Bio
Residency:Stanford University, Internal Medicine
Medical Education: Baylor College of Medicine, Houston, TX
Undergraduate: Stanford University, BS in Biology with Distinction
Clinical Focus
- Internal Medicine
- Hospitalist medicine
Academic Appointments
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Clinical Assistant Professor, Medicine
Administrative Appointments
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Director, Stanford Health Care Tri-Valley Medical Director of Education (2018 - Present)
Boards, Advisory Committees, Professional Organizations
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Member, Alpha Omega Alpha Honor Medical Society (2014 - Present)
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Member, Society of Hospital Medicine (2018 - Present)
Professional Education
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Medical Education: Baylor College of Medicine (2014) TX
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Residency: Stanford University Internal Medicine Residency (2017) CA
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Board Certification: American Board of Internal Medicine, Internal Medicine (2017)
Current Research and Scholarly Interests
Quality improvement, palliative care
All Publications
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Long COVID After Acquisition of the Omicron Variant of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) During Pregnancy Compared With Outside of Pregnancy.
Obstetrics and gynecology
2025
Abstract
To evaluate whether the risk of long COVID among individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy differs from that of individuals who were not pregnant at time of virus acquisition.We conducted a multicenter observational cohort study at 79 NIH RECOVER (Researching COVID to Enhance Recovery) sites. Individuals assigned female at birth aged 18-45 years with an index (first) SARS-CoV-2 infection on or after December 1, 2021, were included. The exposure was pregnancy (any gestational age) at the time of index SARS-CoV-2 infection. The primary outcome was long COVID 6 months after index infection, defined as RECOVER-Adult Long COVID Research Index score 11 or higher based on a detailed symptom survey. To account for confounding and differential selection between participants who were pregnant and not pregnant at infection, propensity score-matching methods were used to balance the groups on variables potentially associated with both pregnancy status and long COVID.Overall 2,423 participants were included; 580 (23.9%) were pregnant at index SARS-CoV-2 infection. The median age at infection was 33 years (interquartile range 28-38 years), and 2,131 of participants (90.0%) with known vaccination status were vaccinated. After propensity score matching, the adjusted long COVID prevalence estimates 6 months after index infection were 10.2% (95% CI, 6.2-14.3%) among those pregnant at infection and 10.6% (95% CI, 8.8-12.4%) among those not pregnant at infection. Pregnancy was not associated with a difference in adjusted risk of long COVID (adjusted risk ratio 0.96, 95% CI, 0.63-1.48).Acquisition of SARS-CoV-2 during pregnancy was not associated with a differential risk of long COVID at 6 months compared with similar-aged individuals who acquired SARS-CoV-2 outside of pregnancy.
View details for DOI 10.1097/AOG.0000000000006067
View details for PubMedID 41037811
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Olfactory Dysfunction After SARS-CoV-2 Infection in the RECOVER Adult Cohort.
JAMA network open
2025; 8 (9): e2533815
Abstract
Olfactory dysfunction is common after SARS-CoV-2 infection and has been associated with cognitive loss in other conditions. Formal testing is needed to characterize the presence, severity, and patterns of olfactory dysfunction.To characterize long-term olfactory dysfunction after SARS-CoV-2 infection.This prospective cohort study included adults enrolled in the Researching COVID to Enhance Recovery (RECOVER)-Adult study. All those with and a random sample of those without self-reported change or loss in smell or taste were offered olfactory testing, performed at 83 sites in 35 US states and territories. Participants included 2956 enrollees with prior infection (1393 with and 1563 without self-reported change or loss) and 569 without prior infection (9 with and 560 without self-reported change or loss in taste) who underwent olfactory testing a mean (SD) of 671.6 (417.8) days after the index date. Data were collected from October 29, 2021, to June 6, 2025.SARS-CoV-2 infection.Olfactory function, as defined by age- and sex-standardized performance on the University of Pennsylvania Smell Identification Test (UPSIT), a well-validated test comprising 40 unique odors.The study included 3525 participants with a mean (SD) age of 47.6 (15.2) years; of 3520 with data available, 2548 (72.4%) were female or intersex. Among 1393 infected participants with self-reported change or loss, 1111 (79.8%) had hyposmia on the UPSIT, including 321 (23.0%) with severe microsmia or anosmia. Among 1563 infected participants without self-reported change or loss, 1031 (66.0%) had hyposmia, including 128 (8.2%) with severe microsmia or anosmia. Participants with prior infection and self-reported change or loss scored at the 16th age- and sex-standardized UPSIT percentile, compared with the 23rd and 28th percentiles for those without self-reported change or loss with and without prior known infection, respectively. Younger women had scores corresponding to lower mean age- and sex-standardized percentiles. Among participants who self-reported change or loss in smell, those with abnormal UPSIT scores more often reported cognitive problems (742 of 1111 [66.8%]) than those with normal UPSIT scores (179 of 282 [63.5%]).In this cohort study of RECOVER-Adult participants, self-reported change or loss in smell or taste was an accurate signal of verified hyposmia, but a high rate of hyposmia among those with no reported change or loss was also observed. Formal smell testing may be considered in those with prior SARS-CoV-2 infection to diagnose occult hyposmia and counsel patients about risks.
View details for DOI 10.1001/jamanetworkopen.2025.33815
View details for PubMedID 40996759
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2024 Update of the RECOVER-Adult Long COVID Research Index
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
2024
Abstract
Classification of persons with long COVID (LC) or post-COVID-19 condition must encompass the complexity and heterogeneity of the condition. Iterative refinement of the classification index for research is needed to incorporate newly available data as the field rapidly evolves.To update the 2023 research index for adults with LC using additional participant data from the Researching COVID to Enhance Recovery (RECOVER-Adult) study and an expanded symptom list based on input from patient communities.Prospective, observational cohort study including adults 18 years or older with or without known prior SARS-CoV-2 infection who were enrolled at 83 sites in the US and Puerto Rico. Included participants had at least 1 study visit taking place 4.5 months after first SARS-CoV-2 infection or later, and not within 30 days of a reinfection. The study visits took place between October 2021 and March 2024.SARS-CoV-2 infection.Presence of LC and participant-reported symptoms.A total of 13 647 participants (11 743 with known SARS-CoV-2 infection and 1904 without known prior SARS-CoV-2 infection; median age, 45 years [IQR, 34-69 years]; and 73% were female) were included. Using the least absolute shrinkage and selection operator analysis regression approach from the 2023 model, symptoms contributing to the updated 2024 index included postexertional malaise, fatigue, brain fog, dizziness, palpitations, change in smell or taste, thirst, chronic cough, chest pain, shortness of breath, and sleep apnea. For the 2024 LC research index, the optimal threshold to identify participants with highly symptomatic LC was a score of 11 or greater. The 2024 index classified 20% of participants with known prior SARS-CoV-2 infection and 4% of those without known prior SARS-CoV-2 infection as having likely LC (vs 21% and 5%, respectively, using the 2023 index) and 39% of participants with known prior SARS-CoV-2 infection as having possible LC, which is a new category for the 2024 model. Cluster analysis identified 5 LC subtypes that tracked quality-of-life measures.The 2024 LC research index for adults builds on the 2023 index with additional data and symptoms to help researchers classify symptomatic LC and its symptom subtypes. Continued future refinement of the index will be needed as the understanding of LC evolves.
View details for DOI 10.1001/jama.2024.11370
View details for Web of Science ID 001381236900001
View details for PubMedID 39693079
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Management of eosinophilic esophagitis in pediatric patients undergoing oral immunotherapy for food allergies: A two-center case series.
The journal of allergy and clinical immunology. In practice
2024
View details for DOI 10.1016/j.jaip.2024.11.016
View details for PubMedID 39615749
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Post-Acute Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) After Infection During Pregnancy.
Obstetrics and gynecology
2024
Abstract
To estimate the prevalence of post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) after infection with SARS-CoV-2 during pregnancy and to characterize associated risk factors.In a multicenter cohort study (NIH RECOVER [Researching COVID to Enhance Recovery]-Pregnancy Cohort), individuals who were pregnant during their first SARS-CoV-2 infection were enrolled across the United States from December 2021 to September 2023, either within 30 days of their infection or at differential time points thereafter. The primary outcome was PASC, defined as score of 12 or higher based on symptoms and severity as previously published by the NIH RECOVER-Adult Cohort, at the first study visit at least 6 months after the participant's first SARS-CoV-2 infection. Risk factors for PASC were evaluated, including sociodemographic characteristics, clinical characteristics before SARS-CoV-2 infection (baseline comorbidities, trimester of infection, vaccination status), and acute infection severity (classified by need for oxygen therapy). Multivariable logistic regression models were fitted to estimate associations between these characteristics and presence of PASC.Of the 1,502 participants, 61.1% had their first SARS-CoV-2 infection on or after December 1, 2021 (ie, during Omicron variant dominance); 51.4% were fully vaccinated before infection; and 182 (12.1%) were enrolled within 30 days of their acute infection. The prevalence of PASC was 9.3% (95% CI, 7.9-10.9%) measured at a median of 10.3 months (interquartile range 6.1-21.5) after first infection. The most common symptoms among individuals with PASC were postexertional malaise (77.7%), fatigue (76.3%), and gastrointestinal symptoms (61.2%). In a multivariable model, the proportion PASC positive with vs without history of obesity (14.9% vs 7.5%, adjusted odds ratio [aOR] 1.65, 95% CI, 1.12-2.43), depression or anxiety disorder (14.4% vs 6.1%, aOR 2.64, 95% CI, 1.79-3.88) before first infection, economic hardship (self-reported difficulty covering expenses) (12.5% vs 6.9%, aOR 1.57, 95% CI, 1.05-2.34), and treatment with oxygen during acute SARS-CoV-2 infection (18.1% vs 8.7%, aOR 1.86, 95% CI, 1.00-3.44) were associated with increased prevalence of PASC.The prevalence of PASC at a median time of 10.3 months after SARS-CoV-2 infection during pregnancy was 9.3% in the NIH RECOVER-Pregnancy Cohort. The predominant symptoms were postexertional malaise, fatigue, and gastrointestinal symptoms. Several socioeconomic and clinical characteristics were associated with PASC after infection during pregnancy.ClinicalTrials.gov, NCT05172024.
View details for DOI 10.1097/AOG.0000000000005670
View details for PubMedID 38991216
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Development of post-acute sequelae of SARS-CoV-2 (PASC) after infection in pregnancy: NIH RECOVER-Pregnancy Cohort
MOSBY-ELSEVIER. 2024: S6
View details for Web of Science ID 001282913900010
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Management of Eosinophilic Esophagitis in Pediatric Patients Undergoing Food Allergen Oral Immunotherapy
MOSBY-ELSEVIER. 2023: AB88
View details for Web of Science ID 000991651900270
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Development of a Definition of Postacute Sequelae of SARS-CoV-2 Infection.
JAMA
2023
Abstract
Importance: SARS-CoV-2 infection is associated with persistent, relapsing, or new symptoms or other health effects occurring after acute infection, termed postacute sequelae of SARS-CoV-2 infection (PASC), also known as long COVID. Characterizing PASC requires analysis of prospectively and uniformly collected data from diverse uninfected and infected individuals.Objective: To develop a definition of PASC using self-reported symptoms and describe PASC frequencies across cohorts, vaccination status, and number of infections.Design, Setting, and Participants: Prospective observational cohort study of adults with and without SARS-CoV-2 infection at 85 enrolling sites (hospitals, health centers, community organizations) located in 33 states plus Washington, DC, and Puerto Rico. Participants who were enrolled in the RECOVER adult cohort before April 10, 2023, completed a symptom survey 6 months or more after acute symptom onset or test date. Selection included population-based, volunteer, and convenience sampling.Exposure: SARS-CoV-2 infection.Main Outcomes and Measures: PASC and 44 participant-reported symptoms (with severity thresholds).Results: A total of 9764 participants (89% SARS-CoV-2 infected; 71% female; 16% Hispanic/Latino; 15% non-Hispanic Black; median age, 47 years [IQR, 35-60]) met selection criteria. Adjusted odds ratios were 1.5 or greater (infected vs uninfected participants) for 37 symptoms. Symptoms contributing to PASC score included postexertional malaise, fatigue, brain fog, dizziness, gastrointestinal symptoms, palpitations, changes in sexual desire or capacity, loss of or change in smell or taste, thirst, chronic cough, chest pain, and abnormal movements. Among 2231 participants first infected on or after December 1, 2021, and enrolled within 30 days of infection, 224 (10% [95% CI, 8.8%-11%]) were PASC positive at 6 months.Conclusions and Relevance: A definition of PASC was developed based on symptoms in a prospective cohort study. As a first step to providing a framework for other investigations, iterative refinement that further incorporates other clinical features is needed to support actionable definitions of PASC.
View details for DOI 10.1001/jama.2023.8823
View details for PubMedID 37278994
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Anti-nucleocapsid antibody levels and pulmonary comorbid conditions are linked to post-COVID-19 syndrome.
JCI insight
2022; 7 (13)
Abstract
BACKGROUNDProlonged symptoms after SARS-CoV-2 infection are well documented. However, which factors influence development of long-term symptoms, how symptoms vary across ethnic groups, and whether long-term symptoms correlate with biomarkers are points that remain elusive.METHODSAdult SARS-CoV-2 reverse transcription PCR-positive (RT-PCR-positive) patients were recruited at Stanford from March 2020 to February 2021. Study participants were seen for in-person visits at diagnosis and every 1-3 months for up to 1 year after diagnosis; they completed symptom surveys and underwent blood draws and nasal swab collections at each visit.RESULTSOur cohort (n = 617) ranged from asymptomatic to critical COVID-19 infections. In total, 40% of participants reported at least 1 symptom associated with COVID-19 six months after diagnosis. Median time from diagnosis to first resolution of all symptoms was 44 days; median time from diagnosis to sustained symptom resolution with no recurring symptoms for 1 month or longer was 214 days. Anti-nucleocapsid IgG level in the first week after positive RT-PCR test and history of lung disease were associated with time to sustained symptom resolution. COVID-19 disease severity, ethnicity, age, sex, and remdesivir use did not affect time to sustained symptom resolution.CONCLUSIONWe found that all disease severities had a similar risk of developing post-COVID-19 syndrome in an ethnically diverse population. Comorbid lung disease and lower levels of initial IgG response to SARS-CoV-2 nucleocapsid antigen were associated with longer symptom duration.TRIAL REGISTRATIONClinicalTrials.gov, NCT04373148.FUNDINGNIH UL1TR003142 CTSA grant, NIH U54CA260517 grant, NIEHS R21 ES03304901, Sean N Parker Center for Allergy and Asthma Research at Stanford University, Chan Zuckerberg Biohub, Chan Zuckerberg Initiative, Sunshine Foundation, Crown Foundation, and Parker Foundation.
View details for DOI 10.1172/jci.insight.156713
View details for PubMedID 35801588
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The Wish Project: Implementation of a Low-Cost End-of-Life Intervention in a Community Setting
ELSEVIER SCIENCE INC. 2022: 895-896
View details for Web of Science ID 000812783700226
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SARS-CoV-2 and Perceived Physical, Mental and Social Health in Northern California
MOSBY-ELSEVIER. 2022: AB46
View details for Web of Science ID 000778999300137
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UTILITY OF A GLUCOCORTICOID SPARING STRATEGY IN THE MANAGEMENT OF PATIENTS FOLLOWING TRANSSPHENOIDAL SURGERY
ENDOCRINE PRACTICE
2016; 22 (9): 1033-1039
Abstract
Following transsphenoidal surgery (TSS), it is important to assess for and manage adrenal insufficiency (AI). The goal of this study is to assess the efficacy and safety of a glucocorticoid (GC) sparing protocol to limit GC exposure in patients undergoing TSS.Adult patients undergoing TSS (excluding Cushing disease) with adequate adrenal function prior to surgery underwent TSS without perioperative GC coverage. Following TSS, daily morning fasting serum cortisol levels were tested. GCs were administered at stress doses for serum cortisol <5 mcg/dL, between 5 and 12 mcg/dL in the presence of clinically significant symptoms of AI, or >12 mcg/dL with severe headache, nausea or vomiting, fatigue, anorexia, or hyponatremia. The primary endpoint was the use of GCs in the immediate postoperative period.Of 178 subjects, GCs were administered to 80 (45%) patients for the following indications: 31.3% for serum cortisol <5 mcg/dL; 36.3% for cortisol between 5 and 12 mcg/dL accompanied by symptoms or signs of AI; 8.8% for moderate to severe postoperative hyponatremia; and 7.5% for severe headache, nausea and vomiting, fatigue, or anorexia with cortisol >12 mcg/dL. Logistic regression analysis showed that longer length of hospital stay (odds ratio [OR] 1.22, confidence interval [CI] 1.02-1.45) and the presence of new postoperative anterior pituitary hormone deficiency (OR 3.3, CI 1.26-8.67) were associated with postoperative GC use. By 12 weeks, only 14% of subjects remained on GCs. There were no adverse events related to withholding GCs.Our protocol for managing GC replacement is both safe and effective for limiting GC exposure in patients undergoing TSS.AI = adrenal insufficiency CI = confidence interval FSH = follicle-stimulating hormone GC = glucocorticoid GH = growth hormone IGF-1 = insulin-like growth factor-1 IV = intravenous LH = luteinizing hormone LOS = length of hospital stay OR = odds ratio TSS = transsphenoidal surgery.
View details for DOI 10.4158/EP161256.OR
View details for Web of Science ID 000384279900001
View details for PubMedID 27124693
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Using induced pluripotent stem cells to investigate cardiac phenotypes in Timothy syndrome
NATURE
2011; 471 (7337): 230-U120
Abstract
Individuals with congenital or acquired prolongation of the QT interval, or long QT syndrome (LQTS), are at risk of life-threatening ventricular arrhythmia. LQTS is commonly genetic in origin but can also be caused or exacerbated by environmental factors. A missense mutation in the L-type calcium channel Ca(V)1.2 leads to LQTS in patients with Timothy syndrome. To explore the effect of the Timothy syndrome mutation on the electrical activity and contraction of human cardiomyocytes, we reprogrammed human skin cells from Timothy syndrome patients to generate induced pluripotent stem cells, and differentiated these cells into cardiomyocytes. Electrophysiological recording and calcium (Ca(2+)) imaging studies of these cells revealed irregular contraction, excess Ca(2+) influx, prolonged action potentials, irregular electrical activity and abnormal calcium transients in ventricular-like cells. We found that roscovitine, a compound that increases the voltage-dependent inactivation of Ca(V)1.2 (refs 6-8), restored the electrical and Ca(2+) signalling properties of cardiomyocytes from Timothy syndrome patients. This study provides new opportunities for studying the molecular and cellular mechanisms of cardiac arrhythmias in humans, and provides a robust assay for developing new drugs to treat these diseases.
View details for DOI 10.1038/nature09855
View details for PubMedID 21307850
https://orcid.org/0000-0002-2172-4716