OBJECTIVES: The aim of this study was to evaluate the characteristics of patients diagnosed with endometriosis in Spanish hospitals, to measure incidence within the hospital setting and the associated medical costs.

METHODS: Admission records of patients with endometriosis registered between 2009 and 2018 were obtained from a Spanish hospital discharge database and analyzed in a retrospective multicenter study. All records of ambulatory visits and hospital admissions in which endometriosis was listed as the admission motive were claimed and the primary diagnosis was used to classify patients according to the tissue affected.

RESULTS: Files from 41,118 individual patients were obtained, with a median age of 37 years (IQR=11). Patient’ age increased significantly over the study period (p<0.0001). Data corresponded primarily to inpatient and programmed admissions, with a median length of stay of 3 days that increased significantly with patients’ age (p<0.0001). Admissions were mainly associated to surgical procedures (73.3%), namely local excision or destruction of lesions. The majority of secondary diagnoses registered corresponded to inflammatory disease of female pelvic organs (21.7%); 9.2% of patients presented neoplasms of uterus and only 0.9% registered ovarian neoplasms. Mean admission cost was €3566 over the study period. The mean costs per admission were €3778, €3433 and €4020 for adenomyosis, ovarian endometriosis and other endometriosis types, respectively. The higher costs per admission were registered in patients admitted due to intestine endometriosis, reaching the €8052. Higher admission costs were associated to programmed admissions, surgical procedures and patients’ age.

CONCLUSIONS: The majority of admissions reviewed in this study corresponded to the removal of ovarian lesions, although data suggested a decrease in the number of cases that were treated as hospital inpatient admissions over the study period. Older patients, surgical procedures and lengthier admissions were associated with higher medical costs.