51, 79/79) in 2014, 2015 and 2016, respectively. When │Z│≤2, the total pass rate was 89.2%, with the lowest being 72.7% (32/44) in 2017 and the highest being 100.0% (43/43) in 2014. From 2009 to 2023, there were a total of 21 provincial-level laboratories that passed the water fluoride detection assessment, including 3 provinces where all prefecture level and county-level laboratories were qualified. The assessment results of urinary fluorine showed that there were 11 qualified provincial-level laboratories and 1 prefecture-level laboratory. From 2014 to 2023, the assessment results of brick-tea fluorine showed that there were 5 provincial-level laboratories that passed the tea fluorine testing assessment and no prefecture-level laboratory.Conclusions:Conclusion: From 2006 to 2023, the number of fluoride testing laboratories participating in external quality control assessment has increased year by year, and most provincial, municipal and county-level laboratories have good fluoride testing capabilities, which can meet the testing needs of endemic disease prevention and monitoring. For some laboratories with problems, targeted rectification should be carried out to improve the quality of detection, in order to provide better technical support for the monitoring of endemic fluorosis areas.