A Cochrane review included no randomized controlled trials. Two prospective cohort studies and five retrospective case control studies were analyzed instead, with a total of 515 patients who had percutaneous endoscopic gastrostomy (PEG) and 1897 oral eater controls. Four studies found no advantage on survival and three reported longer survival after PEG, including the two studies with the strongest research design (prospective). This advantage was not limited to the bulbar onset patients, but applied to the entire group of ALS/MND patients. Three studies reported on nutrition and all suggested a positive outcome of PEG. This was supported by the single prospective study that measured nutritional parameters. Only two studies looked at quality of life changes: neither of these showed evidence for improved QOL after PEG.
Comment: The quality of evidence is downgraded because the data are from observational studies only.