Characteristics of women diagnosed with endometriosis in England: 2011-2021

Introduction Endometriosis is a chronic disease and the second most common gynaecological condition in the UK, affecting approximately 1.5 million women. It is characterised by the growth of endometrial tissue outside the uterus, causing varying symptoms and having far reaching socioeconomic impacts. We utilise population level hospital admissions data and Census 2011 to examine the characteristics of women diagnosed with endometriosis in England.

Using a retrospective cohort design, we used Hospital Episode Statistics (HES) between 2011 and 2021, we linked health data to detailed sociodemographic information from Census 2011, providing individual population-level information on self-reported characteristics. Our outcome of interest was an endometriosis diagnosis in hospital. Our exposures were age on Census Day (five-year age bands), ethnic group, Index of Multiple Deprivation (IMD) decile, household National Statistics Socio- economic Classification (NS-SEC), highest qualification, country of birth, main language, self-reported general health, self-reported disability, rural/urban classification, region, and upper tier local authority (UTLA). We calculated crude and age-standardised rates, and odds of receiving a diagnosis using logistic regression models adjusted sequentially for age and health.

Our results highlight differences in underlying prevalence of endometriosis by sociodemographic characteristic, as well as capturing differences in access to services for women receiving a diagnosis of endometriosis in an NHS hospital. The likelihood of receiving an endometriosis diagnosis was highest in the "White British", "Black Caribbean" and "Mixed White and Black Caribbean" ethnic groups, and lowest in the "Chinese", "Arab" and "Black African" ethnic groups. Women living in the most and least deprived areas were least likely to have an endometriosis diagnosis, possibly . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. Page | 2 reflecting lower access to healthcare services in the most deprived group and more use of private healthcare in the least deprived group. Women self-reporting to be in bad health, or disabled, were more likely to have had an endometriosis diagnosis compared those in very good health or non- disabled women, respectively.

Our results demonstrate significant sociodemographic differences between groups of women receiving an endometriosis diagnosis in England. These results should be used to inform healthcare policies to better support groups of women who are most affected by endometriosis and barriers to receiving a diagnosis. Subsequent work should explore presentations in primary care, as well as the broader socioeconomic ramifications of endometriosis. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 3 Research in context What is already known on this topic Endometriosis is a common gynaecological condition which has debilitating impacts across many domains, including physical, psychological, social and economic. It is estimated to affect 1 in 10 reproductive age women in England, however evidence on the differences in endometriosis diagnosis by sociodemographic characteristics is lacking. What this study adds Our study utilises population-level Census and HES data for England to estimate crude and age- standardised rates of endometriosis diagnosis, and odds of receiving an endometriosis diagnosis by a range of sociodemographic characteristics. We estimate the prevalence of an endometriosis diagnosis to be approximately 2% of reproductive age women in our linked population, with an average age at diagnosis of 35 years. Women living in the most and least deprived areas were least likely to have an endometriosis diagnosis; this possibly reflects less access to healthcare services in the most deprived group and more use of private healthcare in the least deprived group. The likelihood of receiving an endometriosis diagnosis was highest in the "White British", "Black Caribbean", and "Mixed White and Black Caribbean" ethnic groups, and lowest in the "Chinese", "Arab", and "Black African" ethnic groups. This study is the most comprehensive analysis of the characteristics of women with an endometriosis diagnosis in England to date. How this study might affect research, practice or policy This research provides important information to gynaecologists, clinicians and other allied health professionals, as well as policy makers, to illustrate the prevalence of endometriosis and the groups most affected by endometriosis and barriers to receiving a diagnosis. In the Women’s Health Strategy for England, menstrual health and gynaecological conditions were identified as one of the priority areas, with a call for evidence and investment in women’s health research. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 4

Endometriosis is a chronic disease and the second most common gynaecological condition in the UK, estimated to impact approximately 1.5 million women (1). Endometriosis is a condition where endometrial tissue, similar to the lining of the uterus, grows in other places, such as the ovaries and fallopian tubes. Common symptoms include chronic pelvic pain, fatigue, heavy menstrual bleeding, pain during or after sex, painful urination and bowel movements, and reduced fertility (2,3). Symptoms can vary across women, and severity of symptoms often does not reflect the severity of the condition (4). Endometriosis usually affects women during their reproductive years (between menarche and menopause) but can affect women of any age (5). While the exact cause of endometriosis is unknown, several factors have been implicated in its development, including immune, endocrine, genetic, and environmental influences (3,6). Despite the profound impacts endometriosis poses on women’s lives, there has been no population study in England assessing the characteristics of women living with endometriosis. Given the disease is known to have negative impacts across many domains, such as psychological, social, and economic, understanding which groups of women are most affected is imperative to further quantify differences in the progression and burden of this disease, and inform targeted work to reduce these inequalities. This has ramifications clinically, for understanding which groups are most affected, as well as from a policy perspective to provide evidence-based change to targeted populations. The diagnosis of endometriosis can be challenging due to the non-specific nature of its symptoms, the overlap of symptoms with other conditions such as pelvic inflammatory disease or irritable bowel syndrome, and the lack of a definitive non-invasive diagnostic test. In England, it takes on average eight years from onset of symptoms to receiving a diagnosis (7). The gold standard for diagnosis is laparoscopic visualisation and biopsy of the lesions (8). In the current study, we utilise individual population level data from Hospital Episode Statistics (HES) (9) data for England to define a cohort of women who have received a diagnosis of endometriosis in a National Health Service (NHS) hospital over a ten-year period. Using Census 2011 data we estimate differences by sociodemographic characteristics including ethnic group, socioeconomic position, education level, country of birth, health, disability and region. This is of important public health significance due to the prevalence of this condition, its debilitating symptoms, and the broader socioeconomic burden of this disease. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 5

Study design and data sources We conducted a population level retrospective cohort study using the Public Health Data Asset 2011 Cohort (10), which combines Census 2011 data, death registrations, and 2009-2021 Hospital Episode Statistics (HES) Admitted Patient Care (APC) data (11). Census 2011 has been linked to the 2011– 2013 NHS Patient Registers to obtain NHS numbers, with a linkage rate of 94.6% (10). The decennial Census for England and Wales captured population and household characteristics of 56 million people in 2011 with respondents reporting detailed demographic information. HES is a curated data set capturing records of patients attending accident and emergency units, admitted for treatment or attending outpatient clinics at NHS hospitals in England. Each HES record includes up to 20 diagnosis values, with the first value (primary diagnosis) recording the main condition being treated or investigated, and the other values recording any relevant secondary/subsidiary diagnoses (12). Study population The study population includes all women enumerated in the 2011 Census who were usual residents in England on Census Day (27 March 2011) and could be linked to an NHS number [Supplementary Table 3]. We defined two cohorts of women with endometriosis. For our main analysis, we estimated prevalence by identifying women with any endometriosis diagnosis (primary or secondary) during the study period between 27 March 2011 and 31 December 2021 and a control group of women enumerated in Census 2011 with no evidence of endometriosis during the study period. For our supplementary analysis, we estimated incidence by identifying a group of women with a primary endometriosis diagnosis only during our study period and used two years of HES data (1 April 2009 to 26 March 2011) prior to the study start to exclude instances where the diagnosis during the study period was not the first. The control group of women for the supplementary analysis had no diagnosis of endometriosis during the study period, or in the two years prior . All groups were filtered to restrict our cohort to people who self-reported as female in the 2011 Census [Supplementary Table 3]. Outcome Diagnosis of endometriosis was defined from the Admitted Patient Care (APC) data using International Classification of Diseases, Tenth Revision (ICD-10) codes N80.0-N80.9 [Supplementary Table 1]. For our main analysis, an outcome was identified if a diagnosis was recorded as a primary or secondary diagnosis, and for the supplementary analysis an outcome was identified only if endometriosis was the primary diagnosis. The episode must have started and ended within our study period for an outcome to be identified. Outcomes were coded as binary. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 6 Covariates All sociodemographic variables included in the analyses were self-reported in the 2011 Census. Exposures included were age on Census Day (five-year age bands), ethnic group (detailed and aggregated), country of birth, main language, Index of Multiple Deprivation (IMD) decile, National Statistics Socioeconomic Classification (NS-SEC) of the Household Reference Person (HRP), highest level of educational qualification, general health, disability, rural/urban, region and upper tier local authority (UTLA). Groupings of all exposures can be seen in Supplementary Table 4. Where Census data was missing or not applicable, a “Not classified” group was included (13). An indicator of health was determined using number of HES APC admissions in the two years prior (1 April 2009 to 26 March 2011) to our study start date for any reason, excluding mentions of endometriosis. Number of HES APC admissions were grouped into 0 episodes, 1 to 3 episodes, 4 to 6 episodes, 7 to 9 episodes, 10 to 14 episodes, and 15 or more episodes. We did not include self- reported health or self-reported disability status from 2011 Census as health adjustments in the models, as these variables could capture effects from symptoms related to endometriosis. In our descriptive analysis, we investigated age at endometriosis diagnosis and method of hospital admission. Age at endometriosis diagnosis refers to age at first diagnosis during the study period and was obtained from HES data, but if missing or zero (0.01%) in the administrative data it was calculated using the date difference between the date of birth self-reported in 2011 Census and the hospital episode start date. Method of hospital admission (emergency or non-emergency) was sourced from the HES APC data. Emergency admissions are defined in HES as “unpredictable and at short notice because of clinical need” (12), and were classified according to the codes listed in Supplementary Table 2. Statistical Analysis To describe the prevalence of endometriosis, we report crude and age-standardised rates of diagnosis per 100,000 people. Age-standardised rates were calculated as the weighted average of age-specific rates in five-year age bands. The age-specific weights represent the overall age distribution in the observed study population. To identify characteristics associated with endometriosis diagnosis, we used logistic regression models to estimate the odds ratios of being diagnosed with endometriosis at least once during the study period across different exposure groups. Models were first adjusted for age and secondly for age and health (number of pre-study HES APC admissions, excluding mentions of endometriosis). Age was included as a natural spline with boundary knots at the 1st and 99th percentile and five interior knots. The number of knots was chosen using the lowest Akaike information criterion (AIC). General health is a confounder between . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 7 socioeconomic factors and endometriosis; hence we’ve adjusted our models to ensure the relationship between our characteristics of interest and endometriosis are not explained by differences in general health. When looking at general health and disability as exposures, we only adjusted for age. Additionally, for ethnic group, we fitted models also adjusted for main language and country of birth independently and together. For region, we also adjusted for socioeconomic status using IMD decile and highest level of qualification as a proxy. All counts are rounded to the nearest 5 and counts of less than 10 suppressed for disclosure reasons. All analyses were conducted in R version 4.4 and Python version 3.10. Sensitivity tests All demographic information was measured at the time of Census 2011. Some characteristics may change over time, which could introduce a bias in our estimates. We ran sensitivity analyses using just two years of follow-up (27 March 2011 to 31 December 2013) to assess the robustness of our findings across the 10-year period. In addition, we also ran sensitivity analyses when education was the exposure using only women aged 25 years and older on Census Day, as education is more likely to be stable after this age. Ethics and Data Availability We obtained ethical approval for this work from the National Statistics Data Ethics Advisory Committee (NSDEC23(18)). All data relating to this work has been published as an ONS dataset. All code is available in a GitHub repository. Public and Patient Involvement Women with endometriosis have reviewed this manuscript and provided feedback prior to submission. . 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Main results To estimate prevalence of endometriosis diagnosis, we analysed endometriosis diagnoses recorded as either primary or secondary diagnoses in HES APC. 24,560,795 women were included in our main analysis, of which 262,065 had a diagnosis of endometriosis. This is equivalent to approximately 2% of women aged 15 to 49 years on Census Day [Table 1, Figure 1]. Crude rates of endometriosis diagnosis per 100,000 people were highest among women aged 30-34 (2,307.61) and 35-39 (2,492.44) years at the time of Census [Table 2]. The average age at time of diagnosis was 38.9 years (IQR: 30-47 years) [Supplementary Table 16]. Looking at the number of admissions in our cohort over time, which is the first time a woman has a recorded primary or secondary endometriosis diagnosis in our main analysis, and the first time a woman has a recorded primary endometriosis diagnosis in our supplementary analysis, we see that the monthly count has been relatively consistent since 2011, except with a marked reduction during the early coronavirus pandemic of 2020 [Supplementary Table 5]. The most frequent primary diagnosis type by ICD-10 code in our main cohort was endometriosis (n = 116,835, 44.6%), with the next most prevalent being leiomyoma of uterus (n = 21,845, 8.3%). The top ten primary diagnosis codes included a range of other gynaecological presentations such as abdominal and pelvic pain, non-inflammatory disorders of ovary, fallopian tube and broad ligament, as well as excessive frequent and irregular menstruation [Supplementary Table 6]. 18.7% of admissions were emergencies, with the majority (81.3%) being classified as non-emergency presentations [Supplementary Table 17]. Age-standardised rates of endometriosis were highest in the White (1,099.91 per 100,000 persons; 95% confidence interval (CI):1,095.39-1,104.43) and Mixed/Multiple (1,115.95 per 100,000 persons; 95%CI:1,081.00-1,150.90) ethnic groups [Table 2]. These two groups showed similar odds of diagnosis in both the age-adjusted model (Odds Ratio (OR) for Mixed/Multiple compared to White: 0.98; 95%CI:0.95-1.00) and the age- and health-adjusted model (OR:0.98; 95%CI:0.95-1.00) [Table 4]. Compared to the White ethnic group, the largest differences in odds of diagnosis were observed for the Other ethnic group (OR:0.75; 95%CI:0.72-0.79), the Asian/Asian British group (OR:0.78; 95%CI:0.77-0.79) and the Black/African/Caribbean/Black British (OR:0.80; 95%CI:0.78-0.82) ethnic groups. However, when adjusting for country of birth and main language, the odds of diagnosis for the Other ethnic group (OR:0.95; 95%CI:0.91-1.00) were no longer significantly different from the White ethnic group. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 9 Using the more granular breakdown for ethnic group, compared to the White British (White English/Welsh/Scottish/Northern Irish/British) group, the Chinese (Asian/Asian British) (OR:0.46; 95%CI:0.43-0.48) and Arab (Other ethnic group) (OR:0.52; 95%CI:0.48-0.57) ethnic groups had the lowest odds of diagnosis in the age- and health-adjusted model. Compared to the White British group, the odds of diagnosis were significantly lower for the Black African (OR:0.61; 95%CI:0.59-0.64) and Other Black (OR:0.88; 95%CI:0.82-0.93) groups, but not for the Black Caribbean (OR:1.03; 95%CI:0.99-1.06) group. When adjusting for country of birth and main language, the odds ratios for the Black African (OR:0.69; 95%CI:0.67-0.72) and Other Black (OR:0.94; 95%CI:0.88-1.00) groups moved closer to the null, though the odds for the Black African group remained significantly lower than the White British group. In contrast, the odds for the Black Caribbean (OR:1.05; 95%CI:1.02- 1.09) group were significantly higher than for the White British group. Odds of diagnosis were lower for women born outside the UK (compared to those born in the UK; OR:0.72; 95%CI:0.71-0.73), and for women whose main language was not English (compared to those with English as their first language; OR:0.67; 95%CI:0.66-0.68) [Table 5]. Analysis of socioeconomic factors, such as IMD, showed the odds were lowest for women living in the most deprived and least deprived areas of the country [Table 5]. Analysis of household NS-SEC showed the odds were lowest for women in households with the highest and lowest socio-economic classifications. When looking at education level, the odds ratios were lowest for women with Other (foreign or vocational) qualifications (OR:0.87; 95%CI:0.85-0.89) or no qualifications (OR:0.96; 95%CI:0.94-0.97), compared with Level 4 and above qualifications (e.g., degree level). Odds of diagnosis were highest for women self-reporting to be in bad health (OR:2.04; 95%CI:2.00- 2.09) or fair health (OR:1.92; 95%CI:1.90-1.94), compared with those in very good health. Disabled women reporting to be limited a little (OR:1.58; 95%CI:1.55-1.60) or limited a lot (OR:1.38; 95%CI:1.36-1.40) in their day-to-day activities had significantly higher odds of diagnosis, compared with non-disabled women. Compared to London, the odds of a diagnosis were higher for all other regions of the UK (although the 95% CI included the null for the North East (OR:1.02;95%CI:1.00-1.05)) [Supplementary Table 9]. Adjusting for IMD and education level had minimal impact on these results overall, except for Yorkshire and the Humber where the 95% CI included the null after adjustment (OR:1.02;95%CI:1.00- 1.03). Broadly, we did not see clear differences in age-standardised rates of diagnoses by UTLA [Figure 3]. Supplementary results . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 10 To estimate incidence of endometriosis diagnosis, we restricted our analysis to endometriosis diagnoses recorded as primary diagnoses in HES APC. A total of 24,382,270 women were included in our supplementary analysis, with 120,515 having a primary diagnosis of endometriosis [Supplementary Table 3]. The crude rates of endometriosis diagnosis per 100,000 people were highest among women aged 25-29 (1,217.48) and 30-34 (1,210.61) years at the time of Census [Table 2]. The average age at diagnosis was 35 years (IQR: 27-43 years), five years younger than in the main analysis [Supplementary Table 16]. 10.7% of the admissions in this group were classified as emergencies [Supplementary Table 17].Using the aggregated ethnicity breakdown, the odds ratio comparing diagnosis in the Black/African/Caribbean/Black British ethnic group to the White group was lower in the supplementary analysis (OR:0.67; 95%CI :0.65-0.70) compared to the main analysis (OR:0.91; 95%CI:0.89-0.93) in the fully adjusted model [Table 4]. Furthermore, the odds ratios between women self-reporting to be in very good health and those in good, fair, bad or very bad health were lower compared to the main analysis [Table 5]. Similarly, the odds ratios of women self- reporting to be limited a little or a lot in their day-to-day activities compared to those not limited were lower in the supplementary analysis. When looking at region, the odds ratios were generally similar, though Yorkshire and the Humber and the South East showed the most prominent increases in odds ratios compared to the main analysis [Supplementary Table 9]. In general, for all other sociodemographic characteristics we saw the same pattern of results as in the main analysis [Tables 3-5, Supplementary Table 10]. Sensitivity results To assess the robustness of our findings over a 10-year follow-up, we repeated the analysis using just a two-year follow-up. 71,345 women had received an endometriosis diagnosis in our main sensitivity analysis and 32,855 women had received a primary endometriosis diagnosis in our supplementary sensitivity analysis [Supplementary Table 3]. For both groups, the sensitivity results were consistent with the findings from the 10-year follow-up. The odds ratios for women reporting to be in good, fair, bad or very bad health compared to those in very good health were all further from the null in the two-year follow up compared to the 10-year follow up [Table 5 and Supplementary Table 13]. Similarly, the odds ratios for women reporting to be limited a little or a lot in their day-to-day activities compared to those not limited were higher in the two-year follow up. Furthermore, we repeated our analysis of the highest level of educational qualification exposure restricting to women aged 25 years and over on Census Day, since education level is more stable from this age onwards.

followed a similar pattern to the analysis of women of any age [Table 5 and Supplementary Table 13]. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 11

In this large, population-based cohort spanning a decade, we estimated the prevalence of endometriosis to be 2% of reproductive age women in England (14). Our results show that the odds ratios of receiving an endometriosis diagnosis vary significantly by sociodemographic characteristics in England and reflect differences in both the likelihood of having an endometriosis diagnosis by sociodemographic characteristic as well as the likelihood of receiving a diagnosis in an NHS hospital. Previous estimates of prevalence range from 2% to 10% in the general female population and up to 50% in women with infertility (15). Endometriosis UK and the World Health Organization (WHO) estimate that 1 in 10 women of reproductive age have endometriosis (1,16), and pooled estimates of European studies suggest a prevalence rate of 1.4% in the general population (17). Our prevalence estimate of 2% of reproductive age women is lower than some previous studies. However, our estimate reflects the number of women who have been diagnosed with endometriosis in an NHS hospital in England between 2011 and 2021. Additionally, our analysis only includes women whose Census 2011 response could be linked to an NHS number; it does not capture all women who have had a diagnosis in hospital. For our main analysis, our sample includes approximately 85% of all women who received an endometriosis diagnosis in hospital during this period [Supplementary Table 3]. It is important to note that prevalence of endometriosis diagnoses does not reflect the true prevalence of endometriosis, as not all women will have a diagnosis. In the US, for instance, six out of ten cases go undiagnosed (18). The average age at first endometriosis diagnosis, where endometriosis was the primary diagnosis, was 35 years. Given that symptoms of this disease can start in puberty, these findings support previous work suggesting that women are facing barriers and delays in receiving an endometriosis diagnosis (7). In an Australian cohort study of over 10,000 women, 1 in 9 self-reported suspected or confirmed endometriosis by age 44, with most being diagnosed during their early thirties (19). Since 2020, NHS gynaecology waiting lists in England have grown faster than any other elective speciality in percentage terms (20). If left untreated, endometriosis may progress and further negatively impact on quality of life. Future work should explore inequalities in delays in diagnosis across sociodemographic groups. Finding significantly lower odds of being diagnosed with endometriosis for Chinese, Arab or Black African ethnic groups compared to the White English/Welsh/Scottish/Northern Irish/British group is broadly consistent with existing literature from elsewhere in the world, and smaller UK-based studies (21). Many of these findings need to be interpreted with caution due to limited quality literature exploring this topic and selection bias of White women in research studies. Historically, . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 12 endometriosis has been thought to be a disease most prevalent in White women (18), but our results demonstrate the odds of diagnosis are as high in the Mixed and Black Caribbean groups. Differences in prevalence between ethnic groups are likely to be explained by social and structural issues around access to healthcare and systemic racism (21). It is important to highlight that the increase in the number of new first diagnoses from mid-2020 onwards is likely a consequence of increases in post-pandemic admissions for other causes. When looking at primary diagnoses of endometriosis only, as per the supplementary analysis, the number of new monthly cases does not show this trend; the number of monthly cases recovers to the pre- pandemic level and remains consistent [Supplementary Table 5]. Previous survey data has shown that over half of women who had symptoms of endometriosis, without a confirmed diagnosis, attended A&E at least once due to their symptoms (22). Although a small proportion of our cases were identified as emergency admissions (10.7%) [Supplementary Table 17], it is still an important finding that warrants additional exploration. The cost of repeated presentations at A&E centres, as well as emergency treatment costs, in contrast to elective care, should be considered when making recommendations for diagnostic care for women with endometriosis (23). Our sensitivity analyses, using two years of follow-up, showed similar findings to the 10-year follow up. One difference was the odds for women reporting to be limited in their day-to-day activities, compared to those not limited, were higher in the two-year follow up. These findings indicate that symptoms of endometriosis could be contributing to self-reported health and disability status, highlighting how debilitating endometriosis symptoms can be on overall health. A strength of our study is the use of population level data for England, making it the most comprehensive study into the characteristics of women with endometriosis in England to date. Furthermore, the linkage to Census data provides detailed information on socioeconomic characteristics. A key limitation of our work is we only capture women who have an endometriosis diagnosis in an NHS hospital in England which, according to the National Institute for Health and Care Excellence (NICE) guidelines, will capture women who have been referred to gynaecology if initial symptom management in primary care is not effective (8). A laparoscopy should be used to diagnose endometriosis even if an ultrasound or MRI has come back normal. Subsequent research should explore diagnosis of endometriosis using primary care data, in addition to secondary care data, to get a more complete understanding of the burden of disease, as well as capturing symptoms related to diagnosis since many women remain undiagnosed. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 13 In our study, women living in the most deprived and least deprived areas had lower odds of diagnosis, compared to those living in other areas. This might be explained by those living in the most deprived areas facing barriers to seeking treatment (24) including longer NHS waiting times (25), and those living in the least deprived areas being more likely to use private healthcare (26). Following a similar trend, we found lower odds of diagnosis for women in households with the highest and lowest socio-economic classifications. Of all educational groups, women in the Other qualifications group had the lowest odds of diagnosis. This group includes women with foreign qualifications, and therefore may include women who received an endometriosis diagnosis outside England not captured by the HES data. Clinically, endometriosis is typically classified into four stages, from minimal to severe, taking into account location and depth of disease in relation to other pelvic structures (27). We are limited to assessing endometriosis diagnosis as a binary outcome based on our data but implore researchers to evaluate sociodemographic characteristics associated with disease severity in subsequent work. Importantly, treatment and hospital diagnosis are based on severity of symptoms, not clinical stage, which often does not correspond to severity of symptoms and cannot be determined without laparoscopy. Finally, using regional information on place of residence from Census (i.e., at the start of the study period) and HES (i.e., at time of diagnosis) is limited as we are not able to evaluate regional differences in diagnosis or procedures. Across the UK, there are 79 specialist endometriosis centres accredited by the British Society of Gynaecology and Endoscopy (28), and subsequent work should look at differences here. To conclude, our study provides the first systematic assessment of the characteristics of women diagnosed with endometriosis in England. We utilised a decade’s worth of endometriosis diagnoses taking place in NHS hospitals and linked to Census data to provide a granular understanding of the groups who have the highest odds of receiving an endometriosis diagnosis. This work provides important information to gynaecologists, clinicians and other allied health professionals, as well as policy makers to illustrate the prevalence of endometriosis and the groups most affected. Contributions of authors ILW, VN and DA conceptualised and designed the study. ILW, EC and HB prepared the study data. HB performed the statistical analysis, which was quality checked by ILW. All authors contributed to interpretation of the findings. ILW and HB wrote the original draft. All authors contributed to review and editing of the manuscript and approved the final manuscript. ILW is the guarantor . The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted. . 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We would like to thank Endometriosis UK and DHSC for supporting our research and public engagement. We would also like to thank Emily Williams for supporting with a literature review early in the study development. Funding This study received funding from His Majesties Treasury’s Labour Market Evaluation Fund (29). GCS is supported by the Medical Research Council (MR/Z504634). Conflicts of interest The authors have no conflicts to declare.

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Simoens S, Dunselman G, Dirksen C, Hummelshoj L, Bokor A, Brandes I, et al. The burden of endometriosis: costs and quality of life of women with endometriosis and treated in referral centres. Hum Reprod. 2012 May 1;27(5):1292–9. 24. The King’s Fund. Illustrating the relationship between poverty and NHS services [Internet]. 2024 [cited 2024 Dec 10]. Available from: https://www.kingsfund.org.uk/insight-and- analysis/long-reads/relationship-poverty-nhs-services 25. O’Dowd A. Poverty status is linked to worse quality of care. BMJ. 2020 Jan 23;m303. 26. Devaja A. Health inequalities: the unintended consequences of private healthcare policy? Bull R Coll Surg Engl. 2023 Sep;105(6):272–3. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Page | 16 27. American Society for Reproductive Medicine. Revised American Society for Reproductive Medicine classification of endometriosis: 1996. Fertil Steril. 1997 May;67(5):817–21. 28. British Society for Gynaecological Endoscopy (BSGE). All accredited endometriosis centres [Internet]. [cited 2024 Dec 9]. Available from: https://www.bsge.org.uk/centre/category/accredited-centres/ 29. HM Treasury. £12.4 million to help change choices about work [Internet]. 2023 [cited 2024 Dec 9]. Available from: https://www.gov.uk/government/news/124-million-to-help-change- choices-about-work . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Figures and Tables Figure 1: Age distribution of study population at time of first endometriosis diagnosis in study period The number of diagnoses at each year of age for first endometriosis diagnosis in hospital in our main analysis population (blue) and supplementary analysis population (teal). The main population includes any endometriosis diagnosis and the supplementary includes primary diagnoses only. The vertical bar marks the mean age at time of diagnosis for each cohort. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Figure 2: Odds of receiving an endometriosis diagnosis by sociodemographic characteristics The odds ratio of receiving an endometriosis diagnosis by ethic group, main language, IMD decile group, highest level of qualification and disability. The bold vertical line indicates an odds ratio of 1. Point estimates are presented with 95% confidence intervals. All models account for age and health (except for the disability model, which is only age-adjusted). . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Figure 3: Age-standardised rates of endometriosis diagnosis per 100,000 people by upper tier local authority (UTLA) Age-standardised rates of endometriosis diagnosis per 100,000 people shown by UTLA, with darker colours illustrating higher rates. The regions in Greater London have been shown in a second pop-out. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Table 1: Characteristics of the study population Category Subcategory Main analysis Supplementary analysis Count (%), with an endometriosis diagnosis Count (%), no endometriosis diagnosis Count (%), with an endometriosis diagnosis Count (%), no endometriosis diagnosis Total Total 262,065 (100.00%) 24,298,730 (100.00%) 120,515 (100.00%) 24,261,755 (100.00%) Age on Census Day (five-year bands) 0 to 9 years 1,410 (0.54%) 2,708,135 (11.15%) 815 (0.68%) 2,708,130 (11.16%) 10 to 14 years 9,320 (3.56%) 1,347,480 (5.55%) 6,335 (5.26%) 1,347,470 (5.55%) 15 to 19 years 21,035 (8.03%) 1,407,965 (5.79%) 14,085 (11.69%) 1,407,710 (5.80%) 20 to 24 years 29,090 (11.10%) 1,459,880 (6.01%) 17,515 (14.53%) 1,458,270 (6.01%) 25 to 29 years 34,780 (13.27%) 1,563,890 (6.44%) 19,235 (15.96%) 1,560,665 (6.43%) 30 to 34 years 36,525 (13.94%) 1,546,200 (6.36%) 18,890 (15.67%) 1,541,400 (6.35%) 35 to 39 years 40,835 (15.58%) 1,597,595 (6.57%) 19,280 (16.00%) 1,591,170 (6.56%) 40 to 44 years 38,780 (14.80%) 1,788,375 (7.36%) 14,740 (12.23%) 1,780,960 (7.34%) 45 to 49 years 23,420 (8.94%) 1,815,010 (7.47%) 6,365 (5.28%) 1,808,275 (7.45%) 50 to 54 years 10,020 (3.82%) 1,606,830 (6.61%) 1,645 (1.36%) 1,603,825 (6.61%) 55 to 59 years 5,705 (2.18%) 1,432,900 (5.90%) 595 (0.49%) 1,431,685 (5.90%) 60 to 64 years 4,720 (1.80%) 1,532,995 (6.31%) 440 (0.37%) 1,532,125 (6.31%) 65 to 69 years 3,140 (1.20%) 1,222,205 (5.03%) 255 (0.21%) 1,221,590 (5.04%) 70 to 74 years 1,815 (0.69%) 1,013,275 (4.17%) 170 (0.14%) 1,012,880 (4.17%) 75 to 79 years 930 (0.35%) 853,440 (3.51%) 70 (0.06%) 853,200 (3.52%) 80 years and over 540 (0.21%) 1,402,560 (5.77%) 80 (0.07%) 1,402,390 (5.78%) Ethnic group (detailed) White: English/Welsh/Scottish/Northern Irish/British 214,790 (81.96%) 19,797,270 (81.47%) 98,835 (82.00%) 19,766,680 (81.47%) White: Irish 1,870 (0.71%) 239,835 (0.99%) 750 (0.62%) 239,530 (0.99%) White: Gypsy or Irish Traveller 285 (0.11%) 22,510 (0.09%) 145 (0.12%) 22,480 (0.09%) Mixed/multiple: Other White 10,970 (4.19%) 1,058,285 (4.36%) 5,510 (4.57%) 1,056,710 (4.36%) Mixed/multiple: White and Black Caribbean 2,075 (0.79%) 165,525 (0.68%) 1,010 (0.84%) 165,340 (0.68%) Mixed/multiple: White and Black African 575 (0.22%) 62,745 (0.26%) 265 (0.22%) 62,680 (0.26%) Mixed/multiple: White and Asian 1,250 (0.48%) 131,930 (0.54%) 650 (0.54%) 131,800 (0.54%) Mixed/multiple: Other Mixed 1,340 (0.51%) 114,005 (0.47%) 665 (0.55%) 113,860 (0.47%) Asian: Indian 6,435 (2.46%) 610,470 (2.51%) 2,910 (2.41%) 609,540 (2.51%) Asian: Pakistani 5,050 (1.93%) 478,250 (1.97%) 2,370 (1.97%) 477,670 (1.97%) Asian: Bangladeshi 2,130 (0.81%) 184,775 (0.76%) 1,115 (0.93%) 184,585 (0.76%) Asian: Chinese 1,020 (0.39%) 150,135 (0.62%) 460 (0.38%) 149,940 (0.62%) . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Asian: Other Asian 4,125 (1.57%) 338,575 (1.39%) 1,985 (1.65%) 337,950 (1.39%) Black: African 3,725 (1.42%) 404,305 (1.66%) 1,315 (1.09%) 403,775 (1.66%) Black: Caribbean 3,570 (1.36%) 271,760 (1.12%) 1,305 (1.08%) 271,235 (1.12%) Black: Other Black 1,010 (0.39%) 90,670 (0.37%) 365 (0.30%) 90,560 (0.37%) Other: Arab 480 (0.18%) 65,715 (0.27%) 215 (0.18%) 65,640 (0.27%) Other: Any other ethnic group 1,370 (0.52%) 111,975 (0.46%) 655 (0.54%) 111,775 (0.46%) Ethnic group (aggregated) White 227,915 (86.97%) 21,117,900 (86.91%) 105,235 (87.32%) 21,085,400 (86.91%) Mixed/Multiple ethnic groups 5,240 (2.00%) 474,205 (1.95%) 2,590 (2.15%) 473,680 (1.95%) Asian/Asian British 18,760 (7.16%) 1,762,200 (7.25%) 8,835 (7.33%) 1,759,690 (7.25%) Black/African/Caribbean/Black British 8,305 (3.17%) 766,740 (3.16%) 2,980 (2.47%) 765,570 (3.16%) Other ethnic group 1,850 (0.71%) 177,685 (0.73%) 870 (0.72%) 177,415 (0.73%) Country of birth Born in the UK 228,185 (87.07%) 21,138,305 (86.99%) 105,285 (87.36%) 21,106,510 (86.99%) Born outside the UK 33,880 (12.93%) 3,160,425 (13.01%) 15,230 (12.64%) 3,155,245 (13.01%) Main language Main language is English 243,775 (93.02%) 22,515,935 (92.66%) 111,750 (92.73%) 22,481,585 (92.66%) Main language is not English 18,295 (6.98%) 1,782,795 (7.34%) 8,765 (7.27%) 1,780,170 (7.34%) IMD decile group 1 (most deprived) 26,840 (10.24%) 2,320,860 (9.55%) 12,410 (10.30%) 2,317,520 (9.55%) 2 28,175 (10.75%) 2,372,300 (9.76%) 13,110 (10.88%) 2,368,680 (9.76%) 3 28,185 (10.75%) 2,400,785 (9.88%) 13,000 (10.79%) 2,397,215 (9.88%) 4 27,705 (10.57%) 2,418,465 (9.95%) 12,950 (10.75%) 2,414,655 (9.95%) 5 26,905 (10.27%) 2,440,470 (10.04%) 12,325 (10.23%) 2,436,690 (10.04%) 6 26,495 (10.11%) 2,470,245 (10.17%) 12,160 (10.09%) 2,466,405 (10.17%) 7 25,705 (9.81%) 2,448,335 (10.08%) 11,630 (9.65%) 2,444,385 (10.08%) 8 25,290 (9.65%) 2,468,450 (10.16%) 11,595 (9.62%) 2,464,685 (10.16%) 9 24,510 (9.35%) 2,473,380 (10.18%) 11,195 (9.29%) 2,469,625 (10.18%) 10 (least deprived) 22,255 (8.49%) 2,485,440 (10.23%) 10,135 (8.41%) 2,481,890 (10.23%) Household NS-SEC Class 1: Higher managerial, administrative and professional occupations 32,185 (12.28%) 3,176,175 (13.07%) 14,305 (11.87%) 3,171,170 (13.07%) Class 2: Lower managerial, administrative and professional occupations 64,460 (24.60%) 5,551,555 (22.85%) 29,420 (24.41%) 5,541,925 (22.84%) Class 3: Intermediate occupations 31,575 (12.05%) 2,810,730 (11.57%) 14,480 (12.02%) 2,806,250 (11.57%) Class 4: Small employers and own account workers 31,405 (11.98%) 2,878,815 (11.85%) 14,555 (12.08%) 2,874,320 (11.85%) Class 5: Lower supervisory and technical occupations 23,075 (8.81%) 1,955,050 (8.05%) 10,850 (9.00%) 1,951,825 (8.04%) Class 6: Semi-routine occupations 35,325 (13.48%) 3,285,515 (13.52%) 16,130 (13.38%) 3,280,765 (13.52%) Class 7: Routine occupations 28,225 (10.77%) 2,850,570 (11.73%) 12,905 (10.71%) 2,846,665 (11.73%) . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Class 8: Never worked and long-term unemployed 9,415 (3.59%) 1,023,645 (4.21%) 4,310 (3.58%) 1,022,655 (4.22%) Students 4,880 (1.86%) 384,530 (1.58%) 2,705 (2.24%) 384,130 (1.58%) Not classified 1,520 (0.58%) 382,150 (1.57%) 850 (0.71%) 382,045 (1.57%) Highest level of qualification No academic or professional qualifications 27,445 (10.47%) 4,987,950 (20.53%) 9,805 (8.14%) 4,983,360 (20.54%) Level 1 41,690 (15.91%) 2,747,050 (11.31%) 18,565 (15.40%) 2,740,815 (11.30%) Level 2 52,270 (19.95%) 3,332,820 (13.72%) 24,960 (20.71%) 3,325,775 (13.71%) Apprenticeship 2,495 (0.95%) 194,095 (0.80%) 1,230 (1.02%) 193,780 (0.80%) Level 3 41,200 (15.72%) 2,326,415 (9.57%) 20,575 (17.07%) 2,321,240 (9.57%) Level 4 and above 73,295 (27.97%) 5,346,080 (22.00%) 31,835 (26.42%) 5,333,930 (21.98%) Other qualifications 9,455 (3.61%) 1,024,225 (4.22%) 4,055 (3.36%) 1,022,785 (4.22%) Not classified 14,215 (5.42%) 4,340,090 (17.86%) 9,490 (7.87%) 4,340,070 (17.89%) Highest level of qualification, 25 years and over No academic or professional qualifications 23,490 (9.0%) 4,739,170 (19.5%) 7,375 (6.1%) 4,734,710 (19.5%) Level 1 33,115 (12.6%) 2,323,345 (9.6%) 13,300 (11.0%) 2,317,400 (9.6%) Level 2 38,330 (14.6%) 2,600,945 (10.7%) 15,985 (13.3%) 2,594,395 (10.7%) Apprenticeship 1,485 (0.6%) 149,715 (0.6%) 565 (0.5%) 149,450 (0.6%) Level 3 29,300 (11.2%) 1,644,790 (6.8%) 13,005 (10.8%) 1,640,105 (6.8%) Level 4 and above 66,830 (25.5%) 4,967,190 (20.4%) 27,975 (23.2%) 4,955,400 (20.4%) Other qualifications 8,660 (3.3%) 950,115 (3.9%) 3,555 (3.0%) 948,715 (3.9%) Aged 0 to 24 years on Census Day 60,855 (23.2%) 6,923,460 (28.5%) 38,750 (32.2%) 6,921,585 (28.5%) General health Very good health 106,960 (40.81%) 10,991,240 (45.23%) 55,080 (45.70%) 10,979,385 (45.25%) Good health 108,825 (41.53%) 8,454,135 (34.79%) 49,080 (40.73%) 8,437,570 (34.78%) Fair health 33,660 (12.84%) 3,447,010 (14.19%) 12,365 (10.26%) 3,440,875 (14.18%) Bad health 10,260 (3.91%) 1,096,775 (4.51%) 3,350 (2.78%) 1,094,830 (4.51%) Very bad health 2,365 (0.90%) 309,565 (1.27%) 640 (0.53%) 309,095 (1.27%) Disability Day-to-day activities not limited 224,445 (85.64%) 19,621,265 (80.75%) 107,530 (89.23%) 19,591,160 (80.75%) Day-to-day activities limited a little 23,345 (8.91%) 2,477,375 (10.20%) 8,570 (7.11%) 2,473,210 (10.19%) Day-to-day activities limited a lot 14,275 (5.45%) 2,200,090 (9.05%) 4,415 (3.66%) 2,197,385 (9.06%) Rural/urban classification Urban 221,370 (84.47%) 19,900,870 (81.90%) 102,360 (84.94%) 19,870,420 (81.90%) Rural 40,695 (15.53%) 4,397,860 (18.10%) 18,155 (15.06%) 4,391,335 (18.10%) Region North East 11,745 (4.48%) 1,213,585 (4.99%) 5,195 (4.31%) 1,211,880 (5.00%) North West 38,070 (14.53%) 3,246,810 (13.36%) 16,800 (13.94%) 3,241,575 (13.36%) Yorkshire and the Humber 23,920 (9.13%) 2,426,160 (9.98%) 11,515 (9.55%) 2,422,780 (9.99%) East Midlands 24,225 (9.24%) 2,106,400 (8.67%) 10,470 (8.69%) 2,102,550 (8.67%) West Midlands 28,325 (10.81%) 2,567,255 (10.57%) 12,675 (10.52%) 2,563,435 (10.57%) . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint East of England 27,225 (10.39%) 2,725,220 (11.22%) 12,325 (10.23%) 2,721,420 (11.22%) London 37,900 (14.46%) 3,516,895 (14.47%) 17,010 (14.11%) 3,512,015 (14.48%) South East 43,715 (16.68%) 4,012,685 (16.51%) 22,015 (18.27%) 4,006,705 (16.51%) South West 26,945 (10.28%) 2,483,720 (10.22%) 12,510 (10.38%) 2,479,385 (10.22%) Note: For household NS-SEC, “Not classified” includes those not living in a private household in Census 2011, occupations not stated or inadequately described, or not classifiable for other reasons. For highest level of qualification, “Not classified” includes those aged under 16 in Census 2011. Table 2: Age-standardised rates of endometriosis diagnosis per 100,000 people Category Subcategory Main analysis, Age-standardised rate [95% CI] Supplementary analysis, Age-standardised rate [95% CI] Total Total 1,067.01 [1,062.92, 1,071.09] 494.27 [491.48, 497.06] Age on Census Day (five-year bands)* 0 to 9 years 52.04 [49.32, 54.75] 30.01 [27.95, 32.07] 10 to 14 years 686.76 [672.82, 700.71] 468.09 [456.56, 479.61] 15 to 19 years 1,472.01 [1,452.12, 1,491.90] 990.79 [974.43, 1,007.15] 20 to 24 years 1,953.77 [1,931.31, 1,976.22] 1,186.83 [1,169.25, 1,204.40] 25 to 29 years 2,175.44 [2,152.57, 2,198.30] 1,217.48 [1,200.28, 1,234.69] 30 to 34 years 2,307.61 [2,283.94, 2,331.27] 1,210.61 [1,193.34, 1,227.87] 35 to 39 years 2,492.44 [2,468.27, 2,516.62] 1,197.24 [1,180.34, 1,214.14] 40 to 44 years 2,122.37 [2,101.25, 2,143.50] 820.74 [807.49, 833.99] 45 to 49 years 1,273.91 [1,257.60, 1,290.23] 350.81 [342.20, 359.43] 50 to 54 years 619.79 [607.65, 631.92] 102.52 [97.57, 107.48] 55 to 59 years 396.50 [386.21, 406.78] 41.47 [38.14, 44.81] 60 to 64 years 306.88 [298.13, 315.64] 28.64 [25.97, 31.32] 65 to 69 years 256.34 [247.37, 265.30] 20.79 [18.23, 23.34] 70 to 74 years 179.00 [170.77, 187.23] 16.88 [14.35, 19.41] 75 to 79 years 108.97 [101.97, 115.97] 8.09 [6.29, 10.23] 80 years and over 38.63 [35.38, 41.88] 5.70 [4.52, 7.10] Ethnic group (detailed) White: English/Welsh/Scottish/Northern Irish/British 1,133.38 [1,128.57, 1,138.19] 535.50 [532.16, 538.85] White: Irish 893.36 [849.91, 936.82] 399.39 [368.73, 430.04] White: Gypsy or Irish Traveller 1,131.79 [997.11, 1,266.48] 544.29 [452.56, 636.02] White: Other White 735.99 [720.11, 751.87] 338.37 [328.20, 348.53] Mixed/multiple: White and Black Caribbean 1,226.87 [1,162.53, 1,291.20] 496.15 [461.75, 530.55] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Mixed/multiple: White and Black African 960.14 [869.97, 1,050.31] 401.92 [344.65, 459.19] Mixed/multiple: White and Asian 1,056.28 [989.37, 1,123.19] 489.97 [448.59, 531.35] Mixed/multiple: Other Mixed 1,103.76 [1,038.51, 1,169.01] 489.66 [450.45, 528.87] Asian: Indian 866.00 [843.97, 888.02] 373.43 [359.40, 387.46] Asian: Pakistani 953.87 [924.32, 983.43] 394.66 [377.58, 411.74] Asian: Bangladeshi 968.79 [918.98, 1,018.60] 466.77 [432.59, 500.94] Asian: Chinese 552.82 [516.53, 589.11] 226.36 [204.68, 248.05] Asian: Other Asian 906.58 [876.81, 936.35] 414.89 [395.83, 433.95] Black: African 737.11 [708.64, 765.58] 248.30 [230.76, 265.84] Black: Caribbean 1,160.08 [1,121.26, 1,198.90] 446.65 [422.15, 471.14] Black: Other Black 1,035.64 [966.75, 1,104.52] 361.98 [323.51, 400.45] Other: Arab 640.74 [577.32, 704.16] 254.49 [217.39, 291.59] Other: Any other ethnic group 988.75 [933.23, 1,044.27] 455.95 [419.64, 492.26] Ethnic group (aggregated) White 1,099.91 [1,095.39, 1,104.43] 518.66 [515.53, 521.80] Mixed/Multiple ethnic groups 1,115.95 [1,081.00, 1,150.90] 480.88 [460.51, 501.24] Asian/Asian British 879.76 [866.33, 893.18] 385.29 [376.90, 393.68] Black/African/Caribbean/Black British 901.28 [881.12, 921.44] 317.09 [305.52, 328.66] Other ethnic group 870.48 [827.61, 913.35] 385.69 [358.55, 412.83] Country of birth Born in the UK 1,123.29 [1,118.67, 1,127.91] 524.36 [521.19, 527.54] Born outside the UK 795.89 [786.88, 804.90] 346.14 [340.24, 352.05] Main language Main language is English 1,105.20 [1,100.80, 1,109.59] 513.66 [510.64, 516.67] Main language is not English 738.05 [726.25, 749.86] 324.65 [317.24, 332.07] IMD decile group 1 (most deprived) 1,091.42 [1,078.24, 1,104.61] 487.16 [478.52, 495.80] 2 1,103.68 [1,090.69, 1,116.67] 499.36 [490.77, 507.96] 3 1,091.64 [1,078.81, 1,104.47] 493.28 [484.75, 501.80] 4 1,093.81 [1,080.89, 1,106.73] 507.11 [498.35, 515.87] 5 1,081.39 [1,068.46, 1,094.32] 498.32 [489.52, 507.13] 6 1,069.64 [1,056.75, 1,082.52] 498.67 [489.80, 507.54] 7 1,074.34 [1,061.17, 1,087.50] 500.10 [491.00, 509.21] 8 1,059.20 [1,046.09, 1,072.31] 501.59 [492.42, 510.75] 9 1,040.15 [1,027.00, 1,053.29] 493.76 [484.53, 502.98] 10 (least deprived) 972.65 [959.53, 985.76] 465.28 [455.99, 474.57] Household NS-SEC Class 1: Higher managerial, administrative and professional occupations 924.09 [913.67, 934.51] 418.32 [411.23, 425.41] Class 2: Lower managerial, administrative and professional occupations 1,077.35 [1,068.96, 1,085.74] 500.73 [494.95, 506.51] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Class 3: Intermediate occupations 1,176.47 [1,163.44, 1,189.50] 554.51 [545.45, 563.58] Class 4: Small employers and own account workers 1,087.29 [1,075.18, 1,099.40] 515.04 [506.61, 523.46] Class 5: Lower supervisory and technical occupations 1,165.92 [1,150.86, 1,180.98] 550.46 [540.09, 560.83] Class 6: Semi-routine occupations 1,149.28 [1,137.23, 1,161.34] 532.12 [523.86, 540.37] Class 7: Routine occupations 1,097.03 [1,084.15, 1,109.90] 510.60 [501.76, 519.45] Class 8: Never worked and long-term unemployed 943.12 [923.60, 962.63] 409.14 [396.71, 421.56] Students 956.71 [911.46, 1,001.95] 422.31 [400.15, 444.46] Not classified 557.61 [509.49, 605.73] 229.89 [201.42, 258.35] Highest level of qualification No academic or professional qualifications 925.87 [913.88, 937.86] 407.31 [398.99, 415.63] Level 1 1,141.74 [1,130.40, 1,153.07] 528.62 [520.81, 536.43] Level 2 1,153.47 [1,143.35, 1,163.59] 538.38 [531.53, 545.23] Apprenticeship 1,174.24 [1,121.95, 1,226.53] 569.15 [532.40, 605.90] Level 3 1,110.28 [1,098.64, 1,121.92] 512.43 [505.04, 519.81] Level 4 and above 962.71 [949.23, 976.19] 430.45 [419.87, 441.03] Other qualifications 809.37 [791.52, 827.22] 352.08 [339.90, 364.26] Not classified 114.09 [111.61, 116.57] 76.92 [74.88, 78.97] Highest level of qualification, 25 years and over No academic or professional qualifications 737.51 [727.07, 747.94] 291.51 [284.60, 298.42] Level 1 902.17 [892.05, 912.29] 381.04 [374.34, 387.74] Level 2 918.69 [909.41, 927.98] 388.65 [382.59, 394.70] Apprenticeship 909.52 [859.85, 959.20] 393.45 [359.22, 427.69] Level 3 913.54 [902.49, 924.59] 385.20 [378.43, 391.97] Level 4 and above 756.44 [750.56, 762.33] 299.22 [295.67, 302.78] Other qualifications 691.53 [676.66, 706.39] 277.49 [268.20, 286.79] Aged 0 to 24 years on Census Day 247.77 [245.80, 249.74] 158.94 [157.35, 160.52] General health Very good health 856.74 [851.29, 862.19] 408.92 [405.41, 412.43] Good health 1,202.81 [1,195.53, 1,210.09] 568.78 [563.64, 573.92] Fair health 1,665.43 [1,645.16, 1,685.69] 736.43 [722.07, 750.80] Bad health 1,899.49 [1,853.46, 1,945.52] 772.06 [740.71, 803.41] Very bad health 1,609.22 [1,528.88, 1,689.55] 564.92 [513.08, 616.76] Disability Day-to-day activities not limited 1,021.89 [1,017.62, 1,026.15] 479.88 [477.00, 482.75] Day-to-day activities limited a little 1,694.95 [1,670.71, 1,719.19] 750.27 [733.18, 767.35] Day-to-day activities limited a lot 1,458.87 [1,430.50, 1,487.23] 573.82 [554.74, 592.89] Rural/urban classification Urban 1,071.48 [1,067.01, 1,075.95] 493.54 [490.52, 496.57] Rural 1,054.93 [1,044.37, 1,065.49] 504.37 [496.84, 511.89] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Region North East 986.62 [968.74, 1,004.49] 444.00 [431.91, 456.10] North West 1,173.24 [1,161.45, 1,185.03] 523.71 [515.78, 531.63] Yorkshire and the Humber 987.58 [975.05, 1,000.11] 477.90 [469.16, 486.64] East Midlands 1,156.18 [1,141.60, 1,170.76] 508.23 [498.48, 517.98] West Midlands 1,112.52 [1,099.55, 1,125.48] 502.16 [493.41, 510.90] East of England 1,019.01 [1,006.89, 1,031.13] 469.55 [461.25, 477.85] London 938.91 [929.26, 948.56] 409.09 [402.84, 415.34] South East 1,106.97 [1,096.58, 1,117.36] 565.89 [558.40, 573.38] South West 1,147.74 [1,134.00, 1,161.49] 548.28 [538.65, 557.91] * Age on Census Day (five-year bands) shows the crude rates per 100,000 people. All other categories show the age-standardised rates per 100,000 people. Note: For household NS-SEC, “Not classified” includes those not living in a private household in Census 2011, occupations not stated or inadequately described, or not classifiable for other reasons. For highest level of qualification, “Not classified” includes those aged under 16 in Census 2011. Table 3: Odds ratios for endometriosis diagnosis and 95% confidence intervals by age on Census Day (five-year bands) Analysis type Term Adjusted for health, OR [95% CI] Main analysis 0 to 9 years 0.02 [0.02, 0.02] 10 to 14 years 0.31 [0.30, 0.31] 15 to 19 years 0.64 [0.63, 0.65] 20 to 24 years 0.79 [0.78, 0.80] 25 to 29 years 0.86 [0.85, 0.87] 30 to 34 years 0.90 [0.88, 0.91] 40 to 44 years 0.88 [0.87, 0.89] 45 to 49 years 0.53 [0.52, 0.54] 50 to 54 years 0.25 [0.25, 0.26] 55 to 59 years 0.16 [0.16, 0.16] 60 to 64 years 0.12 [0.12, 0.13] 65 to 69 years 0.10 [0.10, 0.10] 70 to 74 years 0.07 [0.06, 0.07] 75 to 79 years 0.04 [0.04, 0.04] 80 years and over 0.01 [0.01, 0.01] Supplementary analysis 0 to 9 years 0.02 [0.02, 0.03] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint 10 to 14 years 0.44 [0.42, 0.45] 15 to 19 years 0.89 [0.87, 0.91] 20 to 24 years 1.01 [0.99, 1.03] 25 to 29 years 1.00 [0.98, 1.02] 30 to 34 years 0.98 [0.96, 1.00] 40 to 44 years 0.71 [0.69, 0.72] 45 to 49 years 0.30 [0.29, 0.31] 50 to 54 years 0.09 [0.08, 0.09] 55 to 59 years 0.04 [0.03, 0.04] 60 to 64 years 0.02 [0.02, 0.03] 65 to 69 years 0.02 [0.01, 0.02] 70 to 74 years 0.01 [0.01, 0.02] 75 to 79 years 0.01 [0.00, 0.01] 80 years and over 0.00 [0.00, 0.01] Note: Reference category: 35 to 39 years Table 4: Odds ratios for endometriosis diagnosis and 95% confidence intervals by ethnic group Analysis type Exposure Term Adjusted for age, OR [95% CI] Adjusted for age and health, OR [95% CI] Adjusted for age, health and country of birth, OR [95% CI] Adjusted for age, health and main language, OR [95% CI] Adjusted for age, health, country of birth and main language, OR [95% CI] Main analysis Ethnic group (detailed) (Reference category: White: English/Welsh/Sc ottish/Northern Irish/British) White: Irish 0.81 [0.77, 0.85] 0.82 [0.79, 0.86] 0.88 [0.84, 0.93] 0.82 [0.79, 0.86] 0.86 [0.82, 0.90] White: Gypsy or Irish Traveller 0.99 [0.88, 1.11] 0.94 [0.84, 1.06] 0.95 [0.85, 1.07] 0.95 [0.85, 1.07] 0.96 [0.85, 1.08] White: Other White 0.63 [0.62, 0.64] 0.66 [0.64, 0.67] 0.74 [0.72, 0.76] 0.74 [0.73, 0.76] 0.78 [0.76, 0.81] Mixed/multiple: White and Black Caribbean 1.05 [1.00, 1.09] 1.02 [0.98, 1.07] 1.03 [0.99, 1.08] 1.03 [0.98, 1.07] 1.03 [0.99, 1.08] Mixed/multiple: White and Black African 0.84 [0.77, 0.91] 0.84 [0.77, 0.91] 0.89 [0.82, 0.97] 0.87 [0.80, 0.95] 0.90 [0.83, 0.98] Mixed/multiple: White and Asian 0.87 [0.82, 0.92] 0.88 [0.84, 0.93] 0.91 [0.86, 0.96] 0.90 [0.85, 0.95] 0.91 [0.86, 0.97] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Mixed/multiple: Other Mixed 0.94 [0.89, 1.00] 0.96 [0.91, 1.01] 1.00 [0.95, 1.06] 0.99 [0.94, 1.04] 1.01 [0.96, 1.07] Asian: Indian 0.75 [0.73, 0.77] 0.77 [0.75, 0.79] 0.82 [0.80, 0.84] 0.82 [0.80, 0.84] 0.84 [0.82, 0.87] Asian: Pakistani 0.78 [0.76, 0.80] 0.76 [0.74, 0.78] 0.81 [0.78, 0.83] 0.82 [0.79, 0.84] 0.84 [0.82, 0.87] Asian: Bangladeshi 0.84 [0.80, 0.87] 0.83 [0.79, 0.86] 0.90 [0.86, 0.94] 0.92 [0.88, 0.97] 0.95 [0.91, 1.00] Asian: Chinese 0.43 [0.40, 0.45] 0.46 [0.43, 0.48] 0.50 [0.47, 0.54] 0.50 [0.47, 0.54] 0.53 [0.50, 0.56] Asian: Other Asian 0.81 [0.78, 0.83] 0.83 [0.80, 0.86] 0.92 [0.89, 0.96] 0.93 [0.90, 0.96] 0.98 [0.94, 1.01] Black: African 0.62 [0.60, 0.65] 0.61 [0.59, 0.64] 0.68 [0.66, 0.71] 0.65 [0.63, 0.68] 0.69 [0.67, 0.72] Black: Caribbean 1.04 [1.01, 1.08] 1.03 [0.99, 1.06] 1.07 [1.03, 1.10] 1.03 [1.00, 1.07] 1.05 [1.02, 1.09] Black: Other Black 0.89 [0.84, 0.95] 0.88 [0.82, 0.93] 0.92 [0.87, 0.98] 0.92 [0.86, 0.98] 0.94 [0.88, 1.00] Other: Arab 0.53 [0.48, 0.58] 0.52 [0.48, 0.57] 0.58 [0.53, 0.63] 0.59 [0.54, 0.64] 0.62 [0.56, 0.68] Other: Any other ethnic group 0.85 [0.81, 0.90] 0.85 [0.81, 0.90] 0.94 [0.89, 0.99] 0.94 [0.89, 1.00] 0.98 [0.93, 1.04] Ethnic group (aggregated) (Reference category: White) Mixed/Multiple ethnic groups 0.98 [0.95, 1.00] 0.98 [0.95, 1.00] 1.02 [0.99, 1.05] 0.99 [0.97, 1.02] 1.01 [0.99, 1.04] Asian/Asian British 0.77 [0.76, 0.78] 0.78 [0.77, 0.79] 0.90 [0.89, 0.92] 0.89 [0.87, 0.90] 0.93 [0.91, 0.95] Black/African/Caribbean/B lack British 0.81 [0.80, 0.83] 0.80 [0.78, 0.82] 0.92 [0.90, 0.95] 0.84 [0.82, 0.86] 0.91 [0.89, 0.93] Other ethnic group 0.76 [0.72, 0.79] 0.75 [0.72, 0.79] 0.91 [0.87, 0.96] 0.90 [0.86, 0.94] 0.95 [0.91, 1.00] Supplementary analysis Ethnic group (detailed) (Reference category: White: English/Welsh/Sc ottish/Northern Irish/British) White: Irish 0.77 [0.72, 0.83] 0.79 [0.74, 0.85] 0.84 [0.78, 0.90] 0.79 [0.74, 0.85] 0.82 [0.76, 0.89] White: Gypsy or Irish Traveller 0.98 [0.83, 1.16] 0.93 [0.79, 1.10] 0.94 [0.80, 1.11] 0.95 [0.80, 1.12] 0.95 [0.81, 1.12] White: Other White 0.63 [0.61, 0.65] 0.66 [0.64, 0.68] 0.73 [0.70, 0.75] 0.73 [0.70, 0.75] 0.76 [0.73, 0.79] Mixed/multiple: White and Black Caribbean 0.93 [0.88, 0.99] 0.92 [0.86, 0.97] 0.92 [0.86, 0.98] 0.92 [0.86, 0.98] 0.92 [0.86, 0.98] Mixed/multiple: White and Black African 0.73 [0.65, 0.83] 0.73 [0.65, 0.83] 0.77 [0.68, 0.87] 0.76 [0.67, 0.85] 0.78 [0.69, 0.88] Mixed/multiple: White and Asian 0.85 [0.78, 0.91] 0.86 [0.80, 0.93] 0.88 [0.82, 0.95] 0.88 [0.81, 0.95] 0.89 [0.82, 0.96] Mixed/multiple: Other Mixed 0.90 [0.83, 0.97] 0.91 [0.84, 0.98] 0.95 [0.88, 1.02] 0.93 [0.86, 1.01] 0.95 [0.88, 1.03] Asian: Indian 0.69 [0.67, 0.72] 0.71 [0.69, 0.74] 0.75 [0.72, 0.78] 0.74 [0.72, 0.77] 0.76 [0.73, 0.79] Asian: Pakistani 0.70 [0.67, 0.73] 0.69 [0.66, 0.72] 0.72 [0.69, 0.75] 0.73 [0.70, 0.76] 0.74 [0.71, 0.77] Asian: Bangladeshi 0.82 [0.78, 0.87] 0.82 [0.77, 0.87] 0.87 [0.82, 0.92] 0.89 [0.83, 0.94] 0.91 [0.85, 0.96] Asian: Chinese 0.38 [0.34, 0.41] 0.40 [0.37, 0.44] 0.44 [0.40, 0.48] 0.44 [0.40, 0.48] 0.45 [0.41, 0.50] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Asian: Other Asian 0.79 [0.76, 0.83] 0.82 [0.78, 0.85] 0.89 [0.85, 0.94] 0.89 [0.85, 0.94] 0.93 [0.88, 0.98] Black: African 0.44 [0.42, 0.46] 0.43 [0.41, 0.46] 0.47 [0.45, 0.50] 0.45 [0.43, 0.48] 0.48 [0.45, 0.50] Black: Caribbean 0.83 [0.79, 0.88] 0.83 [0.78, 0.87] 0.85 [0.80, 0.90] 0.83 [0.78, 0.88] 0.84 [0.80, 0.89] Black: Other Black 0.65 [0.59, 0.72] 0.64 [0.58, 0.71] 0.67 [0.60, 0.74] 0.67 [0.60, 0.74] 0.68 [0.61, 0.75] Other: Arab 0.46 [0.40, 0.52] 0.45 [0.40, 0.52] 0.49 [0.43, 0.56] 0.50 [0.43, 0.57] 0.52 [0.45, 0.59] Other: Any other ethnic group 0.83 [0.77, 0.89] 0.83 [0.77, 0.90] 0.90 [0.83, 0.97] 0.90 [0.83, 0.98] 0.93 [0.86, 1.01] Ethnic group (aggregated) (Reference category: White) Mixed/Multiple ethnic groups 0.90 [0.87, 0.94] 0.90 [0.87, 0.94] 0.94 [0.90, 0.97] 0.92 [0.88, 0.95] 0.93 [0.90, 0.97] Asian/Asian British 0.72 [0.71, 0.74] 0.73 [0.72, 0.75] 0.83 [0.82, 0.85] 0.82 [0.80, 0.84] 0.85 [0.83, 0.87] Black/African/Caribbean/B lack British 0.60 [0.58, 0.62] 0.59 [0.57, 0.62] 0.68 [0.66, 0.71] 0.62 [0.60, 0.65] 0.67 [0.65, 0.70] Other ethnic group 0.71 [0.67, 0.76] 0.71 [0.67, 0.76] 0.85 [0.80, 0.91] 0.84 [0.78, 0.90] 0.88 [0.82, 0.94] Table 5: Odds ratios for endometriosis diagnosis and 95% confidence intervals by country of birth, main language, IMD decile group, household NS-SEC, highest level of qualification, general health, disability and rural/urban classification Analysis type Exposure Term Adjusted for age, OR [95% CI] Adjusted for age and health, OR [95% CI] Main analysis Country of birth (Reference category: Born in the UK) Born outside the UK 0.70 [0.70, 0.71] 0.72 [0.71, 0.73] Main language (Reference category: Main language is English) Main language is not English 0.66 [0.65, 0.67] 0.67 [0.66, 0.68] IMD decile group (Reference category: 10 (least deprived)) 1 (most deprived) 1.14 [1.12, 1.16] 1.07 [1.05, 1.09] 2 1.15 [1.13, 1.17] 1.10 [1.08, 1.12] 3 1.13 [1.11, 1.15] 1.10 [1.08, 1.12] 4 1.13 [1.11, 1.15] 1.11 [1.09, 1.13] 5 1.12 [1.10, 1.14] 1.11 [1.09, 1.13] 6 1.11 [1.09, 1.13] 1.10 [1.08, 1.12] 7 1.12 [1.10, 1.14] 1.11 [1.09, 1.13] 8 1.10 [1.08, 1.12] 1.09 [1.07, 1.11] 9 1.08 [1.06, 1.10] 1.07 [1.05, 1.09] Household NS-SEC (Reference category: Class 1: Higher Class 2: Lower managerial, administrative and professional occupations 1.18 [1.16, 1.19] 1.17 [1.15, 1.19] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint managerial, administrative and professional occupations) Class 3: Intermediate occupations 1.29 [1.27, 1.31] 1.27 [1.25, 1.29] Class 4: Small employers and own account workers 1.19 [1.17, 1.21] 1.17 [1.15, 1.19] Class 5: Lower supervisory and technical occupations 1.28 [1.25, 1.30] 1.24 [1.22, 1.26] Class 6: Semi-routine occupations 1.26 [1.24, 1.27] 1.21 [1.19, 1.23] Class 7: Routine occupations 1.20 [1.18, 1.22] 1.15 [1.13, 1.17] Class 8: Never worked and long-term unemployed 1.03 [1.01, 1.06] 0.96 [0.93, 0.98] Students 0.88 [0.86, 0.91] 0.90 [0.87, 0.93] Not classified 0.56 [0.53, 0.59] 0.57 [0.54, 0.60] Highest level of qualification (Reference category: Level 4 and above) No academic or professional qualifications 1.02 [1.01, 1.04] 0.96 [0.94, 0.97] Level 1 1.24 [1.22, 1.25] 1.18 [1.17, 1.20] Level 2 1.25 [1.24, 1.27] 1.22 [1.20, 1.23] Apprenticeship 1.32 [1.27, 1.38] 1.27 [1.22, 1.32] Level 3 1.18 [1.17, 1.20] 1.17 [1.16, 1.18] Other qualifications 0.88 [0.86, 0.90] 0.87 [0.85, 0.89] Not classified 1.53 [1.48, 1.58] 1.50 [1.45, 1.55] Highest level of qualification, 25 years and over (Reference category: Level 4 and above) No academic or professional qualifications 1.00 [0.99, 1.02] 0.96 [0.94, 0.97] Level 1 1.20 [1.19, 1.22] 1.17 [1.16, 1.19] Level 2 1.23 [1.21, 1.25] 1.21 [1.19, 1.22] Apprenticeship 1.24 [1.17, 1.30] 1.21 [1.15, 1.28] Level 3 1.23 [1.22, 1.25] 1.22 [1.20, 1.23] Other qualifications 0.91 [0.89, 0.93] 0.90 [0.88, 0.92] General health (Reference category: Very good health) Good health 1.43 [1.42, 1.45] x Fair health 1.92 [1.90, 1.94] x Bad health 2.04 [2.00, 2.09] x Very bad health 1.79 [1.71, 1.86] x Disability (Reference category: Day- to-day activities not limited) Day-to-day activities limited a little 1.58 [1.55, 1.60] x Day-to-day activities limited a lot 1.38 [1.36, 1.40] x Rural/urban classification (Reference category: Urban) Rural 0.98 [0.97, 0.99] 0.98 [0.97, 0.99] Supplementary analysis Country of birth (Reference category: Born in the UK) Born outside the UK 0.67 [0.66, 0.68] 0.68 [0.67, 0.69] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Main language (Reference category: Main language is English) Main language is not English 0.64 [0.63, 0.66] 0.66 [0.64, 0.67] IMD decile group (Reference category: 10 (least deprived)) 1 (most deprived) 1.06 [1.03, 1.08] 1.00 [0.97, 1.03] 2 1.08 [1.05, 1.11] 1.04 [1.02, 1.07] 3 1.06 [1.04, 1.09] 1.04 [1.01, 1.07] 4 1.09 [1.07, 1.12] 1.08 [1.05, 1.10] 5 1.08 [1.05, 1.11] 1.06 [1.04, 1.09] 6 1.08 [1.05, 1.11] 1.07 [1.04, 1.10] 7 1.08 [1.05, 1.11] 1.07 [1.04, 1.10] 8 1.09 [1.06, 1.12] 1.08 [1.05, 1.11] 9 1.07 [1.04, 1.10] 1.06 [1.04, 1.09] Household NS-SEC (Reference category: Class 1: Higher managerial, administrative and professional occupations) Class 2: Lower managerial, administrative and professional occupations 1.20 [1.18, 1.23] 1.20 [1.17, 1.22] Class 3: Intermediate occupations 1.33 [1.30, 1.36] 1.31 [1.28, 1.34] Class 4: Small employers and own account workers 1.23 [1.20, 1.26] 1.21 [1.18, 1.24] Class 5: Lower supervisory and technical occupations 1.32 [1.29, 1.35] 1.28 [1.25, 1.32] Class 6: Semi-routine occupations 1.27 [1.25, 1.30] 1.23 [1.20, 1.26] Class 7: Routine occupations 1.22 [1.19, 1.25] 1.18 [1.15, 1.21] Class 8: Never worked and long-term unemployed 0.98 [0.95, 1.01] 0.91 [0.88, 0.94] Students 0.88 [0.84, 0.91] 0.90 [0.86, 0.93] Not classified 0.55 [0.51, 0.59] 0.56 [0.53, 0.61] Highest level of qualification (Reference category: Level 4 and above) No academic or professional qualifications 1.03 [1.00, 1.05] 0.95 [0.93, 0.98] Level 1 1.31 [1.29, 1.34] 1.25 [1.23, 1.27] Level 2 1.34 [1.31, 1.36] 1.29 [1.27, 1.31] Apprenticeship 1.47 [1.39, 1.56] 1.40 [1.32, 1.48] Level 3 1.24 [1.21, 1.26] 1.22 [1.20, 1.24] Other qualifications 0.89 [0.86, 0.92] 0.87 [0.85, 0.90] Not classified 1.64 [1.57, 1.71] 1.59 [1.53, 1.66] Highest level of qualification, 25 years and over (Reference category: Level 4 and above) No academic or professional qualifications 0.99 [0.97, 1.02] 0.95 [0.92, 0.97] Level 1 1.28 [1.26, 1.31] 1.25 [1.22, 1.28] Level 2 1.31 [1.29, 1.34] 1.28 [1.26, 1.31] Apprenticeship 1.35 [1.24, 1.47] 1.32 [1.21, 1.43] . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint Level 3 1.31 [1.28, 1.33] 1.29 [1.26, 1.31] Other qualifications 0.92 [0.89, 0.96] 0.92 [0.88, 0.95] General health (Reference category: Very good health) Good health 1.40 [1.38, 1.42] x Fair health 1.79 [1.76, 1.83] x Bad health 1.84 [1.77, 1.90] x Very bad health 1.35 [1.24, 1.46] x Disability (Reference category: Day- to-day activities not limited) Day-to-day activities limited a little 1.53 [1.50, 1.57] x Day-to-day activities limited a lot 1.20 [1.16, 1.24] x Rural/urban classification (Reference category: Urban) Rural 1.02 [1.00, 1.03] 1.02 [1.00, 1.04] Notes: Values x are not applicable for the given exposure. For household NS-SEC, “Not classified” includes those not living in a private household in Census 2011, occupations not stated or inadequately described, or not classifiable for other reasons. For highest level of qualification, “Not classified” includes those aged under 16 in Census 2011. . CC-BY-NC-ND 4.0 International licenseIt is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in(which was not certified by peer review)preprint The copyright holder for thisthis version posted December 12, 2024. ; https://doi.org/10.1101/2024.12.11.24318835doi: medRxiv preprint