We assessed the concordance between the results expressed as FC drug susceptibility provided by our method (evaluating the 46 plasma samples) and the FC generated using alternative phenotyping methods. We used two methods based on a biological data-driven system for predicting HIV-1 drug susceptibility from a viral genotype (the Vircow TYPE
HIV-1 test and the Stanford HIVdb) and a third method based on an in vitro phenotypic resistance assay that measures the level of resistance of recombinant HIV-1 from plasma samples (Antivirogramw). The two drugs evaluated were tipranavir and darunavir, as these were the agents administered in the patients’ new regimen. Correlation coefficients (Spearman’s r) and the P value (two-tailed) were calculated using GraphPad Prism v5.0 software