Study name :
Respondent-Driven Sampling Survey of HIV-related risk behavior and HIV prevalence in injection drug users in Bangkok and Chiang Mai, Thailand
Research network (Code) : RDS
Principle investigator :
– Dr. Kovit Yongvanitjit
– Dr. Apinun Aramrattana
Co-PI :
– Tasanai Vongchak
Collaborators :
– Ministry of Public Health, Government of Thailand, Nonthaburi, Thailand
Bangkok Metropolitan Administration, Bangkok, Thailand
– O-zone Drop In Center
– Research Institute for Health Sciences, Chiang Mai, Thailand
– Chiang Mai Provincial Health Office
– Thai-US Collaboration, Nonthaburi, Thailand
Funding agency, Sponsored by :
Thailand MoPH -US CDC Collaboration
Study sites :
Bangkok, using a place of medical unit in Bangkok and Chiang Mai, using a place of Research Institute for Health Sciences
Study design :
The study is a cross-sectional survey of IDUs in two locations in Thailand, Bangkok and Chiang Mai province, using RDS. Survey participants are recruited using RDS. RDS is a type of chain-referral sampling designed to sample hard-to-reach populations. It reduces biases from other chain-referral methods by using a dual system of structured compensations both for being interviewed and for recruiting peers. Based on pre-existing contact, survey staffs recruit a handful of members of the target population who serve as seeds (initial, staff-recruited survey participants) from the target population. Seeds receive a compensation for completing the interview (primary compensation) and another compensation for recruiting their peers to participate in the survey (secondary compensation). The objective of the secondary compensation is to encourage participants to recruit their peers for the next wave of participants. Participants are allowed to recruit only a limited number of their peers, which facilitates lengthy recruitment chains and deeper penetration of the target population network. When a seed selects peers from his or her network and the peers complete an interview, the first wave is complete. Likewise, the participants of the first wave then become recruiters, recruiting their peers for the survey.
Study size :
750 IDUs in Bangkok and 300 IDUs in Chiang Mai
Study Duration : 6 Months
Study start : March – September 2009
Study objectives :
1. To estimate the number of injecting drug users (IDU), and the proportions of in- and out-of -treatment IDUs, in Bangkok and Chiang Mai.
2. To estimate the prevalence of HIV among IDU in Bangkok and Chiang Mai.
3. To assess risk behaviors for HIV acquisition and transmission among IDU in Bangkok and Chiang Mai.
Significance :
Respondent-Driven Sampling Survey of HIV-related risk behavior and HIV
prevalence in injection drug users in Bangkok and Chiang Mai provide a more accurate estimation for estimating model on future HIV infection. This method could also be used in developing the more appropriate health care and prevention among this group of population.
Results :
Overall, 746 IDUs were recruited in Bangkok and 309 in CM. Most were men (83% in both Bangkok and CM); Bangkok participants were older [3% < 25 years (95%CI (CI): 1%-5%)] than those in CM [43% < 25 years (CI:32%-51%)]. Most commonly reported drugs injected in last month included heroin (34% in both Bangkok and CM), methamphetamine (63% in Bangkok; 32% in CM), and midazoiam (42% in Bangkok; 4% in CM ). Needle sharing in the past 6 months was reported by 14% (CI: 10%-18%) in Bangkok and 66% (CI: 57%-74%) in CM, while needle sharing with most recent injection was reported by 5% (CI: 3%-8%) in Bangkok and 48% (CI: 39% – 57%) in CM. HIV prevalence was 24% (CI:20%-30%) in Bangkok and 11% (CI:7%-17%) in CM.
Conclusions :
IDUs continue to practice risky injection behaviors and had high HIV prevalence. Risk behavior prevalence differed significantly by location. Injection of drugs other than heroin was common, indicating need for interventions targeting these behaviors. Proven effective interventions such as needle exchange programs should be considered, and interventions need to be targeted to geographic differences in behaviors.
Publications :
