The effects of ART guideline changes on estimates of the need for ART
Background: WHO has updated guidelines issued as 'rapid advice' for when to start adults on ART. These changes expand the number of people eligible for treatment, requiring new estimates of total need.
Methods: We constructed a model that tracks newly infected people as they progress from CD4 counts above 500 at the time of infection to lower categories (350-500, 250-349, 200-249, < 200) and to death. We estimated transition probabilities between each category and AIDS mortality within each category to match the national distribution of CD4 counts reported by the Kenya AIDS Indicator Survey, 2007, and to match the ALPHA network estimates of overall survival by time since infection in untreated cohorts. The resulting model was validated against data on CD4 count distributions from local surveys in Malawi and South Africa. We then applied the model globally and to several key countries to estimate the number of adults eligible for treatment under the old and new guidelines. The model also estimates the life years saved by ART and the effects of ART on HIV transmission.
Results: Switching the eligibility criterion from CD4 count < 200 to < 250 results in an 18% increase in the need for ART while a switch to < 350 results in a 53% increase in need globally. The country results vary from increases of 12%-22% for the switch to 250 and 33%-62% for the switch to 350. Achieving 80% treatment coverage by 2015 would require 49% more person-years of treatment with eligibility at < 350 but would reduce AIDS deaths by 22% and reduce the number of new infections by 11%
Conclusions: The new eligibility criteria will require a rapid expansion of services to meet coverage goals but will provide significant benefits to those living with HIV.
AIDS 2010 - XVIII International AIDS Conference
"J.Stover, et al.
The effects of ART guideline changes on estimates of the need for ART.
AIDS 2010 - XVIII International AIDS Conference: