Between-Groups Study Designs Demand Between-Groups Analyses: A Response to Hernandez-Reif, Shor-Posner, Baez, Soto, Mendoza, Castillo, Quintero, Perez, and Zhang

Abstract

The most recent massage therapy (MT) study by Hernandez-Reif et al. displays flaws persistent in this area of research that are attributable to MT researchers’ frequent mistake of using within-group analyses of dependent variables in studies that are purported to be randomized control trials. This practise violates the logic of using randomization to create treatment and control groups, and thereby fails to control for the validity threats of spontaneous remission, placebo effects, and statistical regression. The result is that a clear understanding of what MT can and cannot do is seriously hampered.