Background Timely assessment of the burden of HIV/AIDS is essential for policy setting and programme evaluation.
In this report from the Global Burden of Disease Study 2015 (GBD 2015), we provide national estimates of levels and
trends of HIV/AIDS incidence, prevalence, coverage of antiretroviral therapy (ART), and mortality for 195 countries
and territories from 1980 to 2015.
Methods For countries without high-quality vital registration data, we estimated prevalence and incidence with data
from antenatal care clinics and population-based seroprevalence surveys, and with assumptions by age and sex on
initial CD4 distribution at infection, CD4 progression rates (probability of progression from higher to lower CD4
cell-count category), on and off antiretroviral therapy (ART) mortality, and mortality from all other causes.
Our estimation strategy links the GBD 2015 assessment of all-cause mortality and estimation of incidence and
prevalence so that for each draw from the uncertainty distribution all assumptions used in each step are internally
consistent. We estimated incidence, prevalence, and death with GBD versions of the Estimation and Projection
Package (EPP) and Spectrum software originally developed by the Joint United Nations Programme on HIV/AIDS
(UNAIDS). We used an open-source version of EPP and recoded Spectrum for speed, and used updated assumptions
from systematic reviews of the literature and GBD demographic data. For countries with high-quality vital registration
data, we developed the cohort incidence bias adjustment model to estimate HIV incidence and prevalence largely
from the number of deaths caused by HIV recorded in cause-of-death statistics. We corrected these statistics for
garbage coding and HIV misclassifi cation.