We know in cross -over trial , there is washout period and new drug / intervention is given to opposite group. Why then it is included in RCT. What is the purpose of randomization here?
In crossover trials, the two groups are randomised to decide the treatment sequence provided to them, i.e. Intervention-washout-placebo or Placebo-washout-intervention. Randomisation will improve interindividual comparisons and improve the comparability of time-varying covariates.