to undetectable levels with an accuracy of approximately 80%, significantly better than just using a genotype with rules-based interpretation. HIV-TRePS In October 2010, following clinical testing in two multinational studies, the RDI made its experimental HIV Treatment Response Prediction System, HIV-TRePS available over the Internet. In January 2011, two clinical studies were published indicating that use of the HIV-TRePS system could lead to clinical and economic benefits. The studies, conducted by expert HIV physicians in the US, Canada and Italy, showed that use of the system was associated with changes of treatment decision to combinations involving fewer drugs overall, which were predicted to result in better virological responses, suggesting that use of the system could potentially improve patient outcomes and reduce the overall number and cost of drugs used. As clinics in resource-limited settings are often unable to afford genotyping, the RDI has developed models that predict treatment response without the need for a genotype, with only a small loss of accuracy. In July 2011, the RDI made these models available as part of the HIV-TRePS system. This version is aimed particularly at resource-limited settings where genotyping is often not routinely available. The most recent of these models, trained with the largest dataset so far, achieved 80% accuracy, which is comparable to models that use a genotype in their predictions and significantly more accurate than genotyping with rules-based interpretation itself. HIV-TRePS is now in use in approximately 90 countries as a tool to predict virological response to therapy and avoid treatment failure. The system has been expanded to enable physicians to include their local drug costs in the modelling. A recent study of data from an Indian cohort demonstrated that the system was able to identify combinations of three locally available drugs with a higher probability of success than the regimen prescribed in the clinic, including those cases where the treatment used in the clinic failed. Moreover, in all these cases some of the alternatives were less costly than the regimen used in the clinic, suggesting that the system could be not only help avoid treatment failure but also reduce costs. References External links RDI official site HIV-TRePS Health informatics organizations Medical databases Applications of artificial intelligence HIV/AIDS organisations in the United Kingdom Database companies