Utilization of healthcare prior to endometriosis diagnosis: a Danish case-control study.

STUDY QUESTION: Do women with endometriosis have higher utilization of primary and secondary healthcare prior to diagnosis compared to women without endometriosis? SUMMARY ANSWER: Women with a hospital-based diagnosis of endometriosis had an overall higher utilization of both primary and secondary healthcare in all 10 years prior to diagnosis. WHAT IS KNOWN ALREADY: Endometriosis is associated with a diagnostic delay, but only a few studies have investigated the potential consequences of this delay with regard to the utilization of healthcare. To the best of our knowledge, no study has investigated it in a period corresponding to the estimated diagnostic delay. STUDY DESIGN, SIZE, DURATION: This national Danish registry-based case-control study included 129 696 women. Cases were women with a first-time hospital-based diagnosis of endometriosis between 1 January 2000 and 31 December 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: We identified 21 616 cases using density sampling. Each case was matched on age at the date of diagnosis (index date) to five women without diagnosed endometriosis (n = 108 080). The utilization of healthcare was assessed for the 10 years before the index. MAIN RESULTS AND THE ROLE OF CHANCE: Cases had significantly higher use of healthcare in all 10 years preceding the index. The mean number of yearly contacts with the GP was 9.99 for cases and 7.85 for controls, with an adjusted incidence rate ratio of 1.28 (1.27; 1.29). For hospital contacts, the association increased slightly in the first 9 years and was most profound in the last year preceding index when the adjusted incidence rate ratio was 2.26 (95% CI 2.28; 2.31). LIMITATIONS, REASONS FOR CAUTION: We were not able to include women with an endometriosis diagnosis from the general practitioner or private gynaecologist. Therefore, our results are only applicable to hospital-based diagnoses of endometriosis. We do not have information on the specific reasons for contacting the healthcare providers and we can therefore only speculate that the higher utilization of healthcare among cases was related to endometriosis. WIDER IMPLICATIONS OF THE FINDINGS: This study is in agreement with the other known studies on the subject. Future studies should include specific reasons for contacting the healthcare system and thereby identify any specific contact patterns for women with endometriosis. With this knowledge, healthcare professionals could be better at relating certain healthcare seeking behaviour to endometriosis earlier and thereby reduce the time from onset of symptoms to diagnosis. STUDY FUNDING/COMPETING INTEREST(S): This study is supported by grants from the project 'Finding Endometriosis using Machine Learning' (FEMaLe/101017562), which has received funding from The European Union's Horizon 2020 research and innovation program and Helsefonden (21-B-0141). K.Z. report grants from Bayer AG, Roche Inc. and Volition, royalties from Oxford-Bayer scientific collaboration in gynaecological therapies, non-financial collaboration with the World Endometriosis Society and World Endometriosis Research Foundation and is a Wellbeing of Women research advisory committee member. All this is outside the submitted work. The other authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

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.

Pre-vaccination vulnerability and suspected adverse events following HPV vaccination. A case-control study nested in the Danish national birth cohort.

Previous studies have indicated that girls experiencing suspected adverse events (AE) following HPV vaccination were more vulnerable prior to vaccination. However, no study has previously investigated differences in vulnerability using prospectively collected self-reported measures of vulnerability. The objective of this study therefore was to describe the distribution of biological and psychosocial indicators of vulnerability in girls referred to a hospital setting due to suspected adverse events and compare it with a sample of non-referred HPV vaccinated girls. The study was conducted as a case control study based within the Danish National Birth Cohort. Cases were defined as HPV vaccinated girls referred to a hospital setting between 2015 and 2017 due to suspected adverse events (n = 80), and 5 controls were randomly selected from the remaining source population, matched to cases on age at vaccination, region of residence and year of vaccination. The final study population consisted of 480 girls. Prior exposures were based on information gathered from an 11 year follow up of the DNBC and included information on self-rated health, frequent health complaints, medication use, bullying, stressful life events and physical activity. Conditional logistic regression analysis was used to estimate the association between each exposure and referral. The percentage of individuals in the exposed category of each exposure was generally higher for cases than controls. Particularly, the odds of being referred were higher for those with low self-rated health compared to high (OR [95%-CI] 2.43 [1.07-5.5]1), those being bullied (OR 3.19 [1.17-8.73]), and those who had taken medication (OR 2.22 [1.32-3.67]). Overall, these results indicated that girls experiencing suspected AE following HPV vaccination were more vulnerable prior to vaccination.