Drug Abuse Research Unit

Study Name : A phase III randomized study to evaluate the efficacy of a network-oriented peer education intervention for the prevention of HIV transmission among injection drug users and their network members
A Study of the HIV Prevention Trials Network
Final Version 2.0 October 23, 2003

Research network (Code) : HPTN 037

Protocol Chair :
Carl Latkin, PhD
Johns Hopkins University
Johns Hopkins Bloomberg School of Public Health
Baltimore, MD USA

Protocol Co-chairs :
David D. Celentano, DSc
Johns Hopkins University
Johns Hopkins Bloomberg School of Public Health
Baltimore, MD USA
David Metzger, PhD
University of Pennsylvania
Center for Studies of Addiction Philadelphia, PA USA

Thailand Site Investigators :
Thira Sirisanthana, MD 
Professor, Department of Medicine
Faculty of Medicine
Director, Research Institute for Health Sciences

Jaroon Jittiwutikarn, MD
The Northern Drug Treatment Center
Department of Medical Services
Ministry of Public Health
Ampur Mae Tang
Chiang Mai Thailand

Apinun Aramrattna, MD, PhD
Assistant Professor
Department of Family Medicine
Faculty of Medicine
Chiang Mai University
Chiang Mai Thailand

Namtip Srirak, RN, PhD
Senior Researcher, Research Institute for Health Sciences, Chiang Mai University

Tasanai Vongchak, RN, MPH
Researcher , Research Institute for Health Sciences, Chiang Mai University

Johns Hopkins University :
Susan Sherman, MPH, PhD
Vu Minh Quan, MD

Philadelphia Site Representatives
Annet Davis-Vogel, RN, MSW
Valerie Simpson, Community Representative, University of Pennsylvania, Philadelphia

Collaborators :
Johns Hopkins Bloomberg School of Public Health, Baltimore, MD USA
University of Pennsylvania, Philadelphia
Research Institute for Health Sciences, Chiang Mai University
Family Health International
The Statistical Center for HIV/AIDS Research & Prevention

Sponsored by :
U.S National Institute of Allergy and Infectious Diseases and
U.S. National Institute of Child Health and Human Development
U.S. National Institute on Drug Abuse
U.S. National Institute of Mental Health
U.S. National Institutes of Health 

Design :
Phase III, multi-site, two-arm, randomized controlled study

Study Population :
HIV-uninfected injection drug users (index participants) and individuals identified
 by each index participant as members of his/her sex and/or drug using networks (network members) in Philadelphia, Pennsylvania, USA and Chiang Mai and Chiang Rai, Thailand

Study Size :
900 networks (300 in Philadelphia, 600 in Thailand) consisting of 900 index participants and approximately 1,350 HIV-uninfected network members (an average of 1.5 per index), for a total of approximately 2,250 HIV-uninfected participants. Allowing for the enrollment of HIV-infected network members and assuming an HIV prevalence of 20% in Philadelphia and 30% in Thailand, approximately 90 and 270 HIV-infected network members will be enrolled in Philadelphia and Thailand, respectively. The average network size across networks, including both HIV-positive and negative network members, is 1.9 network members per index participant, giving a total sample size of 2,610.

Intervention :
Index participants will be randomized in a 1:1 ratio with their network members to
one of two study arms as shown below

Manual for training : 
English Version   www.hptn.org/research_studies/HPTN037InterventionManual.asp
Thai Version  Download
Study Duration :
Approximately 48 months total. Enrollment will require approximately 35 months.
Participants will be followed for a minimum of 12 months and a maximum of 30  months.  : 30 March 2004 – December 2006

Primary Objective :
To determine whether the peer-educator intervention reduces the rate of HIV infection among injection drug users and members of their HIV risk network

Secondary Objectives :
1. To determine whether the intervention reduces reported injection and sexual
    HIV risk behaviors in index participants and/or network members
2. To determine whether the intervention changes substance use network norms
    for injection and sexual HIV risk practices
3. To determine whether the intervention effects on injection and sexual HIV risk
    behaviors differ between index and network participants, or by HIV status in
    each study arm
4. To determine whether the intervention effect on behaviors identified as
    important mediators of the intervention is similar at both sites

Study Sites :
Approximately 2/3 of the participants will be enrolled in Chiang Mai and Chiang Rai,
Thailand with the remaining participants enrolled in Philadelphia, Pennsylvania, USA

Result : 
This HIV Prevention Trials Network study assessed the efficacy of a network-oriented peer education  intervention promoting HIV risk reduction among injection drug users and their drug and sexual network members in Chiang Mai, Thailand and Philadelphia, USA. The study was designed to test impact on HIV infection, but the infection rate was low and the study was terminated early. This paper reports
efficacy on outcomes of self-reported HIV risk behaviors. We enrolled 414 networks with 1,123 participants.

The experimental intervention consisted of six small group peer educator training sessions and two booster sessions delivered to the network index only. All participants in both arms received individual HIV counseling and testing. Follow-up visits occurred every six months for up to 30 months. There were 10  participants with HIV seroconversion, 5 in each arm. The number of participants reporting injection risk behaviors dropped dramatically between baseline and follow-up in both arms at both sites. Index members in the intervention arm engaged in more conversations about HIV risk following the intervention compared to control indexes.

There was no evidence of change in sexual risk as a result of the intervention. Reductions in injection risk behaviors were observed : 37%, 20%, and 26% reduction in odds of sharing cottons, rinse water and cookers, respectively, and 24% reduction in using a syringe after someone else. Analysis of the individual sites suggested a pattern of reductions in injection risk behaviors in the Philadelphia site. In both sites, the intervention resulted in index injection drug users engaging in the community role of discussing reduction in HIV injection risk behaviors. The intervention did not result in overall reductions in self-reported sexual risk behaviors, and although reductions in injection risk behaviors were observed, the overall efficacy in reducing risk was not established.

Publications :

1.Vongchak Tassanai  , Kawichai Surinda , Sherman Susan , Celentano David D., Sirisanthana Thira, Latkin Carl , Wiboonnatakul Kanokporn  , Srirak Namtip, Jittiwutikarn Jaroon, Aramrattana  Apinun (2005). The influence of Thailand’s 2003 ‘war on drugs’ policy on self-reported drug use among injection drug users in Chiang Mai, Thailand. International Journal of Drug Policy 16 (2005) 115–121.
http://www.ijdp.org/article/S0955-3959(04)00132-X/abstract

2.Latkin CA, Donnell D, Metzger D, Sherman S, Aramrattna A, Davis-Vogel A, Quan VM, Gandham S, Vongchak T, Perdue T, Celentano DD. (2009) The efficacy of a network intervention to reduce HIV risk behaviors among drug users and risk partners in Chiang Mai, Thailand and Philadelphia, USA . Social Science & Medicine, 68 (4):740-748. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19070413

3.Latkin C, Donnell D, Celentano DD, Aramrattna A, Liu TY, Vongchak T, Wiboonnatakul K, Davis-Vogel A, Metzger D. (2009) Relationships between social norms, social network characteristics, and HIV risk behaviors in Thailand and the United States. Health Psychology 28 (3):323 329. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19450038