Application of graphic method in external quality assessment of iodized salt / 中华地方病学杂志

ABSTRACT

Objective To evaluate the detection capability for salt iodine test by using graphic method,and to provide reliable detection data for prevention of iodine deficiency disorders.Methods The examination results of external quality assessment for disease control mechanism in Liaoning Province in 2013 were analyzed by using standard Z score and Youden plot.The level of reproduction and type of error were analyzed by Z score sequence diagram in order to find the outliers and results need to be reviewed by the Youden plot.Salt iodine was detected by the general test method in salt industry for determination of iodine (GB/T 13025.7-2012).Results According to single sample evaluation of the Z score,111 laboratories were qualified,the qualified rate was 97.4％ (111/114).Three labs were not qualified,unqualified rate was 2.6％ (3/114).According to double sample evaluation of the Z score,112 laboratories were qualified,the qualified rate was 98.2％ (112/114).Two laboratories were not qualified,unqualified rate was 1.8％ (2/114).According to the Youden plot,5 laboratories were possible outliers with results need to be reviewed.Conclusion Statistical graphic method has displayed the examination results directly,which is helpful in searching targeted improvements,and improving the detection capability.