乘数法估计上海市男男性接触者人群规模

目的估计上海市男男性接触者（MSM）人群规模。方法应用乘数法，选择两家上海市知名MSM网站作为目标机构，通过网络问卷调查确定规定时期内登录网站者中的全部MSM人数（r）。对上海市MSM人群开展专题抽样调查了解MSM人群中同时期内登录过上述网站的比例数，取此比例的倒数获得乘数（m）。r与m相乘即为上海市MSM人群估计数。结果以A网站为目标机构时MSM人群规模为398433，以B网站为目标机构时MSM人群规模为370755，MSM人群估计数分别占上海市15～49岁男性成年人1217．1％和6．6％。结论以MSM网站为目标机构的乘数法估计MSM人群规模是可行的，但应充分考虑调查样本的代表性。

Study on using the multiplier method in estimating the size of men who have sex with men population in Shanghai

OBJECTIVE: To estimate the size of men who have sex with men (MSM) in Shanghai. METHODS: Multiplier method was used in the study and two popular Shanghai-based MSM websites were selected as targeted institutions. The number of MSM (r) who visited website during a given period was investigated by a web-based questionnaire. Meanwhile, a survey was conducted among MSM living in Shanghai to obtain the proportion of MSM who had visited the websites during the given period, the reciprocal number of this proportion was the multiplier (m), therefore, population size can be estimated by r multiplied by m. RESULTS: The MSM population was estimated as 398 433 when website A was selected as target institution and 370 755 was estimated when website B was selected. The estimated population of MSM accounted for 7.1% and 6.6% of male population aged 15 to 49 years old in Shanghai, respectively. CONCLUSION: It was feasible to use multiplier method which selecting MSM website as target institution to estimate the size of MSM population, however, the representativeness of this study sample should be considered seriously.