Temporal and regional differences in the incidence of hospital-diagnosed endometriosis: a Danish population-based study.

INTRODUCTION: Due to diagnostic challenges, normalization of symptoms and an overall lack of awareness among both patients and physicians, endometriosis is an underdiagnosed disease. This can result in delayed treatment and potentially worsening of the disease. Despite initiatives, such as patients' support organizations and specialized endometriosis referral centers, differences in awareness, socioeconomic factors and lifestyle, combined with varying distances to specialized referral centers, could result in regional differences in the degree of underdiagnosing. This study aims to explore temporal and regional variations in the incidence of endometriosis based on the Danish hospital discharge register, and shed light on the degree of underdiagnosing of endometriosis in Denmark. MATERIAL AND METHODS: This registry-based cohort study included all women aged 15-55 living in Denmark from 1990-2017. Participants were identified through the Danish Civil Registration system and endometriosis diagnoses received at a hospital were obtained from the Danish National Patient Registry. Incidence rates of diagnosed endometriosis were calculated for each year of the study period and for each municipality in Denmark. A Cox regression analysis, stratified by calendar time and adjusted for ethnic origin, household composition, highest educational level and family socioeconomic status, was performed to estimate the association between residence and likelihood of receiving a hospital-based diagnosis of endometriosis. RESULTS: The nationwide incidence rate of hospital-diagnosed endometriosis was 7.89 (95% confidence interval [CI] 7.80-7.99) per 10 000 person-years and the prevalence in 2017 was 1.63%. The results showed an overall increase in the incidence of diagnosed endometriosis of 46.8% (95% CI 32.9-62.2) during the study period and also displayed significant regional differences. After adjustments, women living in northern Jutland had the highest probability of receiving a hospital-based diagnosis of endometriosis (hazard ratio 1.13, 95% CI 1.09-1.18), whereas women living in northern Zealand had the lowest probability (hazard ratio 0.63, 95% CI 0.60-0.67) compared with eastern Jutland. These regional differences have become more evident over time. CONCLUSIONS: Our results reveal significant regional differences in the incidence of hospital-diagnosed endometriosis, suggesting that a significant number of women may be left behind without a diagnosis. Further studies are needed to assess the underlying reasons for the significant regional differences.

Is endometriosis associated with irritable bowel syndrome? A cross-sectional study.

OBJECTIVES: Previous studies have found a high prevalence of irritable bowel syndrome (IBS). However, data on this relation in women without bowel endometriosis is limited. The aim of this study was to compare the prevalence of IBS in women with endometriosis to the prevalence in women without endometriosis and to investigate if the prevalence of IBS was associated with bowel involved endometriosis. STUDY DESIGN: Information for this cross-sectional study was collected through an online questionnaire. A total of 373 women completed the questionnaire. After exclusions, 254 with endometriosis and 102 without endometriosis were included (N = 356). Endometriosis was identified by self-reported diagnosis. IBS was identified by; 1. self-reported diagnosis prior to the study and 2. fulfillment of ROME III diagnostic criteria in this study. Odds ratios were calculated to estimate the strength of the association between IBS and endometriosis. A separate analysis, restricted to women without bowel involved endometrioses, was conducted. Adjustment for potential confounders (age, gastroenterological comorbidities and length of education) was performed. RESULTS AND CONCLUSIONS: The prevalence of IBS was higher in women with endometriosis compared to the women without endometriosis (OR = 5.32 (CI: 2.88; 9.81)). In the analysis restricted to women without bowel involved endometriosis, the prevalence was also higher in women with endometriosis compared to women without endometriosis (OR = 6.54 (CI95% 3.22; 13.29)). Thus, this study found a higher prevalence of IBS in women with endometriosis compared to women without endometriosis. This finding seems to be unrelated to bowel involvement. This opens new perspectives in relation to treatment of endometriosis.

Visceral syndrome in endometriosis patients.

OBJECTIVE: Pain related to bowel and bladder function is seen more often in endometriosis. This study explored whether employed endometriosis patients experience multiple visceral symptoms more often than reference women without the disease. STUDY DESIGN: In a cohort study, 610 patients with diagnosed endometriosis and 751 reference women completed an electronic survey based on the EHP-30 questionnaire. Percentages were reported for all data. Principal component analysis was used to find underlying structures of correlations among variables, and Cronbach's alpha reliability analysis was used to demonstrate internal consistency of each scale. The level of statistical significance was set at p<0.025 in all the analyses. RESULTS: Principal component analysis pointed at a specific visceral symptom-complex relating to the abdominal organs. This correlation was called "visceral syndrome" and consisted of the seven symptoms; "abdominal pain with no relation to menstruation", "pain during urination", "pain during defecation", "constipation or diarrhea", "irregular bleeding", "nausea or vomiting" and "feeling tired/lack of energy", with a Cronbach's alpha value α=0.85. More women with endometriosis than reference women suffered between five and seven symptoms from the visceral syndrome (22.7% vs. 2.7%) and more women with endometriosis compared to women with pain from other conditions suffered between five and seven symptoms from the visceral syndrome (22.7% vs. 3.2%). CONCLUSION: These data indicate that a significant number of endometriosis patients suffer from a specific symptom correlation, which is uncommon in women without the disease. These findings and previous data may suggest the occurrence of a visceral syndrome in endometriosis.

The influence of endometriosis-related symptoms on work life and work ability: a study of Danish endometriosis patients in employment.

OBJECTIVE: Little is known about the implications of endometriosis on women's work life. This study aimed at examining the relation between endometriosis-related symptoms and work ability in employed women with endometriosis. STUDY DESIGN: In a cohort study, 610 patients with diagnosed endometriosis and 751 reference women completed an electronic survey based on the Endometriosis Health Profile 30-questionnaire and the Work Ability Index (short form). Percentages were reported for all data. Binary and multivariate logistic regression analyses were used to assess risk factors for low work ability. The level of statistical significance was set at p<0.025 in all analyses. RESULTS: In binary analyses a diagnosis of endometriosis was associated with more sick days, work disturbances due to symptoms, lower work ability and a wide number of other implications on work life in employed women. Moreover, a higher pain level and degree of symptoms were associated with low work ability. Full regression analysis indicated that tiredness, frequent pain, a higher daily pain level, a higher number of sick days and feeling depressed at work were associated with low work ability. A long delay from symptom onset to diagnosis was associated with low work ability. CONCLUSIONS: These data indicate a severe impact of endometriosis on the work ability of employed women with endometriosis and add to the evidence that this disease represents a significant socio-economic burden.