应用枚举法与乘数法估计女性性工作者及嫖客人群规模的研究

目的探索在女性性工作者、嫖客人群中开展规模估计的简便可行的方法,为艾滋病疫情估计和高危人群干预提供依据。方法采用枚举法和乘数法对我省部分地区女性性工作者、嫖客人群规模进行估计。结果衢州市柯城区、湖州市吴兴区、慈溪市浒山镇、海宁市硖石镇女性性工作者规模点估计值和95％可信区间分别为994（826～1161）、1833（862～2805）、1109（571～1647）和1221（975～1466）人,占当地15～49岁年龄组女性人口的0．80％、0．99％、2．15％和2．36%。衢州市柯城区、慈溪市浒山镇、海宁市硖石镇估计嫖客人数和95％可信区间分别为11755（9782～14458）、7342（6752—8046）、7985（7335～8762）人．占当地15—49岁年龄组男性人口的8．99％、13．73％、15．38％。结论采用枚举法和乘数法进行女性性工作者、嫖客人群规模估计操作简便,结果相对准确,但要注意调查人群代表性。     

用乘数法估计江苏省3市吸毒人群规模

目的估计吸毒人群规模,为制定防治策略提供依据。方法采用乘数法对江苏省3市吸毒人群进行估计,并根据注射吸毒比例计算注射吸毒人群规模。结果苏南某市吸毒人群32 914人,注射吸毒人群4 819人;苏中某市吸毒人群3 081人,注射吸毒人群719人;苏北某市吸毒人群5 461人,注射吸毒人群707人。结论利用已有数据和资料,用乘数法估计吸毒人群规模相对简单、易操作。     

用简易乘数法进行吸毒人群规模估计

目的掌握雅安市吸毒人群规模,为预测雅安市艾滋病疫情及防治资源配置提供依据。方法采用简易乘数法进行吸毒人群规模估计。结果 2012年雅安市吸毒人群规模为4 626人。结论采用简易乘数法得到的吸毒人群规模数基本反映了雅安市目前的吸毒人群规模。     

利用乘数法估计成都市区男男性行为人群规模的研究

[目的]利用乘数法估计成都市区男男性行为人群规模数,为制定高危人群防治策略提供依据。[方法]在成都市区选择6家男男性行为人群聚集场所观察3d并计数,采用提名法获得调查目标人群,运用乘数法进行男男性行为人群的规模估计。[结果]成都市区男男性行为人群规模均数为11218人(95%CI:9115～14583人)。[结论]利用乘数法估计结果基本反映了成都市区男男性行为人群中相对活跃的人群规模。     

四川省某市街头性服务嫖客规模估计

目的探讨街头性服务嫖客规模估计的有效方法。方法通过街头暗娼志愿者识别，在街头暗娼站桩点主动接近调查对象，运用间接除数法估计街头性服务嫖客规模。结果该市中心城区街头暗娼集中于8个站桩点，最近1年与街头暗娼发生性交易的嫖客数为3724-4337人，占当地成年男性1．69％～1．96％，性交易频率为16次／年。结论运用间接除数法能简便、快速的估计光顾街头暗娼的嫖客规模。     

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。     

应用乘数法估计淮北市暗娼规模

目的估计淮北市暗娼数量,分析影响评估结果的因素,提高评估结果的准确性,为制定针对性的干预方法提供依据。方法在市辖3区,应用乘数法对暗娼数量进行估算。结果估计全市有暗娼2065名,其中,相山区为1933名,占全市总数的93.61%;烈山和杜集两区分别为40和92名。结论乘数法是艾滋病相关高危人群规模估计的一种实用的方法,具有操作简便、结果可靠、费用低廉、省时省力等优点;但在应用时应注意：调查时间的选择、目标单位的代表性、目标人群的识别、调查人员的培训及调查方法的标准化等,以减少评估结果的偏差。     

用乘数法估计株洲市区吸毒人群的研究

目的科学估计株洲市吸毒人群基数,为掌握此人群中HIV/AIDS流行状况和防治对策提供依据.方法应用两种乘数法对株洲市城区吸毒人群基数进行估计.结果公安部门估计吸毒人群4 083人,吸毒率0.54%,乘数法1估计吸毒人群2 879人,吸毒率0.37%,乘数法2估计吸毒人群3 255人,吸毒率0.42%.乘数法1和乘数法2估计数无显著性差异,公安部门估计数过高.结论乘数法可很好地估计吸毒人员基数.     

邯郸市男性同性恋人群规模调查估计

目的调查估计邯郸市男性同性恋人群规模,分析影响评估结果的因素。方法结合乘数法和捕获-再捕获法对邯郸市男性同性恋活动场所进行调查估计。结果计算得出男性同性恋人群为1 453人,95%可信区间为（1 227,1 681）。结论捕获-再捕获法和乘数法都是比较可行的对男同性恋人群进行规模估计的间接方法。用时短,花费低,适合在卫生资源有限的情况下进行艾滋病高危人群的规模估计。     

应用乘数法估计艾滋病男性高危人群基数

目的 探索在我国现状下估计艾滋病男性高危人群基数的有效方法。方法 通过女性性服务者中志愿者和在性病门诊、长途汽车站、建筑工地、长途货运站进行调查以及采用提名法等多种途径接近调查对象，运用乘数法估计乐山市中心城区艾滋病男性高危人群基数。结果 乐山市中心城区最近1年与暗娼发生性交易的人数为25926～29863人；性访问频率为15．39次／年。结论 通过女性性服务者中志愿者、长途汽车站和采用提名法可有效地接近调查对象，并能保证样本的代表性；运用乘数法能简便、快速的估计艾滋病男性高危人群基数。     

Population Size Estimation of Men Who Have Sex with Men in Ho Chi Minh City and Nghe An Using Social App Multiplier Method

This study aims to estimate the number of men who have sex with men (MSM) in Ho Chi Minh City (HCMC) and Nghe An province, Viet Nam, using a novel method of population size estimation, and to assess the feasibility of the method in implementation. An innovative approach to population size estimation grounded on the principles of the multiplier method, and using social app technology and internet-based surveys was undertaken among MSM in two regions of Viet Nam in 2015. Enumeration of active users of popular social apps for MSM in Viet Nam was conducted over 4 weeks. Subsequently, an independent online survey was done using respondent driven sampling. We also conducted interviews with key informants in Nghe An and HCMC on their experience and perceptions of this method and other methods of size estimation. The population of MSM in Nghe An province was estimated to be 1765 [90% CI 1251–3150]. The population of MSM in HCMC was estimated to be 37,238 [90% CI 24,146–81,422]. These estimates correspond to 0.17% of the adult male population in Nghe An province [90% CI 0.12–0.30], and 1.35% of the adult male population in HCMC [90% CI 0.87–2.95]. Our size estimates of the MSM population (1.35% [90% CI 0.87%–2.95%] of the adult male population in HCMC) fall within current standard practice of estimating 1–3% of adult male population in big cities. Our size estimates of the MSM population (0.17% [90% CI 0.12–0.30] of the adult male population in Nghe An province) are lower than the current standard practice of estimating 0.5–1.5% of adult male population in rural provinces. These estimates can provide valuable information for sub-national level HIV prevention program planning and evaluation. Furthermore, we believe that our results help to improve application of this population size estimation method in other regions of Viet Nam.     

应用乘数法估计某地男性同性恋人群基数的研究

目的通过调查估计某地区男性同性恋(MSM)人群基数,为该地区制订艾滋病预防控制策略提供科学依据。方法应用乘数法对目标人群基数进行估计。通过指定网站统计在规定时间内登陆该网站的该地区MSM人数(r),通过对当地MSM人群活动场所内、外的调查获得同时期内登陆上述网站人数的比例(p),从而获得乘数m(1/p),r与m相乘即为估算的当地MSM人群数(N)。结果在规定的时间内登陆指定网站的MSM人群中,每月去场所1次以上者和不去场所的MSM人数分别为403人、327人,二者的乘数(m)分别为1.253和1.563,该地区MSM人群估计人数为1016人,约占当地15～49岁男性成年人口数的0.48%。结论采用乘数法估计MSM人群的基数是可行的,但应充分考虑调查样本的代表性。     

Personality Characteristics of Male Clients of Female Commercial Sex Workers in Australia

The personality characteristics of male clients of female sex workers and their motivations for seeking the services of sex workers were examined. It was hypothesized that clients of sex workers would differ from nonclients in that they would adopt less feminine sex roles, exhibit lower social–sexual effectiveness, and show higher levels of sensation-seeking behavior. Sixty-six clients of sex workers and 60 nonclients volunteered to complete a short questionnaire to assess demographic characteristics, sex role, social–sexual effectiveness, and sensation-seeking behavior. Clients and nonclients did not differ on demographic variables such as age, education, marital status, or occupation. However, clients were significantly less feminine in sex-role orientation, scored lower in social–sexual effectiveness, and scored higher on sensation seeking. Closer analysis of the client group revealed the existence of two distinct subgroups. The first was characterized by low social–sexual effectiveness and appeared motivated to visit sex workers because of an interpersonal need for intimacy. The second was characterized by high sensation seeking and appeared motivated to visit sex workers because of a need for novelty and variety in sexual encounters.     

Assessment of Respondent Driven Sampling for Recruiting Female Sex Workers in Two Vietnamese Cities: Reaching the Unseen Sex Worker

Respondent driven sampling (RDS) is a relatively new method to sample hard-to-reach populations. Until this study, female sex workers (FSWs) in Vietnam were sampled using a variety of methods, including time location sampling (TLS), which may not access the more hidden types of FSWs. This paper presents an analysis from an HIV biological and behavioral surveillance survey to assess the feasibility and effectiveness of RDS to sample FSWs, to determine if RDS can reach otherwise inaccessible FSWs in Vietnam and to compare RDS findings of HIV risk factors with a theoretical TLS. Through face-to-face interviews with FSWs in Ho Chi Minh City (HCMC) and Hai Phong (HP), data were collected about the venues where they most often solicit their clients. These data were used to create three variables to assess whether FSWs solicit their clients in locations that are visible, semi-visible and non-visible. For this analysis, the visible group simulates a sample captured using TLS. Survey results in HIV prevalence and related risk factors and service utilization, adjusted for sampling methodology, were compared across each of the three FSW visibility groups to assess potential bias in TLS relative to RDS. The number of self-reported visible FSWs (HCMC: n=311; HP: n=162) was much larger than those of the semi-visible (HCMC: n=65; HP: n=43) and non-visible (HCMC: n=37; HP: n=10) FSWs in HCMC and HP. Non-visible FSWs in both cities were just as likely as visible and semi-visible FSWs to be HIV positive (HCMC: visible 14.5%, semi-visible 13.8%, non-visible 13.5%, p value = 0.982; HP: visible 35.2%, semi-visible 30.2%, non-visible 30.0%, p value = 0.801), to practice behaviors that put them at risk for contracting and transmitting HIV (injecting drug use—HCMC: visible 13.8%, semi-visible 12.3%, non-visible 5.4%, p value = 0.347; HP: visible 38.9%, semi-visible 23.3%, non-visible 30.0%, p value = 0.378, to have no condom use in the past month —HCMC only: visible 52.7%, semi-visible 63.1%, non-visible 48.6%, p value = 0.249) and to have symptoms of a sexually transmitted infection (STI) in the past year (HCMC: visible 16.1%, semi-visible 12.3%, non-visible 16.2%, p value = 0.742; HP: visible 13.6%, semi-visible 18.6%, non-visible 20.0%, p value = 0.640). There was a difference found among the visible, semi-visible and non-visible groups in HP for no past month condom use (visible 53.1%, semi-visible 79.1%, non-visible 60.0%, p value = 0.009). This study found that RDS was successful at recruiting hidden types of FSWs in Vietnam. Past reports of FSWs in Vietnam have assessed the more visible FSWs as being the most vulnerable and at risk for HIV. Although the number of visible FSWs is much higher than those of the semi and non-visible groups, this study found that the non-visible FSWs are very vulnerable to HIV infection. If prevention programs are targeting and responding to those who are most likely to be assessed (e.g., more visible types of FSWs) then this analysis indicates that a significant proportion of the FSW population at risk for HIV may not be receiving optimal HIV information and services.     

Correlates of Self-Efficacy for Condom Use Among Male Clients of Female Sex Workers in Tijuana,Mexico

Male clients of female sex workers (FSWs) in Tijuana, Mexico engage in high levels of unprotected sex. While behavioral change theories posit that self-efficacy predicts condom use, correlates of self-efficacy for condom use remain largely unstudied. We examined these correlates among male clients of FSWs in Tijuana. Eligible male clients were at least 18 years of age, HIV-negative, lived in Tijuana or San Diego, reported unprotected sex with a Tijuana FSW at least once in the past 4 months, and agreed to be treated for sexually transmitted infections (STIs). Participants completed an interviewer-administered questionnaire including demographics, substance use, psychosocial and psychosexual characteristics (e.g., outcome expectancies for negotiation of safer sex, social support, and sexual sensation seeking), and sexual behaviors. Participants also underwent HIV/STI testing. A stepwise hierarchical multiple regression analysis identified correlates of self-efficacy for condom use. Of 393 male clients, median age was 37 years. Participants were mostly Spanish-speaking and employed. Factors independently associated with higher self-efficacy for condom use were higher positive outcome expectancies for negotiation of safer sex, lower sexual sensation seeking scores, and higher social support scores. Both psychosocial and psychosexual factors may influence self-efficacy for condom use among male clients of FSWs. These factors represent central constructs in sociocognitive models that explain behavioral change and could be intervention targets for improving self-efficacy for condom use and, ultimately, safer sex behavior.     

Pornography,Sexual Enhancement Products,and Sexual Risk of Female Sex Workers and their Clients in Southern India

Despite their large numbers, and important role in the HIV epidemic in India, male clients of female sex workers (FSWs) are a difficult to reach population and little is known about their sexual behaviors. Using data from an integrated behavioral and biological assessment of 684 clients in Bangalore in 2012, we examined factors associated with their reports of having sex with three or more different female sex workers in the last month, and anal sex with sex workers. We included sociodemographic and sexual behavior factors and, for the first time in client studies in India, included data on the use of pornography and sexual enhancement products (SEPs) such as pills, oils, and sprays, in our multivariable analyses of client risk. Seventy-eight percent of clients had seen pornographic material and 8 % reported ever having used SEPs. The profiles of men practicing the two risk behaviors examined were quite different. Travel in the past year, drunkenness in the past month, young age at first commercial sex, non-use of condoms at last sex, and finding sex workers in public places (but not use of pornography and SEPs) were independently associated with multiple partnering. Sex with a man or transsexual, being a white collar worker, seeking out FSWs at home, pornography and SEP use, and condom use at last FSW sex, were all independently associated with anal sex with an FSW. More research is needed to better understand the links between pornography and SEPs, and HIV risk behaviors, and HIV prevention programs need to be cognizant of the importance of ensuring that condom use is adequately promoted and supported in the context of anal sex in female sex worker–client interactions.