Earlier initiation of antiretroviral therapy should be the highest priority for global expansion of HIV patient care. This finding, from a paper published in this week's PLoS Medicine, should help resource-limited nations to phase in the implementation of the new 2010 WHO recommendations for HIV treatment.

"Immediate scale-up of the entire WHO guideline package may be prohibitively expensive in some settings," said lead author Rochelle P. Walensky, MD, MPH of the Massachusetts General Hospital, Boston, USA. "In many resource-limited settings, the relevant policy question is: What to do first?"

The new WHO guidelines include three major changes: initiation of ART when CD4 levels drop below 350/µl, rather than waiting until they reach 200/µl; replacing the antiretroviral drug stavudine with the less-toxic but more expensive tenofovir for first-line treatment, and switching patients to second-line ART regimens when the first-line regimen fails.

Findings from Walensky and colleagues demonstrate that earlier ART initiation increased 5-year survival from 80 to 87% and showed substantially improved early clinical outcomes compared to either using tenofovir for first-line treatment or providing second-line regimens. In settings where ART initiation at 350/μl is already available, switching stavudine to tenofovir offers clinical benefit and is less costly than adding second-line regimens. Finally, the authors demonstrate that the availability of second-line regimens offers major survival benefits (greater than 4 years per person) but at substantial increases in cost.

The authors conclude: "The entire package of recommendations proposed by the WHO is cost-effective in South Africa (incremental cost-effectiveness ratio of US$2,370 per year of life saved). However, in settings where immediate implementation of all of the new WHO treatment guidelines is not currently feasible, antiretroviral treatment initiation at CD4 < 350/µl provides the greatest short- and long-term survival advantage and is highly cost-effective."

More information: Walensky RP, Wood R, Ciaranello AL, Paltiel AD, Lorenzana SB, et al. (2010) Scaling Up the 2010 World Health Organization HIV Treatment Guidelines in Resource-Limited Settings: A Model-Based Analysis. PLoS Med 7(12): e1000382. doi:10.1371/journal.pmed.1000382