Got Evidence? Stem Cells, Bias, and the Level of Evidence Ladder

Abstract

O hateful Error, Melancholy’s child, Why dost thou show to the apt thoughts of men The things that are not? Shakespeare, Julius Caesar Stem cells have captured the attention and imagination of the public, appearing to be a “magic bullet,” sexy and omnipotent, capable of curing health concerns from cancer and cardiac disease to warts and wrinkles. While the scientific enthusiasm for the potential therapeutic impact of stem cells seems justified, the great hope currently placed on stem cell therapies makes the public vulnerable to emotional manipulation, deceptive marketing, or even outright fraud. Concerned by the cacophony of marketing for the so-called stem cell facelift, stem cell breast augmentation, and other “stem cell” procedures, the leadership of the American Society for Aesthetic Plastic Surgery (ASAPS) and American Society of Plastic Surgeons (ASPS) established the Joint Stem Cell and Fat Grafting Task Force in 2010. The task force was charged with gathering information about current stem cell procedures and marketing claims, monitoring stem cell training courses, initiating a dialogue with the Food and Drug Administration, and developing collaborations with key stem cell scientists within and outside the plastic surgery field. In addition, the task force was directed to perform a systematic assessment of the world’s peer-reviewed literature on the clinical uses of stem cells in aesthetic procedures. The “ASAPS/ASPS Position Statement on Stem Cells and Fat Grafting” resulted from that systematic review and critical analysis.1 While the stem cell future may be bright, there is currently scant peer-reviewed evidence to substantiate marketing claims for stem cell aesthetic procedures. What little information is present is mostly of lower levels of evidence (LOE). But why do we consider LOE in the first place, and what purpose do they serve? What does “lower” really mean, why might such evidence be inadequate, and what …