Large-Sample Confidence Intervals for the Treatment Difference in a   Two-Period Crossover Trial, Utilizing Prior Information
  Consider a two-treatment, two-period crossover trial, with responses that are continuous random variables. We find a large-sample frequentist 1-alpha confidence interval for the treatment difference that utilizes the uncertain prior information that there is no differential carryover effect. 
Paul Kabaila, Khageswor Giri