Educational and occupational outcomes during early adulthood following surgically verified endometriosis at a young age-A register-based study

E. Rasp contributed to conceptualization, methodology, formal analysis, data curation, writing—original draft, and visualization. L. Saavalainen contributed to conceptualization, validation, data curation, writing—review and editing, supervision, and project administration. K. Rönö contributed to conceptualization, validation, writing—review and editing, and supervision. M. Gissler contributed to conceptualization, methodology, and writing—review and editing. P. Härkki contributed to conceptualization and writing–review and editing. A. But contributed to conceptualization, methodology, investigation, data curation, and writing—review and editing. O. Heikinheimo contributed to conceptualization, resources, writing—review and editing, supervision, and funding acquisition.

The ethics committee of the Hospital District of Helsinki and Uusimaa approved the study (238/13/03/03/2013) on September 19, 2013. The registry‐keeping authorities approved data retrieval and linkage: the Finnish Institute for Health and Welfare (THL/5393/14.06.00/2023), Statistics Finland (TK/3123/07.03.00/2023), and Digital and Population Data Services Agency (DVV).

The Hospital District of Helsinki and Uusimaa. The first author acknowledges financial support from the Finnish Society of Obstetrics and Gynecology and the Finnish Medical Foundation.

The endometriosis cohort included 4532 women with surgically diagnosed endometriosis before age 25, and 9014 age‐ and municipality‐matched reference women. At the index date, their median age was 22.9 years (IQR 21.3, 24.1), and over 77% of them were born in the 1970s and 1980s. Before the index date, women with endometriosis were more often blue‐collar workers and lower‐level employees, and less often upper‐level employees or students compared to the reference women. They also had more preindex diagnoses of pain and depression or anxiety, and lower parity compared to those without endometriosis (Table  1 ). Of the women with endometriosis, 2333 were diagnosed with peritoneal, 1003 with ovarian‐only, 970 with combined/other types, and 226 with deep endometriosis at the time of the index date. Characteristics on the index date for the endometriosis cohort and the reference cohort, matched by age and municipality at the time of surgical diagnosis of endometriosis. n , (%). Abbreviation: IQR, interquartile range. Those aged under 15 or outside the labor force if not assigned the same socioeconomic group as the reference person in the household, long‐term unemployed, or others. Those aged under 18, unemployed, retired, or students. Analyses by the age groups of 26–30, 31–35, and 36–40 were performed among women reaching at least the ages of 26 ( n  = 13 323, 98.4%), 31 ( n  = 12 465, 92.0%), and 36 ( n  = 10 293, 76.0%) years, respectively. Table  S3 provides the characteristics of these subgroups. During the study period, 68 (2%) deaths and 123 (2.7%) emigrations occurred in the endometriosis cohort, compared to 97 (1%) deaths and 323 (3.6%) emigrations in the reference cohort. Across all the age groups, women with endometriosis were less likely to achieve upper tertiary education and more likely to complete only secondary or primary education compared to the reference group ( p  < 0.001). Women with endometriosis were less often upper‐level employees and more frequently lower‐level employees ( p  < 0.001). Additionally, they were less often students before age 25 ( p  < 0.001). Consistently, more women with endometriosis worked as upper white‐collar and blue‐collar workers compared to the reference cohort ( p  < 0.001). From the age group of 26–30 years onward, women in the reference group were more often working as managers and professionals than those with endometriosis ( p  < 0.001, Table  2 , Figure  1 ). Analysis of the most recent occupational and socioeconomic statuses before each age group confirmed similar trends (Table  S4 ). Educational level, socioeconomic status, and occupational level attained by women achieved before or at the age of 25, and at the age groups of 26–30, 31–35, and 36–40 in the endometriosis and the reference cohort. % of the initial cohort. % of those reached a certain age. Those aged under 15 or outside the labor force if not assigned the same socioeconomic group as the reference person in the household, long‐term unemployed, or others. Those aged under 18, unemployed, retired, or students. Educational level, socioeconomic status, and occupational level of the endometriosis and reference cohorts achieved by women before or at age 25, and aged 26–30, 31–36, and 36–40 years. Percentages were counted for 4532 women in the endometriosis and 9014 women in the reference cohort for the group before 25 years; for 4501 women in the endometriosis and 8917 women in the reference cohort reaching the age of 26; for 4253 women in the endometriosis and 8394 women in the reference cohort reaching the age of 31; and 3537 women in the endometriosis and 6999 women in the reference cohort reaching the age of 36 before the end of 2019. Cases of death and emigration were excluded in each age category. E refers to endometriosis, and R refers to women. Of the women completing upper tertiary education, women with endometriosis did so at an older age (median 29.6, IQR [26.6, 35.0]) compared to women without endometriosis (28.1, [26.3, 31.7]; p  < 0.001). Minor differences in age were observed for secondary education (19.9, [19.4, 21.7] vs. 19.8, [19.4, 21.4]; p  < 0.001) and lower tertiary education (25.2, [23.4, 28.8] vs. 25.0, [23.5, 27.7], p  < 0.001). Within the endometriosis cohort, women diagnosed with ovarian‐only endometriosis were more likely to achieve upper tertiary education compared to those with other subtypes of endometriosis at later ages. This difference was seen by ages 26–30 (12% vs. 8%, p  < 0.05) and became more pronounced at later ages (16% vs. 11% at 31–35 and 19% vs. 13% at 36–40, respectively, p  < 0.001). By the age of 25, women with ovarian endometriosis were less often working in upper white‐collar and blue‐collar occupations and more often categorized as others, including those outside the labor force ( p  < 0.001) (Table  3 ). Educational level, socioeconomic status, and occupational level attained by women achieved before or at the age of 25, and at the age groups of 26–30, 31–35, and 36–40 in the endometriosis cohort according to the type of endometriosis. % of the initial cohort. % of those reached a certain age. Those aged under 15 or outside the labor force if not assigned the same socioeconomic group as the reference person in the household, long‐term unemployed, or others. Those aged under 18, unemployed, retired, or students. Among women with endometriosis, those with a preindex diagnosis of depression or anxiety were less likely to attain tertiary education and more likely to have only primary or secondary education across the younger age groups. From the age group of 26–30 years onward, they were more often students or pensioners and less frequently employed as upper‐ or lower‐level employees ( p  < 0.001). They were less often working as managers or professionals and more often classified as “others,” including those who were unemployed ( p  < 0.001) (Table  4 ). Educational level, socioeconomic status, and the occupational level attained by women achieved before or at the age of 25, and at the age groups of 26–30, 31–35, and 36–40 in the endometriosis cohort according to the preindex depression or anxiety. % of the initial cohort. % of those reached a certain age. Combined due to a low number of events. Those aged under 18, unemployed, retired, or students. Those aged under 15 or outside the labor force if not assigned the same socioeconomic group as the reference person in the household, long‐term unemployed, or others. Women with endometriosis appeared more likely to reach higher occupational levels and were less frequently categorized as “others” when compared to the occupational status achieved by the reference counterpart by the same time (Table  S5 , Comparison 1). These differences remained after including depression/anxiety, parity, and pain prior to the attainment of the highest occupational status in the model. In contrast, when comparing the highest occupational status achieved during follow‐up for both the endometriosis and the reference groups (i.e., without limiting time for evaluation of occupational status among controls), these differences largely diminished. When analyzing the highest occupation attained over the entire follow‐up by women with and without endometriosis (Comparison 2), women with endometriosis had lower crude odds of being managers and professionals (OR 0.88, 95% CI [0.81–0.96]) than of being blue‐collar workers. After inclusion of age, parity, and depression/anxiety before the highest occupation, this association disappeared but slightly reversed following further inclusion of pain to the model (OR 1.15, [1.04–1.28]). Across comparisons between women with and without endometriosis, all variance inflation factors (VIFs) for diagnoses of depression/anxiety, parity, and pain prior to their highest occupational status remained below 3, indicating low multicollinearity. In mediation analyses, when limiting attainments to the reference cohort by time (Comparison 1), simplifying occupational status to a binary outcome (blue‐collar workers vs. others) showed no significant indirect effects for depression/anxiety or prior pain diagnoses. However, parity before the highest occupational status emerged as a significant mediator, accounting for approximately 10% of the total effect. Redefining the occupational outcome as managers and professionals versus others revealed a suppressive pattern. Depression/anxiety diagnoses accounted for −6% of the total effect, and prior pain diagnoses for −20%. Parity was not a mediator in this model. For Comparison 2, when using the blue collars versus others, no significant mediation effects were found for depression/anxiety, pain, or parity. However, comparing managers and professionals to others revealed that depression/anxiety (24% mediated) and pain (100% mediated) significantly mediated the association with endometriosis. Parity showed no effect in this comparison.

Receiving a surgical diagnosis of endometriosis at a young age seems to negatively affect educational and occupational outcomes in early adulthood. Using longitudinal data and focusing on long‐term educational and occupational attainment, we found that women with endometriosis were less likely than reference women to complete higher levels of education. Among those who did, educational attainment occurred at older ages. These women were also more likely to work in lower‐level occupational positions. Additionally, those with ovarian‐only endometriosis were more likely to complete upper tertiary education than women with other subtypes. Furthermore, women with endometriosis who had a preindex diagnosis of depression or anxiety were more often students or pensioners and less frequently employed in upper‐ or lower‐level positions. In contrast to our approach, prior studies have mainly relied on cross‐sectional designs, questionnaires, or interviews and have not assessed actual long‐term occupational outcomes. Few studies have examined the impact of endometriosis on education, but existing research generally suggests a negative association. Consistent with our findings, studies from Australia (2021) and Sweden (2024) also report that women with endometriosis are less likely to complete university education. 8 , 27 Interview‐based studies further support these findings, highlighting that endometriosis is linked to missed educational and career opportunities. 9 , 28 A Swedish historical questionnaire study from 2016 examined age‐related differences, finding that younger women were more likely to be students and had often quit their education due to endometriosis compared to older women. 11 We hypothesized that ovarian‐only endometriosis, typically associated with less pain, would show a more favorable effect on educational outcomes compared to other subtypes. 25 , 26 Indeed, women with ovarian‐only endometriosis were more likely to complete upper tertiary education after the age of 30. This finding aligns with previous studies. A French study from 2011 linked deep endometriosis to increased school absenteeism during menstruation, and a Danish study from 2025 reported that women with higher education had fewer symptoms of endometriosis. 15 , 29 As young adults with chronic pain are at risk for reduced educational attainment and lower occupational status, 12 it is likely that young women with endometriosis, especially those with more painful subtypes, face similar risks. Among women with endometriosis, those with a preindex diagnosis of depression or anxiety were more likely to attain only primary or secondary education and less likely to complete tertiary education compared to those without such diagnoses. This finding is consistent with prior research highlighting the negative impact of mental health on education. A U.S. study from 2011 showed that poor mental health at age 18 negatively affected educational and occupational achievements by age 30. 22 Similarly, a 2015 study from the Netherlands found that mental health issues during adolescence increased the likelihood of having only primary education or being neither employed nor in education. 23 Our findings on reduced occupational attainment align with previous studies, which have shown that endometriosis is associated with higher rates of short‐term absenteeism, poorer work performance, and less satisfaction with desired professions. A 2023 Australian study associated endometriosis with reduced workability, even after adjusting for factors like depression and socioeconomic status. 19 A 2019 German study highlighted that women with endometriosis were less likely to work in their desired profession and had to consider health‐related limitations when making career decisions. 7 A Danish case–control study from 2013 found that women aged 23–35 years with endometriosis reported poorer workability and more sick days due to symptoms. 17 Our findings from the multinomial regression analysis suggest that women with endometriosis tended to attain their highest occupational status when reference women may have still been pursuing education or progressing in their careers by the same time. This is further supported by age‐specific analyses, where women without endometriosis were more frequently categorized as “others” (most likely students) before the age of 25. When comparing the highest occupational status achieved during the follow‐up for both the endometriosis and the reference groups, these differences largely disappeared. When assessing the highest occupational outcomes across groups, including the model pain diagnoses recorded before the highest occupational status, it revealed potential restrictive effects of pain. Specifically, pain may limit progression into cognitively demanding (managers and professionals) roles among women with endometriosis. We did not observe a higher rate of early retirement during early adulthood. A U.S. longitudinal case–control study from 2020 reported increased risks of short‐term disability and slower salary growth, though no impact on long‐term disability among those with endometriosis. 30 Similarly, a Finnish study from 2021, partially overlapping with our cohort, reported reduced workability at age 46, with more absenteeism and short‐term disability, though fewer days were lost to unemployment. 16 In contrast, an Australian longitudinal cohort study from 2022 found that women with confirmed or suspected endometriosis were more likely to work part‐time or be unemployed over a 20‐year follow‐up. 27 However, since our follow‐up data do not extend beyond 40 years of age, it is possible that the trends observed in older women may differ. We did not observe statistically significant differences in occupational outcomes between ovarian‐only and other subtypes of endometriosis. However, when pain was included in the multinomial regression model, the results changed, indicating that pain significantly contributes to the association between endometriosis and career outcomes. However, the severity of endometriosis‐related pain seems to impact occupational outcomes. A 2024 Danish study found that those with more severe symptoms of endometriosis reported more limited occupational opportunities. 29 Similarly, a Danish study from 2013 linked higher pain levels to lower workability. 17 Additionally, a Puerto Rican cross‐sectional study from 2009 also found that severe endometriosis‐related pain led to greater work disruptions. 31 This interpretation is further supported by our mediation analysis, which suggested that prior pain diagnoses suppressed high‐status occupational attainment among women with endometriosis. We found that women with endometriosis and a preindex diagnosis of depression or anxiety were less likely to work in higher‐level roles and more likely to be pensioners or students. Our mediation analysis supported this, showing that depression or anxiety reduced the likelihood of reaching higher occupational roles among women with endometriosis. This aligns with previous research indicating that psychiatric comorbidities in women with endometriosis contribute to increased sick leave and reduced workability. 8 , 17 Our findings are consistent with studies examining the association between mental health disorders and occupational outcomes. For example, a U.S. interview‐based study from 2011 demonstrated that mental health issues in adolescence negatively impacted both educational and occupational attainment by age 30. 22 Similarly, a Dutch study from 2015 showed that mental health problems beginning in childhood deteriorated educational and occupational outcomes. 23 Furthermore, a Finnish case–control study from 2020 found that mood disorders and nonaffective psychotic disorders were associated with lower educational attainment and income levels. 32 In Finland, mental disorders are generally the leading cause of disability retirement, with over one‐third of women on disability pensions due to mental health issues. 33 Parity may influence educational and occupational outcomes due to potential maternity‐related interruptions in studies or careers. A Norwegian study from 2011 showed that early childbearing is associated with lower educational attainment. 34 Similarly, a 2021 Finnish study associated the high educational level of the municipality with lower teenage childbirths and induced abortion rates. 35 A 2014 U.K. study showed that having children reduces labor force participation, particularly among women in their 20s and 30s. 36 In our cohort, women with endometriosis had lower parity prior to diagnosis but were more often parous than controls at ages 26 and 31, with the difference disappearing by age 36. However, the inclusion of parity prior to the highest occupational status in the multinomial regression analysis did not affect our results. While it could be expected that lower early life parity would provide better opportunity for educational and occupational advancement within the endometriosis group, this was not observed. In mediation analyses, parity showed a modest indirect effect in only one comparison, accounting for 10% of the association between endometriosis and occupational status when defined as blue‐collar workers versus other roles. In all other comparisons, parity did not significantly mediate the association. These findings suggest that parity alone does not explain the observed occupational differences. There are several strengths in our study. We focused on women diagnosed with endometriosis at a young age and tracked their educational and occupational outcomes in early adulthood. Many previous studies have assessed occupational outcomes primarily by focusing on reported sick leave or by using questionnaires and interviews. To our knowledge, this is the first register‐based study to show differences in actual occupational outcomes between endometriosis and reference groups during early adulthood. A strength of our study is Finland's universal access to the same standard of health care, ensuring equal opportunities for diagnosis and management. Additionally, education in Finland is free and accessible to all, which strengthens the reliability of the analysis of the primary outcomes. The registers used consist of high‐quality data. 37 Moreover, we were able to compare outcomes between women with ovarian‐only endometriosis to other subtypes, and women with and without preindex diagnoses of depression or anxiety. Finally, the use of mediation analyses allowed us to explore potential explanatory mechanisms, particularly the roles of pain, mental health, and parity. While our study provides valuable insights into long‐term occupational and educational outcomes on young women's endometriosis, several limitations exist. Our findings highlight associations, but the underlying mechanisms remain unclear. Despite matching cohorts by age and municipality, residual confounding cannot be ruled out. We lacked data on parental socioeconomic status, which is known to influence both educational and occupational outcomes of offspring. Further, we lacked data on medication use. The outcomes may differ between women who receive comprehensive medical treatment and those who do not. Additionally, the presence of unmeasured confounding cannot be excluded. As our analysis focused on highest attained outcomes and only secondarily on latest occupational or socioeconomic statuses, students seem to be underrepresented, particularly among younger individuals who may have transitioned into working roles or combined work and study. Due to the small cell counts and the lack of key components such as income, we focused our multinomial logistic regression analyses on occupational outcomes instead of the socioeconomic variable. Education was further assessed by analyzing the difference between the ages of receiving the highest educational status. Women undergoing early surgery for endometriosis may have more severe forms of the disease, and new subtypes could develop over time. The distinction between ovarian‐only and other subtypes may not fully capture symptom complexity. Lastly, as the study was conducted in Finland and focused on young women undergoing surgery for endometriosis, the findings may not be generalizable to different populations.

Endometriosis diagnosed at a young age may result in negative long‐term impacts on socioeconomic outcomes. We find that early surgical diagnosis of endometriosis is associated with lower educational and occupational levels in early adulthood compared to women without endometriosis. More painful subtypes of endometriosis seem to be related to lower educational attainment. Additionally, preexisting diagnoses of depression or anxiety are associated with poorer educational and occupational outcomes, as well as a higher likelihood of early retirement. Future research should focus on further understanding of the differences in educational and occupational outcomes between those with and without endometriosis. Timely diagnosis and treatment, effective pain management, and access to mental health and educational support may help mitigate these challenges.

Endometriosis is a chronic inflammatory, estrogen‐dependent disease affecting 6%–10% of women of reproductive age. 1 , 2 The condition is characterized by a range of symptoms, including pelvic pain, dysmenorrhea, dyspareunia, and infertility. 3 Besides gynecological symptoms, endometriosis is associated with an increased risk of several psychiatric and somatic comorbidities and associated healthcare use. 4 , 5 , 6 These impact daily life, possibly posing limitations in achieving life goals, pursuing or completing educational aims, making career choices, or advancing within a chosen profession. 7 The onset of symptoms typically occurs at a critical period in life when many life‐changing decisions are being made. 1 The socioeconomic impact of endometriosis, particularly among those diagnosed at a young age, remains understudied. While existing research suggests that endometriosis can negatively influence educational and occupational progression, high‐quality longitudinal studies on this topic are limited. Most existing studies are cross‐sectional, rely on self‐reported data, and often lack control groups. Women with endometriosis have been shown to be less likely to complete tertiary education, 8 and many report not pursuing further education due to the condition. 9 , 10 Younger women with endometriosis report a negative impact on education and career plans, 11 and chronic illness or persistent pain during adolescence can disrupt both education and future work. 12 , 13 , 14 Deep endometriosis and high pain levels are associated with poorer educational attainment. 15 In the workforce, women with endometriosis experience higher rates of absenteeism, presenteeism, short‐term disability, and reduced workability. 16 , 17 , 18 , 19 , 20 Poorer workability is often associated with higher pain levels. 17 , 18 However, to our knowledge, no previous studies have directly assessed the attained occupational levels during early adulthood in this population. Endometriosis is also associated with a higher risk of depression and anxiety, including among adolescents. 4 , 21 These mental health challenges, when experienced early in life, are independently associated with lower educational achievement and poorer occupational outcomes in adulthood. 22 , 23 We studied long‐term educational and occupational outcomes in early adulthood (before age 40) among women who received a surgical diagnosis of endometriosis before the age of 25. Outcomes were compared to those of an age‐ and municipality‐matched reference cohort. These women were compared within multiple age groups (under 25, 26–30, 31–35, and 36–40 years). Additionally, we explored whether these outcomes varied according to subtypes of endometriosis. Given the association between endometriosis, depression, anxiety, reduced parity, and pain, and the established impact of these factors on socioeconomic status, we also examined whether they mediate the relationship between endometriosis and highest achieved occupational status.

The authors report no conflicts of interest concerning the present work.

The present study is part of a nationwide register‐based study on endometriosis. Women receiving the first surgical diagnosis of endometriosis ( n  = 49 956) in 1987–2012 were identified from the Finnish Hospital Discharge Register (FHDR), currently known as the Care Register for Health Care. Both elective and emergency procedures, with endometriosis as a primary or secondary diagnosis, were included. Women with adenomyosis only were excluded, as adenomyosis is considered a distinct condition from endometriosis and histological or radiological verification of diagnosis could not be consistently ensured based on register data. To form the endometriosis cohort, we included cases with a valid diagnostic code for endometriosis accompanied by relevant surgical procedure code(s), ensuring that the cases were surgically verified. The cohort formation has been described previously, and a previous quality assessment demonstrated a good diagnostic accuracy. 24 The index day was the hospital discharge day for the endometriosis patients. The reference cohort ( n  = 98 824) of women of the same age and municipality at the index date, without a surgical diagnosis of endometriosis before 2012, was retrieved from the Finnish Population Information System (FPIS), maintained by the Digital and Population Data Services Agency (DVV). This study included 4532 women receiving their first surgical diagnosis of endometriosis before the age of 25 years in 1987–2012. The reference group consisted of 9014 women matched by age and municipality on the index day. The diagnostic system used was the International Classification of Diseases, Ninth Revision (ICD‐9) from 1987 to 1995, and Tenth Revision (ICD‐10) from 1996 onward. We further divided endometriosis into subtypes of pure peritoneal (i.e., superficial), ovarian, and deep, as well as combined and other forms of endometriosis, based on the FHDR codes. Diagnoses of endometriosis and diagnoses of pain, depression, and anxiety were obtained from the FHDR up to the end of 2019 using ICD‐9 and ICD‐10 codes (Table  S1 ). The FHDR contains records of inpatient hospital visits from 1987 onward and outpatient hospital visits from 1998 onward. For pain and depression/anxiety, only the primary diagnostic codes were considered when assessing the corresponding preindex (before the index date) characteristics of women as well as characteristics before the highest occupational achievements. Data on deaths were retrieved from the Finnish Register of Causes of Death maintained by Statistics Finland, whereas data on emigration were obtained from FPIS. The data on parity were obtained from the FPIS in 1935–1986 and the Medical Birth Register in 1987–2019 (maintained by the Finnish Institute for Health and Welfare), respectively. To assess the outcomes of interest, we retrieved data from the year 1990 until December 31, 2019, on education, socioeconomic status, and occupation from Statistics Finland, using international and national classifications (Table  S2 ). Education was categorized as upper tertiary, lower tertiary, secondary, and primary, with primary assumed for those with no registered education. Primary education is free of charge and compulsory for all in Finland, and therefore, it is not specifically registered. No individuals were categorized with unknown education. Educational data, collected during the last week of the year, were standardized to December 31st. Socioeconomic status was classified as self‐employed, upper‐level employees, lower‐level employees, manual workers, students, pensioners, and others. Socioeconomic status is provided for women entering the labor force. Occupation was divided into five groups: managers and professionals, upper white‐collar workers, lower white‐collar workers, blue‐collar workers, and others. Occupational data are provided for employees and entrepreneurs aged 18–74, based on their main employment during the last week of the year. Missing occupational data for unemployed, retired, or students were categorized as “others,” as individuals in these groups were not assigned specific occupational statuses. The primary outcomes were the highest educational attainment, socioeconomic status, and occupational levels at certain ages in early adulthood (age groups: before 25, 26–30, 31–35, and 36–40). In the analyses by age groups, we included women reaching at least the ages of 26, 31, and 36, from the index date to the end of 2019. In age group‐specific analyses, we ensured that matching by age and municipality at the index date remained intact by only including those with corresponding matched control(s). We included the highest outcomes before December 31, 2019, emigration, death, or the age of 40 years. In addition to analyzing the highest socioeconomic and occupational outcomes, we examined the latest outcomes in each age group. We also examined whether the subtype of endometriosis affected the outcomes, comparing women with diagnostic codes for ovarian‐only endometriosis at the index day procedure to those with other subtypes (peritoneal, deep infiltrating, or combined/other types). This classification was chosen to distinguish between less painful and more painful subtypes of endometriosis, based on both clinical experience and prior studies. 25 , 26 Furthermore, we evaluated whether a preindex diagnosis of depression or anxiety influenced the outcomes within the endometriosis cohort. Categorical variables are presented as frequencies and percentages, and continuous variables as medians and interquartile ranges (IQR). Differences in categorical variables were analyzed using Pearson's chi‐squared test and continuous variables with the Wilcoxon test. All statistical analyses were performed with R statistical software version 6.2.561. We performed multinomial logistic regression analyses to investigate the association between endometriosis and highest occupational outcomes received during the follow‐up using odds ratios (ORs). To compare achievements of the highest occupational status between women with and without endometriosis, we calculated ORs and corresponding 95% confidence intervals (CIs) by fitting univariate and multivariable multinomial logistic regression models. Comparisons were performed in two different ways. In the first comparison, to preserve matching, we considered the highest occupational status attained during follow‐up by women with endometriosis and compared it to the occupational status of their corresponding reference individuals recorded during or before the same calendar year in which the endometriosis case achieved her highest status. The second comparison considered the highest occupational status achieved at any point during follow‐up (and most likely at different ages) by both women with and without endometriosis. Both comparisons were restricted to those with available occupational data, including the year of status attainment. In addition to the univariate regression analysis of the highest occupational status, we fitted multivariable regression models to study changes in OR estimates when including parity and diagnoses of depression/anxiety, and further diagnosis of pain before the highest occupational status. We tested for multicollinearity of these factors. In the second comparison, we also adjusted for age at the time of reaching the highest occupational status. To assess the potential mediating role of parity and diagnoses of depression/anxiety, and pain, we conducted a mediation analysis in which we simplified occupational status to a binary outcome (blue‐collar workers/managers and professionals vs. others).

Supporting Information Table S1. Classification of endometriosis, and mental and behavioral health disorders: versions 9 (ICD‐9) 1987–1995 and 10 (ICD‐10) 1996. Supporting Information Table S2. Classification of the national level of education, socioeconomic groups, and classification of occupations. Supporting Information Table S3. Characteristics of the endometriosis cohort and the reference cohort at certain ages. 1 n , (%). Supporting Information Table S4. The latest occupational and socioeconomic statuses attained by women before or at the age of 25 and at the age groups of 26–30, 31–35, and 36–40 in the endometriosis and the reference cohort. Supporting Information Table S5. Crude and adjusted odds ratios (ORs) and 95% confidence intervals from the multinomial regression models on the relationship between occupational outcomes and endometriosis compared to reference group without endometriosis. Comparison 1 includes the highest occupational status during follow‐up among women with endometriosis and their corresponding reference individuals (with occupational information available by the corresponding year). Comparison 2 includes the highest occupational status achieved during follow‐up for both groups. Both models include only women with matched baseline pair(s) for whom occupational information (including year) was available.