Little research was published on MT before 2009, and much of the research since then has been of low quality. Out of 115 publications between 2012 and 2017 about using mirror therapy to treat phantom limb pain, a 2018 review, found only 15 studies whose scientific results should be considered. From these 15 studies, the reviewers concluded that "MT seems to be effective in relieving PLP, reducing the intensity and duration of daily pain episodes. It is a valid, simple, and inexpensive treatment for PLP."