... 10/ 15 sites), 14% of theDuration of first, second and third combination treatmentFigure 1Duration of first, second and third combination treatment.0.00 0. 25 0 .50 0. 75 1.00survival probability0 ... combina-tion, type of treatment (d4T/3TC/NVP; combinations of ART with NNRTI no PI, other than d4T/3TC/NVP; combi-nations of ART with PI no NRTI; and NNRTI only), coun-try income category [14] and ... univariate analyses factorsrelated to rate ratios of combination treatment changewere; country income category (p = 0.002), drug classcombination at baseline (p < 0.001), number of combina-tions...