两次全国血吸虫病流行病学抽样调查未控制流行区调查样本的构成分析

Proportion analysis on the sampling of the second and third nation wide epidemiological survey for schistosomiasis in the endemic areas

目的分析两次全国血吸虫病流行病学调查(简称流调)未控制流行地区的调查样本人口结构,了解主要构成的不同,为进一步准确推断病人数和确定感染率打好基础,同时为以后的流调工作提供参考。方法采用第2次流调的粪检人数和第3次流调的血检人数比较其不同流行类型、年龄、性别和职业构成所带来的影响。结果第2和第3次全国流调未控制流行地区抽样所得抽样点各省构成差异无显著性(χ2=3.06,P=0.08);各省的调查人数总体构成有一定的变化;流行类型、年龄和职业总体构成差异有显著性(χ2值分别为1612.53、4207.02、55.66,P<0.01)。结论未控制流行地区两次流调在流行类型、年龄和职业的总体构成上存在一定的差别。这些差别可能来自于调查方法和对象的不同,也可能是某次调查因为客观原因造成调查对象不够全面而产生的偏差,流行病学调查过程中只有扩大人口资料的收集,同时充分估计这些偏差的大小,才能得出相对准确的结论。

Objective To find out the differences between the two national sampling surveys for schistosomiasis in the endemic areas, make foundation for inferring infected persons and infection rates, provide reference for later epidemiological survey. Methods Comparison between persons with stool examination results in the second epidemiological survey and those with serological test results in the third epidemiological survey was made in terms of different endemic types, age, sex, and occupational proportion. Results No significant differences were found in the proportion of the endemic areas in the provinces between the two sampling surveys（x^2=3.06, P=0.08）. The proportion of persons undergoing the surveys had some changes. The differences of constituent in endemic types, age and occupation were significant （P〈0.01）. Conclusion Some differences were fotind in the proportion of endemic types, age and occupation between the second and third nation-wide epidemiological surveys in schistosomiasis endemic areas. The difference might be caused by the different survey methods and survey subjects, and any bias might be produced by the objective reason with less survey samples. The epidemiological survey can reach a relatively accurate conclusion only when an extended population data are collected, and in the meantime bias produced by different population proportion is fully estimated.