Personalized Medicine Must Integrate Sex and Gender to Prevent Health Inequalities

Personalized medicine seeks to tailor prevention, diagnosis, and treatment to each person’s characteristics. However, this goal will remain incomplete unless biomedical research and clinical practice systematically incorporate sex- and gender-related differences. This is the argument put forward by Dr. Maria Rosa Ballester, Head of Responsible Research and Innovation at the Institut de Recerca Sant Pau (IR Sant Pau), in an editorial published in the European Journal of Internal Medicine.

The article examines how many diagnostic and therapeutic protocols considered universal have been developed based primarily on evidence obtained from male populations. This situation has created knowledge gaps regarding women’s health that can lead to delayed diagnoses or treatments that are less effective and safe.

“We cannot speak of truly personalized medicine if we continue to apply knowledge derived from only part of the population as though it were equally valid for everyone. Incorporating sex and gender improves the precision, safety, and quality of healthcare,” explains Dr. Ballester.

Differences That Affect Diagnosis and Treatment

Sex encompasses biological characteristics that can influence, for example, how the body absorbs, distributes, metabolizes, and eliminates medications. Gender includes social and cultural factors that shape exposure to certain risks, the perception, and expression of symptoms, healthcare-seeking behavior, and adherence to treatment. Both dimensions also interact with age, ethnic background, socioeconomic status, and other personal circumstances.

The article presents examples involving conditions such as depression, chronic obstructive pulmonary disease, and acute myocardial infarction. In the latter case, women may experience symptoms such as nausea, fatigue, or jaw pain, which have traditionally been considered “atypical,” and face longer delays in diagnosis and access to treatment.

“When these differences are not investigated, they can easily go unnoticed and ultimately carry over into clinical guidelines and healthcare delivery. The result is not only a lack of equity but also less precise medicine,” the researcher notes.

From Evidence to Action

To address this gap, the editorial calls for balanced representation of women in clinical studies, the analysis of results disaggregated by sex and gender, and more extensive training for researchers and healthcare professionals. It also advocates effectively incorporating this knowledge into clinical guidelines and medical education.

In this context, the editorial refers to the ten-point action plan Health Without Bias: 10 Keys to a Catalan Healthcare System With a Sex and Gender Perspective, developed as part of the Health Without Bias initiative. The document sets out ten proposals for advancing toward a more equitable healthcare system and calls on, among other stakeholders, the institutions responsible for funding research and designing public policies.

This approach is also connected to the creation of XWHIN (Women’s Health Innovation Network), the Catalan women’s health innovation network led by IR Sant Pau and directed by Dr. Ballester. The initiative brings together stakeholders from research, clinical practice, innovation, technology transfer, and civil society to incorporate a sex and gender perspective throughout every stage of R&D&I and promote more precise and equitable solutions.

“The editorial explains why this change is necessary and which transformations need to be promoted, while initiatives such as XWHIN enable us to advance its implementation through a stable collaborative structure. The goal is for this perspective to no longer depend on isolated initiatives and to be integrated from the formulation of research questions through to the application of findings in clinical practice,” concludes Dr. Ballester.

Reference Article:

Ballester-Verneda MR. Sex and gender in the era of personalized medicine: beyond one-size-fits-all. Eur J Intern Med 2026:107092. https://doi.org/10.1016/j.ejim.2026.107092.