Baseline characteristics of study subjects.

1Subject characteristics were grouped according to R5 or non-R5 (X4) concordance between the genotypic tropism test (GTT) using triplicate population sequencing with reflex to ultradeep sequencing as described in Methods, and the Trofile Enhanced Sensitivity assay.
2The HIV-1 subtype was determined by the geno2pheno software from the Envelope V3 loop sequence.
3Phenotypic uncensored weighted optimized background therapy susceptibility score.
4There were no significant differences between groups (1–4) in the proportions of subjects who were male vs female, Caucasian vs non-Caucasian and infected with subtype B vs non-B virus (P>0.05).