Shared Decision-Making Aids Choice of PrEP

Neil Osterweil

October 28, 2020

A patient-centered approach can help guide people at risk for HIV exposure to decide on the best choice of pre-exposure prophylaxis (PrEP) regimens for them, stifling the noise generated by direct-to-consumer advertising, an infectious disease specialist recommends.

The decision for patients whether to start or remain on the PrEP combination of tenofovir disoproxil fumarate (TDF) plus emtricitabine (FTC; Truvada and generic) or on tenofovir alafenamide (TAF) plus FTC (Descovy) is made more fraught by confusion regarding the use of the newer and allegedly safer TAF prodrug of tenofovir in HIV treatment regimens, said Oni Blackstock, MD, founder and executive director of Health Justice and an attending physician in the division of infectious diseases at Harlem Hospital, New York City.

"There have been commercials on TV as well as on social media around class-action lawsuits against [Truvada maker] Gilead," she said in an online presentation during IDWeek 2020, an annual scientific meeting on infectious diseases, held virtually this year.

"These lawsuits focus on TDF for HIV treatment, but they have sown a great deal of confusion about TDF versus TAF for PrEP among potential and actual PrEP users," she added.

Blackstock described her approach to shared decision-making regarding TDF/FTC versus TAF/FTC, and to helping patients understand the relative benefits and risks of each formulation.

In January 2020, Blackstock, who was then assistant commissioner of the HIV bureau of the New York City Department of Health and Mental Hygiene, issued with other Bureau members a "dear colleague" letter stating why they believed that TDF/FTC should remain the first-line regimen for PrEP.

That opinion, she said, was bolstered by an editorial published in February 2020 by Douglas E. Krakower, MD, from Beth Israel Deaconess Medical Center in Boston, and colleagues, which questioned the rush to shift from TDF to TAF in HIV treatment, and cautioned against the same approach to PrEP.

"Despite evidence that TAF/FTC would not be cost-effective, compared with generic TDF/FTC , the newer regimen quickly and irrevocably displaced TDF/FTC for HIV treatment in the US. A similar shift for PrEP — especially for populations in which TAF/FTC is untested — would be premature, costly, and counterproductive for population impact," Krakower et al wrote.

Shared Decision-Making

Clinicians can help patients who may be a candidate for either PrEP regimen by engaging them in shared decision-making.

"The clinician provides information in this case about a prevention strategy, options, benefits and risks, alternatives, and the patient provides their preferences and values, and together the clinician and patient make a decision," Blackstock said.

The process differs from the model of informed decision-making, where the clinician gives the patient the information and the patient comes to a decision, or the old, "paternalistic" model in which the clinician gives information and makes recommendations to the patient.

"Shared decision-making has been studied extensively and has been shown to improve patient satisfaction, patient communication, and also potentially reducing health inequities that we see," she said.

The model for shared decision-making for clinical practice includes three distinct portions: a choice talk, option talk, and decision talk.


To begin the discussion, the physician informs the patients of the availability of choices and justifies them, saying, for example, "there is good information about how these two PrEP options differ that I'd like to discuss with you," and "the two PrEP options have different side effects...some will matter more to you than other people."

At this stage the clinician should defer closure by offering a more detailed discussion of the choices.


Here the clinician solicits information about what the patient has heard or read about PrEP, describes each option in practical terms, and points out where the two regimens differ, being specific about the pros and cons of each (for example, potential bone mineral density loss or renal complications with TDF, and potential weight gain with subsequent metabolic and cardiovascular consequences with TAF).

The TDF versus TAF-based PrEP discussion could also focus on what's known about the comparative effectiveness of each regimen.

For example, TDF/FTC has been shown to be about 99% effective at preventing infection in men who have sex with men and in transgender women, also about 99% effective in heterosexual women and men, and 74%-84% effective in persons who inject drugs.

In contrast, TAF/FTC has been shown to be about 99% effective in men who have sex with men and transgender women, but it's efficacy in the other two categories is unknown, Blackstock said.

The option discussion should include a comparison of the evidence base for each regimen, including the real-world experience with TDF/FTC since 2012, and much more limited experience with TAF/FTC.

Discussing relative costs, although the wholesale costs of the regimens are similar, there is now a generic version of TDF/FTC made by Teva Pharmaceuticals that sells for about $400 less per month than the brand name, which might make the option more acceptable to health insurers.


The decision talk is about considering the patients preferences and deciding with them what is best.

The clinician could say, for example: "What, from your point of view, matters most to you?"

The clinician should also be willing to allow the patient to defer a decision or to guide them depending on their stated wish, asking something like: "Are you ready to decide, or do you want more time? Do you have more questions? Are there more things we should discuss?"

Offering the patient a chance to review the decision can also be a good way to arrive at closure, Blackstock said.

Robert Goldstein, MD, PhD, an infectious disease specialist and medical director of the transgender health program at Massachusetts General Hospital in Boston, who comoderated the session where Blackstock presented her talk, said that he also uses a similar approach to the PrEP discussion.

"I use a very patient-centered approach of providing information and talking through the data that are available," he said.

"I will say that, as patients come to me talking about the transition from TDF to TAF for pre-exposure prophylaxis, I am very clear with them about the limited benefit or no benefit that I see with TAF for pre-exposure prophylaxis, and all of my patients have remained on TDF for pre-exposure prophylaxis," he added.

No funding source for the presentation was reported. Blackstock and Goldstein reported having no conflicts of interest to disclose.

IDWeek 2020: Shared Decision-Making With Patients About PrEP Options. Presented October 22, 2020.

This article originally appeared on, part of the Medscape Professional Network.


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