JOGC

Prevalence, Symptomatic Burden, and Diagnosis of Endometriosis in Canada: Cross-Sectional Survey of 30 000 Women

Open AccessPublished:January 27, 2020DOI:https://doi.org/10.1016/j.jogc.2019.10.038

      Abstract

      Objective

      This study sought to estimate the prevalence of diagnosis of endometriosis (DxE) in Canada and to assess the symptomatic and diagnostic experience of Canadian women with DxE.

      Method

      A cross-sectional, online survey of women in Canada aged 18 to 49 was conducted from December 7, 2018 through January 24, 2019. Survey data were weighted by Canadian population statistics to estimate the prevalence, symptomatic burden, and diagnostic experience of DxE. Logistic regressions were used to assess differences in symptom burden between women with and without DxE.

      Results

      The estimated prevalence of DxE was 7.0% (2004 women of 28 532 women surveyed). Almost half (47.5%) of women with DxE were aged 18 to 29 when they received an endometriosis diagnosis, and 84.1% experienced symptoms before diagnosis. More women with versus without DxE experienced menstrual pelvic pain or cramping (70.3% vs. 50.7%), non-menstrual pelvic pain or cramping (49.5% vs. 18.7%), dyspareunia (52.5% vs. 28.0%), and infertility (22.3% vs. 6.3%). Women with DxE were more likely to report severe menstrual pelvic pain or cramping (odds ratio [OR] 2.9; 95% confidence interval [CI] 2.5–3.3), non-menstrual pelvic pain or cramping (OR 3.4; 95% CI 2.8–4.2), general abdominal pain (OR 3.0; 95% CI 2.5–3.6), and pelvic pressure (OR 3.0; 95% CI 2.3–3.8). Women with DxE reported an average 5.4-year diagnostic delay, with a 3.1-year delay from onset of symptoms to physician consultation and a 2.3-year delay between physician consultation and diagnosis.

      Conclusion

      Self-reported DxE is prevalent among Canadian women and is associated with a substantial symptomatic burden. The 5.4-year diagnostic delay reported here indicates an important unmet need for more timely diagnosis of endometriosis in Canada.

      Résumé

      Objectif

      Cette étude visait à estimer la prévalence des diagnostics d'endométriose au Canada et à évaluer l'expérience des Canadiennes ayant reçu un diagnostic d'endométriose relativement à leurs symptômes et au processus diagnostique.

      Méthodologie

      Une enquête transversale en ligne a été menée du 7 décembre 2018 au 24 janvier 2019 auprès de Canadiennes âgées de 18 à 49 ans. Les données de l'enquête ont été pondérées au moyen des statistiques démographiques canadiennes pour estimer la prévalence, le fardeau des symptômes et l'expérience du processus diagnostique de l'endométriose. Des régressions logistiques ont été utilisées pour évaluer les différences par rapport au fardeau des symptômes entre les femmes qui ont ou non reçu un diagnostic d'endométriose.

      Résultats

      La prévalence estimée du diagnostic d'endométriose était de 7,0 % (2004 des 28 532 femmes ayant participé à l'enquête). Près de la moitié (47,5 %) des femmes ayant reçu un diagnostic d'endométriose avaient entre 18 et 29 ans au moment du diagnostic et 84,1 % ont éprouvé des symptômes avant le diagnostic. Par rapport aux autres femmes, celles ayant reçu un diagnostic d'endométriose ont été plus nombreuses à éprouver des crampes ou des douleurs pelviennes menstruelles (70,3 % par rapport à 50,7 %), à éprouver des crampes ou des douleurs pelviennes non menstruelles (49,5 % par rapport à 18,7 %), à souffrir de dyspareunie (52,5 % par rapport à 28,0 %) et à être infertiles (22,3 % par rapport à 6,3 %). Toujours par rapport aux autres femmes, celles ayant reçu un diagnostic d'endométriose étaient plus susceptibles; d'affirmer éprouver des crampes ou douleurs pelviennes menstruelles importantes (rapport de cotes [RC] 2,9; intervalle de confiance [IC] à 95 % 2,5–3,3), des crampes ou douleurs pelviennes non menstruelles (RC 3,4; IC de 95 % 2,8–4,2), des douleurs abdominales générales (RC 3,0; IC de 95 % 2,5–3,6) et de la pression exercée sur le pelvis (RC 3,0; IC de 95 % 2,3–3,8). En moyenne, les femmes ayant reçu un diagnostic d'endométriose ont rapporté un temps moyen de 5,4 ans avant d'obtenir un diagnostic avec un délai de 3,1 ans de l'apparition des symptômes à la consultation avec un médecin et un délai de 2,3 ans entre la consultation et le diagnostic.

      Conclusion

      Le diagnostic d'endométriose autodéclaré est prévalent chez les Canadiennes et est associé à un important fardeau des symptômes. Le temps de 5,4 ans avant l'obtention d'un diagnostic rapporté ci-dessus indique d'importantes lacunes quant à la nécessité d'améliorer le délai d'obtention du diagnostic de l'endométriose au Canada.

      Keywords

      INTRODUCTION

      Endometriosis is a chronic inflammatory disease that predominantly affects women of reproductive age and is characterized by the growth of endometrial-like tissue outside of the uterus.
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      Women with endometriosis experience a range of symptoms, including pelvic pain and cramping during menstruation, non-menstrual pelvic pain, painful intercourse (dyspareunia), heavy menstrual bleeding, and chronic fatigue.
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      Subfertility or infertility is also commonly associated with endometriosis.
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      Endometriosis and infertility.
      The chronicity and severity of endometriosis-related symptoms considerably affect all aspects of women's quality of life.
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      Although the prevalence of endometriosis in women of reproductive age is commonly cited as 10%,
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      global estimates vary widely, ranging from 2% to 45%
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      and anywhere from 2% to 77% in women with infertility.
      • Eskenazi B
      • Warner ML.
      Epidemiology of endometriosis.
      Historically, prevalence estimates have been based on studies of women who were hospitalized or undergoing surgery and were not necessarily representative of the general female population.
      • Eskenazi B
      • Warner ML.
      Epidemiology of endometriosis.
      ,
      • Rawson JM.
      Prevalence of endometriosis in asymptomatic women.
      Differences in the populations of women included in studies (e.g., surgical cases), the definition of disease, and the diagnostic method used contribute to the substantial variability among prevalence estimates.
      • Eskenazi B
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      Epidemiology of endometriosis.
      ,
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      What makes a good case-control study? Design issues for complex traits such as endometriosis.
      The overlap between endometriosis-related pelvic-abdominal pain symptoms and other chronic pain conditions contributes to difficulty in diagnosing endometriosis.
      • Kennedy S
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      ESHRE guideline for the diagnosis and treatment of endometriosis.
      ,
      • Seaman HE
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      Endometriosis and its coexistence with irritable bowel syndrome and pelvic inflammatory disease: findings from a national case-control study–Part 2.
      Furthermore, clinical examination findings in women with endometriosis may often be normal.
      • Kennedy S
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      • et al.
      ESHRE guideline for the diagnosis and treatment of endometriosis.
      The traditional gold standard for definitively diagnosing endometriosis is laparoscopic visualization of lesions and histologic confirmation, and only recently has there been a push towards non-surgical methods of diagnosis in Canada.
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      Society of Obstetricians and Gynaecologists of Canada. Endometriosis: diagnosis and management.
      For these and other reasons, many women experience a significant delay from the time of symptom onset to diagnosis. Worldwide, estimates of diagnostic delay range from 4 to 11 years.
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      Factors associated with time to endometriosis diagnosis in the United States.
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      This lengthy delay in diagnosis may result in prolonged suffering, reduced productivity, and worse health-related quality of life for women with endometriosis.
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      • Wright J
      What's the delay? A qualitative study of women's experiences of reaching a diagnosis of endometriosis.
      Importantly, there have been no studies on the prevalence of endometriosis in Canada. In fact, Levy et al. sought to evaluate the economic burden of endometriosis in Canada but relied on prevalence estimates from a study of women in the United States.
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      • et al.
      Economic burden of surgically confirmed endometriosis in Canada.
      Moreover, information about the symptom burden and diagnostic experience of Canadian women with endometriosis is lacking. Therefore, in this study, data were collected from a nationally representative, large-scale, cross-sectional survey of women in Canada with the goals of (1) estimating the prevalence of self-reported diagnosis of endometriosis (DxE) in Canada, (2) comparing the symptom experience with that of women without endometriosis, and (3) evaluating the diagnostic experience (e.g., diagnostic methods, diagnosing physician's specialty, and time to diagnosis) of women with DxE in Canada.

      METHODS

       Study Design and Participants

      This comprehensive cross-sectional survey was undertaken to determine the prevalence and symptomatic burden of DxE among the general population of women in Canada and to characterize the diagnostic experience of Canadian women with DxE. Three independent response panels were used as sampling frames for this research to maximize the response rate and ensure adequate representation of the Canadian female population: the Survey Sampling International (SSI) panel (now Dynata, Shelton, CT; www.dynata.com), the Leger panel (Toronto, ON; leger360.com), and the Lightspeed panel (now Kantar, Vancouver, BC; www.lightspeedresearch.com/). Panel members were invited to participate in the survey via an email stating that the latest SSI survey was open and directing those interested to the survey website. Female Canadian residents aged 18 to 49 who completed the study consent form were eligible to participate. Survey responses from 30 000 Canadian women were collected from December 7, 2018 through January 24, 2019. To ensure the survey sample was representative of the national Canadian population of women, survey data were weighted on the basis of the 2016 Canada Census data
      • Simoens S
      • Dunselman G
      • Dirksen C
      • et al.
      The burden of endometriosis: costs and quality of life of women with endometriosis and treated in referral centres.
      on distributions of age, education, geographic region, and household income by using a random iterative method.
      The survey contained two sections. The first section, a prevalence screener, included questions on demographics, whether respondents had received a DxE and, if so, the diagnostic method or methods used, and questions regarding symptom experience. DxE was self-reported, and no cross-referencing or verification was possible. For diagnostic methods, respondents were asked to select all methods that applied, and methods were grouped into four broader categories during analysis. Surgical methods included laparoscopy, laparotomy, and other surgical procedures. Empirical methods included patient description of pain, confirmed diagnosis that was based on response to medication, and physician suspects endometriosis but has not confirmed with surgery. Diagnostic methods leading physician to suspect endometriosis (physician-suspected methods) included ultrasound or sonogram, other imaging testing (e.g., magnetic resonance imaging), physical or pelvic examination, patient description of heavy or irregular bleeding, family history, blood test for anemia, hysterectomy, and infertility. The other or unsure category included the responses “other” or “unsure” and patients who declined to answer.
      Respondents were asked to select symptoms they had ever experienced from an extensive list of endometriosis-related symptoms, to select symptoms currently being experienced (within 4 weeks before the survey), to indicate symptom severity (mild, moderate, or severe), and to describe how bothersome symptoms were (not at all, somewhat, or extremely bothersome). The second part of the survey asked participants about endometriosis-specific information such as diagnostic experience, treatment patterns, health-related quality of life, health-related productivity losses, and health care resource use. This report focuses on prevalence, symptom burden, and diagnostic experience.

       Data Analyses

      Data for each survey question were reported only for respondents who answered the question; participants with missing responses about a symptom were assigned to the “no symptom” category for that specific question or symptom. Continuous variables were summarized by means, and categorical variables were reported as percentages. Trends in the prevalence of DxE across age groups and geographic regions were assessed. Comparisons were made between the percentages of women with DxE and women without DxE who ever experienced symptoms, those currently experiencing symptoms, those currently experiencing severe symptoms, and the degree to which symptoms bothered women. Logistic regression models controlling for age were used to assess differences in the frequencies of symptoms experienced by women with DxE versus women without DxE. The likelihood (odds ratio [OR]) of experiencing symptoms, along with the corresponding 95% confidence interval (CI), were determined. Logistic models that controlled for age were used to determine the odds of a respondent reporting a severe symptom or an extremely bothersome symptom as a function of whether the respondent had DxE. All data analyses were performed using IBM SPSS Statistics software version 25 (IBM Corp., Armonk, NY).
      This study was reviewed and approved by the Copernicus Group Institutional Review Board.

      RESULTS

       Prevalence

      A total of 30 000 women in Canada met the inclusion criteria and completed the survey prevalence screener. Sampling weights were applied to survey data according to Canada population statistics.
      • Simoens S
      • Dunselman G
      • Dirksen C
      • et al.
      The burden of endometriosis: costs and quality of life of women with endometriosis and treated in referral centres.
      After weighting, a total of 2004 women (7.0%) reported receiving a DxE (Figure A). Demographics of the study population are shown in Table 1. All Canadian provinces and territories were represented by respondents of the survey. Extrapolating these results to the overall population projects that an estimated 516 327 women in Canada aged 18 to 49 have a self-reported DxE. The average age at the time of DxE was 27.9 years, and approximately half (47.5%) of women with DxE were in the 18 to 29 age group when they received a DxE. The majority (84.1%) of women with DxE experienced symptoms before diagnosis. The prevalence of self-reported DxE was highest among women in the 35 to 39 age group (9.6%), followed by the 30 to 34 age group (8.4%) (Figure A). Similar prevalence rates were reported for women in Ontario, the Prairies, the Atlantic, and Québec, with the highest prevalence in western Canada (Figure B).
      Figure
      FigureTotal population prevalence of endometriosis by age group and geographic region. (A) Total population prevalence of endometriosis: overall and by age group. (B) Total population prevalence of endometriosis by Canada geographic region.
      BC: British Columbia; NB: New Brunswick; NL: Newfoundland and Labrador; NS: Nova Scotia; PEI: Prince Edward Island.
      Table 1Demographics of study population
      ParameterWomen with DxE

      (n = 2004)
      Women without DxE

      (n = 26 528)
      Average age, years, mean ± SD35.5 ± 8.133.6 ± 9.2
      Age group, years, %
       18–2925.637.2
       30–3419.516.0
       35–3921.415.3
       40–4416.015.5
       45–4917.616.1
      Average age at diagnosis, years, mean ± SD27.9 ± 8.1
      Age group at diagnosis, years, %
       <188.4
       18–2947.5
       30–3425.9
       35–3911.8
       40–445.3
       45–491.0
      Ethnicity, %
       White88.878.0
       Black1.03.1
       Hispanic1.01.1
       Other8.416.3
      When patients began experiencing symptoms, %
       Before diagnosis84.1
       At time of diagnosis3.7
       After diagnosis6.0
       Unsure6.2
      Had hysterectomy, %29.43.7
      Canadian province, %
       Ontario37.539.1
       Québec18.624.0
       British Columbia16.712.7
       Alberta15.310.4
       Manitoba3.33.5
       Nova Scotia3.22.8
       Saskatchewan2.53.0
       Newfoundland and Labrador1.41.5
       New Brunswick1.12.4
       Prince Edward Island0.30.4
       Northwest Territories00.1
       Nunavut00.1
       Yukon00.1
      DxE: diagnosis of endometriosis.

       Symptom Burden

      Canadian women with self-reported DxE were more likely to have ever experienced endometriosis-related symptoms than women without DxE, according to age-adjusted ORs (Table 2). Women with DxE had the highest odds of experiencing non-menstrual pelvic pain or cramping (OR 4.4; 95% CI 4.0–4.9), infertility (OR 4.1; 95% CI 3.6–4.6), pelvic pressure (OR 3.9; 95% CI 3.5–4.3), and dyspareunia (OR 3.0; 95% CI 2.7–3.3) compared with women without DxE. A greater percentage of women with DxE were experiencing “typical” endometriosis symptoms in the 4 weeks before the survey than women without DxE: menstrual pelvic pain or cramping (54.0% vs. 39.3%), non-menstrual pelvic pain or cramping (39.4% vs. 14.2%), and dyspareunia (38.3% vs. 17.7%) (Table 3). Although all endometriosis-related symptoms were reported with greater prevalence by women with DxE than by those without DxE, the age-adjusted OR was highest for infertility (OR 4.4; 95% CI 3.8–5.1), non-menstrual pelvic pain or cramping (OR 4.2; 95% CI 3.8–4.6), and pelvic pressure (OR 4.1; 95% CI 3.7–4.6).
      Table 2Endometriosis symptoms ever experienced
      SymptomWomen with DxE

      (n = 2 004), %
      Women without DxE

      (n = 26 528), %
      Odds ratio

      (95% CI)
      Menstrual pelvic pain or cramping70.350.72.4 (2.1–2.6)
      Non-menstrual pelvic pain or cramping49.518.74.4 (4.0–4.9)
      Dyspareunia52.528.03.0 (2.7–3.3)
      Fatigue, weariness, or anemia67.456.31.6 (1.5–1.8)
      Heavy menstrual bleeding68.747.12.5 (2.2–2.7)
      Excessive or irregular bleeding (e.g., spotting between periods)47.625.72.7 (2.4–2.9)
      Passage of clots43.523.52.4 (2.2–2.6)
      Irregular periods (timing and/or duration)61.447.61.8 (1.7–2.0)
      Pelvic pressure32.711.33.9 (3.5–4.3)
      Lower back pain66.563.41.1 (1.0–1.3)
      General abdominal pain52.233.72.2 (2.0–2.5)
      Constipation, bloating, or diarrhea66.562.61.2 (1.1–1.3)
      Difficulty having bowel movement47.636.11.6 (1.5–1.8)
      Frequent urination or urinary urgency40.527.11.8 (1.7–2.0)
      Infertility22.36.34.1 (3.6–4.6)
      Depressed feelings or mood swings64.262.81.1 (1.0–1.2)
      Dizziness during period44.626.32.5 (2.2–2.7)
      Anxiety or stress74.173.81.1 (1.0–1.2)
      Complications during pregnancy and labour25.314.11.9 (1.7–2.1)
      DxE: diagnosis of endometriosis.
      Table 3Endometriosis-related symptoms and severity
      Currently experiencing symptomsCurrently experiencing severe symptoms
      SymptomWomen with DxE

      (n = 2004), %
      Women without DxE

      (n = 26 528), %
      Odds ratio

      (95% CI)
      Women with DxE

      (n = 2004), %
      Women without DxE

      (n = 26 528), %
      Odds ratio

      (95% CI)
      Menstrual pelvic pain or cramping54.039.31.9 (1.7–2.1)37.317.62.9 (2.5–3.3)
      Non-menstrual pelvic pain or cramping39.414.24.2 (3.8–4.6)25.39.33.4 (2.8–4.2)
      Dyspareunia38.317.73.1 (2.8–3.4)17.39.22.1 (1.7–2.6)
      Heavy menstrual bleeding48.033.32.0 (1.8–2.2)38.322.82.1 (1.8–2.4)
      Excessive or irregular bleeding (e.g., spotting between periods)31.815.62.6 (2.4–2.9)24.812.32.3 (1.9–2.9)
      Passage of clots26.414.92.0 (1.8–2.2)22.711.32.3 (1.8–2.8)
      Irregular periods (timing and/or duration)41.731.31.7 (1.5–1.8)30.017.62.1 (1.8–2.4)
      Pelvic pressure27.68.74.1 (3.7–4.6)20.27.93.0 (2.3–3.8)
      Lower back pain61.656.21.2 (1.1–1.4)26.916.91.8 (1.6–2.1)
      General abdominal pain44.927.42.3 (2.1–2.5)22.49.13.0 (2.5–3.6)
      Constipation, bloating, or diarrhea60.152.21.4 (1.3–1.5)18.510.22.0 (1.7–2.4)
      Difficulty having bowel movement41.828.81.8 (1.6–2.0)16.810.81.7 (1.4–2.0)
      Fatigue, weariness, or anemia61.751.71.5 (1.4–1.7)31.720.01.9 (1.7–2.2)
      Frequent urination or urinary urgency34.820.72.0 (1.8–2.2)23.515.21.7 (1.4–2.1)
      Infertility15.03.84.4 (3.8–5.1)55.354.41.0 (0.8–1.3)
      Depressed feelings or mood swings60.455.81.3 (1.2–1.4)27.722.71.5 (1.3–1.7)
      Dizziness during period32.319.32.2 (2.0–2.4)19.38.82.7 (2.1–3.3)
      Anxiety or stress70.969.51.1 (1.0–1.3)31.026.81.4 (1.2–1.5)
      Complications during pregnancy and labour10.03.92.6 (2.2–3.1)43.834.61.5 (1.1–2.0)
      DxE: diagnosis of endometriosis.
      In addition to a higher prevalence of endometriosis symptoms, women with DxE were also more likely to experience severe symptoms than women without DxE. For example, 37.3% of women with DxE versus 17.6% of women without DxE were experiencing severe menstrual pelvic pain or cramping (OR 2.9; 95% CI 2.5–3.3) in the 4 weeks before the survey. Other severe symptoms with high age-adjusted ORs included non-menstrual pelvic pain or cramping (OR 3.4; 95% CI 2.8–4.2), general abdominal pain (OR 3.0; 95% CI 2.5–3.6), and pelvic pressure (OR 3.0; 95% CI 2.3–3.8). A substantial percentage of women with DxE indicated that endometriosis-related symptoms were extremely bothersome, compared with women without DxE (Table 4). Women with DxE were most likely to report extremely bothersome menstrual pelvic pain or cramping (OR 2.3; 95% CI 2.0–2.6), non-menstrual pelvic pain or cramping (OR 2.6; 95% CI 2.2–3.1), general abdominal pain (OR 2.6; 95% CI 2.2–3.0), and pelvic pressure (OR 2.3; 95% CI 1.8–2.9).
      Table 4Degree to which survey respondents were bothered by endometriosis-related symptoms
      Not at all bothersomeSomewhat bothersomeExtremely bothersome
      SymptomWomen with DxE

      (n = 2004), %
      Women without DxE

      (n = 26 528), %
      Odds ratio

      (95% CI)
      Women with DxE

      (n = 2004), %
      Women without DxE

      (n = 26 528), %
      Odds ratio

      (95% CI)
      Women with DxE

      (n = 2004), %
      Women without DxE

      (n = 26 528), %
      Odds ratio

      (95% CI)
      Menstrual pelvic pain or cramping11.918.10.6 (0.5–0.7)47.157.20.7 (0.6–0.7)41.024.72.3 (2.0–2.6)
      Non-menstrual pelvic pain or cramping12.423.40.5 (0.4–0.6)53.659.40.8 (0.7–0.9)34.017.22.6 (2.2–3.1)
      Dyspareunia13.320.60.6 (0.5–0.7)50.257.00.7 (0.6–0.9)36.522.42.1 (1.8–2.4)
      Heavy menstrual bleeding8.615.70.5 (0.4–0.6)43.949.00.8 (0.7–0.9)47.535.31.7 (1.4–1.9)
      Excessive or irregular bleeding (e.g., spotting between periods)15.724.80.6 (0.5–0.7)47.150.80.9 (0.7–1.0)37.224.51.8 (1.5–2.2)
      Passage of clots30.944.10.6 (0.5–0.7)44.841.31.1 (0.9–1.4)24.314.61.8 (1.5–2.3)
      Irregular periods (timing and/or duration)18.129.40.5 (0.4–0.6)46.550.50.9 (0.7–1.0)35.420.02.2 (1.9–2.6)
      Pelvic pressure10.926.20.3 (0.3–0.5)61.159.21.1 (0.9–1.3)28.014.62.3 (1.8–2.9)
      Lower back pain11.217.40.6 (0.5–0.7)51.757.00.8 (0.7–0.9)37.125.71.8 (1.6–2.0)
      General abdominal pain10.922.30.4 (0.3–0.5)57.861.70.8 (0.7–1.0)31.316.12.6 (2.2–3.0)
      Constipation, bloating, or diarrhea13.120.40.6 (0.5–0.7)58.059.90.9 (0.8–1.0)28.919.71.7 (1.5–2.0)
      Difficulty having bowel movement16.020.60.7 (0.6–0.9)54.358.80.8 (0.7–0.9)29.720.61.7 (1.4–2.0)
      Fatigue, weariness, or anemia8.313.60.6 (0.5–0.7)51.856.30.8 (0.7–0.9)39.830.21.6 (1.4–1.8)
      Frequent urination or urinary urgency11.615.70.7 (0.6–0.9)52.556.70.8 (0.7–1.0)35.927.71.5 (1.2–1.7)
      Infertility18.621.50.8 (0.6–1.2)31.624.81.4 (1.1–1.9)49.853.70.9 (0.7–1.1)
      Depressed feelings or mood swings9.610.60.8 (0.7–1.0)44.450.80.7 (0.6–0.8)46.038.71.5 (1.3–1.7)
      Dizziness during period15.620.40.7 (0.6–0.9)55.060.90.8 (0.7–0.9)29.418.71.9 (1.5–2.2)
      Anxiety or stress8.611.60.7 (0.5–0.8)45.549.40.8 (0.7–0.9)45.938.91.5 (1.3–1.7)
      Complications during pregnancy and labour14.526.70.5 (0.3–0.7)40.532.91.4 (1.0–1.9)45.040.41.2 (0.9–1.6)
      CI: confidence interval; DxE: diagnosis of endometriosis.

       Diagnostic Experience

      Among 1686 women with DxE who reported experiencing symptoms before DxE, the mean overall delay from symptom onset to diagnosis was 5.4 years. The mean patient-related delay (time from symptom onset to the first consultation with a physician) was 3.1 years, and the mean physician-related delay (time from the first consultation with a physician to receiving a diagnosis) was 2.3 years. More than half (53.0%) of women with DxE were diagnosed by an obstetrician-gynaecologist. Approximately 19.0% of women with DxE reported receiving a diagnosis from a primary care physician, 17.0% from a general surgeon, 7.3% from an infertility specialist, 1.1% from a urologist, and 2.5% from an “other” specialist. On average, women with DxE reported consulting three physicians about endometriosis. As part of the survey, women with DxE indicated the method or methods used to confirm the DxE, with the option to select multiple methods. Surgical diagnostic methods were reported by 30.8% of women, whereas empirical and physician-suspected diagnostic methods were reported by 32.7% and 56.4% of women, respectively. Approximately 2% of women with DxE selected response options in the “other or unsure” category.

      DISCUSSION

      The current study is the first to estimate the prevalence of self-reported DxE among women in Canada on the basis of a large survey and to characterize the symptomatic burden and diagnostic experience of Canadian women with DxE. The prevalence of DxE among Canadian women was 7.0% in this survey, which is greater than that reported by a small, population-based study of Canadian women aged 15 to 49 (5.2%)
      • Bernuit D
      • Ebert AD
      • Halis G
      • et al.
      Female perspectives on endometriosis: findings from the Uterine Bleeding and Pain Women's Research Study.
      and similar to prevalence estimates of DxE among women in the United States (6.1%–6.6%).
      • Fuldeore MJ
      • Soliman AM.
      Prevalence and symptomatic burden of diagnosed endometriosis in the United States: national estimates from a cross-sectional survey of 59,411 women.
      ,
      • Bernuit D
      • Ebert AD
      • Halis G
      • et al.
      Female perspectives on endometriosis: findings from the Uterine Bleeding and Pain Women's Research Study.
      In this survey, at least 65% of Canadian women with DxE reported ever experiencing menstrual pelvic pain or cramping; fatigue, weariness, or anemia; heavy menstrual bleeding; lower back pain; constipation, bloating, or diarrhea; and anxiety or stress. In contrast, the only symptom ever experienced by at least 65% of women without DxE was anxiety or stress. These findings are consistent with symptomatology of women with DxE in the United States.
      • Soliman AM
      • Coyne KS
      • Zaiser E
      • et al.
      The burden of endometriosis symptoms on health-related quality of life in women in the United States: a cross-sectional study.
      The high odds of Canadian women with DxE experiencing infertility in the month before the survey is in line with the strong association between infertility and endometriosis.
      • Bulletti C
      • Coccia ME
      • Battistoni S
      • et al.
      Endometriosis and infertility.
      For most endometriosis-related symptoms, two to three times as many women with DxE experienced severe symptoms as women without DxE, and the most frequently severe symptoms (non-menstrual pelvic pain, general abdominal pain, pelvic pressure, menstrual pelvic pain or cramping) were also most often reported as extremely bothersome. These results suggest that Canadian women with DxE have a substantial disease burden. Understanding the frequency and severity of endometriosis symptoms lays the foundation for assessing the impact of endometriosis on Canadian women's health-related quality of life because previous studies have shown a correlation between a greater number and severity of symptoms and worse health-related quality of life.
      • Soliman AM
      • Coyne KS
      • Zaiser E
      • et al.
      The burden of endometriosis symptoms on health-related quality of life in women in the United States: a cross-sectional study.
      ,
      • Soliman AM
      • Coyne KS
      • Gries KS
      • et al.
      The effect of endometriosis symptoms on absenteeism and presenteeism in the workplace and at home.
      Canadian women with DxE reported an average diagnostic delay of approximately 5 years from the time of symptom onset. Delayed diagnosis contributes to the disease burden of endometriosis by prolonging pain symptoms and preventing women from receiving appropriate treatment.
      • Ballard K
      • Lowton K
      • Wright J
      What's the delay? A qualitative study of women's experiences of reaching a diagnosis of endometriosis.
      Previous studies have reported an average endometriosis diagnostic delay of 6.8 years
      • Bernuit D
      • Ebert AD
      • Halis G
      • et al.
      Female perspectives on endometriosis: findings from the Uterine Bleeding and Pain Women's Research Study.
      and 10 years in Canadian women.
      • Levy AR
      • Osenenko KM
      • Lozano-Ortega G
      • et al.
      Economic burden of surgically confirmed endometriosis in Canada.
      The latter study surveyed only a small number of women with surgically confirmed endometriosis, a factor that could increase reported time to diagnosis.
      • Levy AR
      • Osenenko KM
      • Lozano-Ortega G
      • et al.
      Economic burden of surgically confirmed endometriosis in Canada.
      Furthermore, 53% of women in this study were diagnosed by obstetrician-gynaecologists, which may account for a shorter time to diagnosis than previously reported for Canadian women.
      • Soliman AM
      • Fuldeore M
      • Snabes MC
      Factors associated with time to endometriosis diagnosis in the United States.
      Only 31% of women here reported a surgical diagnosis, a finding suggesting that other non-invasive methods were used to evaluate suspected endometriosis. The influence of diagnostic method on time to DxE remains to be determined.
      Various factors contribute to diagnostic delay of endometriosis on the part of both patients and physicians. Women may be unable to distinguish “normal” from “abnormal” menstrual experiences or may normalize pain symptoms as a result of embarrassment, thereby delaying consultation with a physician after onset of symptoms.
      • Ballard K
      • Lowton K
      • Wright J
      What's the delay? A qualitative study of women's experiences of reaching a diagnosis of endometriosis.
      Physicians may also normalize pain symptoms reported by patients or may misdiagnose conditions.
      • Ballard K
      • Lowton K
      • Wright J
      What's the delay? A qualitative study of women's experiences of reaching a diagnosis of endometriosis.
      ,
      • Hudelist G
      • Fritzer N
      • Thomas A
      • et al.
      Diagnostic delay for endometriosis in Austria and Germany: causes and possible consequences.
      In this survey, the average time from symptom onset to physician consultation was slightly longer than the delay between consulting a physician and receiving a diagnosis. Additional research is needed to better understand factors contributing to diagnostic delay to reduce the overall time to diagnosis. Further studies are also needed to determine the impact of delayed pain symptom management on the development of chronic pain syndromes that are resistant to endometriosis therapy.
      • As-Sanie S
      • Harris RE
      • Harte SE
      • et al.
      Increased pressure pain sensitivity in women with chronic pelvic pain.
      Initiatives to raise awareness about endometriosis and programs that educate young women about menstrual health may improve symptom recognition and reduce the stigma associated with menstrual irregularities, thus prompting patients to seek care earlier.
      • Ballard K
      • Lowton K
      • Wright J
      What's the delay? A qualitative study of women's experiences of reaching a diagnosis of endometriosis.
      ,
      • As-Sanie S
      • Black R
      • Giudice LC
      • et al.
      Assessing research gaps and unmet needs in endometriosis.
      • van der Zanden M
      • Nap AW
      Knowledge of, and treatment strategies for, endometriosis among general practitioners.
      • Bush D
      • Brick E
      • East MC
      • et al.
      Endometriosis education in schools: a New Zealand model examining the impact of an education program in schools on early recognition of symptoms suggesting endometriosis.
      Similarly, education of health care providers regarding endometriosis symptoms and diagnostic strategies may help reduce the time to diagnosis.
      • As-Sanie S
      • Black R
      • Giudice LC
      • et al.
      Assessing research gaps and unmet needs in endometriosis.
      ,
      • van der Zanden M
      • Nap AW
      Knowledge of, and treatment strategies for, endometriosis among general practitioners.
      The large sample size and weighting of data to accurately represent the Canadian general population reinforce the generalizability of these findings. The limitations of the current study are common to cross-sectional surveys. Non-response bias may arise from the exclusion of women not registered with the online panels used. Respondents may have received a DxE several years before the survey, and this could introduce recall bias regarding diagnostic experience. The accuracy of DxE and disease severity could not be confirmed because this study relied on patient reports not substantiated by medical records or clinical evaluations. Therefore, a similar patient survey study with use of electronic medical records databases to confirm DxE against patient-reported diagnoses would provide useful information. Given the frequency with which women reported non-surgical diagnostic methods, which can be less precise than surgical diagnosis, the prevalence reported here may be an underestimate or overestimate. It is important to note that women without DxE in this study may have included women with symptomatic but undiagnosed or unsuspected endometriosis; therefore, the prevalence and symptomatic differences between groups may be underestimated. This analysis did not control for potential impacts of prior or current treatments on symptomatic burden. Finally, surveys are needed to determine the perceptions of health care providers regarding DxE and disease burden and whether these reflect patient-reported experiences.

      CONCLUSION

      In this large, cross-sectional survey, there was a 7.0% prevalence of self-reported DxE in Canada, which equates to over half a million Canadian women affected by endometriosis. Similar prevalence rates were reported across all provinces, except for slightly higher rates in western Canada. Moreover, women with DxE reported a substantial symptomatic burden and an average diagnostic delay of 5 years. These findings indicate that further research is needed to examine the impact of symptomatic burden on women's health-related quality of life and to establish the direct and indirect costs of endometriosis in Canada. Future studies are required to ascertain factors contributing to diagnostic delay and to identify steps to reduce time to diagnosis.

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