Figure 1.

Hazard of mortality among persons with human immunodeficiency virus infection according to baseline CD4 cell count, KwaZulu-Natal, South Africa, 2007–2011. Black dots (●) indicate the raw mortality hazard (incidence) for each 10-cell/μL group. The solid lines are fitted regression lines showing the incidence of mortality as a function of the earliest CD4 cell counts above and below the threshold (dashed line). The dashed gray line is the projection for the curve below the threshold, which is the estimate of what mortality incidence would have been for persons who were above the threshold (and thus not eligible for immediate initiation of antiretroviral therapy (ART)) if they had actually been eligible for ART immediately. The discontinuity at the threshold is the estimate of the effect of ART eligibility on mortality incidence.