Putting a stop to misconceptions about race and endometriosis

by Olga Bougie, Rajan Gill, Andrew W Horne, Sukhbir S Singh, and Leslie V Farland

When we go back to look at the first decades of research into potential explanations for why women develop endometriosis, there is a strong theme around two misconceptions: that endometriosis is more common in white women and that endometriosis is more common in women of higher socioeconomic status.

The societal structure in the United States at the time largely contributed to these misconceptions, as white women of higher socioeconomic status were more likely to delay childbearing and may have felt more empowered to discuss their symptoms with their healthcare providers.

Fast forward to 2020, we know that endometriosis does not occur more often in women of higher socioeconomic status, but we still know little about the whether endometriosis is more or less likely to occur in women of different racial/ethnic backgrounds.

What does the science say?

A systematic review and meta-analysis (ie. a study that tries to summarise the results of all other studies looking at the same question) found that compared with white women, black woman were ~50% less likely to be diagnosed with endometriosis, whereas Asian women were ~60% more likely to have this diagnosis [1].

Hispanic women were also ~50% less likely to be diagnosed with endometriosis, compared to white women.

One of the largest studies that explored this question is the Nurses Health Study II [2]. They studied 1,721 women who were diagnosed with endometriosis between 1989 and 1999.

Their findings were similar: compared to white women, black women were ~40% less likely to be diagnosed with endometriosis. However, they saw similar rates of endometriosis in Hispanic and Asian women, compared to white women, albeit the number of women in these racial/ethnic minorities was small in the group.

Challenge of studying relationship between race/ethnicity in endometriosis

So, why exactly is it so challenging to study the relationship between race/ethnicity and endometriosis?

To start, it can be very difficult to diagnose endometriosis. There are many factors that contribute to a common delay in endometriosis diagnosis including inconsistent symptom recognition by both the patient and the healthcare provider, delayed transfer to specialty care, and surgical-confirmation of endometriosis (which currently serves as the gold standard for diagnosis).

To illustrate this, one of our endometriosis patients wrote the following account of her experience:

I am in my late forties, of East-Indian descent and I was diagnosed and treated for endometriosis stage IV this past year. When I think back to the time when I started having menstrual periods, all I can think of is pain and heavy bleeding. The topic of menstrual flow is considered a very private matter and not openly discussed in my culture.

I remember trying to talk to my mother and grandmother about it but they just made me believe that what I was experiencing was normal. I remember being confused about how this much pain and bleeding could be normal. After becoming an adult, I remember raising this up with my family physicians in hopes that they could give me an answer and/or cure but they just treated the symptoms and didn’t feel further investigations were required.

Even in 2020, the early endometriosis research that characterised endometriosis patients as affluent, nulliparous women, may contribute to unconscious diagnostic biases and stereotypes. In some countries and social settings, there are known disparities in health care coverage and quality across racial and socioeconomic groups.

Given these known barriers to receiving healthcare in many countries, it is challenging to interpret endometriosis research related to race/ethnicity:

Are women from under-represented racial/ethnic groups less likely to have endometriosis lesions? OR
Are they less likely to receive appropriate care? OR
Are they less-likely to discuss their symptoms with their healthcare providers?

Admittedly, it is very hard to design and carry out an appropriate study to look at the relationship between race/ethnicity and endometriosis.

The vast majority of research on this topic has reported relatively basic information on prevalence of the disease (how many people have the disease at any one point in time) by racial/ethnic groups, with little information on disease stage, severity, or symptom profiles.

Moving research in endometriosis forward

We, therefore, suggest that moving forward, patients and their health care providers advocate to dispel the myth that the prevalence of endometriosis differs in women of different racial/ethnic groups.

Future research should focus on patient experience and should recognise that patients from different racial/ethnic backgrounds may present with different symptoms, may express different treatment preferences, and may respond differently to treatments.