1982年3～8月,对北京市城区及近郊区城镇的卡介苗接种普及情况进行了一次随机抽样调查,现将结果报告于下: 对象与方法对象为本市城镇1～6年级的小学生,按行政管辖划分为11个地区。样本数按公式计算,需2,400人。据此,决定每一地区按随机数字表抽取一所小学,抽取比例为1∶48,每个学校1～6年级的第一班为调查对象,总共抽 From March to August 1982, a randomized sample survey on the prevalence of BCG vaccination was conducted in urban areas and suburban areas in Beijing. The results are reported as follows: Subjects and Methods Target pupils in grade 1 to grade 6 cities and towns in this Municipality Administrative jurisdiction is divided into 11 regions. The number of samples according to the formula, 2,400 people need. Accordingly, it is decided that each district should select a primary school according to a random number table, with a ratio of 1:48. The first class of each school from grade 1 to grade 6 is the target of investigation.