The system provides an estimate of in vivo efficacy of commonly used antiretroviral drug combinations based on user-defined information of HIV genotype (mandatory) and additional patient information (recommended). The engine is not intended as a replacement for standard of care but can be used by HIV specialists as an additional treatment decision support tool. Although analysis of a large data set of medical records has shown a good performance of the system, there is no warranty that its use will improve patient health. HIV care must rely on a solid knowledge of the complex host-virus interaction and proper consideration of patient status and commitment.