To the Editor We were surprised that Landman et al1 felt able to draw strong conclusions about the nonefficacy of device-guided breathing for treatment of hypertension based on a methodologically limited study. Conclusions about nonefficacy should only be drawn from negative results when a trial is adequately powered to determine treatment effects. The authors’ study was small (with only 48 participants) and was underpowered based on wide confidence intervals around estimates of blood pressure.
Huang AJ, Subak LL. What Constitutes an Adequate Evaluation of Device-Guided Breathing?. JAMA Intern Med. 2014;174(4):637. doi:10.1001/jamainternmed.2013.13791