Factorial Designs in Clinical Trials

Different antibiotic protocols in the treatment of severe chronic periodontitis: A 1‐year randomized trial

“…Table presents secondary factorial analyses for the four antibiotic groups, considering either the dose or the duration. This type of analysis allows the evaluation of different experimental factors at the same time, providing that there is no interaction between them (Piantadosi, ). As no interaction between time of antibiotic intake and MTZ dose was determined by two‐way ANOVA (Appendix Table), the main effects of dose and treatment interval were tested at once (Table ).…”

“…Table 4 presents secondary factorial analyses for the four antibiotic groups, considering either the dose or the duration. This type of analysis allows the evaluation of different experimental factors at the same time, providing that there is no interaction between them (Piantadosi, 2008).…”

Control of periodontal infections: A randomized controlled trial I. The primary outcome attachment gain and pocket depth reduction at treated sites

“…A major reason for conducting studies with a factorial design is to test whether or not treatments interact with each other (Piantadosi ). The test of interaction between therapies (cross products) for 24‐month CAL gain and PPD reduction revealed no statistical significance.…”

Rhythm-based assessment and training for children with attention deficit hyperactivity disorder (ADHD): a feasibility study protocol

“…Randomized crossover trials, clinical experiments in which participants are assigned randomly to a sequence of treatments and each participant serves as one's own control in estimating treatment effect (Senn, 2002;Piantadosi, 2005), will be used in the present study. Participants will be assigned randomly to either rhythm training followed by cognitive training or cognitive training followed by rhythm training (Figure 1).…”