Analyses of survey results of the external quality control network on indine deficiency disorders laboratory from 2000 to 2007 in Qinghai Province

Objective To analyze the examination results of external quality assessment(EQA) on all levels of iodine deficiency disorders(IDD) laboratory in Qinghai in order to further improve the quality of EQA. Methods The examination results of EQA were statistically analyzed in accordance with the national reference laboratory of IDD(2000-2007). Results The survey results showed that the provincial level laboratory were all qualified in testing urine iodine and salt iodine in 8 years, and the ability and the quality to test urine iodine and salt iodine in prefectural level improved year by year. Feedback rates and passing rates reached 100.0% in 2007. Because Yushu State did not report survey results in 2006, feedback rates (87.5 %, 87.5 %) and passing rates (62.5%, 62.5%) were lower than those in 2005 (100.0%, 100.0%, 87.5%, 87.5%). Feedback rates of county level laboratory reached 100% in 2005 and 2007 year, and passing rates also increased year by year. The passing rate of external quality control at prefectural(city) level was positively correlated with county-level(r=0.829, P < 0.01); The passing rate of external quality control in salt iodine and urinary iodine also showed a positive corrlation (r= 0.907, P < 0.01). Conclusion Determination accuracy of salt iodine and urine iodine is closely related with IDD laboratory condition and personnel and technology strength. Key words: Iodine; Deficiency diseases; Quality control