Figure 4.

Viral load, CD4⁺ cell count, and survival time. For a given seroconversion CD4⁺ cell count, higher viral load is associated with faster decline and shorter predicted survival time (a); but counterintuitively, for a given viral load, higher seroconversion CD4⁺ cell count does not change predicted survival time (b). The dependence on seroconversion CD4⁺ cell count can be overlooked if large groups of patients are studied instead of individuals.