What's in a Guideline? Developing Collaborative and Sound Research Designs that Substantiate Best Practice Recommendations for Transgender Health Care.

Transgender medicine presents a particular challenge for the development of evidence-based guidelines, due to limitations in the available body of evidence as well as the exclusion of gender identity data from most public health surveillance activities. The guidelines that have been published are often based on expert opinion, small studies, and data gathered outside the US. The existence of guidelines, however, helps legitimate the need for gender-affirming medical and surgical interventions. Research conducted on transgender populations should be grounded in gender-affirming methodologies and focus on key areas such as health outcomes after gender-affirming interventions.