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. 2025 Jan-Dec:24:23259582251370236.
doi: 10.1177/23259582251370236. Epub 2025 Aug 19.

Lack of Knowledge and Understanding of Undetectable Equals Untransmittable (U = U) Among People Living with HIV in the United States: Results from a Cross-Sectional Survey

Bekana K Tadese  1 , M Janelle Cambron-Mellott  2 , Jean Marie Arduino  1 , Bridget L Balkaran  2 , Shakiba Eslamimehr  2 , José M Zuniga  3
Affiliations

Lack of Knowledge and Understanding of Undetectable Equals Untransmittable (U = U) Among People Living with HIV in the United States: Results from a Cross-Sectional Survey

Bekana K Tadese et al. J Int Assoc Provid AIDS Care. 2025 Jan-Dec.

Abstract

BackgroundLaunched in the United States (US) in 2016, the 'undetectable equals untransmittable' (U = U) message has revolutionized human immunodeficiency virus (HIV) management by affirming that individuals on antiretroviral therapy (ART) with undetectable viral loads (VL) cannot sexually transmit the virus. This study aimed to assess the knowledge and understanding of U = U and factors associated with the lack of understanding among people living with HIV (PLHIV) in the US.MethodsA cross-sectional, online survey was fielded from February to June 2022 in the US to PLHIV aged ≥18 years who were currently taking ART. Data on sociodemographic variables, HIV-related and general health characteristics were collected. The study assessed the knowledge and understanding of U = U and sources of U = U information. Multivariable analyses were used to identify the factors associated with the lack of U = U understanding among PLHIV.ResultsA total of 781 PLHIV completed the study and were included in the analysis. Most participants were <50 years old (67.0%), cisgender males (56.2%), and majority having at least some college education (80.5%). More than half (54.5%) of the participants did not know the meaning of the U = U. Sources of learning about the meaning of 'undetectable' included a healthcare provider (HCP) alone (50.4%), the U = U campaign alone (7.6%), both an HCP and the U = U campaign (14.7%), and sources other than HCPs or the U = U campaign (32.2%); 3.1% of participants reported having never heard the term before. About 12.0% of the participants were unaware of their VL status. After adjusting for covariates, PLHIV who lacked an understanding of U = U were more likely to have a college degree or higher education (OR: 0.6, 95% CI: 0.41-0.86, P = 0.006), recent HIV diagnosis (6 months to <12 months) (OR: 2.06, 95% CI: 1.14-3.77, P = 0.018), suboptimal ART adherence (OR: 2.74, 95% CI: 1.88-4.01, P < 0.001), and lack HCP communication about the importance of an undetectable VL compared to those who understood U = U.ConclusionThe study highlights substantial gaps in understanding U = U among PLHIV and in HCP-patient communication. These findings underscore the need for targeted education for both PLHIV and HCPs, emphasizing the clinical implications and benefits of U = U in relation to HIV prevention.

Keywords: HIV; antiretroviral therapy (ART); patient-provider communication; sexual transmission; undetectable equals untransmittable (U = U); viral load; zero-risk.

Plain language summary

Lack of Knowledge and Understanding of Undetectable Equals Untransmittable (U = U) Among People Living with HIV in The United StatesThe U = U message means that people living with HIV who are on treatment and have undetectable levels of the virus in their blood cannot pass the virus to others through sex. The study shows that many people living with HIV and healthcare providers do not fully understand the U = U message. It highlights the importance of educating both these groups about how U = U can help prevent HIV transmission and improve patient care.

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Conflict of interest statement

Declaration of Conflicting InterestsThe authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: M.J. Cambron-Mellott is an employee of, and B.L. Balkaran, and S. Eslamimehr are former employees of Oracle Life Sciences, Oracle Corporation, which received funding from Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., NJ, USA, to conduct and report on the study. M.J. Cambron-Mellott and B.L. Balkaran own stock in Oracle Corporation. José M. Zuniga received consulting fee from Gilead Sciences (Advisory Board) and Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA (research study). Bekana K. Tadese and Jean Marie Arduino are employees of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA. Jean Marie Arduino owns stock in Merck & Co., Inc., Rahway, NJ, USA.

Figures

Figure 1.
Figure 1.
Flow Chart Showing the Construction of the Study Sample.
Figure 2.
Figure 2.
Patient Source of Information About the Meaning of ‘Undetectable’.
Figure 3.
Figure 3.
HIV Medication Adherence and Understanding of U = U.
Figure 4.
Figure 4.
Multivariable Analysis Showing Factors Associated with a Lack of Understanding of U = U among PLHIV.
See this image and copyright information in PMC

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