Evidence and reporting standards in N-of-1 medical studies: a systematic review.

N-of-1 trials, a special case of Single Case Experimental Designs (SCEDs), are prominent in clinical medical research and specifically psychiatry due to the growing significance of precision/personalized medicine. It is imperative that these clinical trials be conducted, and their data analyzed, using the highest standards to guard against threats to validity. This systematic review examined publications of medical N-of-1 trials to examine whether they meet (a) the evidence standards and (b) the criteria for demonstrating evidence of a relation between an independent and an outcome variable per the What Works Clearinghouse (WWC) standards for SCEDs.