Sex and Gender Research Considerations


Sex refers to a set of biological attributes in humans and animals. It is primarily associated with physical and physiological features including chromosomes, gene expression, hormone levels and function, and reproductive/sexual anatomy. Sex is usually categorized as female or male but there is variation in the biological attributes that comprise sex and how those attributes are expressed. “Assigned” or “designated” sex refers to the sex noted on a birth certificate for that person.

Gender refers to the socially constructed roles, behaviors, expressions and identities of girls, women, boys, men, and gender diverse people. It influences how people perceive themselves and each other, how they act and interact, and the distribution of power and resources in society. Gender is usually conceptualized as a binary (girl/woman and boy/man), yet there is considerable diversity in how individuals and groups understand, experience, and express it.

Transgender is an umbrella term for people whose gender identity and/or gender expression differs from their assigned sex at birth (i.e., the sex listed on their birth certificates). Some groups define the term more broadly (e.g., by including intersex people) while other people define it more narrowly (e.g., nonbinary people who do not consider themselves transgender). Transgender people may or may not choose to alter their bodies hormonally and/or surgically. While “transgender” is a popularly used word and generally seems to be a safe default term to use, some people find the term offensive as a descriptor of themselves. It is best to ask participants which terms, if any, they use or prefer.

Nonbinary people are those whose assigned sex is different from their gender identity, but who identify as neither male nor female. Many nonbinary people consider themselves transgender, and this group is often included as a subset of transgender people.  However, some nonbinary people do not consider themselves transgender, so it is best to include nonbinary as an option in gender identity questions (or use it as an example of how you are using “transgender” if you must limit response items) to capture this rapidly growing population (35% of transgender respondents in the 2015 US Trans Survey identified as nonbinary).

Gender Nonconforming People are people whose gender expression is different from traditional or stereotypic expectations of how a man or woman “should” appear or behave.

Genderqueer is generally used in two ways: (1) most commonly, by a subset of individuals who are born anatomically female or male, but feel their gender identity is neither female or male, to describe themselves; or (2) as an umbrella term that includes all people whose gender varies from their assigned sex at birth, akin to the use of the word “queer” to refer to people whose sexual orientation is not heterosexual only. Note that this second usage, like the use of “queer,” is controversial and can be highly offensive to some, so this word should not be used to describe someone who has not used it first to describe themselves.

Gender Fluid is a term similar to genderqueer, used to refer to gender variations other than the traditional, dichotomous view of male and female. People who self-refer with this term may identify and present themselves as both or alternatively male and female, as no gender, or as a gender outside the male/female binary.

Guidelines for Your Research in Consideration of Transgender Subjects

If you are recording sex or gender for your study, consider if there is a scientific or subject safety rationale for needing to know whether a potential subject is transgender (i.e., an individual whose gender identity and/or gender expression differs from biological sex assigned at birth). You will also be prompted to think about how transgender subjects may impact your study in the Protocol template.

  • If there is a scientific and/or safety rationale for collecting information on whether a subject is transgender, consider the following:
    • Why is information on sex and/or gender being collected?
    • Are transgender individuals eligible for participation in this study?
      • Transgender subjects may not be excluded unless there is a scientific or subject safety rationale for doing so.
    • Incorporate relevant questions for transgender and gender nonconforming individuals into relevant study documents (i.e. protocol eligibility, screening forms, demographic questionnaires, surveys), per the website guidance.
      • Whenever possible, place sex and gender-related questions on self-administered portions of a survey.
    • If there is no scientific or safety-related rationale for needing to identify sex or gender for your study, you should not collect information on transgender and gender nonconforming people’s identification. As with all data collected for research, the minimum amount of data necessary to answer the research question at hand should be recorded in an effort to decrease burden and protect subject privacy.
    • Here are examples of questions for identifying transgender and gender nonconforming people. Whenever possible, these questions should be visible on the same page of your study documents to allow transgender people to see all options that are available for selection:
  1. What is your current gender identity? (Check all that apply.)
  • Male
  • Female
  • Transgender female / trans woman (or Male-to-Female (MTF) transgender, transsexual, or on the trans female spectrum)
  • Transgender male / trans man (or Female-to-Male (FTM) transgender, transsexual, or on the trans male spectrum)
  • Non-binary, genderqueer, or genderfluid
  • Other gender identity:
  1. What sex were you born/assigned at birth (i.e. sex written on original birth certificate)?
  • Male
  • Female
  • Other:

[Asking pronouns might also be helpful]

  1. What pronouns would you like study staff to use when referring to you?
  • He/him/his
  • She/her/hers
  • They/them/theirs
  • Other (please specify):

Tips for Researchers

  • Use the terms sex when reporting biological factors and gender when reporting gender identity, psychosocial or cultural factors.
  • Consider if it is relevant to include questions regarding sexual health history and/or sexual orientation (for example, if a study drug impacts fertility and requires specific birth control methods reference “people who could become pregnant”).
  • Consider how best to respect pronoun and honorific preferences in template letters, lab results, telephone scripts, in-person interactions, etc. It may be useful to color-code files based on such preferences.
  • Do not assume pronouns or honorifics when interacting with a subject until they identify their preference.
  • Avoid presuming roles whenever possible. For example, use terms such as “spouse/partner” rather than “husband/wife,” “boyfriend/girlfriend,” etc.
  • Consider online or self-administered disclosure of sexual identification, if possible with your research study, to allow subjects to self-identify in a more private manner. Since sexual identification is sensitive in nature, it may be helpful to review the Confidentiality and Data Security Guidelines for Electronic Research Data to ensure protection of this information.
  • Avoid using “I’d rather not say” as a designated option around sex and/or gender in your study documents. If you are requesting this information from subjects, you are already identifying that there is a scientific and/or safety-related rationale for requiring this information.
  • Incorporate gender-neutral diagrams in research materials.
  • For studies that involve referring to body parts, ask transgender participants if there are certain terms they prefer you use other than the medical ones (for example, “front hole” rather than “vagina”).
  • Train your research team members to increase their comfort level in asking and answering sensitive questions from subjects.
    • Consider starting the conversation with – “We ask all participants these questions…”
    • The Fenway Institute has a multitude of training resources!
  • Transgender populations are more susceptible to socioeconomic disadvantages. Make your best effort to ensure that your research is accessible to all socioeconomic groups.


1. “Do Ask, Do Tell: Talking to Your Health Care Provider About Being LGBT” brochure
2. Fenway Health: Glossary of Gender and Transgender Terms
3. Reporting Sex, Gender, or Both in Clinical Research?
4. Ready, Set, Go! Guidelines and Tips for Collecting Patient Data on Sexual Orientation and Gender
5. Sex and Gender Equity in Research: rationale for the SAGER guidelines and recommended use
6. Canadian Institutes of Health Research Online Training Modules: Integrating Sex & Gender in Health Research

Online training modules:

• Sex and Gender Considerations in Biomedical Research
• Sex and Gender Considerations in Data Collection in Humans

7. Reviewer Guidance to Evaluate Sex as a Biological Variable [PDF (228 KB) – external link] (U.S. National Institutes of Health)
Best practices for asking questions to identify transgender and other gender minority respondents on population-based surveys (The Williams Institute)
Lesbian, Gay, Bisexual and Transgender Persons & Socioeconomic Status (American Psychological Association)