BACKGROUND
The optimal time for the initiation of antiretroviral therapy for asymptomatic patients
with human immunodeficiency virus (HIV) infection is uncertain.
METHODS
We conducted two parallel analyses involving a total of 17,517 asymptomatic patients
with HIV infection in the United States and Canada who received medical care during
the period from 1996 through 2005. None of the patients had undergone previous
antiretroviral therapy. In each group, we stratified the patients according to the CD4+
count (351 to 500 cells per cubic millimeter or >500 cells per cubic millimeter) at the
initiation of antiretroviral therapy. In each group, we compared the relative risk of
death for patients who initiated therapy when the CD4+ count was above each of the
two thresholds of interest (early-therapy group) with that of patients who deferred
therapy until the CD4+ count fell below these thresholds (deferred-therapy group).
RESULTS
In the first analysis, which involved 8362 patients, 2084 (25%) initiated therapy at a
CD4+ count of 351 to 500 cells per cubic millimeter, and 6278 (75%) deferred therapy.
After adjustment for calendar year, cohort of patients, and demographic and clinical
characteristics, among patients in the deferred-therapy group there was an increase
in the risk of death of 69%, as compared with that in the early-therapy group (relative
risk in the deferred-therapy group, 1.69; 95% confidence interval [CI], 1.26 to 2.26;
P<0.001). In the second analysis involving 9155 patients, 2220 (24%) initiated therapy
at a CD4+ count of more than 500 cells per cubic millimeter and 6935 (76%) deferred
therapy. Among patients in the deferred-therapy group, there was an increase in the
risk of death of 94% (relative risk, 1.94; 95% CI, 1.37 to 2.79; P<0.001).
CONCLUSIONS
The early initiation of antiretroviral therapy before the CD4+ count fell below two
prespecified thresholds significantly improved survival, as compared with deferred
therapy
