Understanding endometriosis knowledge among diagnosed and symptomatically at-risk individuals in Australia

Sampling procedure The study received ethical approval from the Western Sydney University Human Research Ethics Committee (ID H16020) confirming that this study complied with the Declaration of Hels inki. Participants were recruited between May 26 and July 31, 2024, through targeted social media adver- t i s e m e n t s( M e t a )t op e o p l ei nA u s t r a l i aa g e d1 8–45 years. Eligibility criteria included: (1) being between 18–45 years old, (2) born as female, (3) living in Australia, and (4) reporting at least one symptom related to endometriosis (see measures section for assessment criteria). Design We conducted an online survey targeting Australian citizens who met the screening criteria. After providing informed consent, participants com- pleted a self-assessment for endometriosis and shared information regarding their awareness and personal diagnosis of the condition. Subse- quently, we assessed participants’ endometriosis knowledge and examined variables related to menstrual and endometriosis (the more specific findings related to stigma will be reported separately). Overall, the study design was adapted from a previous study of the authors 2. Sample The final study sample included 427 participants who either had a formal diagnosis of endometriosis (n = 143) or were classified as at-risk based on their reported symptoms (n = 284). At-risk status was de fined as experi- encing severe menstrual pelvic pain at least occasionally despite taking painkillers, in combination with at least one of the following symptoms occurring occasionally: diarrhea and/or bowel pain during menstruation, abdominal pain unrelated to menstruation, or pain during intercourse. To ensure data quality, participants with a mean survey completion time of less than 3 min were excluded. Of the final sample, 87.8% (n = 375) identified as women, while 11.2% (n =4 8 ) i d e n t ified as other (i.e., male, genderqueer, transgender, or non- binary), and another 1% (n = 4) preferred not to say. Regarding education, 34.4% ( n = 147) had lower to medium education levels (up to upper secondary and post-secondary vocational education), and 64.4% (n = 275) held a tertiary degree (n = 5 preferred not to disclose their edu- cational status). A slightly higher proportion of participants in the at-risk group did not hold a university degree, which could have in fluenced response patterns in the knowledge me asurement. However, it is worth https://doi.org/10.1038/s44294-025-00096-6 Brief communication npj Women's Health | (2025) 3:46 3 noting that only one participant in the at-risk group had no formal school qualification, while all others had completed at least a secondary school degree (equivalent to Year 10), indic ating an overall high educational baseline across the sample. All participants reported being familiar with the term endometriosis. A detailed description of the sample can be found in Table 1. Measures The self-test for endometriosis symptoms2 included the most common symptoms of the condition. Participants rated their experiences on a scale from 1 (never) to 5 (always). Items included pelvic pain during menstrua- tion, the use of painkiller medication, and pelvic pain despite medication intake. Additional questions addressed diarrhea and/or bowel pain during menstruation, pain during sexual int ercourse, and pelvic pain occurring several days a month, independent of menstruation. Participants’ endometriosis diagnosis status was assessed with a dichotomous variable:“Have you yourself been diagnosed with endome- triosis?” (0 = no, 1 = yes). Lastly, knowledge of endometriosis was evaluated through nine single-choice questions covering the disease ’sd e finition, incidence, symptoms, and treatment options 8. Each question offered one correct answer and three distractors. Correct responses were summed to create a knowledge score ranging from 0 ( “no correct answers ”)t o9 (“all answers correct ”). An overview of all knowledge items is pro- vided in Table 2. Table 1 | Sample characteristics Overall Diagnosed At-risk n % n % n % Gender identity Female 375 87.8 135 94.4 240 84.5 Other 48 11.2 8 5.6 40 14.1 Prefer not to say 4 1.0 –– 4 1.4 Education Lower/medium 147 34.4 34 23.8 113 39.8 Higher 275 64.4 98 68.5 167 58.8 Prefer not to say 5 1.2 10 7.0 4 1.4 Sociodemographic characteristics of the overall sample ( N = 427), the diagnosed subsample (N = 143), and the at-risk subsample (N = 284). The table reports distributions of gender identity and educational attainment. The gender category “other” includes participants identifying as male, genderqueer, transgender, or non-binary. Table 2 | Knowledge questionnaire Name Question Response options K1 Which of these is the main contributor to endometriosis symptoms? 1 = “Cells similar to the lining of the uterus found in the pelvis ” 2 = “Sexually transmitted infections such as Herpes or Chlamydia ” 3 = “Side effects of contraception pills ” 4 = “Complications during pregnancy/birth ” K2 What is a typical symptom of endometriosis? 1 = “Severe menstrual pain ” 2 = “Increased estrogen levels ” 3 = “Photosensitivity” 4 = “Joint pain” K3 What is another common symptom of endometriosis? 1 = “Pain during sex ” 2 = “Increased body temperature during the period ” 3 = “Increased progesterone levels ” 4 = “Mood changes” K4 What is the most widely accepted way to diagnose endometriosis? 1 = “Blood test” 2 = “Ultrasound examination” 3 = “Laparoscopy” 4 = “Via a vaginal swab ” K5 How long, on average, does it take to get an endometriosis diagnosis in Australia? 1 = “Approximately 10–12 months” 2 = “Approximately 2–3 years” 3 = “Approximately 6–8 years” 4 = “Approximately 10–12 years” K6 What is a possible consequence of endometriosis? 1 = “Infertility” 2 = “Gynecomastia (abnormal non-cancerous enlargement of one or both breasts)” 3 = “Hemorrhoids” 4 = “Increased blood sugar levels ” K7 What other condition is commonly experienced by people with endometriosis? 1 = “Mental health issues (e.g., depression) ” 2 = “Weight gain” 3 = “Increased risk for infections such as Herpes ” 4 = “Hair loss” K8 How can endometriosis be treated? 1 = “Surgical removal of the tissue ” 2 = “Testosterone injections” 3 = “Medication for muscle relaxation ” 4 = “Antibiotics” K9 What is the current estimate for how many women and people assigned female at birth are affected by endometriosis in Australia? 1 = “2–3% (2 to 3 out of 100) ” 2 = “5–7% (5 to 7 out of 100) ” 3 = “8–15% (8 to 15 out of 100) ” 4 = “15–18% (15 to 18 out of 100) ” Overview of all knowledge items and corresponding response options (single choice format). Correct response options are indicated in bold. https://doi.org/10.1038/s44294-025-00096-6 Brief communication npj Women's Health | (2025) 3:46 4 Data availability The datasets and R codes for this study are available in the Open Science Framework repository and can be accessed via this link:https://osf.io/spzej/? view_only=17961cfb1a664e6eb70be280a4b1d7c2. Code availability The underlying code for this study is available in the Open Science Fra- mework repository and can be accessed via this link: https://osf.io/spzej/? view_only=17961cfb1a664e6eb70be280a4b1d7c2. Received: 22 April 2025; Accepted: 23 July 2025;

1. Reid, R. et al. The prevalence of self-reported diagnosed endometriosis in the Australian population: results from a nationally- representative survey. BMC Res. Notes 12, 88 (2019). 2. Eitze, S. & Reinhardt, A. Keep Period Pain a Secret? Expanding the Theory of Planned Behavior with Endometriosis Knowledge and Menstrual Stigma to Explain Women ’sI n t e n t i o n st oT a l k About Menstrual Discomfort. Health Psychol. 44, 437 –447 (2025). 3. Armour, M. et al. Endometriosis and chronic pelvic pain have similar impact on women, but time to diagnosis is decreasing: an Australian survey. Sci. Rep. 10, 16253 (2020). 4. Armour, M. et al. Evaluation of a web-based resource to improve menstrual health literacy and self-management in young women. J. Psychosom. Res. 162, 111038 (2022). 5. DiVasta, A. D., Vitonis, A. F., Laufer, M. R. & Missmer, S. A. Spectrum of symptoms in women diagnosed with endometriosis during adolescence vs adulthood. Am. J. Obstet. Gynecol. 218, 324.e1–324.e11 (2018). 6. Bontempo, A. C. Conceptualizing symptom onvalidation as experienced by patients with endometriosis. Qual. Health Res. 35, 248–263 (2025). 7. Zaman, R. T. & Mohiuddin, M.dF. Impact of menstruation-related stigma and behavior on female employee performance in Bangladesh: mediating role of non-work related stress. South Asian J. Bus. Stud. 12, 169–185 (2023). 8. Reinhardt, A. & Eitze, S. Breaking the endometriosis silence: a social norm approach to reducing menstrual stigma and policy resistance among young adults. Psychol. Health 40, 881–903 (2025). 9. Hawkey, A., Chalmers, K. J., Micheal, S., Diezel, H. & Armour, M. “A day-to-day struggle”: A comparative qualitative study on experiences of women with endometriosis and chronic pelvic pain. Fem. Psychol. 32, 482–500 (2022). 10. Armour, M., Dahlen, H. G. & Smith, C. A. More than needles: The importance of explanations and self-care advice in treating primary dysmenorrhea with acupuncture. Evid. Based Compl. Alternat. Med. 2, 3467067 (2016). 11. Harder, C., Velho, R. V., Brandes, I., Sehouli, J. & Mechsner, S. Assessing the true prevalence of endometriosis: A narrative review of literature data. Int. J. Gynecol. Obstet. 167, 883–900 (2024). 12. Sims, O. T., Gupta, J., Missmer, S. A. & Aninye, I. O. Stigma and endometriosis: A brief overview and recommendations to improve psychosocial well-being and diagnostic delay. Int. J. Environ. Res. Public. Health 18, 8210 (2021). 13. Ussher, J. M. Managing the monstrous feminine in Regulating the reproductive body: Managing the monstrous feminine (ed. Ussher, J. M.) 1–18 (Routledge, 2006). 14. Kocas, H. D., Rubin, L. R. & Lobel, M. Stigma and mental health in endometriosis. Eur. J. Obstet. Gynecol. Reprod. Biol. X 19, 100228 (2023). 15. Khan, K. N. et al. A targeted educational programme improves fundamental knowledge of menstrual pain and endometriosis in young women: The Endometriosis Awareness Promotion Project. Reprod. Biomed. Online 45, 1216–1229 (2022). 16. Hirsch, M., Aggarwal, S., Barker, C., Davis, C. J. & Duffy, J. M. N. Googling endometriosis: a systematic review of information available on the Internet. Am. J. Obstet. Gynecol. 216, 451–458.e1 (2017).

This study received no funding. Author contributions A.R.: Conceptualization, Methodology, Formal Analysis, Data Curation, Writing (Original Draft), Writing (Review & Editing), Visualization, Supervision, Project Administration M.M.: Methodology, Software, Investigation, Writing (Original Draft), Writing (Review & Editing), Project Administration SE: Conceptualization, Methodology, Writing (Original Draft), Writing (Review & Editing) H.A.: Writing (Original Draft), Writing (Review & Editing) D.H.: Writing (Original Draft), Writing (Review & Editing) M.O.: Writing (Original Draft), Writing (Review & Editing) M.A.: Conceptualization, Resources, Writing (Original Draft), Writing (Review & Editing), Supervision, Project Administration. Funding Open Access funding enabled and organized by Projekt DEAL. Competing interests The authors declare no competing interests. Additional information Supplementary informationThe online version contains supplementary

available at https://doi.org/10.1038/s44294-025-00096-6 . Correspondenceand requests for materials should be addressed to Anne Reinhardt. Reprints and permissions informationis available at http://www.nature.com/reprints Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article ’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ . © The Author(s) 2025 https://doi.org/10.1038/s44294-025-00096-6 Brief communication npj Women's Health | (2025) 3:46 5