p-value

The probability of seeing the observed (or more extreme) result if the null hypothesis were true.

Definition

A p-value is the probability under the null hypothesis (no treatment effect) of observing data at least as extreme as what was seen. Convention: p<0.05 = "statistically significant", but most modern Phase 3 oncology trials pre-specify p<0.025 for primary endpoints (alpha split for interim analyses).

See also

Other clinical terms