“…11,13,15,19,21 However, in addition to the small sample size of these studies, their retrospective designs do not allow definitive conclusions owing to the significant biases introduced when comparing such outcomes in noncontrolled, noncontemporaneous cohorts. 27 The current reported rates of perioperative adverse events with POEM range from 5% to 24.2%, 13,39,40 and 9 recent comparative studies of LHM to POEM have shown similar perioperative adverse events rates between the 2 procedures. 12e16,19e22 A large retrospective multicenter study from 12 tertiary-care centers (5 in the United States, 4 in Europe, 2 in Asia, and 1 in Australia) that included 1,826 patients who had POEM (without a group of patients that had LHM) between 2009 and 2015 reported an overall rate of adverse events requiring intervention as 7.5%, with y The Rao-Scott c 2 test does not provide a P value when 1 cell value equals 0.…”