Bayesian Mode Regression

This article has been made available through the Brunel Open Access Publishing Fund.Like mean, quantile and variance, mode is also an important measure of central tendency of a distribution. Many practical questions, particularly in the analysis of big data, such as \Which element (gene or le or signal) is the most typical one among all elements in a network?" are directly related to mode. Mode regression, which provides a convenient summary of how the regressors a ect the conditional mode, is totally di erent from other models based on conditional mean or conditional quantile or conditional variance. Some inference methods for mode regression exist but none of them is from the Bayesian perspective. This paper introduces Bayesian mode regression by exploring three different approaches, including their theoretic properties. The proposed approacher are illustrated using simulated datasets and a real data set

The National Children\u27s Study: recruitment outcomes using an enhanced household-based approach.

OBJECTIVES: Ten National Children\u27s Study (NCS) study locations with diverse demographic characteristics used an enhanced household-based recruitment (EHBR) approach to enroll preconceptional and pregnant women. Study centers used different types and dosages of community outreach and engagement (COE) activities and supplemental strategies. The goal of the study was to determine whether variability in enumeration and recruitment outcomes correlated with study location characteristics or types and dosages of COE activities (number of COE events, number of advance household mailings, total media expenditures, and total COE expenditures). METHODS: Each of the sites provided data on COE activities, protocol implementation, supplemental recruitment activities, location demographic characteristics, and enumeration/recruitment outcomes. RESULTS: COE activities varied across sites in breadth and scope. Numerous strategies were used, including media advertising, social media, participation in community-wide events, presentations to stakeholders, and creation of advisory boards. Some sites included supplemental recruitment efforts. EHBR sites enrolled 1404 women at the initial pregnancy screening. No significant relationships were found between study location demographic characteristics or between the types and dosages of COE activities and recruitment outcomes. CONCLUSIONS: Probability sampling for a long-term study requires a positive image with stakeholders and within communities; this requirement may be especially true for door-to-door recruitment. EHBR sites successfully recruited a representative sample of preconceptional and pregnant women. Sites reported implementing similar COE activities but with varying dosage and cost; however, analyses did not support a benefit of COE strategies on study recruitment

Contact tracing for the control of infectious disease epidemics: Chronic Wasting Disease in deer farms

Contact tracing is a crucial component of the control of many infectious diseases, but is an arduous and time consuming process. Procedures that increase the efficiency of contact tracing increase the chance that effective controls can be implemented sooner and thus reduce the magnitude of the epidemic. We illustrate a procedure using Graph Theory in the context of infectious disease epidemics of farmed animals in which the epidemics are driven mainly by the shipment of animals between farms. Specifically, we created a directed graph of the recorded shipments of deer between deer farms in Pennsylvania over a timeframe and asked how the properties of the graph could be exploited to make contact tracing more efficient should Chronic Wasting Disease (a prion disease of deer) be discovered in one of the farms. We show that the presence of a large strongly connected component in the graph has a significant impact on the number of contacts that can arise. Keywords: Chronic Wasting Disease, Contact tracing, Directed graphs, Strongly connected component

Optimal process parameters under LINEX loss function with general input quality characteristic

Asymmetric loss function, Taguchi quality model, Gamma distribution, Double exponential distribution, Laplace distribution,

Fetal Alcohol Spectrum Disorders in a Pacific Southwest City: Maternal and Child Characteristics

BACKGROUND:There are limited data on the characteristics of children with fetal alcohol spectrum disorders (FASD) and their mothers from the general population in the United States. METHODS:During the 2012 and 2013 academic years, first-grade children in a large urban Pacific Southwest city were invited to participate in a study to estimate the prevalence of FASD. Children who screened positive on weight, height, or head circumference ≤25th centile or on parental report of developmental concerns were selected for evaluation, along with a random sample of those who screened negative. These children were examined for dysmorphology and neurobehavior and their mothers or collateral sources were interviewed. Children were classified as fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (pFAS), alcohol-related neurodevelopmental disorder (ARND), or No FASD. RESULTS:A total of 854 children were evaluated; 5 FAS, 44 pFAS, 44 ARND, and 761 No FASD. Children with FAS or pFAS were more likely to have dysmorphic features, and 32/49 (65.3%) of those met criteria for neurobehavioral impairment on cognitive measures with or without behavioral deficits. In contrast, 28/44 (63.6%) of children with ARND met criteria on behavioral measures alone. Mothers of FASD children were more likely to recognize pregnancy later, be unmarried, and report other substance use or psychiatric disorders, but did not differ on age, socioeconomic status, education, or parity. Mothers of FASD children reported more drinks/drinking day each trimester. The risk of FASD was elevated with increasing number of drinks/drinking day prior to pregnancy recognition, even at the level of 1 drink per day (adjusted odds ratio 3.802, 95% confidence interval 1.634, 8.374). CONCLUSIONS:Data from this general population sample in a large urban region in the United States demonstrate the variability of expression of FASD and point to risk and protective factors for mothers in this setting

The Prevalence of Fetal Alcohol Spectrum Disorders in An American Indian Community.

The prevalence of fetal alcohol spectrum disorders (FASD) differs among populations and is largely unknown among minority populations. Prevalence and characterization of FASD is necessary for prevention efforts and allocation of resources for treatment and support. However, prevalence data are lacking, including among many minority populations. The aim of this study was to obtain an FASD prevalence estimate in a Southern California American Indian community employing active case-ascertainment. In 2016, American Indian children aged 5-7 years and their caregivers were recruited in collaboration with Southern California Tribal Health Clinic. Children were assessed using physical examinations and neurobehavioral testing. Parent or guardian interviews assessed child behavior and prenatal exposures including alcohol. Of 488 children identified as eligible to participate, 119 families consented and 94 completed assessments to allow a classification for FASD. Participating children (n = 94) were an average of 6.61 ± 0.91 years old and half were female. Most interviews were conducted with biological mothers (85.1%). Less than one third (29.8%) of mothers reported consuming any alcohol in pregnancy and 19.1% met study criteria for risky alcohol exposure prior to pregnancy recognition. Overall 20 children met criteria for FASD, resulting in an estimated minimum prevalence of 41.0 per 1000 (4.1%). No cases of fetal alcohol syndrome (FAS) were identified; 14 (70.0%) met criteria for alcohol related neuro- developmental disorder (ARND). Minimum prevalence estimates found in this sample are consistent with those noted in the general population

Best Practices for Engaging Pregnant and Postpartum Women at Risk of Substance Use in Longitudinal Research Studies: a Qualitative Examination of Participant Preferences

There are significant barriers in engaging pregnant and postpartum women that are considered high-risk (e.g., those experiencing substance use and/or substance use disorders (SUD)) into longitudinal research studies. To improve recruitment and retention of this population in studies spanning from the prenatal period to middle childhood, it is imperative to determine ways to improve key research engagement factors. The current manuscript uses a qualitative approach to determine important factors related to recruiting, enrolling, and retaining high-risk pregnant and postpartum women. The current sample included 41 high-risk women who participated in focus groups or individual interviews. All interviews were analyzed to identify broad themes related to engaging high-risk pregnant and parenting women in a 10-year longitudinal research project. Themes were organized into key engagement factors related to the following: (1) recruitment strategies, (2) enrollment, and (3) retention of high-risk pregnant and parenting women in longitudinal research studies. Results indicated recruitment strategies related to ideal recruitment locations, material, and who should share research study information with high-risk participants. Related to enrollment, key areas disclosed focused on enrollment decision-making, factors that create interest in joining a research project, and barriers to joining a longitudinal research study. With regard to retention, themes focused on supports needed to stay in research, barriers to staying in research, and best ways to stay in contact with high-risk participants. Overall, the current qualitative data provide preliminary data that enhance the understanding of a continuum of factors that impact engagement of high-risk pregnant and postpartum women in longitudinal research with current results indicating the need to prioritize recruitment, enrollment, and retention strategies in order to effectively engage vulnerable populations in research

Best Practices for Engaging Pregnant and Postpartum Women at Risk of Substance Use in Longitudinal Research Studies: a Qualitative Examination of Participant Preferences.

There are significant barriers in engaging pregnant and postpartum women that are considered high-risk (e.g., those experiencing substance use and/or substance use disorders (SUD)) into longitudinal research studies. To improve recruitment and retention of this population in studies spanning from the prenatal period to middle childhood, it is imperative to determine ways to improve key research engagement factors. The current manuscript uses a qualitative approach to determine important factors related to recruiting, enrolling, and retaining high-risk pregnant and postpartum women. The current sample included 41 high-risk women who participated in focus groups or individual interviews. All interviews were analyzed to identify broad themes related to engaging high-risk pregnant and parenting women in a 10-year longitudinal research project. Themes were organized into key engagement factors related to the following: (1) recruitment strategies, (2) enrollment, and (3) retention of high-risk pregnant and parenting women in longitudinal research studies. Results indicated recruitment strategies related to ideal recruitment locations, material, and who should share research study information with high-risk participants. Related to enrollment, key areas disclosed focused on enrollment decision-making, factors that create interest in joining a research project, and barriers to joining a longitudinal research study. With regard to retention, themes focused on supports needed to stay in research, barriers to staying in research, and best ways to stay in contact with high-risk participants. Overall, the current qualitative data provide preliminary data that enhance the understanding of a continuum of factors that impact engagement of high-risk pregnant and postpartum women in longitudinal research with current results indicating the need to prioritize recruitment, enrollment, and retention strategies in order to effectively engage vulnerable populations in research