# Using Coincidence Analysis to Investigate Factors Affecting PrEP Initiation and Continuation in Southern ending the Epidemic Counties

> **NIH NIH P30** · YALE UNIVERSITY · 2022 · $364,081

## Abstract

Project Summary
Since 2012, pre-exposure prophylaxis (PrEP), typically delivered as a daily pill or more recently as a bimonthly
injection, has been available as a method of HIV prevention. Despite PrEP being highly effective at reducing a
person’s risk of acquiring HIV, uptake of the prevention method has been low – especially in the Southern US,
which is already disproportionately impacted by HIV. In this study we will examine existing programs
implementing PrEP and assess which implementation strategies and contextual factors lead to the best rates
of PrEP initiation and persistence; these findings will contribute to improving PrEP delivery and the ongoing
Ending the HIV Epidemic efforts in the south. The study contains two aims: Aim 1) Identify the implementation
strategies and contextual factors affecting PrEP implementation within clinical and community-based
organizations in southern EHE counties and Aim 2) Determine the combination(s) of implementation strategies
and contextual factors that produce the most effective delivery of PrEP to populations at greatest risk of HIV
acquisition. To achieve Aim 1 we will collect and summarize data through three phases. In Phase 1 we will
request aggregate data from organizations that conduct HIV prevention and PrEP-related activities in
Hillsborough, Pinellas, Tarrant, and Dallas Counties to measure the study outcomes (i.e., the proportions of
eligible individuals who start PrEP and who have maintained PrEP use over 3-month and 6-month periods) and
identify preliminary variation in the implementation strategies and site-level contextual factors that may affect
PrEP implementation. In Phase 2 we will conduct quantitative surveys with staff members at a subset of sites
to assess the impact of CFIR factors and presence or absence of implementation strategies on PrEP
implementation outcomes. In Phase 3 we will complete semi-structured interviews to gain a more detailed and
nuanced understanding of implementation strategies, contextual factors and within-site variation from Phase 2
responses. To achieve Aim 2 we will conduct Coincidence Analysis (CNA) to determine the sets of
implementation strategies and contextual factors leading to high proportions of eligible individuals who both
start and maintain PrEP (i.e., optimized implementation). CNA is a method of causal inference and determines
the combinations of factors that are minimally necessary or sufficient for an outcome of interest. In this
application we will examine which combinations of contextual factors and implementation strategies result in
optimized PrEP implementation. The models will be run for three outcomes based on the following: proportion
of clients who initiate PrEP; and proportion of clients continuing PrEP use after 3 and 6 months, each of which
will either be dichotomized (high vs. low) or trichotomized (high, medium, low). Additional factors, representing
differences in client populations (e.g., MSM, women, youth) will be included...

## Key facts

- **NIH application ID:** 10601235
- **Project number:** 3P30MH062294-20S3
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** Trace S Kershaw
- **Activity code:** P30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $364,081
- **Award type:** 3
- **Project period:** 2001-09-30 → 2023-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10601235

## Citation

> US National Institutes of Health, RePORTER application 10601235, Using Coincidence Analysis to Investigate Factors Affecting PrEP Initiation and Continuation in Southern ending the Epidemic Counties (3P30MH062294-20S3). Retrieved via AI Analytics 2026-06-14 from https://api.ai-analytics.org/grant/nih/10601235. Licensed CC0.

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