Prevalence and Time of Diagnosis of Endometriosis across Racial and Ethnic Groups in the US

Background: Endometriosis is associated with substantial adverse health and psychosocial consequences. However, the prevalence of endometriosis across different racial and ethnic groups in the US has not been established and to what extent the difference in prevalence might be associated with systemic barriers to receiving the diagnosis is unknown. We aimed to estimate the prevalence of endometriosis across different racial and ethnic groups and examine the association between race/ethnicity and the time of diagnosis. Methods: Using cross-sectional data from the National Health and Nutrition Examination Survey 1999-2006, we estimated race/ethnicity-specific prevalence of self-reported diagnosis of endometriosis among 5,557 women aged 20-54 years. Multivariable generalized linear regression model examined the association between race/ethnicity and the age of endometriosis diagnosis, accounting for socioeconomic indicators, health insurance, lifestyle and reproductive characteristics. Results: Endometriosis was prevalent in 9.0% overall, 11.1% among non-Hispanic white, 5.8% among non-Hispanic black, 2.7% among Hispanic, and 6.4% among the other racial and ethnic groups combined. The mean age of endometriosis diagnosis was 29.0 years (range 13-52). Compared with non-Hispanic white, non-Hispanic black women were diagnosed on average at 2.6 years older (95% confidence interval [CI], 0.5-4.6), Hispanic women 3.8 years older (95% CI, 1.5-6.2), and women in the other group 1.0 years younger (95% CI, -4.6 to 2.5). Conclusions: Prevalence of endometriosis varied across different racial and ethnic groups. Among women with a diagnosis of endometriosis, black and Hispanic women were diagnosed at older ages than non-Hispanic white women. Future research is needed to determine whether such age disparity in endometriosis diagnosis persists.