To evaluate the safety and efficacy of Stribild®, a single tablet regimen (STR) containing fixed doses of elvitegravir (EVG)/cobicistat (COBI [GS-9350])/emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) versus efavirenz (EFV)/FTC/TDF (Atripla®) in HIV-1 infected, antiretroviral treatment-naive adults. Stribild offers an alternative STR for patients who are not candidates for non-nucleoside reverse transcriptor-based STRs.