CAPE TOWN, SOUTH AFRICA In South Africa, starting anti-HIV treatment earlier than recommended in current World Health Organization guidelines for the developing world would save lives and reduce opportunistic infections.
Such a change in clinical practice would also be cost effective, according to Dr. Rochelle Walensky of the Massachusetts General Hospital in Boston and colleagues.
The conclusions are based on a mathematical model of the HIV epidemic in South Africa and are intended to guide clinical practice until several formal clinical trials studying the issue are complete, Dr. Walensky and colleagues reported (Ann. Intern. Med. 2009; 151).
The researchers also reached similar conclusions using data from Cote d'Ivoire and presented them in a poster at the International AIDS Society Conference on Pathogenesis, Treatment, and Prevention.
The current standard for starting HIV treatment in South Africa followed WHO guidelines for the developing world: A patient is eligible for treatment when his or her CD4-positive T-cell count falls below 200 per cubic millimeter of plasma or when there is an AIDS-defining illness.
But guidelines in the developed world now suggest starting at a higher level350 cells per cubic millimeterand some recent studies have suggested that clinical outcomes would be even better if the threshold were set to 500 cells or more.
Clinical trials are underway in Africa to settle the issue, but they won't report for another 5 years. In the meantime, Dr. Walensky and colleagues said, their model may provide guidance to clinicians.
They explained that the bottom line is that in all cases, starting therapy at the 350-cell threshold saved more lives, prevented more disease, and cost more, compared with a threshold of 250 cells.
The researchers estimated that such a threshold would mean 4.7 million people would be eligible for therapy in South Africa over the next 5 years.
Under the assumption that 10% of those patients would be identified and given care using the 350-cell threshold would result in 1,599,900 deaths, compared with 1,622,000 for the lower level, the investigators said.
There would also be 1,664,500 opportunistic infections, compared with 1,689,700 using the lower threshold.
On the other hand, costs would increase by $141,977,100 (U.S.), using the higher threshold, they said. At the other extreme, if all eligible patients were identified and linked to care, the higher threshold would avert 221,000 opportunistic diseases and 253,000 deaths.
The additional costs in that scenario would rise to $1.4 billion, the researchers said.
Either scenario would increase long-term survival by at least 7.9 years, with an average per-person life expectancy of 3.8 years with no therapy and 12.5 years at the 350-cell threshold.
Compared with the 250-cell threshold, starting at the 350-cell threshold had an incremental cost-effectiveness ratio of $1,200 per year of life saved, the researchers said.
"It is probably both effective and cost effective" to allow therapy to start at the higher level, the researchers said.
The study was supported by the National Institute of Allergy and Infectious Diseases and the Doris Duke Charitable Foundation.
The researchers did not report conflicts.