儿童疫苗接种率调查抽样方法的评价

Evaluation on sampling methods for vaccination coverage study in children

目的比较三种接种率调查抽样方法的结果,以期选择最适宜现阶段的接种率调查抽样方法。方法分别采用PPS法、系统抽样法和分层整群抽样法对天津市1～2岁儿童建卡率、建证率、卡证符合率、计划免疫疫苗接种率,以及乙肝首针及时接种率、麻疹疫苗及时接种率进行调查比较,计算率进行χ2检验。结果 PPS法调查适龄儿童2 695人、系统抽样法调查适龄儿童1 073人、分层整群抽样法调查适龄儿童192人。PPS法、系统抽样法和分层整群抽样法调查的建证率两两比较差异无统计学意义(χ2=0.794,P>0.05;χ2=0.003,P>0.05;χ2值=0.15,P>0.05),建卡率比较差异有统计学意义(χ2=12.25,P<0.05;χ2=194.85,P<0.05;χ2=24.652,P<0.05)。系统抽样法调查的儿童建卡率、建证率、卡证符合率、五苗合格接种率、卡介苗接种率、脊灰疫苗接种率、百白破疫苗接种率、麻疹疫苗接种率、乙肝疫苗接种率、乙肝首针及时接种率、麻疹疫苗及时接种率与PPS法结果进行比较,除脊灰疫苗接种率差异有统计学意义外,其他差异均无统计学意义。而分层整群抽样法调查的结果与PPS法相比较,除百白破疫苗接种率和麻疹疫苗首针及时接种率差异无统计学意义以外,其他差异均有统计学意义。系统抽样法和分层整群抽样法调查结果比较,除脊灰疫苗接种率、百白破疫苗接种率和麻疹疫苗首针及时接种率差异无统计学意义意外,其他差异均有统计学意义。PPS法和系统抽样法调查的结果一致率达到87.5%。结论与抗体水平监测相比接种率调查也能相对客观的反映儿童的接种水平。在高接种率状态下,系统抽样法和PPS法所得结果一致,为节省人力物力能用系统抽样法替代PPS法。分层整群抽样法更能发现工作中存在的问题和不足,可用于考核基层工作。

Objective To compare and evaluate three sampling methods in order to determine the optimal one for the vaccination coverage survey in children.Methods PPS,systematic sampling and stratified cluster sampling methods were used to analyze the vaccination coverage among children aged 1-2 years in Tianjin which included vaccination card rate,certificate rate,card-certificate matching rate and vaccination coverage rate.Results A total of 2 965,1 073 and 192 children were surveyed by PPS,systematic sampling and stratified cluster sampling separately.There were no significant differences of certificate rates in between（χ^2=0.794,P〉0.05;χ^2=0.003,P〉0.05;χ^2=0.15,P〉0.05）,however,the card rates were statistically different（χ^212.25,P〈0.05;χ^2194.85,P〈0.05;χ^224.652,P〈0.05）.The differences of almost all vaccination related parameters analyzed by systematic sampling method were not significant compared to those surveyed by PPS（P〈0.05）,except for the coverage of OPV（P〈0.05）.While,compared to PPS and systematic sampling method,the differences of majority vaccination-related parameters analyzed by stratified cluster sampling method were statistically significant（P〈0.05）except for the coverage of DPT and MV（P〈0.05）and for the coverage of OPV,DPT and on time shot of the first MV（P〈0.05）.There was as high as 87.5% result consistence between PPS and systematic sampling.Conclusions PPS method can be replaced by systematic sampling one which is able to save manpower and resources under higher vaccination coverage situation.While,stratified cluster sampling method can be used for the inspection of the work in subordinate unit.