Study design
Phase 3 trial
A larger confirmatory trial designed to test effectiveness and safety for clinical use.
What it means
Definition
Phase 3 trial. Phase 3 trials provide more decisive evidence than earlier phases when they are well-designed, adequately powered and use relevant outcomes. They still need scrutiny for population, comparator and endpoint choice.
What it can tell you
It can show how close the evidence is to a real human health outcome.
What it cannot tell you
It cannot prove that a treatment works in people unless human outcome data are available.
Headline trap
Why this matters in headlines
A phase 3 benefit in selected trial patients may not apply equally to all real-world patients.