The regression estimator in cluster random sampling 整群抽样回归估计量
In order to study the awareness , treatment and control rates andthe risk factors of hypertension in qingdao rural residents , a cluster random sampling method was used 为了调查青岛农村居民高血压的患病率、知晓率、服药率、控制率及其影响因素,采用整群随机抽样法,对7个村的18岁以上居民进行血压测量及相关因素调查。