In the first, Diener et al. studied AAC-100 (APAP 200 mg, ASA 250 mg, and caffeine 50 mg), which is available OTC in Germany, in patients with TTH and migraine using a 6-arm, randomized, double-blind, parallel-group factorial design.
7. Aloia J, Bojadzievski T, Yusupov E, et al. The relative influence of calcium intake and vitamin D status on serum parathyroid hormone and bone turnover biomarkers in a double-blind, placebo-controlled parallel group, longitudinal factorial design.
Design Parallel group, 2×2 factorial, randomised controlled trial.
Here we seek information on the type of trial, such as parallel group or factorial, and the conceptual framework, such as superiority or non-inferiority, and other related issues not addressed elsewhere in the checklist.
Studies of parallel group, crossover, cluster, factorial, and split body design were included.
We included all studies of parallel group, crossover, cluster, factorial, and split body design.
Study sample All primary reports of randomised trials indexed in PubMed in December 2000 (n=519) and December 2006 (n=616), including parallel group, crossover, cluster, factorial, and split body study designs.
Examples are the design of the randomized assignment (conventional, crossover, parallel group, 2 × 2 factorial) or the method of blinding (single or double blinded, open label).
Function after spinal treatment, exercise and rehabilitation (FASTER) is a multi-centre, factorial, randomised, parallel group controlled trial using validated measures of outcome and with a parallel economic analysis.
On the other hand, unlike parallel groups trials a factorial design does enable investigation of interactions in the analysis, albeit with limited power.
