Giving preventive drug to men at high risk for HIV would be cost-effective, study shows

April 16, 2012, Stanford University Medical Center

A once-a-day pill to help prevent HIV infection could significantly reduce the spread of AIDS, but only makes economic sense if used in select, high-risk groups, Stanford University researchers conclude in a new study.

The researchers looked at the of the tenofovir-emtricitabine, which was found in a landmark 2010 trial to reduce an individual's risk of HIV infection by 44 percent when taken daily. Patients who were particularly faithful about taking the reduced their risk to an even greater — by 73 percent.

The results generated so much interest that the Stanford researchers decided to see if it would be cost-effective to prescribe the pill daily in large populations, a prevention technique known as pre-exposure prophylaxis, or PrEP. They created an economic model focused on men who have sex with other men, or MSM, as they account for more than half of the estimated 56,000 new infections annually in the United States, according to the Centers for Disease Control and Prevention.

"Promoting PrEP to all men who have sex with men could be prohibitively expensive," said Jessie Juusola, a PhD candidate in management science and engineering in the School of Engineering and first author of the study. "Adopting it for men who have sex with men at high risk of acquiring HIV, however, is an investment with good value that does not break the bank."

For instance, using the pill in the general MSM population would cost $495 billion over 20 years, compared to $85 billion when targeted to those at particularly high risk, the researchers found. The study will be published in the April 17 issue of the Annals of Internal Medicine.

Senior author Eran Bendavid, MD, assistant professor of medicine in the School of Medicine, said the results are a departure from a previous study, which found PrEP was not cost-effective when compared with other commonly accepted prevention programs. The new Stanford study differs in a few important respects, taking into consideration the decline in transmission rates over time as more individuals take the pill. The Stanford team also assumed individuals would stop taking PrEP after 20 years, not stay on the drug for life, as the previous study had assumed.

The pill combination, marketed under the brand name Truvada, is widely used for treating . But it wasn't until a landmark trial, published in the New England Journal of Medicine in November 2010, that individuals and their doctors began to seriously consider using the drug as a preventive therapy. The drug's maker, Foster City, Calif.-based Gilead Sciences Inc., has filed a supplemental new drug application to market it for prevention purposes.

The CDC issued interim guidelines on the drug's use in January 2011, suggesting that if practitioners prescribe it as a preventive measure, they regularly monitor patients for side effects and counsel them about adherence, condom use and other methods to reduce their risk of infection.

In developing their model, the Stanford researchers took into account the cost of the drug — about $26 a day, or almost $10,000 a year — as well as the expenses for physician visits, periodic monitoring of kidney function affected by the drug, and regular testing for HIV and sexually transmitted diseases.

"We're talking about giving uninfected people a drug that has some toxicities, so it's crucial to have them monitored regularly," Bendavid said, who is also an affiliate of Stanford Health Policy, part of the Freeman Spogli Institute for International Studies.

Without PrEP, the researchers calculated there would be more than 490,000 new infections among the MSM population in the United States in the next 20 years. If just 20 percent of these men took the pill daily, there would be nearly 63,000 fewer infections.

However, the costs are substantial. Use of the drug by 20 percent of the MSM population would cost $98 billion over 20 years; if every man in this group took PrEP for 20 years, the costs would be a staggering $495 billion.

Given these figures, the researchers looked at the option of giving PrEP only to men who are at high risk — those who have five or more sexual partners in a year. If just 20 percent of these high-risk individuals took the drug, 41,000 new infections would be prevented over 20 years at a cost of about $16.6 billion.

At less than $50,000 per quality-adjusted life year gained (a measure of how long people live and their quality of life), that strategy represents relatively good value, according to Juusola.

"However, even though it provides good value, it is still very expensive," she said. "In the current health-care climate, PrEP's costs may become prohibitive, especially given the other competing priorities for resources, such as providing treatment for infected individuals."

She said the costs could be significantly reduced if the pill is found to be effective when used intermittently, rather than on a daily basis. Current trials are examining the effectiveness of the drug when used less often.

Explore further: Researchers suggest unconventional approach to control HIV epidemics

Related Stories

Researchers suggest unconventional approach to control HIV epidemics

December 7, 2011
(Medical Xpress) -- A new weapon has emerged to prevent HIV infection. Called pre-exposure prophylaxis, or PrEP, it is a strategy of providing medications to at-risk people before they are exposed to the virus. Having shown ...

When prophecy fails: How to better predict success in HIV prevention clinical trials

December 7, 2011
New research from the University of North Carolina at Chapel Hill schools of medicine and pharmacy may help explain the failure of some recent clinical trials of prevention of HIV infection, compared to the success of others ...

Pivotal study in Africa finds that HIV medications prevent HIV infection

July 13, 2011
In a result that will fundamentally change approaches to HIV prevention in Africa, an international study has demonstrated that individuals at high risk for HIV infection who took a daily tablet containing an HIV medication ...

Recommended for you

HIV-1 genetic diversity is higher in vaginal tract than in blood during early infection

January 18, 2018
A first-of-its-kind study has found that the genetic diversity of human immunodeficiency virus type 1 (HIV-1) is higher in the vaginal tract than in the blood stream during early infection. This finding, published in PLOS ...

War in Ukraine has escalated HIV spread in the country: study

January 15, 2018
Conflict in Ukraine has increased the risk of HIV outbreaks throughout the country as displaced HIV-infected people move from war-affected regions to areas with higher risk of transmission, according to analysis by scientists.

Researchers offer new model for uncovering true HIV mortality rates in Zambia

January 12, 2018
A new study that seeks to better ascertain HIV mortality rates in Zambia could provide a model for improved national and regional surveillance approaches, and ultimately, more effective HIV treatment strategies.

New drug capsule may allow weekly HIV treatment

January 9, 2018
Researchers at MIT and Brigham and Women's Hospital have developed a capsule that can deliver a week's worth of HIV drugs in a single dose. This advance could make it much easier for patients to adhere to the strict schedule ...

New long-acting, less-toxic HIV drug suppresses virus in humanized mice

January 8, 2018
A team of Yale researchers tested a new chemical compound that suppresses HIV, protects immune cells, and remains effective for weeks with a single dose. In animal experiments, the compound proved to be a promising new candidate ...

Usage remains low for pill that can prevent HIV infection

January 8, 2018
From gritty neighborhoods in New York and Los Angeles to clinics in Kenya and Brazil, health workers are trying to popularize a pill that has proven highly effective in preventing HIV but which—in their view—remains woefully ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.