Balaam design is a crossover design for comparison of regimen A with regimen B in which subjects are randomly allocated to one of four sequences: AA, AB, BA or BB. Sequence AA means that the subjects in this group receive regimen A in period-1 followed by regimen A again in period-2. Sequence AB means regimen A followed by regimen B, etc. Thus all subjects receive the regimens two times. The advantages of Balaam design opposed to the usual crossover design is that it works when the effect of a treatment in first period could be different from its effect in period-2. Most commonly this happens when carry-over effect is present.
Is it true to say that there is no need of a washout period in this design ?
