Geographical variations in risk factors associated with HIV infection among drug users in a prefecture in Southwest China.
BACKGROUND
Previous studies have shown inconsistent or even contradictory results for some risk factors associated with HIV infection among drug users, and these may be partially explained by geographical variations.


METHODS
Data were collected from 11 methadone clinics in the Liangshan Yi Autonomous Prefecture from 2004 to 2012. A non-spatial logistical regression model and a geographically weighted logistic regression model were fitted to analyze the association between HIV infection and specific factors at the individual level.


RESULTS
This study enrolled 6,458 patients. The prevalence of HIV infection was 25.1 %. The non-spatial model indicated that being divorced was positively associated with HIV infection. The spatial model also showed that being divorced was positively associated with HIV infection, but only for 49.4 % of individuals residing in some northern counties. The non-spatial model suggested that service sector work was negatively associated with HIV infection. However, the spatial model indicated that service work was associated with HIV infection, but only for 23.0 % of patients living in some western counties. The non-spatial model did not show that being married was associated with HIV infection in our study field, but the spatial model indicated that being married was negatively associated with HIV infection for 12.0 % of individuals living in some western counties. For other factors, the non-spatial and spatial models showed similar results.


CONCLUSIONS
The spatial model may be useful for improving understanding of geographical heterogeneity in the relationship between HIV infection and individual factors. Spatial heterogeneity may be useful for tailoring intervention strategies for local regions, which can consequently result in a more efficient allocation of limited resources toward the control of HIV transmission.
Department of Epidemiology, School of Public Health, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, China. ybzhou@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China. ybzhou@fudan.edu.cn.|Center for Tropical Disease Research, Fudan University, Shanghai, China. ybzhou@fudan.edu.cn.
Yi-Biao
YB
Zhou
Center for Disease Prevention and Control of the Liangshan Yi Autonomous Prefecture, Sichuan, China. qxw2008@sina.com.
Qi-Xing
QX
Wang
Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA. songliang@ufl.edu.|Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA. songliang@ufl.edu.
Song
S
Liang
Center for Disease Prevention and Control of the Liangshan Yi Autonomous Prefecture, Sichuan, China. xc0082@163.com.
Yu-Han
YH
Gong
Xuhui Center for Disease Prevention and Control, Shanghai, China. ymeixia@sina.com.
Mei-Xiao
MX
Yang
School of Epidemiology, Public Health and Preventive Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada. Yue.Chen@uottawa.ca.
Yue
Y
Chen
Department of Epidemiology, School of Public Health, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, China. 11211020008@fudan.edu.cn.
Shi-Jiao
SJ
Nie
Center for Disease Prevention and Control of the Liangshan Yi Autonomous Prefecture, Sichuan, China. nl67nn1113@163.com.
Lei
L
Nan
Department of Epidemiology, School of Public Health, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, China. 10211020082@fudan.edu.cn.
Ai-Hui
AH
Yang
Center for Disease Prevention and Control of the Liangshan Yi Autonomous Prefecture, Sichuan, China. liaoqiang411@163.com.
Qiang
Q
Liao
Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA. yangyang@phhp.ufl.edu.|Department of Biostatistics, University of Florida, Gainesville, FL, USA. yangyang@phhp.ufl.edu.
Yang
Y
Yang
Department of Epidemiology, School of Public Health, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, China. xxsong@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China. xxsong@fudan.edu.cn.|Center for Tropical Disease Research, Fudan University, Shanghai, China. xxsong@fudan.edu.cn.
Xiu-Xia
XX
Song
Department of Epidemiology, School of Public Health, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, China. jiangqw@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Shanghai, China. jiangqw@fudan.edu.cn.|Center for Tropical Disease Research, Fudan University, Shanghai, China. jiangqw@fudan.edu.cn.
Qing-Wu
QW
Jiang
D002681:China / Q000453:epidemiology; D055030:Drug Users; D005260:Female; D062306:Geography, Medical; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D008297:Male; D015233:Models, Statistical; D015995:Prevalence; D012307:Risk Factors