Historically, there has been a considerable lack of research on care for transgender individuals. Expanding on this data could go a long way toward addressing the health inequities that disproportionately affect this group as well as toward understanding and meeting their unique health care needs.

Nevertheless, the first step in gathering more healthcare data on transgender people is to accurately identify these patients in electronic medical records. Multiple studies have attempted to identify transgender individuals’ health care records using International Classification of Diseases (ICD) codes related to gender identity.

The problem is that ICD codes related to gender identity have not been consistent over time. They have changed from “sexual and gender identity disorders” in the Ninth Revision of the ICD (ICD-9), to “transsexualism” and “gender identity disorder” in the Tenth Revision of the ICD (ICD-10).

Gender-related diagnoses were completely removed from the Eleventh Revision of the ICD (ICD-11) since being transgender is not a medical diagnosis. Certainly, this is a good step toward ceasing to treat transgender identity like a medical condition, but since there is no specific code for transgender identity, identifying these patients can become a challenge.

Recently, a team of researchers tested the sensitivity and specificity of 5 frequently used ICD codes to identify transgender individuals in the Veterans Affairs (VA) medical database. They used the ICD-9 codes 302.5 (transsexualism) and 302.6 (gender identity disorder of childhood), as well as the ICD-10 codes F64.0 (transsexualism), F64.8 (diagnosis of other gender identity disorders), and F64.9 (gender identity disorder, unspecified).

Specifically, the researchers aimed to identify transgender women in the VA database (as the majority of veterans are assigned male at birth). Therefore, they also looked for ICD codes for bilateral orchiectomy, which is a surgery to remove both testicles. Importantly, people may identify as transgender without pursuing any gender-affirming treatments like hormone therapy or surgery, but bilateral orchiectomy is a common gender-affirming surgery for transgender women.

A total of 10,738 patients in the VA electronic medical record were identified as having one of the 5 ICD codes related to gender identity. The researchers then randomly selected 32 patients for each code (half with and half without orchiectomy) for a more in-depth review of their charts to determine if they identify as transgender.

This analysis revealed that for each ICD code, 88% to 100% of the patients (with or without orchiectomy) had a confirmed transgender identity upon more extensive analysis. Most of the transgender women in this study (66%-100% per ICD code) were undergoing gender-affirming hormone therapy.

Based on these results, the investigators determined that the 5 ICD codes are very sensitive in identifying transgender status, and these codes along with orchiectomy are extremely sensitive in identifying transgender women in particular.

References:

• Nik-Ahd, F., Waller, J., De Hoedt, A.M., Garcia, M.M., Figueiredo, J.C., Carroll, P.R., Cooperberg, M.R., & Freedland, S.J. (2023). Seeing the unseen: how can we best identify transgender women within the Veterans Affairs healthcare system’s electronic medical record?. The Journal of Sexual Medicine, 20(4), 559-567. https://doi.org/10.1093/jsxmed/qdac033
  
  
• World Health Organization. (2023). International Statistical Classification of Diseases and Related Health Problems (ICD). https://www.who.int/standards/classifications/classification-of-diseases