Karthik Natarajan
A5080516734- Vaccine Coverage and Hesitancy
- SARS-CoV-2 and COVID-19 Research
- COVID-19 Clinical Research Studies
- Biomedical Text Mining and Ontologies
- Machine Learning in Healthcare
- Influenza Virus Research Studies
- Long-Term Effects of COVID-19
- Electronic Health Records Systems
- Topic Modeling
- COVID-19 diagnosis using AI
- COVID-19 and healthcare impacts
- Mobile Health and mHealth Applications
- COVID-19 epidemiological studies
- Data Quality and Management
- Artificial Intelligence in Healthcare
- Respiratory viral infections research
- Data-Driven Disease Surveillance
- Global Maternal and Child Health
- Ethics in Clinical Research
- Genomics and Rare Diseases
- AI in cancer detection
- Scientific Computing and Data Management
- Artificial Intelligence in Healthcare and Education
- Research Data Management Practices
- Chronic Disease Management Strategies
Columbia University Irving Medical Center
2016-2025
NewYork–Presbyterian Hospital
2013-2025
Columbia University
2014-2025
National Institute of Technology Tiruchirappalli
2025
New York Hospital Queens
2013-2024
Vinayaka Missions University
2024
Twin Cities Orthopedics
2024
University of Minnesota
2014-2024
Intermountain Healthcare
2021-2024
Ahmedabad Civil Hospital
2018-2024
To characterize patients with coronavirus disease 2019 (covid-19) in a large New York City medical center and describe their clinical course across the emergency department, hospital wards, intensive care units.Retrospective manual record review.NewYork-Presbyterian/Columbia University Irving Medical Center, quaternary academic City.The first 1000 consecutive positive result on reverse transcriptase polymerase chain reaction assay for severe acute respiratory syndrome 2 (SARS-CoV-2) who...
Coronavirus disease 2019 (COVID-19) poses societal challenges that require expeditious data and knowledge sharing. Though organizational clinical are abundant, these largely inaccessible to outside researchers. Statistical, machine learning, causal analyses most successful with large-scale beyond what is available in any given organization. Here, we introduce the National COVID Cohort Collaborative (N3C), an open science community focused on analyzing patient-level from many centers.The...
BackgroundThere are limited data on the effectiveness of vaccines against symptomatic coronavirus disease 2019 (Covid-19) currently authorized in United States with respect to hospitalization, admission an intensive care unit (ICU), or ambulatory emergency department urgent clinic.MethodsWe conducted a study involving adults (≥50 years age) Covid-19–like illness who underwent molecular testing for severe acute respiratory syndrome 2 (SARS-CoV-2). We assessed 41,552 admissions 187 hospitals...
CDC recommends that all persons aged ≥12 years receive a booster dose of COVID-19 mRNA vaccine ≥5 months after completion primary vaccination series and immunocompromised third dose.* Waning protection 2 doses has been observed during the period SARS-CoV-2 B.1.617.2 (Delta) variant predominance† (1-5), but little is known about durability 3 periods Delta or B.1.1.529 (Omicron) predominance. A test-negative case-control study design using data from eight VISION Network sites§ examined...
Estimates of COVID-19 mRNA vaccine effectiveness (VE) have declined in recent months (1,2) because waning induced immunity over time,* possible increased immune evasion by SARS-CoV-2 variants (3), or a combination these and other factors. CDC recommends that all persons aged ≥12 years receive third dose (booster) an ≥5 after receipt the second immunocompromised individuals primary dose.† A BNT162b2 (Pfizer-BioNTech) increases neutralizing antibody levels (4), three studies from Israel shown...
The volume of healthcare data is growing rapidly with the adoption health information technology. We focus on automated ICD9 code assignment from discharge summary content and methods for evaluating such assignments.
Obesity is a risk factor for pneumonia and acute respiratory distress syndrome.
The
Immunocompromised persons, defined as those with suppressed humoral or cellular immunity resulting from health conditions medications, account for approximately 3% of the U.S. adult population (1). adults are at increased risk severe COVID-19 outcomes (2) and might not acquire same level protection mRNA vaccines do immunocompetent (3,4). To evaluate vaccine effectiveness (VE) among immunocompromised adults, data VISION Network* on hospitalizations persons aged ≥18 years COVID-19-like illness...
The efficacy of the BNT162b2 (Pfizer-BioNTech) vaccine against laboratory-confirmed COVID-19 exceeded 90% in clinical trials that included children and adolescents aged 5-11, 12-15, 16-17 years (1-3). Limited real-world data on 2-dose mRNA effectiveness (VE) persons 12-17 (referred to as this report) have also indicated high levels protection SARS-CoV-2 (the virus causes COVID-19) infection COVID-19-associated hospitalization (4-6); however, VE B.1.1.529 (Omicron) variant duration are...
To estimate the effectiveness of mRNA vaccines against moderate and severe covid-19 in adults by time since second, third, or fourth doses, age immunocompromised status.Test negative case-control study.Hospitals, emergency departments, urgent care clinics 10 US states, 17 January 2021 to 12 July 2022.893 461 (≥18 years) admitted one 261 hospitals 272 department 119 centers for covid-like illness tested SARS-CoV-2.The main outcome was waning vaccine with BNT162b2 (Pfizer-BioNTech) mRNA-1273...
Data on COVID-19 vaccine effectiveness (VE) since the B.1.617.2 (Delta) variant of SARS-CoV-2, virus that causes COVID-19, became predominant circulating strain in United States are limited (1-3). CDC used VISION Network* to examine medical encounters (32,867) from 187 hospitals and 221 emergency departments (EDs) urgent care (UC) clinics across nine states during June-August 2021, beginning date Delta accounted for >50% sequenced isolates each facility's state. Network methods have been...
The association between physical activity and human disease has not been examined using commercial devices linked to electronic health records. Using the records data from All of Us Research Program, we show that step count volumes as captured by participants' own Fitbit were associated with risk chronic across entire phenome. Of 6,042 participants included in study, 73% female, 84% white 71% had a college degree, median age 56.7 (interquartile range 41.5-67.6) years body mass index 28.1...
The Omicron variant (B.1.1.529) of SARS-CoV-2, the virus that causes COVID-19, was first identified in United States November 2021, with BA.1 sublineage (including BA.1.1) causing largest surge COVID-19 cases to date. sublineages BA.2 and BA.2.12.1 emerged later by late April 2022, accounted for most cases.* Estimates vaccine effectiveness (VE) can be reduced newly emerging variants or evade vaccine-induced immunity (1), protection from previous SARS-CoV-2 infection unvaccinated persons (2),...
During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of sequenced viral genomes in United States, with further diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral strain component plus updated BA.4/BA.5 sublineages. On September 1, a single bivalent booster dose was recommended adults who had completed primary vaccination series (with or without subsequent doses), last administered ≥2 months earlier (1). 13-November 18, VISION...
Persons with moderate-to-severe immunocompromising conditions might have reduced protection after COVID-19 vaccination, compared persons without (1-3). On August 13, 2021, the Advisory Committee on Immunization Practices (ACIP) recommended that adults receive an expanded primary series of 3 doses mRNA vaccine. ACIP followed recommendations September 23, for a fourth (booster) dose and 1, 2022, new bivalent vaccine booster dose, containing components BA.4 BA.5 sublineages Omicron (B.1.1.529)...
On September 1, 2022, CDC's Advisory Committee on Immunization Practices (ACIP) recommended a single bivalent mRNA COVID-19 booster dose for persons aged ≥12 years who had completed at least monovalent primary series. Early vaccine effectiveness (VE) estimates among adults ≥18 showed receipt of provided additional protection against COVID-19-associated emergency department and urgent care visits hospitalizations compared with that in received only doses (1); however, insufficient time...
Importance Recent SARS-CoV-2 Omicron variant sublineages, including BA.4 and BA.5, may be associated with greater immune evasion less protection against COVID-19 after vaccination. Objectives To evaluate the estimated vaccine effectiveness (VE) of 2, 3, or 4 doses mRNA vaccination among immunocompetent adults during a period BA.5 predominant circulation; to relative severity in hospitalized patients across BA.1, BA.2 BA.2.12.1, sublineage periods. Design, Setting, Participants This...
In September 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (monovalent XBB.1.5)COVID-19 vaccination for all persons aged ≥6 months to prevent COVID-19, including severe disease.However, few estimates of vaccine effectiveness (VE) against medically attended illness are available.This analysis evaluated VE an COVID-19 dose COVID-19-associated emergency department (ED) or urgent care (UC) encounters and hospitalization among immunocompetent adults ≥18...
During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of sequenced viral genomes in United States, with further diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral strain component plus updated BA.4/BA.5 sublineages. On September 1, a single bivalent booster dose was recommended adults who had completed primary vaccination series (with or without subsequent doses), last administered ≥2 months earlier (1). 13-November 18, VISION...
In September 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (monovalent XBB.1.5) COVID-19 vaccination for all persons aged ≥6 months to prevent COVID-19, including severe disease. As with past vaccines, additional doses may be considered immunocompromising conditions, who are at higher risk and might have decreased response vaccination. this analysis, vaccine effectiveness (VE) of an dose against COVID-19-associated hospitalization was evaluated during...
Objectives. We conducted 2 studies to determine the impact of text message immunization reminder–recalls in an urban, low-income population. Methods. In 1 study, reminders were sent a random sample parents (n = 195) whose children aged 11 18 years needed either or both meningococcal (MCV4) and tetanus–diphtheria–acellular pertussis (Tdap) immunizations. compared receipt MCV4 Tdap at 4, 12, 24 weeks with age- gender-matched controls. other we attendance postshortage Haemophilus influenzae B...
Funding for humanitarian operations in the global health sector is highly variable and unpredictable. We study problem of managing inventory presence funding constraints over a finite planning period. Our goal to determine optimal procurement policy given complexities associated with also analyze impact amount, schedule, uncertainty around timing on operations. use multiperiod stochastic model financial demonstrate that despite complexities, replenishment state-independent can be easily...
Abstract Comorbid conditions appear to be common among individuals hospitalised with coronavirus disease 2019 (COVID-19) but estimates of prevalence vary and little is known about the prior medication use patients. Here, we describe characteristics adults COVID-19 compare them influenza We include 34,128 (US: 8362, South Korea: 7341, Spain: 18,425) patients, summarising between 4811 11,643 unique aggregate characteristics. patients have been majority male in US Spain, predominantly female...