Introduction: Endometriosis diagnostic delay can exacerbate pain and infertility, contribute to mental‑health burdens, and increase economic strain. Women in underrepresented, underserved, and under-reported (U3) groups may face even greater barriers, contributing to disparities that remain poorly understood. Our objectives were to characterize the distribution of endometriosis diagnostic delay within a large population-based cohort and quantify sociodemographic disparities.

Methods: We used the Utah Population Database to build a cohort of women with pelvic pain and assess burden of endometriosis diagnostic delay. U3 status was characterized by race/ethnicity, education, and residence. Diagnostic delay was calculated as the time between first pelvic pain and endometriosis diagnosis, with a six‑month washout period. Associations between U3 characteristics and continuous diagnostic delay were analyzed using generalized linear models (gamma distribution) to produce adjusted geometric mean ratios (GMRs) with 95% CIs.

Results: Among our cohort of 29,154 women, diagnostic delay averaged 7.4 years (median 5.67; range 0.50–29.02 years). 28.9% had one U3 characteristic and 7.5% had two or more (Figure 1). After adjusting for age at baseline and other U3 characteristics, women who identified as Hispanic or non-white had a 6% higher aGMR delay compared with those who identified as non-Hispanic and white (95% CI 3%, 9%). Women with some high school or less had a 7% higher aGMR delay than those with higher education (95% CI 4%, 10%). Living in rural or frontier areas, compared to urban, showed no difference in diagnostic delay (aGMR -3%, 95% CI -6, 0% and aGMR 2%, 95% CI -3%, 8%).

Conclusion: Among this population-based Utah cohort, average endometriosis diagnostic delay exceeded seven years and was longer for women who identified as Hispanic or non‑white, and those with lower‑education. Further exploration of geographic residence in relation to diagnostic delay is warranted.