A. Empirical SPVL trends overlaid onto distributions of simulated 20-year trends.

<p>Distributions of linear SPVL trends (log₁₀ HIV RNA copies/mL/year) were estimated from 100 randomly sampled 20-year time periods for 10 replicate simulations for each initial mean SPVL = 3.5, 4.5 or 5.5 log₁₀ HIV RNA copies/mL (creating 1000 total 20-year trends for each initial mean SPVL). Empirical (published) annual linear SPVL trends are overlaid (arrows and references). References with asterisks are seroprevalent cohorts; all others are seroconverter cohorts. <b>B. </b><b>Selection of an appropriate null changes the distribution of simulated SPVL trends.</b> Separate null distributions, each spanning a different subset of the complete 100-year simulated epidemics: all 100 years of the model output; years 10–100 of the model output, as European and North American subtype B epidemics began ∼1970, and studies of empirical SPVL trends began sampling at the earliest in 1984, leaving a ∼10-year window of the HIV epidemic not sampled by the cohorts; years 0–40 of the model output, as the empirical studies of SPVL trends include years up to ∼2010, so this represents the first 40 years of the subtype B epidemic (∼1970 to 2010); and years 10–40, reflecting the empirical sampling years ∼1980 to 2010.