A5084451114- Advanced Causal Inference Techniques
- Statistical Methods and Inference
- Statistical Methods and Bayesian Inference
- Health Systems, Economic Evaluations, Quality of Life
- Statistical Methods in Clinical Trials
- Acute Ischemic Stroke Management
- Long-Term Effects of COVID-19
- COVID-19 Clinical Research Studies
- Opioid Use Disorder Treatment
- Cerebrovascular and Carotid Artery Diseases
- Atrial Fibrillation Management and Outcomes
- Healthcare Policy and Management
- Urban, Neighborhood, and Segregation Studies
- Intracerebral and Subarachnoid Hemorrhage Research
- Heart Failure Treatment and Management
- Neurosurgical Procedures and Complications
- Substance Abuse Treatment and Outcomes
- Traumatic Brain Injury and Neurovascular Disturbances
- Sepsis Diagnosis and Treatment
- Cardiovascular Function and Risk Factors
- Respiratory Support and Mechanisms
- COVID-19 and healthcare impacts
- Bayesian Methods and Mixture Models
- Intracranial Aneurysms: Treatment and Complications
- Cardiac Imaging and Diagnostics
New York University
2022-2025
University of Bern
2023-2024
University Hospital of Bern
2023-2024
Cornell University
2015-2023
Weill Cornell Medicine
2015-2023
National Oncologic Institute
2022-2023
Stroke Association
2021-2023
Columbia University
2018-2022
University of Arizona
2022
Faculty of Public Health
2022
<h3>Importance</h3> It is uncertain whether coronavirus disease 2019 (COVID-19) associated with a higher risk of ischemic stroke than would be expected from viral respiratory infection. <h3>Objective</h3> To compare the rate between patients COVID-19 and influenza, illness previously stroke. <h3>Design, Setting, Participants</h3> This retrospective cohort study was conducted at 2 academic hospitals in New York City, York, included adult emergency department visits or hospitalizations March...
Patients with ischemic stroke attributed to large- or small-vessel disease are not considered at high risk for atrial fibrillation (AF), and the AF incidence rate in this population is unknown.To determine whether long-term cardiac monitoring more effective than usual care detection patients through 12 months of follow-up.The STROKE-AF trial was a randomized (1:1), multicenter (33 sites US) clinical that enrolled 496 between April 2016 July 2019, primary end point follow-up August 2020....
Background: Despite potential harm that can result from polypharmacy, real-world data on polypharmacy in the setting of heart failure (HF) are limited. We sought to address this knowledge gap by studying older adults hospitalized for HF derived REGARDS study (Reasons Geographic and Racial Differences Stroke). Methods: examined 558 aged ≥65 years with adjudicated hospitalizations 380 hospitals across United States. collected baseline assessment, medical charts HF-adjudicated hospitalizations,...
We describe semiparametric estimation and inference for causal effects using observational data from a single social network. Our asymptotic results are the first to allow dependence of each observation on growing number other units as sample size increases. In addition, while previous methods have implicitly permitted only one two possible sources among network observations, we both due transmission information across ties latent similarities nodes sharing ties. propose new that...
Objective To determine whether cerebrovascular risk factors are associated with subsequent diagnoses of Parkinson disease, and these associations similar in magnitude to those Alzheimer disease. Methods This was a retrospective cohort study using claims data from 5% random sample Medicare beneficiaries 2008 2015. The exposures were stroke, atrial fibrillation, coronary hyperlipidemia, hypertension, sleep apnea, diabetes mellitus, heart failure, peripheral vascular chronic kidney obstructive...
Most causal inference methods consider counterfactual variables under interventions that set the exposure to a fixed value. With continuous or multi-valued treatments exposures, such counterfactuals may be of little practical interest because no feasible intervention can implemented would bring them about. Longitudinal modified treatment policies (LMTPs) are recently developed nonparametric alternative yield effects immediate relevance with an interpretation in terms meaningful as reducing...
Mechanical thrombectomy helps prevent disability in patients with acute ischemic stroke involving occlusion of a large cerebral vessel. Thrombectomy requires procedural expertise and not all hospitals have the staff to perform this intervention. Few population-wide data exist regarding access mechanical thrombectomy.We examined for using discharge from calendar years 2016 2018 nonfederal emergency departments care across 11 US states encompassing 80 million residents. Facilities were...
Summary In recent decades, the fields of statistical and machine learning have seen a revolution in development data-adaptive regression methods that optimal performance under flexible, sometimes minimal, assumptions on true functions. These developments impacted all areas applied theoretical statistics allowed data analysts to avoid biases incurred pervasive practice parametric model misspecification. this commentary, I discuss issues around use estimation causal inference parameters. To...
Background and Purpose— The risk of arterial ischemic events after intracerebral hemorrhage (ICH) is poorly understood given the lack a control group in prior studies. This study aimed to evaluate acute stroke myocardial infarction (MI) among patients with without ICH. Methods— We performed retrospective cohort using claims data from Medicare beneficiaries 2008 2014. Our exposure was ICH, identified validated International Classification Diseases, Ninth Revision, Clinical Modification...
Time is of the essence in evaluating potential drugs and biologics for treatment prevention COVID-19. There are currently 876 randomized clinical trials (phase 2 3) treatments COVID-19 registered on clinicaltrials.gov. Covariate adjustment a statistical analysis method with to improve precision reduce required sample size substantial number these trials. Though covariate recommended by U.S. Food Drug Administration European Medicines Agency, it underutilized, especially types outcomes...
<h3>Importance</h3> Intracerebral hemorrhage and arterial ischemic disease share risk factors, to our knowledge, but the association between 2 conditions remains unknown. <h3>Objective</h3> To evaluate whether intracerebral was associated with an increased of incident stroke myocardial infarction. <h3>Design, Setting, Participants</h3> An analysis conducted pooled longitudinal participant-level data from 4 population-based cohort studies in United States: Atherosclerosis Risk Communities...
Abstract Mediation analysis is appealing for its ability to improve understanding of the mechanistic drivers causal effects, but real-world data complexities challenge successful implementation, including (i) existence post-exposure variables that also affect mediators and outcomes (thus, confounding mediator-outcome relationship), may be (ii) multivariate, (iii) multivariate mediators. All three challenges are present in mediation we consider here, where our goal estimate indirect effects...
Summary For a continuous treatment, the generalised propensity score (GPS) is defined as conditional density of given covariates. GPS adjustment may be implemented by including it covariate in an outcome regression. Here, unbiased estimation dose–response function assumes correct specification both and outcome‐treatment relationship. This paper introduces machine learning method, ‘Super Learner’, to address model selection this context. In two‐stage approach proposed, Super Learner selects...
Background and Purpose— Carotid artery plaque with <50% luminal stenosis may be an underappreciated stroke mechanism. We assessed how many causes might reclassified after accounting for nonstenosing plaques high-risk features. Methods— included patients enrolled in the Cornell Acute Stroke Academic Registry from 2011 to 2015 who had anterior circulation infarction, magnetic resonance imaging of brain, angiography neck. High-risk was identified by intraplaque hemorrhage ascertained routine...
Background and Purpose: One-fifth of ischemic strokes are embolic undetermined source (ESUS). Their theoretical causes can be classified as cardioembolic versus noncardioembolic. This distinction has important implications, but the categories’ proportions unknown. Methods: Using data from Cornell Acute Stroke Academic Registry, we trained a machine-learning algorithm to distinguish non-cardioembolic strokes, then applied ESUS cases determine predicted proportion with an occult source. A...
Summary Interventional effects for mediation analysis were proposed as a solution to the lack of identifiability natural (in)direct in presence mediator-outcome confounder affected by exposure. We present theoretical and computational study properties interventional effect estimands based on efficient influence function nonparametric statistical model. use develop two asymptotically optimal estimators that leverage data-adaptive regression estimation nuisance parameters: one-step estimator...
Importance: Case series without control groups suggest that Covid-19 may cause ischemic stroke, but whether is associated with a higher risk of stroke than would be expected from viral respiratory infection uncertain. Objective: To compare the rate between patients and influenza, illness previously linked to stroke. Design: A retrospective cohort study. Setting: Two academic hospitals in New York City. Participants: We included adult emergency department visits or hospitalizations March 4,...
Violations of the positivity assumption (also called common support condition) challenge health policy research and can result in significant bias, large variance, invalid inference. We define single- multiple-timepoint (i.e., longitudinal) evaluation setting, discuss real-world threats to positivity. show empirical evidence practical violations that when attempting estimate effects policies (in this case, Naloxone Access Laws). In such scenarios, an alternative is effect a shift law...
The STROKE AF study found that in patients with prior ischemic stroke attributed to large-artery atherosclerotic disease (LAD) or small-vessel occlusive (SVD), 12% developed over 1 year when monitored an insertable cardiac monitor (ICM). occurrence subsequent years is unknown.
This tutorial discusses a methodology for causal inference using longitudinal modified treatment policies. method facilitates the mathematical formalization, identification, and estimation of many novel parameters mathematically generalizes commonly used parameters, such as average effect. Longitudinal policies apply to wide variety exposures, including binary, multivariate, continuous, can accommodate time-varying treatments confounders, competing risks, loss follow-up, well survival, or...
Importance The profile of gastrointestinal (GI) tract outcomes associated with the postacute and chronic phases COVID-19 in children adolescents remains unclear. Objective To investigate risks GI symptoms disorders during (28-179 days after documented SARS-CoV-2 infection) (180-729 pediatric population. Design, Setting, Participants This retrospective cohort study was performed from March 1, 2020, to September 2023, at 29 US health care institutions. included patients 18 years or younger...
ABSTRACT Platform trials are multi‐arm designs that simultaneously evaluate multiple treatments for a single disease within the same overall trial structure. Unlike traditional randomized controlled trials, they allow treatment arms to enter and exit at distinct times while maintaining control arm throughout. This comprises both concurrent controls, where participants concurrently either or arm, non‐concurrent who when under study is unavailable. While flexible, platform introduce challenge...
Cortical thickness measurements from magnetic resonance imaging, an important biomarker in many neurodegenerative and neurological disorders, are derived by tools initial voxel-wise tissue segmentation. White matter (WM) hypointensities T1-weighted such as those arising multiple sclerosis or small vessel disease, known to affect the output of brain segmentation methods therefore bias cortical measurements. These effects well-documented among traditional but have not been studied extensively...