LETTER TO THE EDITOR Disagreement with categorization of clinical trials included in Treadwell et al. systematic review and meta-analysis Behavioral interventions for migraine prevention: A systematic review and meta-analysis Jonathan R. Treadwell PhD, Amy Y. Tsou MD, Benjamin Rouse MS, Ilya Ivlev MD, PhD, Julie Fricke PhD, Dawn C. Buse PhD, Scott W. Powers PhD, Mia Minen MD, Christina L. Szperka MD, MS, CE, Nikhil K.