利用网络规模迭加法估计北京市大学生男男性行为人群规模

目的探讨网络规模迭加法估计北京在校大学生社交网络规模和男男性行为人群规模。方法利用网络规模迭加法估计北京市大学生的社交网规模,并通过反向预测法和态度倾向校正方法分别对社交网络规模c值和目标人群规模进行调整。结果北京市大学生平均社交网络规模为97人,不同专业类型、年级的大学生社交网络规模存在差异;应用网络规模迭加法估计的北京市大学生男男性行为人群规模为16 260人,占在校大学生的3.96%。结论运用网络规模迭加法计算社交网络规模和敏感人群规模具有一定的可信性。     

利用网络规模迭加法估计上海市闵行区吸毒人群规模的调查研究

目的估计上海市闵行区吸毒人群规模,为制定吸毒人群艾滋病干预措施提供参考依据。方法采用多阶段随机抽样的方法在上海市闵行区社区人群中招募调查对象,并进行问卷调查,利用网络规模迭加法(network scale-up method,NSUM)来估计吸毒人群的规模。结果共调查合格对象3 907人,其中男性1 920人,女性1 987人;调查对象年龄为(40.54±11.69)岁。初步估计上海市闵行区居民社交网络规模均值为206人,经调整校正后为240人;进一步依据网络规模迭加法估计可得该区吸毒人群规模为3 664人。结论网络规模迭加法估计敏感人群具有一定的可信度,值得进一步推广。     

利用网络规模迭加法估计重庆市男男性行为人群规模的研究

目的利用网络规模迭加法估计重庆市男男性行为者(MSM)人群规模。方法法采用多阶段随机抽样的方法在重庆市开展社区人群的问卷调查,利用网络规模迭加法估计重庆市一般人群的社交网络规模(C),进而根据社交网络规模和调查对象认识MSM的人数及歧视程度,估计和调整重庆市MSM人群的规模。结果重庆市居民的社交网络规模平均为330人,不同区县(P结论论网络规模迭加法是一种全新的人群规模估计方法,具有简便和快捷的特性及一定的推广价值。     

网络规模迭加法中社交网络规模值的校正

目的探讨采用网络规模迭加法进行敏感人群规模估计时,社交网络规模值(C值)的校正方法。方法通过对上海市某区的调查实例分析,尝试采用不同方法对网络规模迭加法中C值进行校正。结果采用反向预测法、回归模型法以及两者结合等三种不同校正方法估计出的C值分别为231、249、297,三者差异存在统计学意义(P0.001)。结论不同校正方法的结果存在差异,结合R2值可初步提示利用反向预测和回归模型结合的方法对结果估计具有一定的可信性。     

网络规模迭加法及其在男男性接触者人群规模估计中的应用

男男性接触传播正逐渐成为中国艾滋病流行的重要途径之一,准确估算此高危人群基数对于控制艾滋病流行具有重要意义.男男性接触者隐匿性强、不易触及,而网络规模迭加法不同于需要针对目标人群进行抽样调查的传统方法,只需要针对全人群代表性抽样来进行调查,易于获得数据,在国外已被广泛应用,此文将就此方法作了详细介绍.     

基于网络规模迭加法潍坊市潍城区MSM人群规模估计

目的基于网络规模迭加法(NSUM)估计山东省潍坊市潍城区男男性行为者(MSM)人群规模,为艾滋病高危人群的防控提供理论依据。方法于2018年8—12月采用多阶段随机抽样方法在潍坊市潍城区抽取3 185名社区居民进行问卷调查,应用NSUM估计潍城区一般人群的社交网络规模(c),并根据c和调查对象认识的MSM人数及认可程度、规模比和传递率估计和校正潍城区MSM人群的规模。结果通过稳定性分析,经性别、年龄、文化程度、婚姻状况、居住时间的校正及异常值剔除后使用NSUM估计潍城区MSM人群规模为1 036人,经规模比和传递率对MSM规模的校正后,最终估计结果为4 054人。结论采用NSUM对潍城区MSM人群规模进行估计具有推广价值。     

网络规模叠加法在潍坊市某城区女性性工作者人群规模估计中的应用

目的利用网络规模叠加法(NSUM)估计潍坊市某城区女性性工作者人群规模。方法采用多阶段随机抽样的方法,对潍坊市某城区居住满6个月的18～60岁的居民进行问卷调查,利用网络规模叠加法估计潍坊市某城区女性性工作者人群规模,并利用调查对象对待女性性工作者人群的不同态度对其人群规模进行校正。结果共调查潍坊市某城区常住人口3 500人,其中有效问卷3 185份。剔除13个已知人群及社交网络规模的离群值后,利用剩余的12个已知人群共2 911份调查问卷进行了潍坊市某城区女性性工作者人群规模的估计,结果显示潍坊市某城区女性性工作者社交网络规模为1 745(95%CI:1 690～1 800)人。结论采用网络规模叠加法,并对其结果进行校正,对潍坊市某城区女性性工作者人群规模进行估计是可行的。     

利用网络规模叠加法估计北京市大学生毒品使用人群规模

利用网络规模叠加法估计北京在校大学生中毒品使用人群规模,为探讨在高校大学生中开展毒品预防教育提供参考依据.方法 采用多阶段整群随机抽样的方法在高校开展大学生问卷调查,利用网络规模叠加法计算大学生的社交网络规模、利用调查对象对待事件人群的不同态度对其进行校正,在此基础上对大学生中毒品使用人群规模进行估计和校正.结果 共调查2 005人,其中有效问卷1 776份,剔除1个已知人群和社交网络规模的异常值后,最终分析问卷1 761份.北京市大学生平均社交网络规模为97人.大学生毒品使用人群规模为3 447人,占在校大学生的0.42%.结论 采用网络规模叠加法,通过随机抽样调查对大学生吸毒人群规模进行估计是可信的,但需对结果进行校正.     

受访者驱动抽样在人群规模估计中的应用进展

受访者驱动抽样（RDS）是一种专门针对隐匿人群的抽样方法,常用于跨性别者、暗娼、MSM等因耻辱感和法律制度的约束难以识别和接触的人群,并逐渐应用于一般人群。随着RDS的不断改进和完善,研究发现对RDS样本的社交网络规模赋予权重可以估计总体的情况及人群规模。本文对目前RDS在人群规模估计中的应用进展进行综述,为RDS的发展及使用该方法开展相关研究提供思路。     

乘数法估计嫖客人群规模调查研究

目的 探索嫖客人群规模估计的有效方法,摸清某地区嘌客人群规模,为当地艾滋病防治工作提供基础信息. 方法 研究采用乘数法,通过在娱乐场所对女性性工作者(FSW)和嫖客人群调查获得相关参数. 结果 估计该地区最近1年嫖客人数为:9 023～10 181人. 结论 在性交易场所通过直接接触调查嫖客人群,采用乘数法估计嫖客人群的规模是可行的.     

Assessing network scale-up estimates for groups most at risk of HIV/AIDS: evidence from a multiple-method study of heavy drug users in Curitiba, Brazil

One of the many challenges hindering the global response to the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) epidemic is the difficulty of collecting reliable information about the populations most at risk for the disease. Thus, the authors empirically assessed a promising new method for estimating the sizes of most at-risk populations: the network scale-up method. Using 4 different data sources, 2 of which were from other researchers, the authors produced 5 estimates of the number of heavy drug users in Curitiba, Brazil. The authors found that the network scale-up and generalized network scale-up estimators produced estimates 5-10 times higher than estimates made using standard methods (the multiplier method and the direct estimation method using data from 2004 and 2010). Given that equally plausible methods produced such a wide range of results, the authors recommend that additional studies be undertaken to compare estimates based on the scale-up method with those made using other methods. If scale-up-based methods routinely produce higher estimates, this would suggest that scale-up-based methods are inappropriate for populations most at risk of HIV/AIDS or that standard methods may tend to underestimate the sizes of these populations.     

用于估计难以计数人群规模的网络扩大法研究进展

网络扩大法(NSU法)基于社会学"社会网络"理论,调查过程避免了直接估计难以计数的人群规模,可行性强;一次调查可以同时估计多个人群,被认为是一种较有应用前景的估计方法.此文主要就NSU法的历史背景、原理及应用、最新进展等方面进行综述.     

用于估计难以计数人群规模的网络扩大法研究进展

网络扩大法(NSU法)基于社会学"社会网络"理论,调查过程避免了直接估计难以计数的人群规模,可行性强;一次调查可以同时估计多个人群,被认为是一种较有应用前景的估计方法.此文主要就NSU法的历史背景、原理及应用、最新进展等方面进行综述.     

If You Are Not Counted,You Don’t Count: Estimating the Number of African-American Men Who Have Sex with Men in San Francisco Using a Novel Bayesian Approach

African-American men who have sex with men (AA MSM) have been disproportionately infected with and affected by HIV and other STIs in San Francisco and the USA. The true scope and scale of the HIV epidemic in this population has not been quantified, in part because the size of this population remains unknown. We used the successive sampling population size estimation (SS-PSE) method, a new Bayesian approach to population size estimation that incorporates network size data routinely collected in respondent-driven sampling (RDS) studies, to estimate the number of AA MSM in San Francisco. This method was applied to data from a 2009 RDS study of AA MSM. An estimate from a separate study of local AA MSM was used to model the prior distribution of the population size. Two-hundred and fifty-six AA MSM were included in the RDS survey. The estimated population size was 4917 (95 % CI 1267–28,771), using a flat prior estimated 1882 (95 % CI 919–2463) as a lower acceptable bound, and a large prior estimated 6762 (95 % CI 1994–13,863) as an acceptable upper bound. Point estimates from the SS-PSE were consistent with estimates from multiplier methods using external data. The SS-PSE method is easily integrated into RDS studies and therefore provides a simple and appealing tool to rapidly produce estimates of the size of key populations otherwise difficult to reach and enumerate.     

采用乘数法结合社交软件估计南京市MSM人群规模

目的 估计南京市MSM规模,为艾滋病疫情估计和防治策略制定提供科学依据.方法 基于乘数法原理结合Blued社交软件,并同时采用现场调查和网络调查对南京市的MSM规模进行估计,通过男同社交软件Blued的后台统计连续7d在南京市范围内登录人数的平均值作为记录数(record,r),通过网络和现场调查了解MSM同时期内登录...     

Titer measurement of HIV-1 envelope trimeric glycoprotein in cell culture media by a new tandem ion exchange and size exclusion chromatography (IEC-SEC) method

An efficient and specific liquid chromatography (LC)-based assay was developed to monitor the production of recombinant HIV-1 trimeric envelope glycoprotein (HIV Env trimer), a candidate vaccine for HIV-1 infection, in cell culture media to support scale-up process development. In this method, titer measurement was achieved by coupling a weak anion exchange chromatography (IEC) column with a size exclusion chromatography (SEC) column. This assay was specific, accurate, precise, and has been qualified for its intended purpose, with a limit of quantification (LOQ) of 10 µg/mL. This tandem separation strategy offered a reliable and timely analytical support to directly monitor the titer of HIV Env trimer during cell growth, without any extra sample purification steps.     

Optimal distribution of medical backpacks and health surveillance assistants in Malawi

Despite recent progress, Malawi continues to perform poorly on key health indicators such as child mortality and life expectancy. These problems are exacerbated by a severe lack of access to health care. Health Surveillance Assistants (HSAs) help bridge this gap by providing community-level access to basic health care services. However, the success of these HSAs is limited by a lack of supplies and long distances between HSAs and patients. To address this issue, we used large-scale weighted p-median and capacitated facility location problems to create a scalable, three-tiered plan for optimal allocation of HSAs, HSA designated medical backpacks, and backpack resupply centers. Our analysis uses real data on the location and characteristics of hospitals, health centers, and the general population. In addition to offering specific recommendations for HSA, backpack, and resupply center locations, it provides general insights into the scope of the proposed HSA backpack program scale-up. In particular, it demonstrates the importance of local health centers to the resupply network. The proposed assignments are robust to changes in the underlying population structure, and could significantly improve access to medical supplies for both HSAs and patients.     

Random vs. Nonrandom Mixing in Network Epidemic Models

In this paper we compare random and nonrandom mixing patterns for network epidemic models. Several of studies have examined the impact of different mixing patterns using compartmental epidemic models. We extend the work on compartmental models to the case of network epidemic models. We define two nonrandom mixing patterns for a network epidemic model and investigate the impact that these mixing patterns have on a number of epidemic outcomes when compared to random mixing. We find that different mixing assumptions lead to small but statistically significant differences in disease prevalence, cumulative number of new infections, final population size, and network structure. Significant differences in outcomes were more likely to be observed for larger populations and longer time horizons. Sensitivity analysis revealed that greater differences in outcomes between random and nonrandom mixing were associated with a larger incremental mortality rate among infected individuals, a larger average number of partners, and a greater probability of forming new partnerships. When adjusted for the initial population size, differences between random and nonrandom mixing models were approximately constant across all population sizes considered. We also considered the impact that differences between mixing models might have on the cost effectiveness ratio for epidemic control interventions.