Developing Measures of 

Intersex Status/Differences in 

Sex Development at the 

Population Level

Katharine Dalke, M.D.

Penn State University 

Committee on Measuring Sex, Gender Identity, and Sexual Orientation

Tara Becker

National Academies of Sciences, Engineering, and Medicine

Study Director, Committee on Measuring Sex, Gender Identity, and Sexual 

Orientation

MAY 12, 2022 AAPOR ANNUAL MEETING
Is the “I” for Invisible?

Biological factors:

• Intersex populations are defined by biological variations

– Variations can be of any sex characteristic, internal and/or external

• Intersex variations typically thought of as low frequency

– Highest estimates of sex variation are 1.7%

– Genital difference (ambiguity) much less common, 0.02-0.05%

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Is the “I” for Invisible?

Legal and Psychosocial Factors:

• Most people are assigned either male or female at birth

• Medical treatment has emphasized a binary approach:

– Concealment of diagnostic and treatment history prioritized

– Early surgical intervention standard treatment, especially for people with 

genital difference

• Shame and concealment are common experiences among intersex 

populations

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However, most people with intersex traits 

report that they are willing to disclose this 

information in a survey setting.

(Tamar-Mattis et al., 2018)

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But how, and where?

• As a measure of sex, intersex/DSD status is a demographic measure

• Intersex/DSD status is also associated with a range of medical conditions

• When provided with the option, most people with intersex traits will choose 

“intersex” as a component of their gender identity (Rosenwohl-Mack et al, 

2020)

• Many surveys that assess intersex status do so as an option for sex 

assigned at birth (on the original birth certificate)

• Several community and advocacy groups have recommended a separate 

intersex status question

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Conclusion 2:

Intersex status is an important component of demographic status, private 

medical information, and an aspect of identity. Although there are barriers to 

disclosure, people appear to want to disclose their status. 

Because of historical, legal, and medical factors, almost no person in the 

United States is assigned intersex at birth. Therefore, it is inappropriate 

to assess intersex status primarily with an “intersex” response 

option for sex assigned at birth; however, when sex assigned at birth is 

asked, it may be appropriate to include “prefer not to answer” or “do not 

know” options.

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Recommendation 6:

When the National Institutes of Health seeks to identify 

people with intersex traits or differences of sex 

development in clinical, survey, research, and 

administrative settings, they should do so by using a 

standalone measure that asks respondents to report 

their intersex status. They should not do so by adding 

“intersex” as a third response category to a binary measure of 

sex.

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Intersex/DSD Status Measures with the Strongest 

Evidentiary Support

• Very little evidence on the quality of intersex/DSD status measures is 

available.

– Only one study asked community members for feedback on a measure (TamarMattis et al., 2018)

– Three studies used variations of recommended measures in LGBTQ+ populationbased surveys with low non-response rates but wide range of positive responses 

(Medina and Mahowald, 2021; Price et al., 2021; Bradbury-Sullivan, 2021)

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Intersex/DSD Status Measures with the Strongest 

Evidentiary Support

• Three question stems have been tested in population-based surveys, but 

little evidence is available to assess their relative quality:

– Have you ever been diagnosed by a medical doctor or other health professional 

with an intersex condition or a difference of sex development (DSD) or were you 

born with (or developed naturally in puberty) genitals, reproductive organs, or 

chromosomal patterns that do not fit standard definitions of male or female?

– Were you born with a variation in your physical sex characteristics? (This is 

sometimes called being intersex or having a difference in sex development, or 

DSD.)

– Have you ever been diagnosed by a medical doctor with an intersex condition or a 

difference of sex development’?

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Conclusion 3:

Based on the best available evidence, community guidance, and expert 

opinion, intersex status can be measured using the following question: 

Have you ever been diagnosed by a medical doctor or other health 

professional with an intersex condition or a difference of sex development 

(DSD) or were you born with (or developed naturally in puberty) genitals, 

reproductive organs, or chromosomal patterns that do not fit standard 

definitions of male or female?

□ Yes

□ No

(Don’t know)

(Prefer not to answer)

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Intersex/DSD Status: Topics for Future Research

RECOMMENDATION 7: To improve the quality and inclusivity of current measures of 

intersex status, the National Institutes of Health should fund and conduct research on 

the following topics:

• The use of a single-item intersex/DSD status question

• The relative quality of the three measures of intersex/DSD status identified by the 

panel

• The effects of using terminology such as “intersex” or “DSD” or definitions of these 

terms in question stems or supplemental text

• The prevalence of “intersex” as a gender identity term among people with intersex 

traits

• Proxy reporting of intersex/DSD status, particularly by parents

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Thank you!

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Access The Report:

https://nap.nationalacademies.org/catalog/26424/measur

ing-sex-gender-identity-and-sexual-orientation

Staff Contacts

Tara Becker, Study Director

tbecker@nas.edu

Katrina Stone, Senior Program Officer

kstone@nas.edu