Scientific Inference Does Not Rest on Statistical Testing

The Strategic Timing of AntiRetroviral Treatment (START) trial found that in patients with HIV and CD4⁺ cell counts above 500 cells/mm³ who had not previously received treatment, immediate initiation of antiretroviral therapy reduced the risk of serious adverse outcomes compared with delaying treatment initiation only when the CD4⁺ cell count fell below 350 cells/mm³.¹ After the trial's completion, people with HIV not receiving therapy were offered the opportunity to start it without regard to their CD4⁺ cell count. In this issue of NEJM Evidence, the START group reports data from an additional 5 years of follow-up.².