Figure 1.

Adjusted survival curve for time-varying viremia copy-years among 2027 treatment-naive HIV-infected patients, CFAR Network of Integrated Clinical Systems (CNICS), 2000–2008. Adjusted survival curves modeling all-cause mortality among 2027 treatment-naive HIV-infected patients following antiretroviral therapy (ART) initiation stratified by levels of time-updated viremia copy-years. Viremia copy-years, the principal exposure of interest, is a time-varying measure of cumulative plasma HIV burden calculated as described in the methods section. Viral load values prior to 24 weeks of ART initiation were excluded from calculating viremia copy-years to best capture the effect of cumulative viral load exposure on mortality after allowing patients a reasonable window to respond to therapy. The survival curves were adjusted for confounding and selection bias due to age, sex, race/ethnicity, HIV transmission risk group, initial ART, year of ART initiation, CNICS site, most recent CD4 count, and visit frequency using inverse probability unstabilized weights, which were a product of viremia copy-years density weight, censoring weight, and visit attendance weight.