Publications by authors named "Bryan Blette"

Background/objective: Osteosarcoma treatment incorporates chemotherapy and surgery. Resection of the primary tumor usually occurs after induction chemotherapy. Occasionally, scheduling challenges and medical complications result in delay.

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Background: Data on long-term neurodevelopmental outcomes of normocephalic children (born with normal head circumference) exposed to Zika virus in utero are scarce. We aimed to compare neurodevelopmental outcomes in normocephalic children up to age 48 months with and without Zika virus exposure in utero.

Methods: In this prospective cohort study, we included infants from two cohorts of normocephalic children born in León and Managua, Nicaragua during the 2016 Zika epidemic.

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  • Estimands help clarify treatment effects in research, especially in cluster-randomised trials where additional factors must be defined.
  • The paper defines estimands using potential outcomes notation and examines the differences between them along with associated estimators and their assumptions.
  • A re-analysis of a published cluster-randomised trial illustrates that different estimands and estimators can significantly influence the interpretation of results and treatment effect estimates.
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Understanding whether and how treatment effects vary across subgroups is crucial to inform clinical practice and recommendations. Accordingly, the assessment of heterogeneous treatment effects based on pre-specified potential effect modifiers has become a common goal in modern randomized trials. However, when one or more potential effect modifiers are missing, complete-case analysis may lead to bias and under-coverage.

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Postpartum depression (PPD) affects nearly 20% of postpartum women in Sub-Saharan Africa (SSA), where HIV prevalence is high. Depression is associated with worse HIV outcomes in non-pregnant adults and mental health disorders may worsen HIV outcomes for postpartum women and their infants. PPD is effectively treated with psychosocial or pharmacologic interventions; however, few studies have evaluated the acceptability of treatment modalities in SSA.

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  • The study investigates how inaccuracies in patients' expectations of their health affect their quality of life, focusing on those with severe COPD over a 24-month period.
  • It found that many patients held overly optimistic views about their future symptoms, which led to a decline in their health-related quality of life within the first 3 months.
  • Despite a diverse group of 207 participants, there was no clear link between demographic factors and the accuracy of health expectations, suggesting that communication with healthcare providers may be inadequate.
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  • The COVE trial examined the effects of the mRNA-1273 vaccine by randomizing participants to receive either the vaccine or a placebo with key immune responses measured on Days 29 and 57.
  • Using new analytical approaches, the study found that varying the antibody levels post-vaccination correlated strongly with vaccine efficacy against COVID-19, estimating effectiveness between 84.2% and 97.6% based on antibody levels.
  • Findings indicated consistent results across several immune markers, reinforcing their role as reliable correlates of protection against the virus at both time points of analysis.
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Background: Recent work has shown that cluster-randomised trials can estimate two distinct estimands: the participant-average and cluster-average treatment effects. These can differ when participant outcomes or the treatment effect depends on the cluster size (termed informative cluster size). In this case, estimators that target one estimand (such as the analysis of unweighted cluster-level summaries, which targets the cluster-average effect) may be biased for the other.

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  • The study investigates whether short-term risk scores for pulmonary arterial hypertension (PAH) can predict long-term outcomes like clinical worsening and mortality in patients.
  • It uses data from three randomized clinical trials, analyzing risk assessments from various PAH risk score tools and their correlation with adverse clinical events.
  • Results indicated significant insights into the potential of these risk scores as surrogates for predicting long-term survival and health deterioration in PAH patients.
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The currently recommended dose of dexamethasone for patients with severe or critical COVID-19 is 6 mg per day (mg/d) regardless of patient features and variation. However, patients with severe or critical COVID-19 are heterogenous in many ways (e.g.

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Small trials and professional recommendations support mobilization interventions to improve recovery among critically ill patients, but their real-world effectiveness is unknown. To evaluate a low-cost, multifaceted mobilization intervention. We conducted a stepped-wedge cluster-randomized trial across 12 ICUs with diverse case mixes.

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BACKGROUND: Pediatric out-of-hospital cardiac arrest results in high morbidity and mortality. Currently, there are no recommended therapies beyond supportive care. The THAPCA-OH (Therapeutic Hypothermia after Pediatric Cardiac Arrest Out-of-Hospital) trial compared hypothermia (33.

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Introduction: Postpartum depression (PPD) is a prevalent and debilitating disease that may affect medication adherence and thus maternal health and vertical transmission among women with HIV. We assessed the feasibility of a trial of interpersonal psychotherapy (IPT) versus antidepressant medication (ADM) to treat PPD and/or anxiety among postpartum women with HIV in Lusaka, Zambia.

Methods: Between 29 October 2019 and 8 September 2020, we pre-screened women 6-8 weeks after delivery with the Edinburgh Postnatal Depression Scale (EPDS) and diagnosed PPD or anxiety with the Mini International Neuropsychiatric Interview.

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  • Norovirus and sapovirus significantly contribute to acute gastroenteritis in young children, prompting a study on their protective effects after initial infections.
  • A study conducted in León, Nicaragua with 444 newborns tracked gastroenteritis episodes over 36 months, using stool samples to identify the viruses present.
  • Findings indicated that prior infections with sapovirus or norovirus greatly reduced the risk of future episodes, suggesting potential benefits for developing vaccines targeting these viruses in children.
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The American Zika virus (ZIKV) epidemic has highlighted the need to gain a better understanding of this emerging virus. The goal of this study was to describe the clinical symptoms, laboratory findings, and risk factors for symptomatic ZIKV infection in an area with ongoing transmission of other arboviral infections. We recruited patients at least 2 years of age seeking care at public health centers in León, Nicaragua, between January 2016 and August 2017, for fever, maculopapular rash, and/or nonsuppurative conjunctivitis with a duration of less than 1 week.

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Background: Neurodevelopmental outcomes of asymptomatic children exposed to Zika virus (ZIKV) in utero are not well characterized.

Methods: We prospectively followed 129 newborns without evidence of congenital Zika syndrome (CZS) up to 24 months of age. Participants were classified as ZIKV exposed or ZIKV unexposed.

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Background: Sapovirus is increasingly recognized as an important cause of acute gastroenteritis (AGE) in children. We identified risk factors and characterized the clinical profile of sapovirus AGE in a birth cohort in León, Nicaragua.

Methods: We conducted a case-control study nested within a birth cohort (n = 444).

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Background: Zika virus caused thousands of congenital anomalies during a recent epidemic. Because Zika emerged in areas endemic for dengue and these related flaviviruses elicit cross-reactive antibodies, it is challenging to serologically monitor pregnant women for Zika infection.

Methods: A prospective cohort of 253 pregnant women was established in León, Nicaragua.

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While the HVTN 505 trial showed no overall efficacy of the tested vaccine to prevent HIV infection over placebo, markers measuring immune response to vaccination were strongly correlated with infection. This finding generated the hypothesis that some marker-defined vaccinated subgroups were partially protected whereas others had their risk increased. This hypothesis can be assessed using the principal stratification framework (Frangakis and Rubin, 2002) for studying treatment effect modification by an intermediate response variable, using methods in the sub-field of principal surrogate (PS) analysis that studies multiple principal strata.

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HVTN 505 is a preventative vaccine efficacy trial testing DNA followed by recombinant adenovirus serotype 5 (rAd5) in circumcised, Ad5-seronegative men and transgendered persons who have sex with men in the United States. Identified immune correlates of lower HIV-1 risk and a virus sieve analysis revealed that, despite lacking overall efficacy, vaccine-elicited responses exerted pressure on infecting HIV-1 viruses. To interrogate the mechanism of the antibody correlate of HIV-1 risk, we examined antigen-specific antibody recruitment of Fcγ receptors (FcγRs), antibody-dependent cellular phagocytosis (ADCP), and the role of anti-envelope (anti-Env) IgG3.

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Introduction: High school physical activity and nutrition policies can substantially affect student behavior and outcomes. Although public health officials and legislators have advocated for policy improvements, the extent to which policies have changed at local levels is not well understood. This study identifies latent classes of physical activity and nutrition policy environments and explores changes in prevalence of these classes from 2000 to 2016.

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Background: Streptococcus pneumoniae causes about 826,000 deaths of children in the world each year and many health facility visits. To reduce the burden of pneumococcal disease, many nations have added pneumococcal conjugate vaccines to their national immunization schedules. Nicaragua was the first country eligible for GAVI Alliance funding to introduce the 13-valent pneumococcal conjugate vaccine (PCV13) in 2010, provided to infants at 2, 4, and 6 months of age.

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