Routine HIV testing clinically and economically justified, and would cut spread of HIV, say US researchers

Expanding routine HIV screening would increase the life-expectancy of individuals with previously undiagnosed HIV infection, cut HIV transmission rates by 20%, and be as cost effective as screening programmes for other disease areas, according to a study published in the February 10^th edition of the New England Journal of Medicine. A second study published in the same edition of the journal argued that in all but the lowest risk populations, routine HIV testing every three to five years could be justified on both clinical and cost grounds, and that there are also health and economic grounds for one-off HIV testing of individuals with the very lowest risk of HIV.

Current US HIV testing policy

The studies should be viewed within the context of changes attitudes towards routine HIV testing in the US in recent years. In May 2002 the Centers for Disease and Control (CDC) recommended that all sexually active gay and bisexual men have an annual HIV test, and in 2003 the CDC issued its Advancing HIV Prevention strategy which encouraged healthcare providers to make testing for HIV as routine as screening for other chronic conditions such as hepatitis B virus or diabetes in areas with a high HIV prevalence (above 1% of the population), or in clinics serving populations with a high risk of HIV infection (such as sexual health services).

It is currently estimated that there are as many as 280,000 undiagnosed cases of HIV in the US.

Screening in the era of HAART

Investigators from the US Department of Veteran Affairs, a major provider of HIV care, Duke University, Stanford University, and St. Michael’s Hospital, Toronto, developed a model to estimate the health benefits and costs of performing voluntary, but routine HIV testing in a healthcare setting. As per current US HIV treatment guidelines, they calculated that patients identified as HIV-positive would start anti-HIV therapy once their CD4 cell count fell to below 350 cells/mm³. Historical data for CD4 cell count decline and viral load increase were used to calculate the rate of HIV disease progression for patients not taking HAART. The probability of sexual transmission was calculated factoring viral load, knowledge of HIV status on sexual behaviour, and the efficacy of HIV prevention efforts.

Earlier identification of HIV would increase the life-expectancy of an individual by 18 months, the investigators calculated. In addition, the investigators calculated that screening would reduce annual HIV transmission by 21%.

Screening would be highly cost effective, according to the investigators' model, with routine testing every five years costing $57,100 per quality-adjusted life year gained. This compares favourably to the costs of routine screening for hypertension, colon cancer and diabetes, which cost in the region of $48,000 - $57,000 per quality-adjusted life year gained.

Study finds routine testing cost effective for nearly all

A second study, conducted by investigators at Yale University, found that for the US population with an HIV prevalence of between 1% - 0.12% testing every three to five years increased the life expectancy of individuals identified as HIV-positive and was cost effective. Even in the population with the very lowest HIV prevalence (0.1% - 0.01%) the investigators found that one-off HIV testing would be cost effective.