In a cohort of 1028 children and adolescents infected with human immunodeficiency virus type 1 (HIV-1), the use of combination therapy including protease inhibitors increased from 7 percent in 1996 to 73 percent in 1999. Over the four-year period, mortality declined from 5.3 percent to 0.7 percent. This analysis was adjusted for multiple potentially confounding variables; the authors estimate that the use of combination therapy including protease inhibitors in HIV-1–infected children reduces the risk of death by 67 percent. The use of combination therapy reduces the risk of death by 67 percent. The combination of human immunodeficiency virus (HIV)–specific protease inhibitors with nucleoside reverse-transcriptase inhibitors, nonnucleoside reverse-transcriptase inhibitors, or both has been demonstrated in adults to slow the progression of HIV type 1 (HIV-1) disease dramatically and to lower mortality. 1 , 2 Recent studies provide some evidence of the efficacy and safety of these regimens in children and adolescents, 3 – 6 but there is only limited evidence of reductions in mortality and morbidity. 7 , 8 Current guidelines for the treatment of HIV infection in both adults and children recommend combination therapy including protease inhibitors. 9 , 10 We undertook the present study to estimate the effect of . . .