2005-2012年北京市居民食用盐碘含量监测聚类与相关分析

Clustering and correlation analysis of surveillance data of iodine concentration in salt in Beijing from 2005 to 2012

目的分析北京市碘盐监测情况的地区分布特征,探讨地区差异的原因,为北京市碘缺乏病的控制提供依据。方法采用随机抽样的方法抽取41 844份盐样,利用直接滴定法测定食盐碘含量,并计算碘盐覆盖率、合格碘盐食用率及碘盐合格率;采用描述性分析方法分析2005-2012年北京市居民食用盐碘含量监测数据,采用系统聚类分析的方法分析碘盐合格率、合格碘盐食用率、碘盐覆盖率的地区分布特征;采用线性相关分析的方法分析居民合格碘盐食用率与碘盐覆盖率的关系。结果 2005-2012年北京市年均碘盐覆盖率为96.30%(40 296/41 844),2005年碘盐覆盖率为92.88%(4 828/5 198),2006-2012年北京市碘盐覆盖率均高于95%;2005-2012年北京市居民合格碘盐食用率均高于90%;聚类分析结果显示,近郊区合格碘盐食用率、碘盐覆盖率相对较低;相关分析结果显示,北京市合格碘盐食用率、碘盐覆盖率之间存在相关关系(r=0.97,P<0.01),东城南区和怀柔区居民合格碘盐食用率与碘盐覆盖率之间不相关(P>0.05)。结论近郊区县碘盐覆盖率、合格碘盐食用率相对较低,个别区县可能存在居民有意购买无碘盐情况,提示应加强碘盐市场监督监管,加强居民碘缺乏病知识健康宣教,指导健康人群选择购买合格碘盐。

Objective To understand the features of distribution of iodized-salt in Beijing,and to analyze the reasons of regional difference,in order to provide basis for the prevention and control of iodine deficiency disorders. Methods A total of 41 844 salt samples were randomly collected,iodine concentrations were measured and iodized-salt coverage rate,qualification rate and the consuming rate of qualified iodized salt were all calculated,which were then analyzed for regional distribution features by systematic clustering analysis.A descriptive analysis method was used to analyze the data of iodine content in salt consumed by residents in Beijing from 2005 to 2012.Linear correlation analysis method was applied to analyze the correlationship between iodized-salt coverage rate and consuming rate of qualified iodized-salt.Data were analyzed by SPSS 16.0. Results The average annual iodized-salt coverage rate was 96.30%(40 296/41 844)and the consuming rate of qualified iodized-salt was higher than 90% from 2005 to 2012.According to the result of clustering analysis,the above two rates were relatively lower in suburb areas and they were correlated by correlation analysis(r=0.97,P<0.01),except for those in Dongchengnan and Huairou district. Conclusions We should pay much attention to the supervision of iodized-salt in markets and educate residents about iodine deficiency disease and skills about how to choose qualified iodized-salt.