The first time I saw a preceptor use the American College of Cardiology’s atherosclerotic cardiovascular disease (mercifully, ASCVD) risk calculator, I was hooked. As a first-year medical student, data nerd, and aspiring primary care provider, I love a good diagnostic tool. Watching as he entered our patient’s pertinent medical history, I ran down the list of risk factors for cardiovascular disease we’d just learned in my head: age, blood pressure, cholesterol, smoking history, sex —

“Hang on,” I asked, looking at the options for sex: male or female. “What do you enter when your patient identifies as transgender?”

I learned to ask this question working as a clinical research coordinator on a study documenting how stress and stigma impact the health of Black and Latina transgender women living with HIV. Participants explained again and again how our medical system’s binary assumptions about sex and gender harmed their health, their relationships with providers, and their trust in a system that was clearly not designed with gender-expansive people in mind.

“Gender-expansive” is a term that encompasses people whose gender identity differs from their sex assigned at birth, including those who identify as transgender, non-binary, and gender non-conforming. Recent estimates suggest that 1.6% of the US adult population — 5.3 million people — identify as gender-expansive. That number climbs to 5.1% among those aged 18-29 as younger generations feel increasingly safe to share their gender identity. 

Providers need to recognize that LGBTQ+, and specifically gender-expansive, individuals make up a growing share of our practice. Unfortunately, medical education and screening tools are lagging behind.

Take the ASCVD calculator, for instance. A recent study evaluated the calculator’s predictions for the cohort of transgender women I worked with last year—first calculating each individual’s risk score using their sex assigned at birth (male,) then using their gender (female,) and lastly their current hormone therapy regimen. The results are striking: when all patients were coded as male, the calculator recommended 35% of them be prescribed statins, versus only 18% when all were coded as female – and still just 22% when coded according to their current hormone therapy regimen.

If your patient fell into that gap, would you prescribe the statin?

Currently, the ASCVD calculator’s estimate of a patient’s 10-year risk of a cardiovascular event relies on five landmark cardiovascular health studies, each of which reported only participants’ sex, not their gender identity, gender expression, or hormone use. Similarly, the calculator’s therapeutic recommendations for cholesterol treatment are based on a systematic review of ten randomized controlled trials that only report sex.

When applying these systems to gender-expansive patients, guessing wrong could mean prescribing unnecessary statins to 17% of our study participants—exposing them to an increased risk for diabetes, hemorrhagic stroke, and muscle pain. On the other hand, providers could end up denying potentially life-saving statins to up to half of the people indicated.

Put simply, the ASCVD calculator is built on binary data, so it only works for people who meet binary assumptions about sex and gender. In a world where sex and gender exist on a spectrum, this fundamental flaw represents a systemic failure in medicine that is harming millions of patients.

Underreporting gender identity and sexual orientation is not unique to cardiology; of the 32,500 articles published in top dermatology journals over the past decade, just 0.02% included and discussed these issues. Federal data are also lagging; only 36 states ask their residents the CDC’s standardized sexual orientation and gender identity (SOGI) questions. This is despite evidence that people are comfortable answering questions about their sex and gender—in fact, preferring it to discussing their income.

Our patients deserve evidence-based care, and we desperately need better data in order to provide it. Recognizing this, the Biden administration has issued the first-ever Federal Evidence Agenda on LGBTQ+ Equity, calling for increased federal SOGI data collection. As researchers and practitioners, it is imperative that we follow suit.

This mission is long overdue, and medicine-wide tasks like updating decision-making tools like the ASCVD calculator– and their underlying bodies of data– require more than day-to-day conversations. However, providers can start small and still make a world of difference. 

Providers report feeling uncomfortable asking patients about gender identity, citing lack of training and nowhere to document their findings in electronic health records. In response, the CDC worked with a LGBTQ+-focused clinic in Boston to develop a comprehensive guide to SOGI data collection in clinic. Resources like this give providers an opportunity to educate themselves on the fundamental medicine, terminology, and documentation needed until we can better incorporate LGBTQ+ health into medical school curricula. Beyond the exam room, clinical research studies must incorporate validated SOGI data collection measures, both for the sake of their own results and for the meta-analysis that follows.

Gender-expansive patients deserve better care than our current medical system and diagnostic tools can provide. As providers, researchers, and advocates for the LGBTQ+ community, it is our responsibility to challenge our assumptions about gender identity and our system to do better– only then can we truly do no harm.

Alexandra Beem is a medical student.