The Incidence of Endometriosis, 2014–2022. An Analysis of Nationwide Claims Data From Physicians in Private Practice

Abstract

Background: The epidemiological characterization of endometri - osis, particularly with regard to its incidence, has been inadequate to date both in Germany and other countries. The goal of this study was to determine trends in the incidence of diagnosed endometri - osis and changes in age structure at the time of first diagnosis over the period 2014-2022.

Methods: Nationwide claims data from physicians in private practice, obtained according to relevant German law (§ 295 SGB V), were used to identify the population at risk for a first assured diagnosis of endometriosis (ICD-10-GM: N80) during each year of the study period, consisting of women and girls aged 10-52 who were insured by the statutory health insurance system and for whom at least two years of prior observation were possible. Patients were defined as incident if they were documented as having received a first confirmed diagnosis of endometriosis, according to the case definition, during the study year. The case definition comprised multiple options for validating the diagnosis.

Results: The incidence of diagnosed endometriosis rose over the period of the study from 2.8 per 1000 persons at risk in 2014 to 4.1 per 1000 in 2022, corresponding to a 44% relative increase. There was also a marked shift in agespecific incidence toward higher values at younger ages: the median age at diagnosis fell from 37 years (2014) to 34 (2022).

Conclusion: This is the first study providing nationwide population-based data on the incidence of endometriosis in Germany. The observed rise in newly diagnosed cases is presumably mainly due to an increased awareness of endometriosis and to the growing recognition of the disease.

Figure 1

Determination of the annual populations at risk after 2-year / 5-year diagnosis-free pre-observation period. The years (2014–2016) for which no 5-year pre-observation period could be depicted due to limited data availability are shown with green arrows only. For years with both a green and a blue arrow, two populations at risk are identified, one for the 2-year (green) and one for the 5-year (blue) pre-observation period. The corresponding absolute values are shown in Table 1.

Figure 2

Development of the annual cumulative incidence of diagnosed endometriosis during the period 2014–2022 with diagnosis-free pre-observation periods of different lengths. Data source: Outpatient claims data from SHI-accredited physicians in private practice, obtained according to section 295 of Book V of the German Social Code (SGB V)

Figure 3

Development of the annual age-specific cumulative incidence of diagnosed endometriosis during the period 2014–2022, based on a diagnosis-free pre-observation period of 2 years. Data source: Outpatient claims data from SHI-accredited physicians in private practice, obtained according to section 295 of Book V of the German Social Code (SGB V)

eFigure

Development of the annual cumulative incidence of diagnosed endometriosis during the period 2014–2022 with diagnosis-free pre-observation periods of two years for each of the individual validation criteria used for the applied case definition as well as two additional validation criteria that are commonly used in health services research. Data source: Outpatient claims data from SHI-accredited physicians in private practice, obtained according to section 295 of Book V of the German Social Code (SGB V) M2QR, diagnosis in one quarter of the calendar year and in at least one of the following three patient-individual quarters (“on a rolling basis“; *Complete validation for the year 2022 of this criterion not possible at the time of analysis, because data were only available up to first quarter 2023); M1Q+FG, diagnosis documented by a specialist (gynecology) in one quarter of the calendar year; M1Q+GOP, diagnosis in one quarter of the calendar year and at least one claimed specific EBM fee schedule item (GOP) in the same treatment case; M1Q+OPS, diagnosis in one quarter of the calendar year and at least one documented specific OPS code (outpatient/by external physician using hospital facilities) in the diagnosis quarter; (OPS, operations and procedures key). *² M1Q, diagnosis in at least one quarter of the calendar year without additional criteria of diagnosis validation; M2Q, diagnosis in at least two quarters of the calendar year. The M1Q and M2Q criteria are common validation criteria used in routine data-based health services research and thus presented in addition to the validation criteria used for this study.