Document Type
Article
Date of Original Version
2024
Department
Pharmacy Practice and Clinical Research
Abstract
We sought to disentangle effects of the components of a peer-education intervention on self-reported injection risk behaviors among people who inject drugs (n = 560) in Philadelphia, US. We examined 226 egocentric groups/networks randomized to receive (or not) the intervention. Peer-education training consisted of two components delivered to the intervention network index individual only: (1) an initial training and (2) “booster” training sessions during 6- and 12-month follow up visits. In this secondary data analysis, using inverse-probability-weighted log-binomial mixed effects models, we estimated the effects of the components of the network-level peer-education intervention upon subsequent risk behaviors. This included contrasting outcome rates if a participant is a network member [non-index] under the network exposure versus under the network control condition (i.e., spillover effects). We found that compared to control networks, among intervention networks, the overall rates of injection risk behaviors were lower in both those recently exposed (i.e., at the prior visit) to a booster (rate ratio [95% confidence interval]: 0.61 [0.46–0.82]) and those not recently exposed to it (0.81 [0.67–0.98]). Only the boosters had statistically significant spillover effects (e.g., 0.59 [0.41–0.86] for recent exposure). Thus, both intervention components reduced injection risk behaviors with evidence of spillover effects for the boosters. Spillover should be assessed for an intervention that has an observable behavioral measure. Efforts to fully understand the impact of peer education should include routine evaluation of spillover effects. To maximize impact, boosters can be provided along with strategies to recruit especially committed peer educators and to increase attendance at trainings.
Publication Title, e.g., Journal
AIDS and Behavior
Volume
28
Citation/Publisher Attribution
Hernández-Ramírez, R.U., Spiegelman, D., Lok, J.J. et al. Overall, Direct, Spillover, and Composite Effects of Components of a Peer-Driven Intervention Package on Injection Risk Behavior Among People Who Inject Drugs in the HPTN 037 Study. AIDS Behav 28, 225–237 (2024). https://doi.org/10.1007/s10461-023-04213-x
Available at: https://doi.org/10.1007/s10461-023-04213-x
Title Page
Buchanan_OverallDirectSpillover_2024_SuppInfo.docx (230 kB)
Supplementary Information
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