Nijhuis RABO, et al. - Since identifying factors correlated with outcomes of patients with achalasia help doctors to select treatments based on patient features, researchers conducted a systematic review and meta-analysis of factors related to response to achalasia treatment by analyzing data from 75 studies (8 randomized controlled trials, 27 prospective cohort studies, and 40 retrospective studies). Through February 21, 2019, MEDLINE, EMBASE, and the Cochrane Library were searched for randomized controlled trials and cohort, case-control, and cross-sectional studies that described patient-specific outcomes of treatment (Botox injection, pneumatic dilation, peroral endoscopic myotomy, or laparoscopic Heller myotomy). Qualitative assessment identified age, manometric subtype, and presence of a sigmoid-shaped esophagus as factors associated with a high level of evidence for achalasia treatment outcomes. There was inconclusive composite evidence for association with chest pain, the severity of symptoms, and lower esophageal sphincter pressure. Age and manometric subtype were found to be associated with treatment outcomes for achalasia. Such detail should be used to guide decision making regarding treatment.