Table 6.

Adaptive trial designs

Key features	Interventions and/or randomization structure altered based on early data according to ‘pre-determined’ rules
Advantages	Smaller sample size (n) Shorter duration Can identify benefits/harm to smaller subgroups Allows for very long-term ‘constantly’ adapting trials
Disadvantages	Short-term ‘definitive’ positive results may mask long-term negatives Too many ‘adaptive’ steps can affect validity of results Power analysis complex Trial design complex requiring detailed expert planning
Example	Stroke Prevention in Atrial Fibrillation (START) trial