Uncertainty bounds of incremental cost effectiveness (ICER) estimates, % of ICER estimates suggesting dominance of the tenofovir (TDF) treatment strategy and % of ICER estimates below the WHO threshold for high cost-effectiveness.

Results were obtained by repeatedly drawing one simulation with TDF as the initial strategy and one simulation with zidovudine (ZDV) in the initial treatment. From this pair of simulations the incremental cost effectiveness ratio was calculated. Dominance was defined by lower costs and higher quality adjusted life year estimates for a specific treatment. By repeating this process 1000 times we obtained an estimate for how frequently the TDF strategy was dominant. Analogous calculations were performed to check how often the ICER estimates were below the WHO threshold for high cost effectiveness (annual per capita gross domestic product of US$ 2154). Uncertainty bounds reflect ranges that include 95% of all ICER estimates.Abbreviations: ICER, incremental cost effectiveness ratio; TDF, tenofovir; WHO, World Health Organization.