Interrater and intrarater reliability in the diagnosis and staging of endometriosis

Validation of administrative health data for the identification of endometriosis diagnosis

STUDY QUESTION

How do endometriosis diagnoses and subtypes reported in administrative health data compare with surgically confirmed disease?

SUMMARY ANSWER

For endometriosis diagnosis, we observed substantial agreement and high sensitivity and specificity between administrative health data-International Classification of Diseases (ICD) 9 codes-and surgically confirmed diagnoses among participants who underwent gynecologic laparoscopy or laparotomy.

WHAT IS KNOWN ALREADY

Several studies have assessed the validity of self-reported endometriosis in comparison to medical record reporting, finding strong confirmation. We previously reported high inter- and intra-surgeon agreement for endometriosis diagnosis in the Endometriosis, Natural History, Diagnosis, and Outcomes (ENDO) Study.

STUDY DESIGN, SIZE, DURATION

In this validation study, participants (n = 412) of the Utah operative cohort of the ENDO Study (2007-2009) were linked to medical records from the Utah Population Database (UPDB) to compare endometriosis diagnoses from each source. The UPDB is a unique database containing linked data on over 11 million individuals, including statewide ambulatory and inpatient records, state vital records, and University of Utah Health and Intermountain Healthcare electronic healthcare records, capturing most Utah residents.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The ENDO operative cohort consisted of individuals aged 18-44 years with no prior endometriosis diagnosis who underwent gynecologic laparoscopy or laparotomy for a variety of surgical indications. In total, 173 women were diagnosed with endometriosis based on surgical visualization of disease, 35% with superficial endometriosis, 9% with ovarian endometriomas, and 14% with deep infiltrating endometriosis. Contemporary administrative health data from the UPDB included ICD diagnostic codes from Utah Department of Health in-patient and ambulatory surgery records and University of Utah and Intermountain Health electronic health records.

MAIN RESULTS AND THE ROLE OF CHANCE

For endometriosis diagnosis, we found relatively high sensitivity (0.88) and specificity (0.87) and substantial agreement (Kappa [Κ] = 0.74). We found similarly high sensitivity, specificity, and agreement for superficial endometriosis (n = 143, 0.86, 0.83, Κ  = 0.65) and ovarian endometriomas (n = 38, 0.82, 0.92, Κ  = 0.58). However, deep infiltrating endometriosis (n = 58) had lower sensitivity (0.12) and agreement (Κ  = 0.17), with high specificity (0.99).

LIMITATIONS, REASONS FOR CAUTION

Medication prescription data and unstructured data, such as clinical notes, were not included in the UPDB data used for this study. These additional data types could aid in detection of endometriosis. Most participants were white or Asian with Hispanic ethnicity reported 11% of the time, which may limit generalizability to some US states. Additionally, given that participants whose administrative health records we utilized were also part of the ENDO Study, the surgeons may have been more vigilant in diagnostic coding due to the operative forms they completed for the ENDO Study, which may have led to increased validity. However, the codes compared in the UPDB would have been entered by medical coders as part of standard clinical practice.

WIDER IMPLICATIONS OF THE FINDINGS

We observed substantial agreement between administrative health data and surgically confirmed endometriosis diagnoses overall, and for superficial and ovarian endometrioma subtypes. These findings may provide reassurance to researchers using administrative healthcare records to assess risk factors and long-term health outcomes of endometriosis. Our findings corroborate prior research that demonstrates high specificity but low sensitivity for deep infiltrating endometriosis, indicating deep infiltrating endometriosis is not reliably annotated in administrative healthcare data. This suggests that medical record-based deep infiltrating endometriosis diagnoses may be suitable for etiologic studies but not for surveillance or detection studies.

STUDY FUNDING/COMPETING INTEREST(S)

The original ENDO Study was funded by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contracts NO1-DK-6-3428; NO1-DK-6-3427; 10001406-02). We acknowledge partial support for the UPDB through grant P30 CA2014 from the National Cancer Institute, University of Utah and from the University of Utah's program in Personalized Health and Center for Clinical and Translational Science. This research was also supported by the NCRR grant, 'Sharing Statewide Health Data for Genetic Research' (R01 RR021746, G. Mineau, PI) with additional support from the Utah Department of Health and Human Services, University of Utah. Additionally, this research was supported by the Utah Cancer Registry, which is funded by the National Cancer Institute's SEER Program, Contract No. HHSN261201800016I, the US Centers for Disease Control and Prevention's National Program of Cancer Registries, Cooperative Agreement No. NU58DP007131, with additional support from the University of Utah and Huntsman Cancer Foundation. Research reported in this publication was also supported by the National Institutes of Health (Award Numbers R01HL164715 [to L.V.F., K.C.S., and A.Z.P.] and K01AG058781 [to K.C.S.]), by the Huntsman Cancer Institute's Breast and Gynecologic Cancers Center, and by the Doris Duke Foundation's COVID-19 Fund to Retain Clinical Scientists funded by the American Heart Association. A.C.K. was supported by Training Grant Number 5T15LM007124 from the National Library of Medicine to K.E. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or other sponsors. There are no competing interests among any of the authors.

TRIAL REGISTRATION NUMBER

N/A.

Is endometriosis typology a potentially better classification system for assessing risk of female infertility?

Objective

To determine whether endometriosis typology, namely ovarian endometriomas (OE), deep infiltrating endometriosis (DIE), or superficial endometriosis (SE), correlates with fertility history.

Design

Prospective cohort.

Setting

One of fourteen surgical centers in Salt Lake City, Utah (n = 5) or San Francisco, California (n = 9).

Patients

A total of 473 women (18-44 years) with no prior endometriosis diagnosis, undergoing laparoscopies/laparotomies, irrespective of indication, in Utah or California (2007-2009).

Exposure

Incident endometriosis.

Main Outcome Measures

Before surgery, we queried women about time to become pregnant for prior planned pregnancies. Generalized linear models were used to calculate adjusted prevalence ratios (aPR) for association between endometriosis typology and infertility, defined as having ever tried >12 months (>6 months for women ≥35 years) to get pregnant. We also generated fecundability odds ratios (aFOR) to capture time to pregnancy.

Results

Twenty-five percent (n = 116) of women were diagnosed with SE only, 5% (n = 23) with OE, 6% (n = 29) with DIE, and 5% (n = 22) with OE + DIE, and 60% (n = 283) with no endometriosis. Compared with women with no endometriosis, women with SE had a 1.58 higher aPR (95% confidence interval [CI], 1.16-2.14), although women with OE and/or DIE had a 2.41 higher aPR for subfertility after adjusting for women's age, body mass index, and site. Compared with women with no endometriosis, women with OE and/or DIE had a 53% lower historic fecundability (aFOR, 0.47; 95% CI, 0.24-0.95); however, no association was found among women with SE (aFOR, 0.81; 95% CI, 0.49-1.33).

Conclusions

Specific endometriosis typologies may be associated with fecundability, with OE and/or DIE associated with nearly a 150% higher prevalence of subfertility and over a 50% lower historic fecundability.

Examining the co-occurrence of endometriosis and polycystic ovarian syndrome

BACKGROUND

Polycystic ovarian syndrome and endometriosis are 2 of the most common reproductive disorders among women but are thought to be unrelated.

OBJECTIVE

This study aimed to examine the overlap and common symptoms of polycystic ovarian syndrome and endometriosis.

STUDY DESIGN

The study population included the Endometriosis, Natural History, Diagnosis, and Outcomes Study (2007-2009) operative cohort: 473 women, aged 18 to 44 years, who underwent a diagnostic and/or therapeutic laparoscopy or laparotomy at 1 of 14 surgical centers located in Salt Lake City, Utah, or San Francisco, California, in addition to a population cohort composed of 127 women from the surgical centers' catchment areas. Age and site-adjusted multinomial regression models were used to estimate adjusted prevalence ratios and 95% confidence intervals of reproductive history characteristics among women with endometriosis only, women with polycystic ovarian syndrome only, and women with both endometriosis and polycystic ovarian syndrome.

RESULTS

Among the operative cohort, 35% had endometriosis only, 9% had polycystic ovarian syndrome only, and 5% had endometriosis and polycystic ovarian syndrome. Among the population cohort, 10% had endometriosis only, 8% had polycystic ovarian syndrome only, and 2% had endometriosis and polycystic ovarian syndrome. In the operative cohort, a history of subfertility was associated with a higher adjusted probability of having both conditions (adjusted prevalence ratio, 10.33; 95% confidence interval, 3.94-27.08), followed by having endometriosis only (adjusted prevalence ratio, 2.45; 95% confidence interval, 1.56-3.84) or polycystic ovarian syndrome only (adjusted prevalence ratio, 1.15; 95% confidence interval, 0.51-2.61), than having neither condition. In addition, experiencing chronic pelvic pain within the past 12 months was associated with a higher probability of having both conditions (adjusted prevalence ratio, 2.53; 95% confidence interval, 1.07-6.00) than having neither condition.

CONCLUSION

Among a cohort of women undergoing gynecologic laparoscopy or laparotomy, our study found that nearly 1 in 20 women had both an incident endometriosis diagnosis and symptoms consistent with polycystic ovarian syndrome. Among a population cohort of women not seeking gynecologic care, polycystic ovarian syndrome and endometriosis overlap prevalence was approximately 1 in 50 women.

Estimation of multiple ordered ROC curves using placement values

In many diagnostic accuracy studies, a priori orders may be available on multiple receiver operating characteristic curves. For example, being closer to delivery, fetal ultrasound measures in the third trimester should be no less accurate than those in the second trimester in predicting small-for-gestational-age births. Such an a priori order should be incorporated in estimating receiver operating characteristic curves and associated summary accuracy statistics, as it can potentially improve statistical efficiency of these estimates. Early work in the literature has mainly taken an indirect approach to this task and has induced the desired a priori order through modeling test score distributions. We instead propose a new strategy that incorporates the order directly through the modeling of receiver operating characteristic curves. We achieve this by exploiting the link between placement value (the relative position of a diseased test score in the healthy score distribution), the cumulative distribution function of placement value, and receiver operating characteristic curve, and by building stochastically ordered random variables through mixture distributions. We take a Bayesian semiparametric approach in using Dirichlet process mixture models so that the placement values can be flexibly modeled. We conduct extensive simulation studies to examine the performance of the proposed methodology and apply the new framework to data from obstetrics and women's health studies.

Endometriosis Classification, Staging and Reporting Systems: A Review on the Road to a Universally Accepted Endometriosis Classification

OBJECTIVE

In the field of endometriosis, several classification, staging and reporting systems have been developed. Which endometriosis classification, staging and reporting systems have been published and validated for use in clinical practice?

DATA SOURCES

A systematic PUBMED literature search was performed. Data were extracted and summarized.

METHODS OF STUDY SELECTION

na TABULATION, INTEGRATION AND RESULTS: Twenty-two endometriosis classification, staging and reporting systems have been published between 1973 and 2021, each developed for specific, and different, purposes. There still is no international agreement on how to describe the disease. Studies evaluating the different systems are summarized showing a discrepancy between the intended and the evaluated purpose, and a general lack of validation data confirming a correlation with pain symptoms or quality of life for any of the current systems. A few studies confirm the value of the ENZIAN system for surgical description of deep endometriosis. With regards to infertility, the endometriosis fertility index has been confirmed valid for its intended purpose.

CONCLUSION

Of the 22 endometriosis classification, staging and reporting systems identified in this historical overview, only a few have been evaluated for the purpose for which they were developed. The literature search was limited to PUBMED. Unpublished classification, staging or reporting systems, or those published in books were not considered. It can be concluded that there is no international agreement on how to describe endometriosis or how to classify it, and that most classification/staging systems show no or very little correlation with patient outcomes. This overview of existing systems is a first step in working towards a universally accepted endometriosis classification.

Endometriosis classification, staging and reporting systems: a review on the road to a universally accepted endometriosis classification. Hum Reprod Open 2021;2021:hoab025. [PMID: 34693032 PMCID: PMC8530712 DOI: 10.1093/hropen/hoab025]

STUDY QUESTION

Which endometriosis classification, staging and reporting systems have been published and validated for use in clinical practice?

SUMMARY ANSWER

Of the 22 endometriosis classification, staging and reporting systems identified in this historical overview, only a few have been evaluated, in 46 studies, for the purpose for which they were developed.

WHAT IS KNOWN ALREADY

In the field of endometriosis, several classification, staging and reporting systems have been developed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A systematic PUBMED literature search was performed. Data were extracted and summarized.

MAIN RESULTS AND THE ROLE OF CHANCE

Twenty-two endometriosis classification, staging and reporting systems have been published between 1973 and 2021, each developed for specific, and different, purposes. There still is no international agreement on how to describe the disease. Studies evaluating the different systems are summarized showing a discrepancy between the intended and the evaluated purpose, and a general lack of validation data confirming a correlation with pain symptoms or quality of life for any of the current systems. A few studies confirm the value of the ENZIAN system for surgical description of deep endometriosis. With regards to infertility, the endometriosis fertility index has been confirmed valid for its intended purpose.

LARGE SCALE DATA

NA.

LIMITATIONS, REASONS FOR CAUTION

The literature search was limited to PUBMED. Unpublished classification, staging or reporting systems, or those published in books were not considered.

WIDER IMPLICATIONS OF THE FINDINGS

It can be concluded that there is no international agreement on how to describe endometriosis or how to classify it, and that most classification/staging systems show no or very little correlation with patient outcomes. This overview of existing systems is a first step in working toward a universally accepted endometriosis classification.

STUDY FUNDING/COMPETING INTEREST(S)

The meetings and activities of the working group were funded by the American Association of Gynecologic Laparoscopists, European Society for Gynecological Endoscopy, European Society of Human Reproduction and Embryology and World Endometriosis Society. A.W.H. reports grant funding from the MRC, NIHR, CSO, Wellbeing of Women, Roche Diagnostics, Astra Zeneca, Ferring, Charles Wolfson Charitable Trust, Standard Life, Consultancy fees from Roche Diagnostics, AbbVie, Nordic Pharma and Ferring, outside the submitted work. In addition, A.W.H. has a patent Serum biomarker for endometriosis pending. N.P.J. reports personal fees from Abbott, Guerbet, Myovant Sciences, Vifor Pharma, Roche Diagnostics, outside the submitted work; he is also President of the World Endometriosis Society and chair of the trust board. S.M. reports grants and personal fees from AbbVie, and personal fees from Roche outside the submitted work. C.T. reports grants, non-financial support and other from Merck SA, non-financial support and other from Gedeon Richter, non-financial support from Ferring Pharmaceuticals, outside the submitted work and without private revenue. K.T.Z. reports grants from Bayer Healthcare, MDNA Life Sciences, Roche Diagnostics Inc, Volition Rx, outside the submitted work; she is also a Board member (Secretary) of the World Endometriosis Society and World Endometriosis Research Foundation, Research Advisory Board member of Wellbeing of Women, UK (research charity), and Chair, Research Directions Working Group, World Endometriosis Society. The other authors had nothing to disclose.

TRIAL REGISTRATION NUMBER

NA.

Endometriosis classification, staging and reporting systems: a review on the road to a universally accepted endometriosis classification

Background

In the field of endometriosis, several classification, staging and reporting systems have been developed. However, endometriosis classification, staging and reporting systems that have been published and validated for use in clinical practice have not been systematically reviewed up to now.

Objectives

The aim of the current review is to provide a historical overview of these different systems based on an assessment of published studies.

Materials and Methods

A systematic Pubmed literature search was performed. Data were extracted and summarised.

Results

Twenty-two endometriosis classification, staging and reporting systems have been published between 1973 and 2021, each developed for specific and different purposes. There is still no international agreement on how to describe the disease. Studies evaluating different systems are summarised showing a discrepancy between the intended and the evaluated purpose, and a general lack of validation data confirming a correlation with pain symptoms or quality of life for any of the current systems. A few studies confirm the value of the Enzian system for surgical description of deep endometriosis. With regards to infertility, the endometriosis fertility index has been confirmed valid for its intended purpose.

Conclusions

Of the 22 endometriosis classification, staging and reporting systems identified in this historical overview, only a few have been evaluated, in 46 studies, for the purpose for which they were developed. It can be concluded that there is no international agreement on how to describe endometriosis or how to classify it, and that most classification/staging systems show no or very little correlation with patient outcomes.

What is new?

This overview of existing systems is a first step in working towards a universally accepted endometriosis classification.

Adiposity and Endometriosis Severity and Typology

STUDY OBJECTIVE

Prior research has collectively shown that endometriosis is inversely related to women's adiposity. The aim of this study was to assess whether this inverse relationship holds true by disease severity and typology.

DESIGN

Cross-sectional study among women with no prior diagnosis of endometriosis.

SETTING

Fourteen clinical centers in Salt Lake City, UT, and San Francisco, CA.

PATIENTS

A total of 495 women (of which 473 were analyzed), aged 18-44 years, were enrolled in the operative cohort of the Endometriosis, Natural History, Diagnosis, and Outcomes (ENDO) Study.

INTERVENTIONS

Gynecologic laparoscopy/laparotomy regardless of clinical indication.

MEASUREMENTS AND MAIN RESULTS

Participants underwent anthropometric assessments, body composition measurements, and evaluations of body fat distribution ratios before surgery. Surgeons completed a standardized operative report immediately after surgery to capture revised American Society for Reproductive Medicine staging (I-IV) and typology of disease (superficial endometriosis [SE], ovarian endometrioma [OE], and deep infiltrating endometriosis [DIE]). Linear mixed models, taking into account within-clinical-center correlation, were used to generate least square means (95% confidence intervals) to assess differences in adiposity measures by endometriosis stage (no endometriosis, I-IV) and typology (no endometriosis, SE, DIE, OE, OE + DIE) adjusting for age, race/ethnicity, and parity. Although most confidence intervals were wide and overlapping, 3 general impressions emerged: (1) women with incident endometriosis had the lowest anthropometric/body composition indicators compared with those without incident endometriosis, (2) women with stage I or IV endometriosis had lower indicators compared with women with stage II or III, and (3) women with OE and/or DIE tended to have the lowest indicators, whereas women with SE had the highest indicators.

CONCLUSION

Our research highlights that the relationship between women's adiposity and endometriosis severity and typology may be more complicated than prior research indicates.

Diagnostic test evaluation methodology: A systematic review of methods employed to evaluate diagnostic tests in the absence of gold standard - An update

OBJECTIVE

To systematically review methods developed and employed to evaluate the diagnostic accuracy of medical test when there is a missing or no gold standard.

STUDY DESIGN AND SETTINGS

Articles that proposed or applied any methods to evaluate the diagnostic accuracy of medical test(s) in the absence of gold standard were reviewed. The protocol for this review was registered in PROSPERO (CRD42018089349).

RESULTS

Identified methods were classified into four main groups: methods employed when there is a missing gold standard; correction methods (which make adjustment for an imperfect reference standard with known diagnostic accuracy measures); methods employed to evaluate a medical test using multiple imperfect reference standards; and other methods, like agreement studies, and a mixed group of alternative study designs. Fifty-one statistical methods were identified from the review that were developed to evaluate medical test(s) when the true disease status of some participants is unverified with the gold standard. Seven correction methods were identified and four methods were identified to evaluate medical test(s) using multiple imperfect reference standards. Flow-diagrams were developed to guide the selection of appropriate methods.

CONCLUSION

Various methods have been proposed to evaluate medical test(s) in the absence of a gold standard for some or all participants in a diagnostic accuracy study. These methods depend on the availability of the gold standard, its' application to the participants in the study and the availability of alternative reference standard(s). The clinical application of some of these methods, especially methods developed when there is missing gold standard is however limited. This may be due to the complexity of these methods and/or a disconnection between the fields of expertise of those who develop (e.g. mathematicians) and those who employ the methods (e.g. clinical researchers). This review aims to help close this gap with our classification and guidance tools.

Reproducibility of the Endometriosis Fertility Index: a prospective inter-/intra-rater agreement study

OBJECTIVE

To evaluate the reproducibility of the Endometriosis Fertility Index (EFI).

DESIGN

Single-cohort prospective observational study.

SETTING

University hospital.

POPULATION

Women undergoing laparoscopic resection of any rASRM-stage endometriosis.

METHODS

Details of pre- and peroperative findings were collected into a coded research file. EFI scoring was performed en-bloc by three different raters (expert-1 [C.T.], expert-2 [C.M.], junior [C.B.]). Required sample size: 71. Definitions used for agreement: clinical (scores within same range: 0-4, 5-6, 7-10) and numerical (difference ≤1 EFI point).

MAIN OUTCOME MEASURES

Primary outcome: rate of clinical agreement between two experts.

SECONDARY OUTCOMES

expert numerical agreement, clinical and numerical agreement between expert-1 and junior, and within expert-1 (intra-observer), agreement of rASRM score and -stage.

RESULTS

A near 'inter-expert' clinical agreement rate (1.000, 95% CI 0.956-1.000; P = 0.0149) was observed. The numerical agreement between two experts was also high (0.988, 95% CI 0.934-1.000); similarly, high agreement rates were observed for both 'junior-expert' comparisons (clinical 0 .963, 95% CI 0.897-0.992; numerical 0.988, 95% CI 0.934-1.000) and 'intra-expert' comparisons (clinical 0.988, 95% CI 0.934-1.000; numerical 1.000, 95% CI 0.956-1.000). Reasons for disagreements were different scoring of the least-function score and disagreements in rASRM scores. The reproducibility of the rASRM score was clearly inferior to that of the EFI for all comparisons.

CONCLUSION

The EFI can be reproduced reliably by different raters, further supporting its use in daily clinical practice as the principal clinical tool for postoperative fertility counselling/management of women with endometriosis.

TWEETABLE ABSTRACT

A study confirming the high reproducibility of the EFI substantiates its use in daily clinical practice.

A correlated Bayesian rank likelihood approach to multiple ROC curves for endometriosis

In analysis of diagnostic data with multiple tests, it is often the case that these tests are correlated. Modeling the correlation explicitly not only produces valid inference results but also enables borrowing of information. Motivated by the Physician Reliability Study (PRS) that investigated the diagnostic performance of physicians in diagnosing endometriosis, we construct a correlated modeling framework to estimate ROC curves and the associated area under the curves. This correlated approach is quite appealing for the PRS data set that suffers from the problem of small sample sizes, as it enables information borrowing between physician groups and sessions. Given that the test scores appear to be non-normal even after logarithm transformation, we use the ranks of the data to conduct likelihood estimation and inference. We use the deviance information criterion to select competing models and conduct simulation studies to assess model performances. In application to the PRS data set, we found that the physicians are not significantly different in their diagnostic performance between groups; however, they are different between the sessions. This suggests that clinical information may play a more important role in physicians' diagnostic performance than their experiences. Our empirical evidence also demonstrates that when using both woman- and physician-specific random effects, the model parameter estimates are much smoother.

Modifiable life style factors and risk for incident endometriosis

BACKGROUND

Caffeine, alcohol, smoking and physical activity are known to alter sex steroid synthesis, which may affect hormone-dependent gynaecologic disease risk, such as endometriosis; however, few studies have assessed life style factors prior to endometriosis diagnosis.

METHODS

Four hundred and seventy three women, ages 18-44 years, underwent laparoscopy or laparotomy, regardless of clinical indication, at 14 clinic sites, 2007-2009. Women with prior surgically confirmed endometriosis were excluded. Life style factors were assessed prior to surgery. Adjusted risk ratios (RR) of endometriosis by caffeine, alcohol, smoking (serum cotinine), and physical activity were estimated, adjusting for age, marital status, education, race/ethnicity, age at menarche, gravidity, BMI, study site, and other life style factors.

RESULTS

There were no associations between women with endometriosis and alcohol consumption (RR 0.9, 95% CI 0.7, 1.3), caffeine consumption (RR 1.1, 95% CI 0.8, 1.5), or smoking (serum cotinine <10 vs ≥10 ng/mL; RR 1.0, 95% CI 0.7, 1.6). Similar null findings were found between endometriosis and weekly occurrences of physical activity and total walking, moderate, and vigorous activity; a modest trend was found between total daily sitting time and increased endometriosis risk.

CONCLUSIONS

This study, which is unique in its capture of life style exposures prior to incident endometriosis diagnosis, largely found no association between alcohol, caffeine, smoking, and physical activity and risk of endometriosis.

A Bayesian semiparametric approach to correlated ROC surfaces with stochastic order constraints

In application of diagnostic accuracy, it is possible that a priori information may exist regarding the test score distributions, either between different disease populations for a single test or between multiple correlated tests. Few have considered constrained diagnostic accuracy analysis when the true disease status is binary; almost none when the disease status is ordinal. Motivated by a study on diagnosing endometriosis, we propose an approach to estimating diagnostic accuracy measures that can incorporate different stochastic order constraints on the test scores when an ordinal true disease status is in consideration. We show that the Dirichlet process mixture provides a convenient framework to both flexibly model the test score distributions and embed the a priori ordering constraints. We also utilize the Dirichlet process mixture to model the correlation between multiple tests. In taking a Bayesian perspective to inference, we develop an efficient Markov chain Monte Carlo algorithm to sample from the posterior distribution and provide posterior estimates of the receiver operating characteristic surfaces and the associated summary measures. The proposed approach is evaluated with extensive simulation studies, and is demonstrated with an application to the endometriosis study.

The beneficial effects of nerolidol and hesperidin on surgically induced endometriosis in a rat model. Gynecol Endocrinol 2018;34:975-980. [PMID: 29734842 DOI: 10.1080/09513590.2018.1469611]

The objective of this article is to analyze the effects of nerolidol and hesperidin treatment on surgically induced endometriosis in a rat model. Endometriosis was induced in 24 healthy adult female Wistar albino rats via homologous uterine horn transplantation. Three operations were performed on each rat. After the second operation, the rats were randomized into control, nerolidol, and hesperidin treatment groups, and medications were administered for 2 weeks. The effects of the drugs on the endometriotic foci were evaluated after the third operation. Compared with the endometriosis control group, the average volume of the lesions was significantly lower in rats treated with hesperidin and nerolidol. Malondialdehyde levels were significantly reduced in the nerolidol-treated group, and glutathione levels and superoxide dismutase activity were significantly elevated in the endometriotic foci of both the hesperidin- and nerolidol-treated groups compared with the endometriosis group. Hesperidin and nerolidol treatment also improved histological parameters, such as hemorrhage, vascular congestion, necrosis, and inflammatory cell infiltration in the endometriotic foci. The results of this study demonstrated that treatment with the potent antioxidants nerolidol and hesperidin caused a significant regression of surgically induced endometriotic foci in rats.

Negative laparoscopy unveiled

Introduction:

Studies indicate a variable proportion of laparoscopies done for the management of non-acute pelvic pain that do not identify visible pathology and are called negative laparoscopies. Possible explanations have included undetected endometriosis, observer error, and/or neural tissues in the endometrium acting as nociceptive input. The goal was to compare demographic and pain testing measures between women with negative laparoscopies and confirmed endometriosis in a cohort of women presenting with chronic pelvic pain.

Methods:

Women with chronic pelvic pain (n = 255) provided written consent for the study prior to entry. Data were collected at the time of clinic visit and entered contemporaneously into SPSS. Pain sensitization was identified as the presence of cutaneous allodynia. Clinical, pain, and pain sensitization variables were compared using Student’s t-test.

Results:

The frequency of negative laparoscopy was 13.7% (35 cases) and that of confirmed endometriosis was 27.1% (69 cases). There were no differences between women with a negative laparoscopy and women with confirmed endometriosis in clinical, dysmenorrhea, or pain testing measurements.

Conclusion:

The data suggest in the absence of endometriotic tissue in the pelvis, chronic visceral pain may result from a uterine origin and result in a generalized pattern of pain and pain sensitization.

Beyond Body Mass Index: Using Anthropometric Measures and Body Composition Indicators to Assess Odds of an Endometriosis Diagnosis

BACKGROUND

Body mass index (BMI) and endometriosis have been inversely associated. To address gaps in this research, we examined associations among body composition, endometriosis, and physical activity.

MATERIALS AND METHODS

Women from 14 clinical sites in the Salt Lake City, Utah and San Francisco, California areas and scheduled for laparoscopy/laparotomy were recruited during 2007-2009. Participants (N = 473) underwent standardized anthropometric assessments to estimate body composition before surgery. Using a cross-sectional design, odds of an endometriosis diagnosis (adjusted odds ratio [aOR]; 95% confidence interval [CI]) were calculated for anthropometric and body composition measures (weight in kg; height in cm; mid upper arm, waist, hip, and chest circumferences in cm; subscapular, suprailiac, and triceps skinfold thicknesses in mm; arm muscle and fat areas in cm²; centripetal fat, chest-to-waist, chest-to-hip, waist-to-hip, and waist-to-height ratios; arm fat index; and BMI in kg/m²). Physical activity (metabolic equivalent of task-minutes/week) and sedentariness (average minutes sitting on a weekday) were assessed using the International Physical Activity Questionnaire-Short Form. Measures were modeled continuously and in quartiles based on sample estimates. Adjusted models were controlled for age (years, continuous), site (Utah/California), smoking history (never, former, or current smoker), and income (below, within 180%, and above of the poverty line). Findings were standardized by dividing variables by their respective standard deviations. We used adjusted models to examine whether odds of an endometriosis diagnosis were moderated by physical activity or sedentariness.

RESULTS

Inverse relationships were observed between endometriosis and standardized: weight (aOR = 0.71, 95% CI 0.57-0.88); subscapular skinfold thickness (aOR = 0.79, 95% CI 0.65-0.98); waist and hip circumferences (aOR = 0.79, 95% CI 0.64-0.98 and aOR = 0.76, 95% CI 0.61-0.94, respectively); total upper arm and upper arm muscle areas (aOR = 0.76, 95% CI 0.61-0.94 and aOR = 0.74, 95% CI 0.59-0.93, respectively); and BMI (aOR = 0.75, 95% CI 0.60-0.93), despite similar heights. Women in the highest versus lowest quartile had lower adjusted odds of an endometriosis diagnosis for: weight; mid-upper arm, hip, and waist circumferences; total upper arm and upper arm muscle areas; BMI; and centripetal fat ratio. There was no evidence of a main effect or moderation of physical activity or sedentariness.

CONCLUSION

In a surgical cohort, endometriosis was inversely associated with anthropometric measures and body composition indicators.

Women's Reproductive History Before the Diagnosis of Incident Endometriosis

BACKGROUND

Endometriosis is a gynecologic disease reported to be associated with infertility and, possibly, adverse pregnancy outcomes. While considerable research focuses on pregnancy outcomes following diagnosis and/or treatment, few data actually describe women's reproductive history before diagnosis for a more complete understanding of endometriosis and reproduction.

MATERIALS AND METHODS

The study sample comprised 473 women (aged 18-44 years) undergoing laparoscopies or laparotomies, irrespective of surgical indication at 14 clinical sites, during the period 2007-2009. Upon enrollment and before surgery, women were queried about pregnancy intentions and the time required to become pregnant for planned pregnancies. Endometriosis was defined as surgically visualized disease. Using discrete time survival analysis, we estimated fecundability odds ratios (FORs) and 95% confidence intervals (CIs) to assess time to pregnancy (TTP) after adjusting for potential confounders (age, body composition, cigarette smoking, site). Generalized estimating equations accounted for multiple pregnancy attempts per woman. FORs <1.0 denote a longer TTP or diminished fecundity.

RESULTS

Approximately 66% and 69% of women with and without endometriosis, respectively, reported having a planned pregnancy before surgery, respectively. After adjustment, an endometriosis diagnosis was associated with ≈29% reduction in fecundity or a longer TTP across all pregnancy-trying attempts (adjusted FOR = 0.71; 95% CI 0.46-1.10). While FORs were consistently <1.0, irrespective of endometriosis staging, CIs included 1.

CONCLUSIONS

Women with endometriosis had a longer TTP than unaffected women, irrespective of disease severity, although the findings did not achieve significance. Prior reproductive history may be informative for predicting fecundity and pregnancy outcomes following diagnosis/treatment.

Sexual and physical abuse and gynecologic disorders

STUDY QUESTION

Is sexual and/or physical abuse history associated with incident endometriosis diagnosis or other gynecologic disorders among premenopausal women undergoing diagnostic and/or therapeutic laparoscopy or laparotomy regardless of clinical indication?

SUMMARY ANSWER

No association was observed between either a history of sexual or physical abuse and risk of endometriosis, ovarian cysts or fibroids; however, a history of physical abuse was associated with a higher likelihood of adhesions after taking into account important confounding and mediating factors.

WHAT IS KNOWN ALREADY

Sexual and physical abuse may alter neuroendocrine-immune processes leading to a higher risk for endometriosis and other noninfectious gynecologic disorders, but few studies have assessed abuse history prior to diagnosis.

STUDY DESIGN, SIZE, DURATION

The study population for these analyses includes the ENDO Study (2007-2009) operative cohort: 473 women, ages 18-44 years, who underwent a diagnostic and/or therapeutic laparoscopy or laparotomy at 1 of the 14 surgical centers located in Salt Lake City, UT, USA or San Francisco, CA, USA. Women with a history of surgically confirmed endometriosis were excluded.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Prior to surgery, women completed standardized abuse questionnaires. Relative risk (RR) of incident endometriosis, uterine fibroids, adhesions or ovarian cysts by abuse history were estimated, adjusting for age, race/ethnicity, education, marital status, smoking, gravidity and recruitment site. We assessed whether a history of chronic pelvic pain, depression, or STIs explained any relationships via mediation analyses.

MAIN RESULTS AND ROLE OF CHANCE

43 and 39% of women reported experiencing sexual and physical abuse. No association was observed between either a history of sexual or physical abuse, versus no history, and risk of endometriosis (aRR: 1.00 [95% confidence interval (CI): 0.80-1.25]); aRR: 0.83 [95% CI: 0.65-1.06]), ovarian cysts (aRR: 0.67 [95% CI: 0.39-1.15]); aRR: 0.60 [95% CI: 0.34-1.09]) or fibroids (aRR: 1.25 [95% CI: 0.85-1.83]); aRR: 1.36 [95% CI: 0.92-2.01]). Conversely, a history of physical abuse, versus no history, was associated with higher risk of adhesions (aRR: 2.39 [95% CI: 1.18-4.85]). We found no indication that the effect of abuse on women's adhesion risk could be explained by a history of chronic pelvic pain, depression or STIs.

LIMITATIONS, REASONS FOR CAUTION

Limitations to our study include inquiries on childhood physical but not sexual abuse. Additionally, we did not inquire about childhood or adulthood emotional support systems, found to buffer the negative impact of stress on gynecologic health.

WIDER IMPLICATIONS OF THE FINDINGS

Abuse may be associated with some but not all gynecologic disorders with neuroendocrine-inflammatory origin. High prevalence of abuse reporting supports the need for care providers to screen for abuse and initiate appropriate follow-up.

STUDY FUNDING/COMPETING INTERESTS

Supported by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development (contracts NO1-DK-6-3428, NO1-DK-6-3427, and 10001406-02). The authors have no potential competing interests.

Endometriosis diagnosis and staging by operating surgeon and expert review using multiple diagnostic tools: an inter-rater agreement study

OBJECTIVE

To determine agreement on endometriosis diagnosis between real-time laparoscopy and subsequent expert review of digital images, operative reports, magnetic resonance imaging (MRI), and histopathology, viewed sequentially.

DESIGN

Inter-rater agreement study.

SETTING

Five urban surgical centres.

POPULATION

Women, aged 18-44 years, who underwent a laparoscopy regardless of clinical indication. A random sample of 105 women with and 43 women without a postoperative endometriosis diagnosis was obtained from the ENDO study.

METHODS

Laparoscopies were diagnosed, digitally recorded, and reassessed.

MAIN OUTCOME MEASURES

Inter-observer agreement of endometriosis diagnosis and staging according to the revised American Society for Reproductive Medicine criteria. Prevalence and bias-adjusted kappa values (κ) were calculated for diagnosis, and weighted κ values were calculated for staging.

RESULTS

Surgeons and expert reviewers had substantial agreement on diagnosis and staging after viewing digital images (n = 148; mean κ = 0.67, range 0.61-0.69; mean κ = 0.64, range 0.53-0.78, respectively) and after additionally viewing operative reports (n = 148; mean κ = 0.88, range 0.85-0.89; mean κ = 0.85, range 0.84-0.86, respectively). Although additionally viewing MRI findings (n = 36) did not greatly impact agreement, agreement substantially decreased after viewing histological findings (n = 67), with expert reviewers changing their assessment from a positive to a negative diagnosis in up to 20% of cases.

CONCLUSION

Although these findings suggest that misclassification bias in the diagnosis or staging of endometriosis via visualised disease is minimal, they should alert gynaecologists who review operative images in order to make decisions on endometriosis treatment that operative reports/drawings and histopathology, but not necessarily MRI, will improve their ability to make sound judgments.

TWEETABLE ABSTRACT

Endometriosis diagnosis and staging agreement between expert reviewers and operating surgeons was substantial.

An Integrated Bayesian Nonparametric Approach for Stochastic and Variability Orders in ROC Curve Estimation: An Application to Endometriosis Diagnosis

In estimating ROC curves of multiple tests, some a priori constraints may exist, either between the healthy and diseased populations within a test or between tests within a population. In this paper, we proposed an integrated modeling approach for ROC curves that jointly accounts for stochastic and variability orders. The stochastic order constrains the distributional centers of the diseased and healthy populations within a test, while the variability order constrains the distributional spreads of the tests within each of the populations. Under a Bayesian nonparametric framework, we used features of the Dirichlet process mixture to incorporate these order constraints in a natural way. We applied the proposed approach to data from the Physician Reliability Study that investigated the accuracy of diagnosing endometriosis using different clinical information. To address the issue of no gold standard in the real data, we used a sensitivity analysis approach that exploited diagnosis from a panel of experts. To demonstrate the performance of the methodology, we conducted simulation studies with varying sample sizes, distributional assumptions and order constraints. Supplementary materials for this article are available online.

A crossed random effects modeling approach for estimating diagnostic accuracy from ordinal ratings without a gold standard

In diagnostic studies without a gold standard, the assumption on the dependence structure of the multiple tests or raters plays an important role in model performance. In case of binary disease status, both conditional independence and crossed random effects structure have been proposed and their performance investigated. Less attention has been paid to the situation where the true disease status is ordinal. In this paper, we propose crossed subject-specific and rater-specific random effects to account for the dependence structure and assess the robustness of the proposed model to misspecification in the random effects distributions. We applied the models to data from the Physician Reliability Study, which focuses on assessing the diagnostic accuracy in a population of raters for the staging of endometriosis, a gynecological disorder in women. Using this new methodology, we estimate the probability of a correct classification and show that regional experts can more easily classify the intermediate stage than resident physicians.

Trace elements and endometriosis: the ENDO study

There has been limited study of trace elements and endometriosis. Using a matched cohort design, 473 women aged 18-44 years were recruited into an operative cohort, along with 131 similarly aged women recruited into a population cohort. Endometriosis was defined as surgically visualized disease in the operative cohort, and magnetic resonance imaging diagnosed disease in the population cohort. Twenty trace elements in urine and three in blood were quantified using inductively coupled plasma mass spectrometry. Logistic regression estimated the adjusted odds (aOR) of endometriosis diagnosis for each element by cohort. No association was observed between any element and endometriosis in the population cohort. In the operative cohort, blood cadmium was associated with a reduced odds of diagnosis (aOR=0.55; 95% CI: 0.31, 0.98), while urinary chromium and copper reflected an increased odds (aOR=1.97; 95% CI: 1.21, 3.19; aOR=2.66; 95% CI: 1.26, 5.64, respectively). The varied associations underscore the need for continued research.

SEQUENTIAL TESTING OF MEASUREMENT ERRORS IN INTER-RATER RELIABILITY STUDIES

Inter-rater reliability is usually assessed by means of the intraclass correlation coefficient. Using two-way analysis of variance to model raters and subjects as random effects, we derive group sequential testing procedures for the design and analysis of reliability studies in which multiple raters evaluate multiple subjects. Compared with the conventional fixed sample procedures, the group sequential test has smaller average sample number. The performance of the proposed technique is examined using simulation studies and critical values are tabulated for a range of two-stage design parameters. The methods are exemplified using data from the Physician Reliability Study for diagnosis of endometriosis.

Estimating diagnostic accuracy of raters without a gold standard by exploiting a group of experts

In diagnostic medicine, estimating the diagnostic accuracy of a group of raters or medical tests relative to the gold standard is often the primary goal. When a gold standard is absent, latent class models where the unknown gold standard test is treated as a latent variable are often used. However, these models have been criticized in the literature from both a conceptual and a robustness perspective. As an alternative, we propose an approach where we exploit an imperfect reference standard with unknown diagnostic accuracy and conduct sensitivity analysis by varying this accuracy over scientifically reasonable ranges. In this article, a latent class model with crossed random effects is proposed for estimating the diagnostic accuracy of regional obstetrics and gynaecological (OB/GYN) physicians in diagnosing endometriosis. To avoid the pitfalls of models without a gold standard, we exploit the diagnostic results of a group of OB/GYN physicians with an international reputation for the diagnosis of endometriosis. We construct an ordinal reference standard based on the discordance among these international experts and propose a mechanism for conducting sensitivity analysis relative to the unknown diagnostic accuracy among them. A Monte Carlo EM algorithm is proposed for parameter estimation and a BIC-type model selection procedure is presented. Through simulations and data analysis we show that this new approach provides a useful alternative to traditional latent class modeling approaches used in this setting.