Sizes Estimation Of High Risk Populations For HIV/AIDS Using Network Scale-up Method In Xinyu City, Jiangxi Province

Objective:To estimate the social network sizes in general population and the sizes of high risk populations for HIV/AIDS of xinyu city, jiangxi province, using the network scale-up method(NSUM) and explore the feasibility of application of network scale-up method for HIV/AIDS in China.Methods:All participants were selected by multistage sampling randomly between October2013and February2014. A face-to-face questionnaire survey was conducted to estimate the number of personal social network in the general population in Xinyu city through the network scale-up method (NSUM).The average social network sizes (c value) were estimated, and the c value was adjusted by proportion of demographic characteristics, back estimation and outlier elimination. Using the adjusted c value, the number of acquaintance of high risk populations were used to estimate the sizes of high risk populations.Results:A total of1382questionnaires were completed and1325were effective with the95.88%effective rate.464were from Fenyi Country and861from Yushui district. Of all respondents, there were683(51.55%) male and642(48.45%) female with a male-female ratio of1.06:1. The average age is35.65±17.04and most individuals reported a degree of education of over junior high school. The majority of respondents was married and had lived in current region over3years. Mean size of social network of Xinyu resident is697. There were different size of social network among different counties (P<0.05), register (P<0.05), gender (P<0.05) and age group (P<0.05), and the difference is significant.Through NSUM, the estimated Xinyu FSWs size is2564(95%CI:2453～2676), clients size is3030(95%CI:2909～3151), drug user size is2017(95%CI:1918～42117), injection drug user size is1576(95%CI:1488-1663), MSM size is1329(95%CI:1249～1409) and multi-partner group size is4958(95%CI:4802～5113). The size of injection drug user is78.14%of drug user size with an clients/FS Ws ratio of1.18:1. The estimated number of FSWs accounts for0.88%of Xinyu female inhabitants aged15to49, and the size of MSM makes up for0.39%of Xinyu male inhabitants aged15to49. It is evaluated1.44%of all Xinyu inhabitants aged15to49have multi-partner.Conclusions:NSUM can be used to estimate size of one or more high risk groups economically, quickly and easily. But the results may be influenced by several factors, such as selection of given population, natural propagation effect, barrier effect and estimation effect. Results with regard to clients and MSM that show high mobility were lower than traditional methods. For those drug user groups whose propagation effect could be magnified by criminal act, estimated results were higher than number registered in public security bureau, especially for injection drug users. This research adjusted survey region practical situation and draw lessons from both domestic and international experience. Our study provides helpful suggestion and foundation for future research.