Search Methodology

Search Methodology for Research Analysis on the Effect of Gender Transition on Transgender Well-being:

We conducted a comprehensive literature review of all scholarly articles published in English between 1991 and June 2017 that addressed the following question: What does the scholarly research say about the effect of gender transition on transgender well-being?

Our research protocol was developed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Guidelines. We used the PICOS (Participants, Interventions, Comparisons, Outcomes, and Study Design) criteria to organize our approach to this research question:

• Participants: Adults who have been diagnosed with gender dysphoria, who have transitioned gender, or who self-identify as transgender
• Interventions: Any medical service that affirms the individual’s self-identified gender identity; a relevant medical service was any service, treatment, or procedure indicated for the treatment of gender dysphoria in the accepted expert Standards of Care for the Health of Transsexual, Transgender, and Gender-Nonconforming Individuals maintained by the World Professional Association for Transgender Health (version 7, 2011)
• Comparisons: No specific comparison design was required so long as the study investigated the effect of gender transition on transgender well-being
• Outcomes: Assessment of a transgender individual’s mental or social well-being, such as successful functioning, mental status, quality of life, or life or relationship satisfaction
• Study Design: Any peer-reviewed study that undertook an evaluative (quantitative or qualitative) assessment of relevant outcomes for the population of interest; we did not impose requirements regarding minimum length of follow-up or other aspects of the study design

To identify eligible studies, we began by searching PubMed using the Medical Subject Headings (MeSH) “transgender persons,” “transsexualism,” “sex reassignment procedures,” “sex reassignment surgery,” and “health services for transgender persons” in conjunction with text words such as “transgender men,” “transgender women,” “male to female,” “female to male,” “quality of life,” and “outcomes.”

This search returned 4347 non-duplicate articles. We then performed a hand-search of journals known to address transgender issues as well as existing literature reviews on the topic of gender transition and transgender well-being. From this search, we selected additional studies that appeared to address our research question. On the basis of title reviews, we narrowed our list to 589 studies that appeared to address our research question. We then read the abstracts of those studies and further narrowed our list based on whether the studies directly assessed well-being in the context of gender transition. This process yielded 124 studies.

The final step of our search was for two reviewers to independently read the full text of each article to determine if it directly addressed our research question. We eliminated studies, for instance, that did not assess the outcomes of gender transition, that investigated minors instead of adults, and that evaluated physical rather than mental health outcomes (because we did not want to conflate assessments of specific surgical techniques, for example, with the broader question of whether gender transition improves well-being).

We identified 56 peer-reviewed studies consisting of primary research that met all the above criteria. We then classified them according to whether they found improved well-being, had mixed or null findings, or found that gender transition causes harm, and reported both the number of studies in each category, as well as eight findings that emerged from our review of the literature.

Separately from the 56 studies we evaluated, we included in our portal 16 additional articles that consist of literature reviews and practitioner guidelines that we did not count in our tally. We provide these as an added resource for researchers, practitioners, journalists, policymakers and the public with an interest in transgender care issues.