'I don't want to have to teach every medical provider': barriers to care among non-binary people in the Canadian healthcare system

It is well-known that trans and non-binary individuals experience worse health outcomes due to experiences of violence and discrimination. For this reason, accessible healthcare for trans and non-binary people is crucial. There is a lack of Canadian literature on the experiences of non-binary people within the healthcare system. This study sought to understand barriers to healthcare among non-binary people living in a mid-sized urban/rural region of Canada. Interviews were conducted between November 2019 to March 2020 with 12 non-binary individuals assigned female at birth, living in Waterloo Region, Ontario, Canada, as a part of a larger qualitative study exploring experiences within the community, healthcare and employment. Three broad themes were developed: erasure, barriers to access to healthcare, and assessing whether (or not) to come out. Sub-themes included institutional erasure, informational erasure, general healthcare barriers, medical transition healthcare barriers, anticipated discrimination, and assessing safety. Policy and institutional changes are needed to increase the safety and accessibility of healthcare services to non-binary individuals.

‘Getting shut down and shut out’: Exploring ACB patient perceptions on healthcare access at the physician-patient level in Canada

Purpose

The experiences of African, Caribbean and Black (ACB) Canadians are seldom explored in the Canadian context. Family physicians act as a gateway to the rest of the healthcare system and are necessary to provide proper patient care. However, Canada’s history with colonialism may impact the socio-cultural context in which patients receive care.

Method

41 participants from Waterloo Region, Ontario, were engaged in eight focus groups to discuss their experiences in the healthcare system. Data were analysed following thematic analysis.

Results

Style of care, racism and discrimination and a lack of cultural competence hindered access. oor Inadequate cultural competence was attributed to western and biomedical approaches, poor understanding of patients’ context, physicians failing to address specific health concerns, and racism and discrimination. Participants highlighted that the two facilitators to care were having an ACB family physician and fostering positive relationships with physicians.

Conclusion

Participants predominantly expressed dissatisfaction in physicians’ approaches to care, which were compounded by experiences of racism and discrimination. Findings demonstrate how ACB patients are marginalized and excluded from the healthcare syste Iimplications for better access to care included utilizing community healthcare centres, increasing physicians’ capacity around culturally inclusive care, and increasing access to ACB physicians.

Non-Nutritive Suckling System for Real-Time Characterization of Intraoral Vacuum Profile in Full Term Neonates

Infant breastfeeding diagnostics remain subjective due to the absence of instrumentation to objectively measure and understand infant oral motor skills and suckling characteristics. Qualitative diagnostic exams, such as the digital suck assessment which relies upon a clinician's gloved finger inserted into the infant's mouth, produce a diversity of diagnoses and intervention pathways due to their subjective nature. In this paper, we report on the design of a non-nutritive suckling (NNS) system which quantifies and analyzes quantitative intraoral vacuum and sucking patterns of full-term neonates in real time. In our study, we evaluate thirty neonate suckling profiles to demonstrate the technical and clinical feasibility of the system. We successfully extract the mean suck vacuum, maximum suck vacuum, frequency, burst duration, number of sucks per burst, number of sucks per minute, and number of bursts per minute. In addition, we highlight the discovery of three intraoral vacuum profile shapes that are found to be correlated to different levels of suckling characteristics. These results establish a framework for future studies to evaluate oromotor dysfunction that affect the appearance of these signals based on established normal profiles. Ultimately, with the ability to easily and quickly capture intraoral vacuum data, clinicians can more accurately perform suckling assessments to provide timely intervention and assist mothers and infants towards successful breastfeeding outcomes.

Knowledge of viral load, PrEP, and HIV-related sexual risk among men who have sex with men in the Waterloo region

Gay, bisexual, and other men who have sex with men (GBMSM) remain most disproportionately affected by HIV in Canada. HIV-related sexual risk behaviours have been linked to high HIV risk among GBMSM, but prior research has not focused on knowledge of viral load, and the risk it presents for HIV acquisition. The purpose of this study was to explore the relationship between HIV-related sexual risk behaviour and knowledge of viral load among GBMSM. A cross-sectional survey was conducted using a convenience sample of individuals age 16 and older who self-identified as LGBTQ and lived, worked, or resided in the Waterloo region, an urban-rural area in southwestern Ontario ( N = 526). Responses were analyzed from those identifying as GBMSM ( N = 269). Logistic regression models were created to explore sociodemographic, outness, social support, and HIV-related sexual risk variables associated with knowledge of viral load. Multivariable regression models were built to explore the same associations while controlling for confounders. HIV risk was not associated with knowledge of viral load in bivariate or multivariable analyses. Point estimates for low/negligible (odds ratio [OR] 1.10; 95% CI 0.46–2.51) and high risk (OR 1.88; 95% CI 0.68–5.20) suggest trends of higher knowledge with increased HIV risk. Men who engage in sexual risk behaviour may have increased sexual health literacy and awareness of biomedical interventions (e.g., pre-exposure prophylaxis, or PrEP) that reduce HIV risk. Policies are needed that promote acceptance of sexual orientation, improve awareness and access to PrEP, and ensure optimal delivery of HIV education to at-risk groups prior to engagement in higher risk activities.

Antenatal preventative pelvic floor muscle exercise intervention led by midwives to reduce postnatal urinary incontinence (APPEAL): protocol for a feasibility and pilot cluster randomised controlled trial

Background

Antenatal pelvic floor muscle exercises (PFME) in women without prior urinary incontinence (UI) are effective in reducing postnatal UI; however, UK midwives often do not provide advice and information to women on undertaking PFME, with evidence that among women who do receive advice, many do not perform PFME.

Methods

The primary aim of this feasibility and pilot cluster randomised controlled trial is to provide a potential assessment of the feasibility of undertaking a future definitive trial of a midwifery-led antenatal intervention to support women to perform PFME in pregnancy and reduce UI postnatally.

Community midwifery teams in participating NHS sites comprise trial clusters (n = 17). Midwives in teams randomised to the intervention will be trained on how to teach PFME to women and how to support them in undertaking PFME in pregnancy. Women whose community midwifery teams are allocated to control will receive standard antenatal care only.

All pregnant women who give birth over a pre-selected sample month who receive antenatal care from participating community midwifery teams (clusters) will be sent a questionnaire at 10–12 weeks postpartum (around 1400–1500 women). Process evaluation data will include interviews with midwives to assess if the intervention could be implemented as planned. Interviews with women in both trial arms will explore their experiences of support from midwives to perform PFME during pregnancy. Data will be stored securely at the Universities of Birmingham and Exeter.

Results will be disseminated through publications aimed at maternity service users, clinicians, and academics and inform a potential definitive trial of effectiveness. The West Midlands–Edgbaston Research Ethics Committee approved the study protocol.

Discussion

Trial outcomes will determine if criteria to progress to a definitive cluster trial are met. These include women’s questionnaire return rates, prevalence of UI, and other health outcomes as reported by women at 10–12 weeks postpartum. Progress to a definitive trial however is likely to be prevented in the UK context by new perinatal pelvic health service, although this may be possible elsewhere.

Trial registration

10.1186/ISRCTN10833250. Registered 09/03/2020

Knowledge of viral load, PrEP, and HIV-related sexual risk among men who have sex with men in the Waterloo region

Gay, bisexual, and other men who have sex with men (GBMSM) remain most disproportionately affected by HIV in Canada. HIV-
related sexual risk behaviours have been linked to high HIV risk among GBMSM, but prior research has not focused on knowledge of viral load, and the risk it presents for HIV acquisition. The purpose of this study was to explore the relationship between HIV-related sexual risk behaviour and knowledge of viral load among GBMSM. A cross-sectional survey was conducted using a convenience sample of individuals age 16 and older who self-identified as LGBTQ and lived, worked, or resided in the Waterloo region, an urban-rural area in southwestern Ontario ( N = 526). Responses were analyzed from those identifying as GBMSM ( N = 269). Logistic regression models were created to explore sociodemographic, outness, social support, and HIV-related sexual risk variables associated with knowledge of viral load. Multivariable regression models were built to explore the same associations while controlling for confounders. HIV risk was not associated with knowledge of viral load in bivariate or multivariable analyses. Point estimates for low/negligible (odds ratio [OR] 1.10; 95% CI 0.46–2.51) and high risk (OR 1.88; 95% CI 0.68–5.20) suggest trends of higher knowledge with increased HIV risk. Men who engage in sexual risk behaviour may have increased sexual health literacy and awareness of biomedical interventions (e.g., pre-exposure prophylaxis, or PrEP) that reduce HIV risk. Policies are needed that promote acceptance of sexual orientation, improve awareness and access to PrEP, and ensure optimal delivery of HIV education to at-risk groups prior to engagement in higher risk activities.

Experiences of discrimination and its impacts on well-being among racialised LGBTQ+ newcomers living in Waterloo region, Ontario, Canada

Discrimination (i.e. racism, homo/bi/transphobia) at both the individual and systemic levels may negatively impact the well-being of racialised LGBTQ+ newcomers living in Waterloo Region, Ontario, Canada. Current research about the experiences of LGBTQ+ newcomers focuses predominantly on homogeneous samples of gay men living in large metropolitan city centres. The present study aims to extend the current literature by exploring the experiences of discrimination and its impacts on well-being among racialised LGBTQ+ newcomers living in a small urban area and representing a variety of intersecting identities (i.e. ethno-racial background, LGBTQ+ identity, newcomer status). Using a qualitative method, 10 individuals were invited to complete a semistructured interview between fall 2019 and summer 2020 about their experiences of discrimination in Waterloo Region, and how such experiences impact their well-being. Using an intersectional lens, a thematic analysis revealed that racialised LGBTQ+ newcomers experienced discrimination before and after settlement in Waterloo Region. Prior to settlement, participants spoke predominantly about experiences of homo/biphobia and the associated feelings of internalised oppression. Alternatively, upon settling in Waterloo Region, experiences of discrimination were predominantly racism, and, in particular, systemic racism, which manifested as an inability to access adequate services and a lack of representation in various spaces throughout Waterloo Region. These results extend previous research by identifying the service barriers experienced by racialised LGBTQ+ newcomers living in a small urban area and can be used to inform best practices for addressing these barriers in Waterloo Region and other small urban areas with similar demographics. Implications and limitations are discussed.

Peripheral Nerve Magnetoneurography With Optically Pumped Magnetometers

Electrodiagnosis is routinely integrated into clinical neurophysiology practice for peripheral nerve disease diagnoses, such as neuropathy, demyelinating disorders, nerve entrapment/impingement, plexopathy, or radiculopathy. Measured with conventional surface electrodes, the propagation of peripheral nerve action potentials along a nerve is the result of ionic current flow which, according to Ampere’s Law, generates a small magnetic field that is also detected as an “action current” by magnetometers, such as superconducting quantum interference device (SQUID) Magnetoencephalography (MEG) systems. Optically pumped magnetometers (OPMs) are an emerging class of quantum magnetic sensors with a demonstrated sensitivity at the 1 fT/√Hz level, capable of cortical action current detection. But OPMs were ostensibly constrained to low bandwidth therefore precluding their use in peripheral nerve electrodiagnosis. With careful OPM bandwidth characterization, we hypothesized OPMs may also detect compound action current signatures consistent with both Sensory Nerve Action Potential (SNAP) and the Hoffmann Reflex (H-Reflex). In as much, our work confirms OPMs enabled with expanded bandwidth can detect the magnetic signature of both the SNAP and H-Reflex. Taken together, OPMs now show potential as an emerging electrodiagnostic tool.

Health care access among transgender and nonbinary people in Canada, 2019: a cross-sectional survey

BACKGROUND

Previous Canadian studies have identified problems regarding health care access for transgender (trans) and nonbinary people, but all-ages national data have been lacking. This study describes access to care among trans and nonbinary people in Canada, and compares health care access across provinces or regions.

METHODS

We conducted a bilingual, multimode cross-sectional survey (Trans PULSE Canada) from July 26 to Oct. 1, 2019. We recruited trans and nonbinary people aged 14 years and older using convenience sampling. We assessed 5 outcomes: having a primary care provider, having a primary care provider with whom the respondent was comfortable discussing trans health issues, past-year unmet health care need, medical gender affirmation status, and being on a wait-list to access gender-affirming medical care. Average marginal predictions were estimated from multivariable logistic regression models with multiply imputed data.

RESULTS

The survey included 2873 participants, and 2217 surveys were analyzed after exclusions. Of the 2217 trans and nonbinary respondents, most had a primary care provider (n = 1803; 81.4%, 95% confidence interval [CI] 79.8%-83.0%), with model-predicted probabilities from 52.1% (95% CI 20.2%-84.1%) in the territories to 92.9% (95% CI 83.5%-100.0%) in Newfoundland and Labrador. Of the respondents, 52.3% (n = 1150; 95% CI 50.3%-54.2%) had a primary care provider with whom they were comfortable discussing trans health issues, and 44.4% (n = 978; 95% CI 42.3%-46.4%) reported an unmet health care need. Among participants who needed gender-affirming medical treatment (n = 1627), self-defined treatment completion ranged from an estimated 16.8% (95% CI 0.6%-32.5%) in Newfoundland and Labrador to 59.1% (95% CI 52.5%-65.6%) in Quebec. Of those who needed but had not completed gender-affirming care at the time of the study (n = 1046), 40.7% (n = 416; 95% CI 37.8%-43.6%) were on a wait-list, most often for surgery. These outcomes, with the exception of having a provider with whom one is comfortable discussing trans issues, varied significantly by province or region (p < 0.05).

INTERPRETATION

Participants reported considerable unmet needs or delays in primary, general and gender-affirming care, with significant regional variation. Our results indicate that, despite efforts toward equity in access to care for trans and nonbinary people in Canada, inequities persist.

Financial Incentives for Preventing Postpartum return to Smoking (FIPPS): study protocol for a three-arm randomised controlled trial

BACKGROUND

Financial incentives are an effective way of helping women to stop smoking during pregnancy. Unfortunately, most women who stop smoking at this time return to smoking within 12 months of the infant's birth. There is no evidence for interventions that are effective at preventing postpartum smoking relapse. Financial incentives provided after the birth may help women to sustain cessation. This randomised controlled trial will assess the effectiveness and cost-effectiveness of financial incentives to help women who are abstinent from smoking at end-of-pregnancy to avoid return to smoking up to 12 months postpartum.

METHODS

This is a UK-based, multi-centre, three-arm, superiority, parallel group, individually randomised controlled trial, with 1:1:1 allocation. It will compare the effectiveness of two financial incentive interventions with each other (one intervention for up to 3 months postpartum offering up to £120 of incentives (£60 for the participant and £60 for a significant other support); the other for up to 12 months postpartum with up to £300 of incentives (£240 for the participant and £60 for a significant other support) and with a no incentives/usual care control group. Eligible women will be between 34 weeks gestation and 2 weeks postpartum, abstinent from smoking for at least 4 weeks, have an expired carbon monoxide (CO) reading < 4 parts per million (ppm), aged at least 16 years, intend remaining abstinent from smoking after the birth and able to speak and read English. The primary outcome is self-reported, lapse-free, smoking abstinence from the last quit attempt in pregnancy until 12 months postpartum, biochemically validated by expired CO and/or salivary cotinine or anabasine. Outcomes will be analysed by intention-to-treat and regression models used to compare the proportion of abstinent women between the two intervention groups and between each intervention group and the control group. An economic evaluation will assess the cost-effectiveness of offering incentives and a qualitative process evaluation will examine barriers and facilitators to trial retention, effectiveness and implementation.

DISCUSSION

This pragmatic randomised controlled trial will test whether offering financial incentives is effective and cost-effective for helping women to avoid smoking relapse during the 12 months after the birth of their baby.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number 55218215 . Registered retrospectively on 5th June 2019.

Pregnant women's use of e-cigarettes in the UK: a cross-sectional survey

OBJECTIVE

To estimate prevalence of vaping in pregnancy. Compare characteristics and attitudes between exclusive smokers and vapers, and between exclusive vapers and dual users (smoke and vape).

DESIGN

Cross-sectional survey.

SETTING

Hospitals across England and Scotland.

POPULATION

Pregnant women attending antenatal clinics in 2017.

METHODS

Women at 8-24 weeks' gestation completed screening questions about their smoking and vaping. Current or recent ex-smokers and/or vapers completed a full detailed survey about vaping and smoking.

MAIN OUTCOME MEASURES

The prevalence of vaping, characteristics and attitudes of women who vape and/or smoke.

RESULTS

Of 3360 pregnant women who completed screening questions, 515 (15.3%, 95% CI 14.1-16.6) were exclusive smokers, 44 (1.3%, 95% CI 1.0-1.8) exclusive vapers and 118 (3.5%, 95% CI 2.9-4.2) dual users. In total, 867 (25.8%) women completed the full survey; compared with smokers (n = 434), vapers (n = 140) were more likely to hold higher educational qualifications (odds ratio [OR) 1.51, 95% CI 1.01-2.25). Compared with exclusive vapers (n = 33), dual users (n = 107) were younger (OR 0.91 95% CI 0.85-0.98) and less likely to hold high qualifications (OR 0.43, 95% CI 0.20-0.96). Compared with smokers, dual users were more likely to be planning to quit smoking (OR 2.27, 95% CI 1.24-4.18). Compared with smokers, vapers were more likely to think vaping was safer than smoking (78.6% versus 36.4%).

CONCLUSIONS

One in 20 pregnant women report vaping, and most also smoke. Dual users are more motivated towards stopping smoking than smokers. Where women have tried but cannot stop smoking, clinicians could encourage them to consider vaping for smoking cessation.

TWEETABLE EXTRACT

One in 20 women report vaping during pregnancy but of those that do vape, most also smoke, despite having intentions to quit.

Factors associated with interest in and knowledge of pre-exposure prophylaxis (PrEP) among gay, bisexual, and other men who have sex with men (GBMSM) in the Region of Waterloo, Ontario, Canada: Insights from the OutLook Study

Pre-exposure prophylaxis (PrEP) is an effective HIV-prevention tool for gay, bisexual, and other men who have sex with men (GBMSM), a group known to be disproportionately affected by HIV/AIDS. We aimed to identify sociodemographic, psychosocial, and health factors associated with awareness of PrEP or interest in PrEP among GBMSM in a mid-sized Canadian city, where PrEP availability is arguably more scarce compared to larger metropolitan regions. The OutLook Study was a comprehensive online survey of LGBTQ health and well-being that collected data from sexual minorities aged 16+ in the Region of Waterloo, Ontario, Canada. Participants were cisgender MSM with an unknown or negative HIV status (n = 203). Bivariate logistic regression was performed to analyze factors associated with both awareness of PrEP and interest in PrEP. Multivariate logistic regression explored sexual behaviours in the past 12 months while controlling for sociodemographic and psychosocial variables. Increasing number of sexual partners (OR: 1.10; 95% CI: 1.03–1.53) was significantly associated with interest in PrEP and lifetime experiences of homophobia remained significant from the bivariate model (ORs ranged from 1.11–1.12). Since GBMSM with low educational attainment were shown to have less knowledge about PrEP, educational campaigns could be targeted in high schools rather than colleges, universities, and trade schools. Prevention initiatives should be aimed at places where single or non-monogamous GBMSM frequent due to these men being disproportionately affected by HIV/AIDS. These findings provide insights for potential interventions targeting MSM from mid-sized cities.

Hearing "That's So Gay" and "No Homo" on Campus and Substance Use Among Sexual Minority College Students

Sexual orientation microaggressions are common on college campuses and can contribute to negative outcomes; yet little is known about their relationship with substance use outcomes. Among a convenience sample of cisgender sexual minority college students (n= 574; 57.0% female, 24.9% people of color, 50.7% gay/lesbian; 72.4% public school) from 37 states (67.8% Midwest), this analysis investigates the association between hearing "that's so gay" and "no homo" on campus and hazardous alcohol use and the frequency of illicit drug use. Using multivariable regression analyses, the commonly heard phrases "that's so gay" and "no homo" were each found to significantly increase the risk for hazardous drinking and the frequency of drug use among students. Efforts should be made to create more welcoming campus climates for sexual minority students by reducing the use of these microaggressions and, in the meantime, offering supports to mitigate their harmful effects.

HIV-related syndemic pathways and risk subjectivities among gay and bisexual men: a qualitative investigation

Life history interviews were conducted with 40 gay and bisexual men to identify modes of syndemic experience and risk practice. Out of the interview narratives emerged one major and two minor modes of developmental pathway whereby syndemic conditions are navigated and expressed: (1) a combination of adverse childhood events with later episodes of depression and/or substantial substance use; (2) personal disruption that led to periods of depression and anxiety associated with the stresses of migration; and (3) a disorientation and an unravelling of life trajectory in the transition from family of origin to college or work. Risk practices fell into three high-risk modes: active and frequent engagement in condomless sex; unassertive deferment to a partner's initiation of condomless sex; and episodic risk combined with a risk reduction strategy. Three low risk modes were also identified: no recent condomlessness but multiple risk history in interview; a trajectory over time from high to low risk; and consistent low risk practice. These different modes of syndemic experience and risk management may have implications for identification of the effective HIV prevention tools that work best for different sets of men.

Factors associated with the effectiveness and reach of NHS stop smoking services for pregnant women in England

BACKGROUND

The UK National Health Service provides Stop Smoking Services for pregnant women (SSSP) but there is a lack of evidence concerning how these are best organised. This study investigates influences on services' effectiveness and also on their propensity to engage pregnant smokers with support in stopping smoking.

METHODS

Survey data collected from 121/141 (86%) of SSSP were augmented with data from Hospital Episode Statistics and the 2011 UK National Census. 'Reach' or propensity to engage smokers with support was defined as the percentage of pregnant smokers setting a quit date with SSSP support, and 'Effectiveness' as the percentage of women who set a quit date who also reported abstinence at four weeks later. A bivariate (i.e. two outcome variable) response Markov Chain Monte Carlo model was used to identify service-level factors associated with the Reach and Effectiveness of SSSP.

RESULTS

Beta coefficients represent a percentage change in Reach and Effectiveness by the covariate. Providing the majority of one-to-one contacts in a clinic rather than at home increased both Reach (%) (β: 6.97, 95% CI: 3.34, 10.60) and Effectiveness (%) (β: 7.37, 95% CI: 3.03, 11.70). Reach of SSSP was also increased when the population served was more deprived (β for increase in Reach with a one unit increase in IMD score: 0.55, 95% CI: 0.25, 0.85), had a lower proportion of people with dependent children (β: -2.52, 95% CI: -3.82, -1.22), and a lower proportion of people in managerial or professional occupations (β: -0.31, 95% CI: -0.59, -0.03). The Effectiveness of SSSP was decreased in those areas that had a greater percentage of people >16 years with no educational qualifications (β: -0.51, 95% CI: -0.95, -0.07).

CONCLUSIONS

To engage pregnant smokers and to encourage them to quit, it may be more efficient for SSSP support to be focussed around clinics, rather than women's homes. Reach of SSSP is inversely associated with disadvantage and efforts should be made to contact these women as they are less likely to achieve abstinence in the short and longer term.

Abstract P5-10-10: Predictors of breast density among Black and Hispanic women presenting for mammographic screening

Background: Increased breast density has been associated with elevated breast cancer risk and complicating mammographic interpretation. Although previous studies have investigated population variations in breast density, Black and Hispanic women are often underrepresented in these analyses. Moreover, it is unclear how breast density differs between these ethnicities. We report on the mammographic density distribution of Black and Hispanic women having breast cancer screening at the Capital Breast Care Center (CBCC) and analyze factors associated with high breast density.

Methods: Retrospective data from electronic medical records at a population-based mammography screening center were abstracted. From 2010 to 2014, data from women undergoing their first breast cancer screening were reviewed. Patient demographics including race, age at screening, education and menopausal status were abstracted in addition to body mass index (BMI) and Breast Imaging-Reporting and Data System (BI-RADS) density category:1- “fatty”, 2- “scattered fibroglandular densities”, 3- “heterogeneously dense” and 4- “extremely dense”. Logistic regression was used to investigate factors associated with breast density.

Results: Density categorization was recorded for 1747 women over the five-year period, with 855 (49%) Black and 892 (51%) Hispanic. Patient characteristics associated with high density (categories 3 and 4) were younger age, Hispanic ethnicity, nulliparity, premenopausal status, and BMI &lt; 30 kg/m2. On multivariate logistic regression, Hispanic ethnicity, premenopausal status, and BMI &lt; 30 kg/m2 were predictive of high mammographic density.

Conclusion: In a sample of women presenting for mammographic screening at CBCC, Hispanic women were more likely to have higher breast density compared to Black women. After controlling for ethnicity, postmenopausal and obese women were less likely to have dense breasts. Additional investigation is needed to further study the impact of obesity on breast density in underserved minority women.

Citation Format: Oppong BA, Dash C, Li Y, Makambi K, Coleman T, Adams-Campbell L. Predictors of breast density among Black and Hispanic women presenting for mammographic screening [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-10-10.

Learning Minimal Latent Directed Information Polytrees

We propose an approach for learning latent directed polytrees as long as there exists an appropriately defined discrepancy measure between the observed nodes. Specifically, we use our approach for learning directed information polytrees where samples are available from only a subset of processes. Directed information trees are a new type of probabilistic graphical models that represent the causal dynamics among a set of random processes in a stochastic system. We prove that the approach is consistent for learning minimal latent directed trees. We analyze the sample complexity of the learning task when the empirical estimator of mutual information is used as the discrepancy measure.