Detailed Explanation
Statistical power quantifies a clinical trial's ability to identify true treatment effects, serving as a critical measure of study adequacy. A trial with 80% power has an 80% probability of demonstrating statistical significance if the true treatment effect matches assumptions used in the power calculation. Conversely, such a trial has a 20% probability of failing to detect a real effect, a Type II error. Higher power reduces the risk of false-negative conclusions but requires larger sample sizes and greater resources.