Application of clustering analysis of data in iodine deficiency disorders surveillance / 中国地方病学杂志

ABSTRACT

Objective To explore the application of clustering analysis in the study for iodine deficiency disorders(IDD)surveillance.Methods System cluster method of average linkage was applied to study the data obtained from national IDD surveilance in 2005 and a clustering analysis' tree chart was drawn.Such data as the rates of consuming qualified iodine salt,coverage rate of iodine salt,median of iodine salt,median urinary iodine,goiter rate detemined by palpation and B-uhrasonography,Child intelligence quotient were investigated.Results Thirty-one provinces or autonomous regions including the Xinjiang Production and Construction Coms had beed assorted into three types.Tibet was claasified into the type Ⅰ;Guangdong,Qinghai,Hainan,Sinkiang were assorted into the type Ⅱ,other areas were assorted into the typeⅢ.The rates of consuming qualified iodine salt,coverage rate of iodine salt and median urinary iodine in the type Ⅰ area were 21.00%,33.20%and 96.70 μg/L,while they were 71.95%,78.50%and 145.40μg/L,respectively,all being lower than that of type Ⅲ(93.20%.97.70%and 245.20μg/L)with statistical significance(P＜0.05).11.50%of the children in the type Ⅰ area were detected by palpation to have goiter;the child intelligence quotient in three types of areas,was 77.00,95.95±4.46 and 104.59±6.77,the differences being statistical significant between any two types(P＜0.05).Conclusion Multiple areas of IDD could be assorted by clustering analysis into distinct types with different epidemic value.More attentions of the government must be paid to the type Ⅱ areas,the prevention and cure work must be enhanced in the second-class areas while it is carried on in the typeⅢareas.The results are helpful for decision making for epidemic supervisors in the government.