Table 7

Factorial trial design

Key features

  • Multiple interventions studied both individually and in combination

  • If interventions are independent, a very efficient study design compared with multiple individual studies for each intervention, level, and combination

Advantages

  • Impact of each intervention and combination evaluable

  • Results valid for a range of conditions

Disadvantages

  • If interventions are not independent, power is decreased

  • Very large sample size (n) for multiple interventions and levels

  • Power analysis complex

  • Complex results analysis specially with multiple interventions and levels

Example

  • Fluid Lavage of Open Wounds (FLOW) trial23