Inappropriate statistical method in a parallel-group randomized controlled trial results in unsubstantiated conclusions

摘要

The conclusions of Cassani et al. in the January 2015 issue of Nutrition Journal (doi:10.1186/1475-2891-14-5) cannot be substantiated by the analysis reported nor by the data themselves. The authors ascribed the observed decrease in inflammatory markers to the components of flaxseed and based their conclusions on within-group comparisons made between the final and the baseline measurements separately in each arm of the randomized controlled trial. However, this is an improper approach and the conclusions of the paper are invalid. A correct analysis of the data shows no such effects.