Increasing the proportion of HIV-positive patients treated with antiretroviral therapy could save the Canadian province of British Columbia US$900 million over 30 years - and prevent 26% of projected new HIV transmissions - investigators report in the on-line edition of AIDS.
The investigators constructed a mathematical model to predict the cost savings which would be achieved if the proportion of HIV-positive patients with a CD4 cell count below 350 cells/mm3 treated with antiretroviral drugs increased from 50% to 75%.
After only four years, increasing the number of treated patients became cost-effective, and after ten years much of the cost benefit could be attributed to the number of new infections averted.
“We demonstrated the potential cost effectiveness of expanding the use of HAART [highly active antiretroviral therapy”, comment the investigators, “increased treatment was found to reduce the incidence of new infections and, despite the up-front acquisition costs associated with HAART use, the strategy was estimated to become cost-effective within 4 years.”
Treatment with antiretroviral drugs can mean that many HIV-positive patients have a near-normal life expectancy. Another benefit of HIV therapy is that it can help to reduce the number of new infections. This is because treatment lowers viral load, and very few new HIV infections have been attributed to individuals taking HIV treatment who have an undetectable viral load.
Access to HIV treatment and care in British Columbia is free. The epidemic in this province is focused in gay and other men who have sex with men, sex workers, and injecting drug users, and the number of individuals newly diagnosed with HIV in British Columbia has increased in recent years.
Current guidelines recommend that patients should start antiretroviral therapy when their CD4 cell count is in the region of 350 cells/mm3. Investigators constructed a mathematical model to determine the cost benefits that would accrue over 30 years if the proportion of patients eligible for HIV therapy were increased from 50% to 75%.
It was assumed that HIV treatment would cost between US$900 - $1100 per patient, per month. Other healthcare costs were also taken into consideration.
Also factored into the model was the potential impact of antiretroviral therapy on infectiousness.
According to the investigators’ calculations, expanded coverage of treatment would become cost effective after four years.
The cumulative cost benefits increased over time, and after 30 years the model predicted that the total saving in healthcare costs would be US$900 million.
Even if the cost of HIV therapy were increased to US$1438 per patient, per month, the strategy of expanding treatment coverage would still be highly cost effective, saving approximately US$760 million over 30 years.
Most of the cost savings during the first years were because of the individual benefits of antiretroviral therapy. But thereafter, an increasing proportion of the economic benefits of expanded coverage of antiretroviral therapy could be attributed to the prevention of new infections.
Indeed, the investigators calculated that 26% of projected new HIV infections could be prevented if the proportion of eligible patients taking antiretroviral therapy was increased to 75%.
“These cost-effectiveness results are consistent with public health objectives”, conclude the investigators,” all individuals who are eligible for an established life-saving treatment should receive it.”
Johnston KM et al. Expanding access to HAART: a cost-effective approach for treating and preventing HIV. AIDS, advance online publication: DOI:10. 1097/QAD.0bo13e32833af85d, 2010.