Effects of an HIV/AIDS peer prevention intervention on sexual and injecting risk behaviors among...
-
Upload
rosalind-cameron -
Category
Documents
-
view
219 -
download
1
Transcript of Effects of an HIV/AIDS peer prevention intervention on sexual and injecting risk behaviors among...
Effects of an HIV/AIDS peer prevention intervention on sexual and injecting risk behaviors among injecting drug users (IDUs) and their risk partners in Thai Nguyen, Vietnam: a randomized
controlled trial
V.Go, C. Frangakis, N. Le Minh, T. Viet Ha, T. Thi Mo, C. Latkin, T. Sripaipan, W. Davis, P. The Vu, V. Minh Quan
1Johns Hopkins Bloomberg School of Public Health2 Thai Nguyen Center for Preventive Medicine
Background
• Globally, 30% of new HIV infections occur in injecting drug users (IDUs).1
• HIV-related sexual and injecting risks persist among IDUs.
• Peer and network interventions have been shown to be effective at reducing HIV risks among IDUs in different settings.2
1Wodak, 20082 Latkin, 2003; Des Jarlais, 1995; Garfein, 2007; Sherman, 2009; Hammett, 2006
HIV epidemic is concentrated among IDUs in Vietnam
• Reported # of IDUs: 274,0001
• 75% of HIV infections are among IDUs1
• Prevalence of HIV2
General population: 0.04%IDUs: 18%
• Marginalized population
________________________1 The Socialist Republic of Viet Nam , 20102 Ministry of Health of Vietnam, 2008
Trial objective
To assess the efficacy of a behavioral, peer network HIV prevention intervention among IDUs in Vietnam on reducing HIV sexual and injecting risk behaviors.
• Primary outcomes: – sharing injecting equipment – unprotected sex
Study overview
• Two arm randomized controlled trial
• Intervention: prevention messaging delivered via existing risk networks
• Index members: HIV-negative IDU males 18-45 living in Thai Nguyen Province
• Network members: injected drugs and/or had sexual intercourse w/ index in past 3 mos.
Screened at Baseline
N=1434
Intervention
N=465
Participants with a Complete Network Group*
N=924
Control
N=459
*Complete Network Group = 1 Index Member + At least 1 Network Member
Recruitment, randomization & data collection
• Participants recruited by field workers who were current or former IDUs
• Block randomization
• Face-to-face interviews at study site & HIV testing and counseling (HTC) per WHO guidelines at baseline, 3, 6, 9 and 12 months
Intervention• Index
Content: Harm reduction, communication
strategies, and problem solving
Delivery: 2 facilitators leading didactic, interactive
discussions and role-playing
Timing: Two-hour sessions weekly for six weeks;
booster sessions at 3, 6, and 9 months
• Network received intervention content via
their index.
Results
1. Total of 935 participants (index = 419; network = 516)
2. Overall retention rate: 85%
3. Among those who dropped out, main reasons included incarceration and moving out of province.
4. 75% of index participants attended at least 4 out of 6 sessions.
Baseline characteristics of sample (n = 935)
ControlIntervention
Age 32.1 31.9
EducationPrimary 10.1% 10.4%Secondary 42.1% 40.9%High School 47.8% 48.7%
Married 32.2% 33.5%
Full-time employed 58.8% 58.0%
Shared needle 3 mos 24.2% 27.3%Unprotected sex 62.2% 60.9%
Baseline 3 Months 6 Months 9 Months 12 Months0tan28a566028
0tan9a56609
0tan19a566019
0tan29a566029
0tan9a56609
0tan19a566019
0tan29a566029
Needle sharing declined in both arms
ControlIntervention
Study Visit
% W
ho
Sh
ared
Nee
dle
s/S
yrin
ges
Wald Test for Follow-up Visits: W=5.95, p=0.20
Baseline 3 Months 6 Months 9 Months 12 Months0tan28a566028
0tan9a56609
0tan19a566019
0tan29a566029
0tan9a56609
0tan19a566019
0tan29a566029
Unprotected sex decreased significantly more in the intervention arm
ControlIntervention
Study Visit
% W
ho
Had
Un
pro
tect
ed S
ex
Wald Test for Follow-up Visits: W=12.2, p=0.02
Secondary analyses
• Secular trends• Social desirability bias• Contamination• Telescoping• Missing HTC sessions
Exploration of pattern of missed HTC visits and % with unprotected sex.
• Among participants who attended baseline and all 4 follow-up assessment visits, no difference between trial arms.
• Among those who missed interim visits, the control was more likely to report unprotected sex than the intervention (p<0.01).
Summary of intervention effect
• Both arms decreased injecting and sexual risk behaviors after baseline.
• At the 12 month visit, the intervention arm was significantly less likely to have unprotected sex as compared to the control arm.
• By accounting for missed visits, we found that the intervention had a lasting effect on sexual behaviors compared to standard HTC.
Implications
• ProgrammaticPeer network interventions may be effective in
facilitating longer term sexual risk behavior change.
HTC may be sufficient for changing injecting risk behaviors.
• Future ResearchExplore the impact of participating in trial
procedures. Sustainability of effects.
Acknowledgements
Thai Nguyen Center for Preventive Medicine
Funding Fogarty International AIDS Research Program NIMH# 1 R01 MH64895-01
Summary of secondary analysis
• No evidence of selection bias, social desirability, telescoping, secular trends or contamination.
• HTC may have reduced injecting behaviors.
• HTC may have had a short term impact on sexual behaviors, but the intervention had a longer term impact.
In Vietnam, as in many countries, the HIV epidemic is concentrated among IDUs1
• Estimated # of IDUs: 274,0001
• 75% of HIV infections are among IDUs2
• Prevalence of HIV1
General population: 0.04%Sex workers: 3%MSM: 17%IDUs: 18%
________________________1 The Socialist Republic of Viet Nam (2010). The fourth country report on following up the implementation to the declaration of commitment on HIV and AIDS.2 Ministry of Health of Vietnam (2008). The third country report on following up the implementation to thedeclaration of commitment on HIV and AIDS (reporting period: January 2006-December 2007).
Secondary Analyses• Secular trends- no difference by times of
enrollment• Social desirability bias- sero-conversions
explained by self-reported risk behaviors• Contamination- HIV discussions did not
increase in control arm• Telescoping- Among those who missed a visit,
no difference in outcomes prior and after the missed visit.
• Missing HTC sessions
Analyses
• Intention to treat analysis
• Missingness of measures at different visits addressed through multiple imputation
• Secondary analyses conducted to explain findings of primary analyses
Effect (I-C) of intervention on needle sharing
Indexes (n = 417) Effect (I-C), % (se)
1 2 3 4 5 Wald Test (2-5)
0(2) -1(1) 6 (3) 3(2) 3(2) W = 3.74, p = 0.44
Networks (n = 2*417) Effect (I-C), % (se)
1 2 3 4 5 Wald Test (2-5)
5(3) 0(1) 0(1) 4(2) 1(1) W = 5.95, p = 0.20
*Multiple imputations