Dramatically increasing the frequency of HIV testing among young men who have sex with men (MSM) who are at high risk of contracting the virus would lead to improved individual health, public health and longevity outcomes in this population—and would be a good financial investment.

So found a new study led by Anne Neilan, MD, MPH, an infectious disease specialist at Massachusetts General Hospital’s division of infectious diseases. As Neilan and her colleagues describe in Clinical Infectious Diseases, they relied on data from the Adolescent Medicine Trials Network for HIV/AIDS Interventions to feed into a mathematical model that yielded various projections of the effects of increasing HIV testing frequency among young MSM.

One in five new HIV transmissions occur among young MSM, defined in this study as those between 13 and 24 years old. The majority of young gay and bisexual men living with the virus are unaware of their infection.

The study authors used the mathematical modeling to examine three HIV testing scenarios for this population: testing once a year, every six months or every three months. The model compared these strategies with current testing patterns, i.e., the status quo.

The model took into account published data (factoring in data specific to young MSM when available), including information on annual HIV acquisition rates (which ranged between 0.91 and 6.41 HIV acquisitions per 100 cumulative years of life); acceptance of HIV testing when offered (80% acceptance rate); linkage to medical care for the virus after a diagnosis (76% linkage rate); HIV transmission to other individuals; the monthly cost of antiretroviral treatment ($2,290 to $3,780); and the cost for each HIV test ($38).

The modeling projected that compared with the status quo, all three HIV testing scenarios would increase the median CD4 count of HIV-positive young MSM at the time of diagnosis, from a CD4 count of 296 to a count ranging between 477 and 515. It is considered optimal for people with HIV to begin treatment for the virus when their CD4 count is above 500—a threshold that suggests a robust immune system.

The testing scenarios would increase life expectancy at age 15 from the current additional 44.4 years (meaning a life expectancy of 69.4 years old) to a range of an additional 48.3 to 48.7 years.

Cost-effectiveness analyses of this sort look to a concept called a quality-adjusted life year (QALY). This is a composite of increased life expectancy and increased quality of life. One additional year of life lived in optimal health is equivalent to 1.0 additional QALY. Alternatively, an intervention could, for example, lead to a gain of an additional QALY by improving an individual’s health rating by 50 percentage points (with 100% being optimal health) and adding an additional six months of life.

The investigators found that screening young MSM every three months was cost effective, costing only $4,500 per additional QALY. This is well below the threshold of $100,000, which in the United States is considered the maximum amount of money that could be spent to add one additional QALY and still have the intervention be cost effective.

Such frequent testing would also reduce young gay and bi men’s annual rate of direct transmission of HIV to others by 40% through the time they turned 30 years old, the study authors projected.

The benefits of such increased testing would be seen only among young MSM at substantial risk of acquiring HIV, meaning they had a recent history of having anal sex without a condom, a sexually transmitted infection diagnosis or multiple sexual partners.

Andrea Ciaranello, MD, MPH, an investigator at Mass General’s division of infectious disease and a senior author of the study, said in a press release, “The improvements in life expectancy and reduction in HIV transmission were substantial. With more frequent screening, we also estimated that there would be additional, important improvements in the proportion of young MSM who are able to engage in HIV treatment and have excellent control of their HIV infection.”

“With so many youth with HIV being unaware of their status, this is an area where there are opportunities not only to improve care for individual youth but also to curb the HIV epidemic in the U.S,” Neilan said. “Despite these numbers, the Centers for Disease Control and Prevention previously determined that there was insufficient youth-specific evidence to warrant changing their 2006 recommendation of an annual HIV screening among men who have sex with men.”

To read a press release about the study, click here

To read the study abstract, click here