This article describes a sampling and estimation scheme for estimating the size of an injecting drug user (IDU) population by combining classical sampling and respondent-driven sampling procedures. It is designed to u...This article describes a sampling and estimation scheme for estimating the size of an injecting drug user (IDU) population by combining classical sampling and respondent-driven sampling procedures. It is designed to use the information from harm reduction programs, especially, Needle Exchange Programs (NEPs). The approach involves using respondent-driven sampling design to collect a sample of injecting drug users who appear at site of NEP in a certain period of time and to obtain retrospective self-report data on the number of friends among the IDUs and number of needles exchanged for each sampled injecting drug user. A methodology is developed to estimate the size of injecting drug users who have ever used the NEP during the fixed period of time, and which allows us to estimate the proportion of injecting drug users in using NEP. The size of the IDU population is estimated by dividing the total number of IDUs who using NEPs during the period of time by the estimated proportion of IDUs in the group. The technique holds promise for providing data needed to answer questions such as “What is the size of an IDU population in a city?” and “Is that size changing?” and better understand the dynamics of the IDU population. The methodology described here can also be used to estimate size of other hard-to-reach population by using information from harm reduction programs.展开更多
Recent interest by physicists in social networks and disease transmission factors has prompted debate over the topology of degree distributions in sexual networks. Social network researchers have been critical of “sc...Recent interest by physicists in social networks and disease transmission factors has prompted debate over the topology of degree distributions in sexual networks. Social network researchers have been critical of “scale-free” Barabasi-Albert approaches, and largely rejected the preferential attachment, “rich-get-richer” assumptions that underlie that model. Instead, research on sexual networks has pointed to the importance of homophily and local sexual norms in dictating degree distributions, and thus disease transmission thresholds. Injecting Drug User (IDU) network topologies may differ from the emerging models of sexual networks, however. Degree distribution analysis of a Brooklyn, NY, IDU network indicates a different topology than the spanning tree configurations discussed for sexual networks, instead featuring comparatively short cycles and high concurrency. Our findings suggest that IDU networks do in some ways conform to a “scale-free” topology, and thus may represent “reservoirs” of potential infection despite seemingly low transmission thresholds.展开更多
目的了解美沙酮门诊吸毒人员丙肝病毒(Hepatitis C virus,HCV)感染流行情况及相关因素。方法基于社区美沙酮门诊吸毒人员的基线调查,收集宜昌市572名吸毒人员相关社会因素和HCV检测情况,进行单因素和多因素Logistic回归分析。结果 572...目的了解美沙酮门诊吸毒人员丙肝病毒(Hepatitis C virus,HCV)感染流行情况及相关因素。方法基于社区美沙酮门诊吸毒人员的基线调查,收集宜昌市572名吸毒人员相关社会因素和HCV检测情况,进行单因素和多因素Logistic回归分析。结果 572名吸毒人员中,男446人(78.0%),女126人(22.0%),平均年龄37岁,平均吸毒年限13年,有过注射吸毒史的517人占90.4%,曾经共用过注射器的140人(24.5%);HCV感染情况经过检测,572人中HCV阳性498人,阳性率87.06%。单因素分析结合Logistic回归分析显示:婚姻状况、吸毒年限、是否注射毒品是HCV感染的主要危险因素。结论尽管湖北省吸毒人群HIV感染不高,但HCV感染率很高,两者传播方式有明显差异,应该加强吸毒人群的HCV感染防治。展开更多
文摘This article describes a sampling and estimation scheme for estimating the size of an injecting drug user (IDU) population by combining classical sampling and respondent-driven sampling procedures. It is designed to use the information from harm reduction programs, especially, Needle Exchange Programs (NEPs). The approach involves using respondent-driven sampling design to collect a sample of injecting drug users who appear at site of NEP in a certain period of time and to obtain retrospective self-report data on the number of friends among the IDUs and number of needles exchanged for each sampled injecting drug user. A methodology is developed to estimate the size of injecting drug users who have ever used the NEP during the fixed period of time, and which allows us to estimate the proportion of injecting drug users in using NEP. The size of the IDU population is estimated by dividing the total number of IDUs who using NEPs during the period of time by the estimated proportion of IDUs in the group. The technique holds promise for providing data needed to answer questions such as “What is the size of an IDU population in a city?” and “Is that size changing?” and better understand the dynamics of the IDU population. The methodology described here can also be used to estimate size of other hard-to-reach population by using information from harm reduction programs.
文摘Recent interest by physicists in social networks and disease transmission factors has prompted debate over the topology of degree distributions in sexual networks. Social network researchers have been critical of “scale-free” Barabasi-Albert approaches, and largely rejected the preferential attachment, “rich-get-richer” assumptions that underlie that model. Instead, research on sexual networks has pointed to the importance of homophily and local sexual norms in dictating degree distributions, and thus disease transmission thresholds. Injecting Drug User (IDU) network topologies may differ from the emerging models of sexual networks, however. Degree distribution analysis of a Brooklyn, NY, IDU network indicates a different topology than the spanning tree configurations discussed for sexual networks, instead featuring comparatively short cycles and high concurrency. Our findings suggest that IDU networks do in some ways conform to a “scale-free” topology, and thus may represent “reservoirs” of potential infection despite seemingly low transmission thresholds.
文摘目的了解美沙酮门诊吸毒人员丙肝病毒(Hepatitis C virus,HCV)感染流行情况及相关因素。方法基于社区美沙酮门诊吸毒人员的基线调查,收集宜昌市572名吸毒人员相关社会因素和HCV检测情况,进行单因素和多因素Logistic回归分析。结果 572名吸毒人员中,男446人(78.0%),女126人(22.0%),平均年龄37岁,平均吸毒年限13年,有过注射吸毒史的517人占90.4%,曾经共用过注射器的140人(24.5%);HCV感染情况经过检测,572人中HCV阳性498人,阳性率87.06%。单因素分析结合Logistic回归分析显示:婚姻状况、吸毒年限、是否注射毒品是HCV感染的主要危险因素。结论尽管湖北省吸毒人群HIV感染不高,但HCV感染率很高,两者传播方式有明显差异,应该加强吸毒人群的HCV感染防治。
