Clinical Trials

❘❙❚■ Chapter 33 | Trial ProfileFigure 4. Trial profile for a crossover-design study of the use of azithromycin as a treatment for childrenwith cystic fibrosis [4].360 assessed for eligibility265 ineligibleor excluded95 approved42 refused/other reasons53 recruited12 unstable/ill/withdrew41 randomized1 withdrew20 assignedazithromycinthen placebo20 assessed forprimary endpoint21 assignedplacebo thenazithromycin21 assessed forprimary endpoint1 missed finalassessment= patients had insufficient data to be included in the analysis.Reprinted with permission from Elsevier (Lancet 2002;360:978–84).1995, 11,324 patients were randomly assigned supplements of n-3 PUFA (1 g daily,n = 2,836), vitamin E (300 mg daily, n = 2,830), both n-3 PUFA and vitamin E(n = 2,830), or none (control, n = 2,828). The trial profile shows the flow of patientsthrough the various stages of the study in each of the four treatment arms: nofurther descriptive text is needed [3].Two-way crossover designIn a crossover trial, participants switch treatments at different time periods orstages of the study. Usually the treatment sequences are treated as parallel groupsin a trial profile, rather than the treatment arms. Figure 4 shows the trial profileof a crossover trial of azithromycin in children with cystic fibrosis [4]. In this study,41 children with cystic fibrosis participated in a randomized, placebo-controlledcrossover trial. Initially, they received either azithromycin or placebo for 6 months.Then, after a 2-month washout period (free of either treatment), they were382