CD4 and AIDS: The median time to AIDS from the first recorded CD4% value was 11.7 years (95% confidence interval [CI], 7.3 to 16.1 years) for faster progressors with a faster CD4% decline and 16.8 years (CI, 12.3 to 21.3 years) for slower progressors with a slower CD4% decline (P = 0.008 [log rank test]) (Fig. 1A).