中华预防医学杂志
中華預防醫學雜誌
중화예방의학잡지
CHINESE JOURNAL OF
2014年
6期
512-516
,共5页
模型,统计学%镉%土壤
模型,統計學%鎘%土壤
모형,통계학%력%토양
Models,statistical%Cadmium%Soil
目的 基于层次结构数据的特点,运用多水平模型分析中部某县人群尿镉水平可能的影响因素,探讨多水平模型实际应用中处理层次结构数据的优势.方法 2013年5月,以整群抽样的方法在中部某县12个行政村抽取年龄≥20岁居民1 460名,进行尿镉水平可能影响因素调查和尿镉水平检测,并对调查区农田土壤特征污染物镉含量进行测定.完成调查并符合纳入标准的对象共计1 410名,调查区农田土壤检测样品共计318份.根据数据特点,将个体看作水平1单位,调查村看作水平2单位,运用SAS 9.3软件中处理层次结构数据的MIXED过程对数据进行多水平分析.在不考虑数据层次结构的情况下,运用SAS 9.3软件拟合一般线性模型,比较多水平模型及一般线性模型的拟合效果.结果 本研究最终纳入1 410名研究对象,年龄(55.2±11.1)岁,其中男性645名(45.74％),女性765名(54.26％).家庭人均每年食用大米量(100.9 ±40.3) kg.有从事采选矿工作经历的占18.65％(262/1 410).尿镉水平为(9.39±2.16) μg/g肌酐.土壤镉普遍超标.一般线性模型对数据拟合结果显示,除了是否从事采选矿工作差异无统计学意义(x2=1.05,P=0.305)以外,村土壤镉水平、年龄、食用自产大米量、性别差异均有统计学意义(x2分别为401.39、34.9、4.16、86.15,P值分别为＜0.01、＜0.01、0.041、＜0.01).空模型拟合结果显示本研究ICC =0.435 5,尿镉在村水平上存在聚集性.多水平模型全模型分析结果显示解释变量村土壤镉水平、年龄、食用自产大米量、性别差异有统计学意义(Wald x2值分别为2.55、6.34、2.37、10.32,P值分别为0.029、＜0.01、0.018、＜0.01),是否从事采选矿工作差异无统计学意义(x2=0.78,P=0.438).用于进行模型比较的拟合优度指标,多水平模型拟合结果均小于一般线性模型.水平2解释变量村土壤镉水平的回归系数为0.84,可解释的变异约占总变异的35.26％.结论 多水平模型分析层次结构数据较一般线性模型更加合理;村土壤镉水平对人群尿镉水平影响较大.
目的 基于層次結構數據的特點,運用多水平模型分析中部某縣人群尿鎘水平可能的影響因素,探討多水平模型實際應用中處理層次結構數據的優勢.方法 2013年5月,以整群抽樣的方法在中部某縣12箇行政村抽取年齡≥20歲居民1 460名,進行尿鎘水平可能影響因素調查和尿鎘水平檢測,併對調查區農田土壤特徵汙染物鎘含量進行測定.完成調查併符閤納入標準的對象共計1 410名,調查區農田土壤檢測樣品共計318份.根據數據特點,將箇體看作水平1單位,調查村看作水平2單位,運用SAS 9.3軟件中處理層次結構數據的MIXED過程對數據進行多水平分析.在不攷慮數據層次結構的情況下,運用SAS 9.3軟件擬閤一般線性模型,比較多水平模型及一般線性模型的擬閤效果.結果 本研究最終納入1 410名研究對象,年齡(55.2±11.1)歲,其中男性645名(45.74％),女性765名(54.26％).傢庭人均每年食用大米量(100.9 ±40.3) kg.有從事採選礦工作經歷的佔18.65％(262/1 410).尿鎘水平為(9.39±2.16) μg/g肌酐.土壤鎘普遍超標.一般線性模型對數據擬閤結果顯示,除瞭是否從事採選礦工作差異無統計學意義(x2=1.05,P=0.305)以外,村土壤鎘水平、年齡、食用自產大米量、性彆差異均有統計學意義(x2分彆為401.39、34.9、4.16、86.15,P值分彆為＜0.01、＜0.01、0.041、＜0.01).空模型擬閤結果顯示本研究ICC =0.435 5,尿鎘在村水平上存在聚集性.多水平模型全模型分析結果顯示解釋變量村土壤鎘水平、年齡、食用自產大米量、性彆差異有統計學意義(Wald x2值分彆為2.55、6.34、2.37、10.32,P值分彆為0.029、＜0.01、0.018、＜0.01),是否從事採選礦工作差異無統計學意義(x2=0.78,P=0.438).用于進行模型比較的擬閤優度指標,多水平模型擬閤結果均小于一般線性模型.水平2解釋變量村土壤鎘水平的迴歸繫數為0.84,可解釋的變異約佔總變異的35.26％.結論 多水平模型分析層次結構數據較一般線性模型更加閤理;村土壤鎘水平對人群尿鎘水平影響較大.
목적 기우층차결구수거적특점,운용다수평모형분석중부모현인군뇨력수평가능적영향인소,탐토다수평모형실제응용중처리층차결구수거적우세.방법 2013년5월,이정군추양적방법재중부모현12개행정촌추취년령≥20세거민1 460명,진행뇨력수평가능영향인소조사화뇨력수평검측,병대조사구농전토양특정오염물력함량진행측정.완성조사병부합납입표준적대상공계1 410명,조사구농전토양검측양품공계318빈.근거수거특점,장개체간작수평1단위,조사촌간작수평2단위,운용SAS 9.3연건중처리층차결구수거적MIXED과정대수거진행다수평분석.재불고필수거층차결구적정황하,운용SAS 9.3연건의합일반선성모형,비교다수평모형급일반선성모형적의합효과.결과 본연구최종납입1 410명연구대상,년령(55.2±11.1)세,기중남성645명(45.74％),녀성765명(54.26％).가정인균매년식용대미량(100.9 ±40.3) kg.유종사채선광공작경력적점18.65％(262/1 410).뇨력수평위(9.39±2.16) μg/g기항.토양력보편초표.일반선성모형대수거의합결과현시,제료시부종사채선광공작차이무통계학의의(x2=1.05,P=0.305)이외,촌토양력수평、년령、식용자산대미량、성별차이균유통계학의의(x2분별위401.39、34.9、4.16、86.15,P치분별위＜0.01、＜0.01、0.041、＜0.01).공모형의합결과현시본연구ICC =0.435 5,뇨력재촌수평상존재취집성.다수평모형전모형분석결과현시해석변량촌토양력수평、년령、식용자산대미량、성별차이유통계학의의(Wald x2치분별위2.55、6.34、2.37、10.32,P치분별위0.029、＜0.01、0.018、＜0.01),시부종사채선광공작차이무통계학의의(x2=0.78,P=0.438).용우진행모형비교적의합우도지표,다수평모형의합결과균소우일반선성모형.수평2해석변량촌토양력수평적회귀계수위0.84,가해석적변이약점총변이적35.26％.결론 다수평모형분석층차결구수거교일반선성모형경가합리;촌토양력수평대인군뇨력수평영향교대.
Objective Based on the characteristics of hierarchical data,a multilevel model was used to analysis possible influencing factors of urinary cadmium levels in one county population,and to discuss the advantages of multilevel model for processing hierarchical data in practical problems.Methods In May 2013,1 460 participants aged 20 and above in 12 administrative villages in one county in central China were recruited by cluster sampling.Urinary cadmium level and its possible influencing factors were investigated,and cadmium level in farmland soil of survey area was also tested.A total of 1 410 participants completed the survey and met the inclusion criterion.318 farmland samples in survey area were detected.According to the data,individuals were set as the level one unit,and the village was set as level two unit.the data were analyzed by MIXED procedure for hierarchical data of SAS 9.3 software.In the case of not considering the hierarchy of data,the general linear model was fitted by SAS 9.3 software,and the fitting results of the two models were compared.Results A total of 1 410 participants were included finally,the age was (55.2 ± 11.1) years.645 (45.74％) were males and 765 (54.26％) were females.The amount of household per capita consumption of rice was (100.9 ±40.3) kg/y.All 18.65％ (262/1 410) of the participants had mining and mineral separation work experience.The urinary cadmium level was (9.39 ± 2.16) μg/g Cr.Most of the soil cadmium levels in villages were greater than tolerance value.The fitting results of general linear model suggested that whether doing mining and mineral separation work does not have significant difference (x2 =1.05,P =0.305).There was significant difference in the village soil cadmium levels,age,the amount of household per capita consumption of rice,and gender (x2 =401.39,34.9,4.16 and 86.15,respectively,P ＜0.01,＜0.01,0.041,＜0.01,respectively).The fitting result of empty model showed the ICC was 0.435 5,the urinary cadmium had clustering at village level.The results of multilevel model showed that the explanatory variables of the village soil cadmium levels,age,the amount of household per capita consumption of rice and gender had significant difference (Wald x2 values 2.55,6.34,2.37 and 10.32,respectively,P =0.029,＜0.01,=0.018 and ＜0.01),while whether doing mining and mineral separation work had no significant difference (x2 =0.78,P =0.438).To the fitting optimization index using for the comparison of models,the results of multilevel model were less than that of general linear model.The regression coefficient of level-2 explanatory variable (the village soil cadmium levels) was 0.84,which could explain the 35.26％ of the total variance.Conclusion Multilevel model could analyze hierarchical data more reasonably than general linear model.Urinary cadmium levels is highly influenced by the village soil cadmium levels.
