Publications by authors named "Bryan E Shepherd"

Observational databases provide unprecedented opportunities for secondary use in biomedical research. However, these data can be error-prone and must be validated before use. It is usually unrealistic to validate the whole database because of resource constraints.

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Article Synopsis
  • - This study focuses on the increased risk of cardiovascular diseases, specifically right ventricular (RV) dysfunction, in people living with HIV (PLWH) in northwest Nigeria, emphasizing the need for more research in low- and middle-income settings.
  • - Researchers conducted a retrospective analysis of 330 adults, including HIV-positive individuals and age- and sex-matched HIV-negative controls, using advanced imaging techniques to evaluate heart function.
  • - Results indicated that 14.5% of HIV-positive participants showed signs of RV dysfunction, linked to factors like age and left ventricular ejection fraction, while no HIV-negative participants exhibited such dysfunction.
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Detection limits (DLs), where a variable cannot be measured outside of a certain range, are common in research. DLs may vary across study sites or over time. Most approaches to handling DLs in response variables implicitly make strong parametric assumptions on the distribution of data outside DLs.

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HIV care continuum outcome disparities by health insurance status have been noted among people with HIV (PWH). We therefore examined associations between state Medicaid expansion and HIV outcomes in the United States. Adults (≥18 years) with ≥1 visit in NA-ACCORD clinical cohorts from 2012-2017 contributed person-time annually between first and final visit or death; in each calendar year, clinical retention was ≥2 completed visits > 90 days apart, antiretroviral therapy (ART) receipt was receipt of ≥3 antiretroviral agents, and viral suppression was last measured HIV-1 RNA < 200 copies/mL.

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Introduction: HIV disproportionately affects Black/African American women in the United States, particularly in the southern states, including Tennessee. Despite this, limited research and intervention are targeting this population, especially regarding biomedical prevention technologies such as pre-exposure prophylaxis (PrEP). This study aims to describe the HIV testing history of a sample of Black women in middle Tennessee, assess their awareness and potential for adopting modern HIV prevention technologies like PrEP, and explore the dyadic and social factors that influence their HIV prevention awareness and use.

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Background: We sought to determine the prevalence of sickle cell trait (SCT) and apolipoprotein-1 ( risk variants in people living with HIV (PLWH) in Nigeria, and to establish if SCT and high-risk status correlate with estimated glomerular filtration rate (eGFR) and/or prevalent chronic kidney disease (CKD).

Methods: Baseline demographic and clinical data were obtained during three cross-sectional visits. CKD was defined as having an eGFR<60 mL/min/1.

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Introduction: There is evidence that a supportive male partner facilitates maternal HIV testing during pregnancy, increases maternal antiretroviral therapy initiation and adherence, and increases HIV-free infant survival. Most male partner engagement clinical strategies have focused on increasing uptake of couple-based HIV testing and counseling. We delivered a couple-based care and treatment intervention to improve antiretroviral therapy adherence in expectant couples living with HIV.

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Introduction: Immune reconstitution following antiretroviral therapy (ART) initiation is crucial to prevent AIDS and non-AIDS-related comorbidities. Patients with suppressed viraemia who fail to restore cellular immunity are exposed to an increased risk of morbidity and mortality during long-term follow-up, although the underlying mechanisms remain poorly understood. We aim to describe clinical outcomes and factors associated with the worse immune recovery and all-cause mortality in people living with HIV (PLWH) from Latin America following ART initiation.

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We sought to determine the association of hormonal contraception (HC) and cardiometabolic outcomes among women with human immunodeficiency virus (HIV). We included women with HIV aged 18-45 years in clinical care in the Southeastern United States between 1998 and 2018. Oral and injectable HC use was captured from medication records.

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Regression models for continuous outcomes frequently require a transformation of the outcome, which is often specified a priori or estimated from a parametric family. Cumulative probability models (CPMs) nonparametrically estimate the transformation by treating the continuous outcome as if it is ordered categorically. They thus represent a flexible analysis approach for continuous outcomes.

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The Vanderbilt-Nigeria Biostatistics Training Program (VN-BioStat) aims to establish a research and training platform for biostatisticians doing HIV-related research in Nigeria, including enhancing mid-level biostatistics capacity through annual workshops. This paper describes findings from the inaugural workshop in Kano, Nigeria. Participants were surveyed before and after the workshop to assess their self-perceived familiarity with and confidence in their abilities to use statistical software and apply specific statistical techniques, as well as to gather feedback regarding the conduct of the workshop and future topic areas.

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Biomedical HIV research is growing in West Africa, but biostatistical expertise is lagging. The Vanderbilt-Nigeria Biostatistics Training Program (VN-BioStat) seeks to establish a research and training platform for biostatisticians doing HIV-related research in Nigeria. The objectives of the program are: 1) Host two Nigerian data scientists per year (a total of 10 over 5 years) at Vanderbilt University Medical Center to gain hands-on biostatistics training and experience via one-year fellowships.

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Introduction: Routine patient care data are increasingly used for biomedical research, but such "secondary use" data have known limitations, including their quality. When leveraging routine care data for observational research, developing audit protocols that can maximize informational return and minimize costs is paramount.

Methods: For more than a decade, the Latin America and East Africa regions of the International epidemiology Databases to Evaluate AIDS (IeDEA) consortium have been auditing the observational data drawn from participating human immunodeficiency virus clinics.

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Validation studies are often used to obtain more reliable information in settings with error-prone data. Validated data on a subsample of subjects can be used together with error-prone data on all subjects to improve estimation. In practice, more than one round of data validation may be required, and direct application of standard approaches for combining validation data into analyses may lead to inefficient estimators since the information available from intermediate validation steps is only partially considered or even completely ignored.

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Introduction: Excessive maternal gestational weight gain (GWG) is strongly correlated with childhood obesity, yet how excess maternal weight gain and gestational diabetes mellitus (GDM) interact to affect early childhood obesity is poorly understood. The purpose of this study was to investigate whether overall and trimester-specific maternal GWG and GDM were associated with obesity in offspring by age 6 years.

Methods: A cohort of 10,335 maternal-child dyads was established from electronic health records.

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Objective: Our objective was to assess the prevalence and patterns of mobility among people with HIV (PWH) in Tennessee and its impact on HIV care outcomes.

Design: Retrospective cohort study.

Methods: We combined residential address and HIV surveillance data from PWH in Tennessee from 2016 to 2018.

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We propose an extension of Spearman's correlation for censored continuous and discrete data that permits covariate adjustment. Previously proposed nonparametric and semiparametric Spearman's correlation estimators require either nonparametric estimation of the bivariate survival surface or parametric assumptions about the dependence structure. In practice, nonparametric estimation of the bivariate survival surface is difficult, and parametric assumptions about the correlation structure may not be satisfied.

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In this observational study, we assessed the extent to which a community-created pilot intervention, providing trauma-informed care for persons with HIV (PWH), affected HIV care retention and viral suppression among PWH attending an HIV Services Organization in the Southern US. PWH with trauma exposure and/or trauma symptoms (N = 166) were offered a screening and referral to treatment (SBIRT) session. Per self-selection, 30 opted-out, 29 received SBIRT-Only, 25 received SBIRT-only but reported receiving other behavioral health care elsewhere, and 82 participated in the Safety and Stabilization (S&S) Intervention.

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Clustered data are common in biomedical research. Observations in the same cluster are often more similar to each other than to observations from other clusters. The intraclass correlation coefficient (ICC), first introduced by R.

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Continuous response data are regularly transformed to meet regression modeling assumptions. However, approaches taken to identify the appropriate transformation can be ad hoc and can increase model uncertainty. Further, the resulting transformations often vary across studies leading to difficulties with synthesizing and interpreting results.

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Background: Cryptococcal meningitis (CM) is a major cause of morbidity and mortality in persons with human immunodeficiency virus (HIV; PWH). Little is known about CM outcomes and availability of diagnostic and treatment modalities globally.

Methods: In this retrospective cohort study, we investigated CM incidence and all-cause mortality in PWH in the International Epidemiology Databases to Evaluate AIDS cohort from 1996 to 2017.

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Background: Updated World Health Organization (WHO) treatment guidelines prioritize all-oral drug-resistant tuberculosis (DR-TB) regimens. Several poorly tolerated drugs, such as amikacin and para-aminosalicylic acid (PAS), remain treatment options for DR-TB in WHO-recommended longer regimens as Group C drugs. Incomplete treatment with anti-TB drugs increases the risk of treatment failure, relapse, and death.

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Background: Racial inequities exist in retention in human immunodeficiency virus (HIV) care and multilevel analyses are needed to contextualize and address these differences. Leveraging data from a multisite clinical cohort of people with HIV (PWH), we assessed the relationships between patient race and residential characteristics with missed HIV care visits.

Methods: Medical record and patient-reported outcome (PRO; including mental health and substance-use measures) data were drawn from 7 participating Center for AIDS Research Network of Integrated Clinical Systems (CNICS) sites including N = 20 807 PWH from January 2010 through December 2015.

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Approximately 15% of people with HIV in sub-Saharan Africa have comorbid depression, which impacts treatment outcomes. We describe predictors of baseline depressive symptoms in 1079 female and 1079 male participants in a cluster-randomized trial in Zambézia Province, Mozambique from November 2017 to December 2020. We modeled each partners' depressive symptoms (Patient Health Questionnaire-9 [PHQ-9]) using proportional odds models adjusted for enrollment date, age, body mass index [BMI], partner's PHQ-9 score, district, relationship status, education, occupation, WHO HIV clinical stage, and antiretroviral therapy use history.

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