摘要目的 评价2017年北京市同伴推动抽样(RDS)法招募MSM人群的随机性和代表性.方法 采用RDS法招募北京市MSM人群进行面对面问卷调查和HIV检测.结果 共招募MSM 600人,其中种子14人,种子的网络规模中位数为10人,高于其他被招募的MSM,招募人数按轮次呈正偏态分布,第4轮招募人数最多.不同种子招募人数差异较大,招募链人数最多的为184人、113人和92人,5个种子的招募链人数不足10人,其中以2名大学生种子招募人数最少,仅各招募1人.主要人口学指标在5～9层达到平衡,各指标绘制的收敛图最终趋于平稳,瓶颈图除婚姻状况和文化程度中部分曲线收敛趋势不明显外,其他曲线最终趋于收敛.主要指标的同质系数除文化程度外均在1左右.HIV感染率为7.9％(95％CI:4.4％～11.4％).结论 采用RDS法招募的MSM样本,主要人口学指标达到平衡,招募过程合理可控,在一定程度上可以代表北京市MSM人群.

abstractsObjective To evaluate the randomness and representativeness of respondent-driven sampling (RDS) tool in conducting the investigation in MSM population,in Beijing,2017.Methods RDS tool was used to recruit MSM population for a face-to-face interview with structured questionnaire and serological tests.Results A total of 600 MSM people were sampled and interviewed.The median number of personal network of seeds was 10,which was higher than other MSM people recruited.The numbers of recruitments by wave presented a skewed positive distribution and the highest number was in the fourth wave.It was also dramatically varied from different seeds.Three seeds had the longest chains and had recruited 184,113 and 92 MSM people,respectively.In contrast,five seeds recruited less than 10 MSM people.Two college students were the most non-generative seeds and each recruited only 1 MSM person.After five to nine waves of sampling,the major demographic characteristics reached equilibrium.Both convergence and bottleneck plots of major demographic characteristics reached convergence,although the plots on marriage and education did not.The homophiles of characteristics were all closed to 1,except for education.The HIV positive rate appeared as 7.9％ (95％CI:4.4％-11.4％). Conclusions Results from this study showed that RDS could be used as a feasible sampling method for the study on MSM population with major demographic characteristics reached equilibrium.The process of recruitment appeared controllable and reasonable,showing that this could represent the MSM population in Beijing,in some degree.