Christ JP, Yu O, Schulze-Rath R, et al. - Researchers herein completed a 10-year retrospective cohort study using Kaiser Permanente Washington electronic health records database with the aim to describe endometriosis incidence and prevalence in a US population. In addition, they investigated the factors affecting these estimates over time. They identified 2,863 incident endometriosis cases among 332,056 eligible women who contributed 1,176,329 person-years during the 10-year study period, indicating an average incidence of 24.3 cases per 10,000 person-years. Analysis suggested a decline in incidence rates over the study interval from a high of 30.2 per 10,000 person-years in 2006 to 17.4 in 2015; the rates were highest among women 36-45 years in most years. The rates declined uniformly across age groups, races/ethnicities, and the main diagnosing modalities and providers. In the US, a shift in practice patterns away from the diagnosis of endometriosis both clinically and surgically is indicated by the declining rates, rather favors more general diagnoses of chronic pelvic pain. Prevalence of endometriosis in 2015 in the US is in line with outcomes from recent researches outside the US utilizing health record data.