Yu O, et al. - Researchers performed a retrospective population-based cohort study of women aged 16–60 years in 2006–2015, enrolled in Kaiser Permanente Washington, a mixed-model health insurance and care delivery system, in order to determine the incidence, 10-year secular trends, and prevalence of adenomyosis diagnoses. In addition, they described symptoms and treatment patterns. ICD codes from the International Classification of Diseases 9th and 10th editions were applied to identify adenomyosis diagnoses and computerized databases were assessed for assessing potential covariates. For incidence calculations, they identified a total of 333,693 women contributing 1,185,855 woman-years (2006–2015). They identified associated symptom-related codes (menorrhagia or abnormal uterine bleeding, dysmenorrhea or pelvic pain, dyspareunia, and infertility) in 90.8%; co-occurrent endometriosis codes were reported in 18.0% and co-occurrent uterine fibroid codes were observed in 47.6%. Analysis here revealed a high incidence of adenomyosis burden to the individual and the health care system. Black women exhibited disproportionately high incidence rates. Given the limitation of the currently available long-term medical therapies beyond hysterectomy, these findings are of concern. The novel data and methodologies inscribed in this work could guide clinicians and health care systems to develop clinical management plans and track outcomes for women with adenomyosis.