Publications by authors named "Emily Voldal"

Stepped wedge trials (SWTs) are a type of cluster randomized trial that involve repeated measures on clusters and design-induced confounding between time and treatment. Although mixed models are commonly used to analyze SWTs, they are susceptible to misspecification particularly for cluster-longitudinal designs such as SWTs. Mixed model estimation leverages both "horizontal" or within-cluster information and "vertical" or between-cluster information.

View Article and Find Full Text PDF
Article Synopsis
  • - The study aimed to explore how placental abnormalities affect the neurodevelopmental outcomes in newborns with hypoxic-ischemic encephalopathy (HIE) who received therapeutic hypothermia, hypothesizing that acute placental issues would lower risks of death or developmental impairments by age 2.
  • - Out of 500 newborns with severe HIE, 321 had their placental pathology examined, revealing various types of abnormalities; however, the risk of negative outcomes between those with and without acute placental issues did not show a significant difference.
  • - The conclusion indicates that while placental abnormalities did not show a clear link to death or neurodevelopmental impairment in HIE cases, the potential connection between multiple chronic
View Article and Find Full Text PDF

Importance: The ability to predict neurodevelopmental impairment (NDI) for infants diagnosed with hypoxic ischemic encephalopathy (HIE) is important for parental guidance and clinical treatment as well as for stratification of patients for future neurotherapeutic studies.

Objectives: To examine the effect of erythropoietin on plasma inflammatory mediators in infants with moderate or severe HIE and to develop a panel of circulating biomarkers that improves the projection of 2-year NDI over and above the clinical data available at the time of birth.

Design, Setting, And Participants: This study is a preplanned secondary analysis of prospectively collected data from infants enrolled in the High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, which tested the efficacy of erythropoietin as an adjunctive neuroprotective therapy to therapeutic hypothermia.

View Article and Find Full Text PDF

Importance: Spanish-speaking participants are underrepresented in clinical trials, limiting study generalizability and contributing to ongoing health inequity. The Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial intentionally included Spanish-speaking participants.

Objective: To describe trial participation and compare clinical and patient-reported outcomes among Spanish-speaking and English-speaking participants with acute appendicitis randomized to antibiotics.

View Article and Find Full Text PDF

Importance: A patient's belief in the likely success of a treatment may influence outcomes, but this has been understudied in surgical trials.

Objective: To examine the association between patients' baseline beliefs about the likelihood of treatment success with outcomes of antibiotics for appendicitis in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial.

Design, Setting, And Participants: This was a secondary analysis of the CODA randomized clinical trial.

View Article and Find Full Text PDF

Objective: To compare secondary patient reported outcomes of perceptions of treatment success and function for patients treated for appendicitis with appendectomy vs. antibiotics at 30 days.

Summary Background Data: The Comparison of Outcomes of antibiotic Drugs and Appendectomy trial found antibiotics noninferior to appendectomy based on 30-day health status.

View Article and Find Full Text PDF
Article Synopsis
  • The CODA trial found that outpatient management of acute appendicitis using antibiotics is a safe and effective alternative to immediate surgery, with about 50% of participants discharged within 24 hours.
  • The cohort study analyzed data from 776 adults with imaging-confirmed appendicitis who received antibiotics and assessed the safety and outcomes of outpatient versus inpatient care.
  • Results indicated that most treated participants managed their appendicitis without needing surgery, and outpatient management could reduce hospital visits, increase convenience, and lower healthcare costs.
View Article and Find Full Text PDF

Stepped wedge cluster randomized controlled trials are typically analyzed using models that assume the full effect of the treatment is achieved instantaneously. We provide an analytical framework for scenarios in which the treatment effect varies as a function of exposure time (time since the start of treatment) and define the "effect curve" as the magnitude of the treatment effect on the linear predictor scale as a function of exposure time. The "time-averaged treatment effect" (TATE) and "long-term treatment effect" (LTE) are summaries of this curve.

View Article and Find Full Text PDF

Importance: For adults with appendicitis, several randomized clinical trials have demonstrated that antibiotics are an effective alternative to appendectomy. However, it remains unknown how the characteristics of patients in such trials compare with those of patients who select their treatment and whether outcomes differ.

Objective: To compare participants in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) randomized clinical trial (RCT) with a parallel cohort study of participants who declined randomization and self-selected treatment.

View Article and Find Full Text PDF

Stepped wedge cluster randomized trials are often analysed using linear mixed effects models that may include random effects for cluster, time and/or treatment. We investigate the impact of misspecification of the random effects structure of the model. Specifically, we considered two cases of misspecification of the random effects in a cross-sectional stepped wedge cluster randomized trials model - fit a linear mixed effects model with random time effects but the true model includes random treatment effects (case 1) or fit a linear mixed effects model with random treatment effect but the true model includes random time effects (case 2) - and derived the variance of the estimated treatment effect under misspecification.

View Article and Find Full Text PDF

Mixed models are commonly used to analyze stepped wedge trials (SWTs) to account for clustering and repeated measures on clusters. One critical issue researchers face is whether to include a random time effect or a random treatment effect. When the wrong model is chosen, inference on the treatment effect may be invalid.

View Article and Find Full Text PDF

Importance: Use of antibiotics for the treatment of appendicitis is safe and has been found to be noninferior to appendectomy based on self-reported health status at 30 days. Identifying patient characteristics associated with a greater likelihood of appendectomy within 30 days in those who initiate antibiotics could support more individualized decision-making.

Objective: To assess patient factors associated with undergoing appendectomy within 30 days of initiating antibiotics for appendicitis.

View Article and Find Full Text PDF

Background: Stepped-wedge designs (SWD) are increasingly used to evaluate the impact of changes to the process of care within health care systems. However, to generate definitive evidence, a correct sample size calculation is crucial to ensure such studies are properly powered. The seminal work of Hussey and Hughes (Contemp Clin Trials 28(2):182-91, 2004) provides an analytical formula for power calculations with normal outcomes using a linear model and simple random effects.

View Article and Find Full Text PDF

Background And Objective: Stepped wedge trials (SWTs) are a type of cluster-randomized trial that are commonly used to evaluate health care interventions. Most SWT-related software packages have restrictive assumptions about the study design and correlation structure of the data. The objective of this paper is to present a package and corresponding web-based graphical user interface (GUI) that provide researchers with another, more flexible option for SWT design and analysis.

View Article and Find Full Text PDF