Early HIV treatment led to life expectancy gains valued at $80 billion for people infected in 1996-2009.

In late 2009 US guidelines for HIV treatment were revised to recommend the initiation of combination antiretroviral therapy (cART) earlier in the course of the disease. We analyzed the life expectancy gains of people infected with HIV between the introduction of cART in 1996 and the 2009 guideline revisions. Compared to people who initiated cART late (defined as having a CD4 cell count of less than 350 per cubic millimeter of blood), those who initiated treatment early (with a CD4 count of 350-500) could expect to live 6.1 years longer, and the earliest initiators (with a CD4 count of more than 500) could expect an extra 9.0 years of life. The total value of life expectancy gains to the early and earliest initiators of treatment was $80 billion, with each life-year valued at $150,000. The value of the survival gains was more than double the increase in drug manufacturers' revenues from early cART initiation. Our results clarify the economic implications of adherence to treatment guidelines.