Abstract
Peer-driven interventions can be effective in reducing HIV injection risk behaviors among people who inject drugs (PWID). We employed a causal mediation framework to examine the mediating role of recall of intervention knowledge in the relationship between a peer-driven intervention and subsequent self-reported HIV injection-related risk behavior among PWID in the HIV Prevention Trials Network (HPTN) 037 study. For each intervention network, the index participant received training at baseline to become a peer educator, while non-index participants and all participants in the control networks received only HIV testing and counseling; recall of intervention knowledge was measured at the 6-month visit for each participant, and each participant was followed to ascertain HIV injection-related risk behaviors at the 12-month visit. We used inverse probability weighting to fit marginal structural models to estimate the total effect (TE) and controlled direct effect (CDE) of the intervention on the outcome. The proportion eliminated (PE) by intervening to remove mediation by the recall of intervention knowledge was computed. There were 385 participants (47% in intervention networks) included in the analysis. The TE and CDE risk ratios for the intervention were 0.47 [95% confidence interval (CI): 0.28, 0.78] and 0.73 (95% CI: 0.26, 2.06) and the PE was 49%. Compared to participants in the control networks, the peer-driven intervention reduced the risk of HIV injection-related risk behavior by 53%. The mediating role of recall of intervention knowledge accounted for less than 50% of the total effect of the intervention, suggesting that other potential causal pathways between the intervention and the outcome, such as motivation and skill, self-efficacy, social norms and behavior modeling, should be considered in future studies.
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Data Availability
The HPTN 037 study data sets are publicly available and can be requested from the Statistical Center for HIV/AIDS Research and Prevention through the ATLAS Science Portal through https://atlas.scharp.org/cpas/project/HPTN/.
Code Availability
Not applicable.
Abbreviations
- CI:
-
Confidence interval
- TE:
-
Total effect
- CDE:
-
Controlled direct effect
- PE:
-
Proportion eliminated
- IPTW:
-
Inverse-probability-of-treatment weight
- IPMW:
-
Inverse-probability-of-mediator weight
- GEEs:
-
Generalized estimating equations
- HPTN:
-
HIV Prevention Trials Network
- HIV:
-
Human Immunodeficiency Virus
- PWID:
-
People who inject drugs
- RR:
-
Risk ratio
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Acknowledgements
We thank Dr. Carl Latkin for providing access to the HPTN 037 data.
Funding
Drs. Ashley Buchanan, Natallia Katenka, M. Elizabeth Halloran and TingFang Lee were supported by the National Institute on Drug Abuse (NIDA) Avenir Award Number DP2DA046856 of the National Institutes of Health. Dr. Hilary Aroke is supported by a NIDA Diversity Supplement Grant (DP2 DA046856). Dr. M. Elizabeth Halloran was also supported by NIH grant number R01 AI085073; Dr. Forrest W. Crawford by NIDA Award Number 1DP2HD091799-01, and Dr. Carl Latkin was supported by grant number R01DA050470. The content of this article is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
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Conception and design: HA, AB, NK, FC. Data Analysis: HA, TL. Data interpretation: All. Manuscript writing: All. Manuscript revisions and approval of final article: All.
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Aroke, H., Buchanan, A., Katenka, N. et al. Evaluating the Mediating Role of Recall of Intervention Knowledge in the Relationship Between a Peer-Driven Intervention and HIV Risk Behaviors Among People Who Inject Drugs. AIDS Behav 27, 578–590 (2023). https://doi.org/10.1007/s10461-022-03792-5
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DOI: https://doi.org/10.1007/s10461-022-03792-5