A simulation model of HIV treatment under drug scarcity constraints

We consider a population of HIV infected patients. In resource poor environments, decision makers must allocate antiretro-viral drugs (ARVs) to patients in need of them the most. Further complicating matters is that once a patient is given ARVs, the decision maker must decide when to deny further access to ARVs. We compare various methods for determining which patients should receive ARVs and when to switch a patient off of ARVs. We examine the World Health Organization´s (WHO) treatment recommendations and how the level of drug shortages can influence the performance of these recommendations. Instead of a single recommendation, the WHO offers three distinct treatment policies with no mention of when to use them. We find that the severity of drug shortages can greatly impact the performance of these policies and the performance gap can be as high as 1.4 years.