About

Gary Chan is a professor in the Department of Biostatistics and the Department of Health Systems and Population Health at the University of Washington. He also holds the position of Adjunct Professor in the Department of Statistics and serves as the Associate Director of the National Alzheimer's Coordinating Center. His research interests include statistical methods for complex designs, interventions, and outcomes, with a focus on nonparametric and semiparametric statistics. His work aims to develop and apply advanced statistical techniques to address challenges in health research, particularly in the context of population health and neurological conditions.

Research topics

• Internal medicine
• Artificial Intelligence
• Surgery
• Medicine
• Computer Science
• Algorithm
• Mathematics
• Statistics
• Mathematical optimization

Selected publications

• Promoting mental health in Latina immigrant women: Results from the Amigas Latinas Motivando el Alma intervention trial

  Social Science & Medicine · 2023 · 19 citations

  • Sociology
  • Gerontology
  • Medicine
  PublisherOA PDFDOI

• <strong>Evaluation of the effectiveness of remote foot temperature monitoring for prevention of amputation in a large integrated healthcare system</strong>

  2023

  • Medicine
  • Internal medicine
  • Surgery

  <p> </p> <p><u>Introduction:</u> We evaluated the effectiveness of remote foot temperature monitoring (RTM) in the Veterans Affairs healthcare system. </p> <p><u>Research Design and Methods:</u> We conducted a retrospective cohort study that included 924 eligible patients enrolled in RTM between 2019 and 2021 who were matched up to 3:1 to 2757 non-enrolled comparison patients. We used conditional Cox regression to estimate adjusted cause-specific hazard ratios (HR) and corresponding 95% confidence intervals (CI) for lower extremity amputation (LEA, primary outcome) and all-cause hospitalization and death (secondary outcomes). </p> <p><u>Results</u>: RTM was not associated with LEA incidence (adjusted HR= 0.92, 95% CI 0.62-1.37) or all-cause hospitalization (aHR = 0.97, 95% CI 0.82-1.14), but was inversely associated (reduced risk) with death (aHR=0.63, 95% CI 0.49-0.82). </p> <p><u>Conclusions</u>: This study does not provide support that RTM reduces the risk of LEA or all-cause hospitalization in individuals with a history of diabetic foot ulcer. Randomized controlled trials can overcome important limitations.</p>

  PublisherOA PDFDOI

• <strong>Evaluation of the effectiveness of remote foot temperature monitoring for prevention of amputation in a large integrated healthcare system</strong>

  2023

  • Medicine
  • Internal medicine
  • Surgery

  <p> </p> <p><u>Introduction:</u> We evaluated the effectiveness of remote foot temperature monitoring (RTM) in the Veterans Affairs healthcare system. </p> <p><u>Research Design and Methods:</u> We conducted a retrospective cohort study that included 924 eligible patients enrolled in RTM between 2019 and 2021 who were matched up to 3:1 to 2757 non-enrolled comparison patients. We used conditional Cox regression to estimate adjusted cause-specific hazard ratios (HR) and corresponding 95% confidence intervals (CI) for lower extremity amputation (LEA, primary outcome) and all-cause hospitalization and death (secondary outcomes). </p> <p><u>Results</u>: RTM was not associated with LEA incidence (adjusted HR= 0.92, 95% CI 0.62-1.37) or all-cause hospitalization (aHR = 0.97, 95% CI 0.82-1.14), but was inversely associated (reduced risk) with death (aHR=0.63, 95% CI 0.49-0.82). </p> <p><u>Conclusions</u>: This study does not provide support that RTM reduces the risk of LEA or all-cause hospitalization in individuals with a history of diabetic foot ulcer. Randomized controlled trials can overcome important limitations.</p>

  PublisherDOI

• Limbic-Predominant Age-Related TDP-43 Encephalopathy

  Neurology · 2022 · 44 citations

  • Psychology
  • Medicine
  • Internal medicine

  BACKGROUND AND OBJECTIVES: Limbic-predominant age-related Tar DNA binding protein 43 (TDP-43) encephalopathy neuropathologic change (LATE-NC) is present in ≈25% of older persons' brains and is strongly associated with cognitive impairment. Hippocampal sclerosis (HS) pathology is often comorbid with LATE-NC, but the clinical and pathologic correlates of HS in LATE-NC are not well understood. METHODS: < 0.05 in this exploratory study. RESULTS: < 0.001). LATE-NC+ brains with HS also tended to have more severe circle of Willis atherosclerosis and arteriolosclerosis pathologies. DISCUSSION: In this cohort skewed toward participants with severe dementia, LATE-NC+ HS pathology was not associated with seizures or with Alzheimer-type pathologies. Rather, the presence of comorbid HS pathology was associated with more widespread TDP-43 proteinopathy and with more severe non-β-amyloid vessel wall pathologies.

  DOI

• A unified Bayesian framework for exact inference of area under the receiver operating characteristic curve

  Statistical Methods in Medical Research · 2021 · 13 citations

  • Computer Science
  • Artificial Intelligence
  • Computer Science

  The area under the receiver operating characteristic curve is a widely used measure for evaluating the performance of a diagnostic test. Common approaches for inference on area under the receiver operating characteristic curve are usually based upon approximation. For example, the normal approximation based inference tends to suffer from the problem of low accuracy for small sample size. Frequentist empirical likelihood based approaches for area under the receiver operating characteristic curve estimation may perform better, but are usually conducted through approximation in order to reduce the computational burden, thus the inference is not exact. By contrast, we proposed an exact inferential procedure by adapting the empirical likelihood into a Bayesian framework and draw inference from the posterior samples of the area under the receiver operating characteristic curve obtained via a Gibbs sampler. The full conditional distributions within the Gibbs sampler only involve empirical likelihoods with linear constraints, which greatly simplify the computation. To further enhance the applicability and flexibility of the Bayesian empirical likelihood, we extend our method to the estimation of partial area under the receiver operating characteristic curve, comparison of multiple tests, and the doubly robust estimation of area under the receiver operating characteristic curve in the presence of missing test results. Simulation studies confirm the desirable performance of the proposed methods, and a real application is presented to illustrate its usefulness.

  DOI

• Stress, social support and their relationship to depression and anxiety among Latina immigrant women

  Journal of Psychosomatic Research · 2021 · 52 citations

  • Clinical psychology
  • Psychology
  • Medicine
  DOI

• Harmonizing neuropsychological assessment for mild neurocognitive disorders in Europe

  Alzheimer s & Dementia · 2021 · 61 citations

  • Political Science
  • Psychology
  • Clinical psychology

  INTRODUCTION: Harmonized neuropsychological assessment for neurocognitive disorders, an international priority for valid and reliable diagnostic procedures, has been achieved only in specific countries or research contexts. METHODS: To harmonize the assessment of mild cognitive impairment in Europe, a workshop (Geneva, May 2018) convened stakeholders, methodologists, academic, and non-academic clinicians and experts from European, US, and Australian harmonization initiatives. RESULTS: With formal presentations and thematic working-groups we defined a standard battery consistent with the U.S. Uniform DataSet, version 3, and homogeneous methodology to obtain consistent normative data across tests and languages. Adaptations consist of including two tests specific to typical Alzheimer's disease and behavioral variant frontotemporal dementia. The methodology for harmonized normative data includes consensus definition of cognitively normal controls, classification of confounding factors (age, sex, and education), and calculation of minimum sample sizes. DISCUSSION: This expert consensus allows harmonizing the diagnosis of neurocognitive disorders across European countries and possibly beyond.

  DOI

• Differentiating among stages of cognitive impairment in aging: Version 3 of the Uniform Data Set (UDS) neuropsychological test battery and MoCA index scores

  Alzheimer s & Dementia Translational Research & Clinical Interventions · 2020 · 51 citations

  • Psychology
  • Audiology
  • Gerontology

  INTRODUCTION: Federally funded Alzheimer's Disease Centers in the United States have been using a standardized neuropsychological test battery as part of the National Alzheimer's Coordinating Center Uniform Data Set (UDS) since 2005. Version 3 (V3) of the UDS replaced the previous version (V2) in 2015. We compared V2 and V3 neuropsychological tests with respect to their ability to distinguish among the Clinical Dementia Rating (CDR) global scores of 0, 0.5, and 1. METHODS: First, we matched participants receiving V2 tests (V2 cohort) and V3 tests (V3 cohort) in their cognitive functions using tests common to both versions. Then, we compared receiver-operating characteristic (ROC) area under the curve in differentiating CDRs for the remaining tests. RESULTS: Some V3 tests performed better than V2 tests in differentiating between CDR 0.5 and 0, but the improvement was limited to Caucasian participants. DISCUSSION: Further efforts to improve the ability for early identification of cognitive decline among diverse racial groups are required.

  DOI

Frequent coauthors

• Alyson J. Littman

  Health Services Research & Development

  3 shared

• Suhail Masadeh

  University of Cincinnati Medical Center

  2 shared

• Anna Korpak

  VA Puget Sound Health Care System

  2 shared

• Suzanne Shirley

  2 shared

• Kenneth T. Jones

  United States Department of Veterans Affairs

  2 shared

• Andrew Timmons

  VA Puget Sound Health Care System

  2 shared

• Ernest Moy

  Veterans Health Administration

  2 shared

• Haolun Shi

  Simon Fraser University

  2 shared

Awards & honors

• UW Biostatistics faculty and alumni named ASA fellows (2020)
• Gary Chan to serve as WNAR president-elect for 2021 (2020)

Similar researchers at University of Washington

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