Publications by authors named "Gowtham Rao"

Objective: Studying rare diseases like dermatomyositis (DM) in single-center cohorts is challenging due to small sample sizes and limited generalizability. This study develops and evaluates case identification algorithms for DM to enable coordinated analysis across multiple data sources.

Methods: Case identification algorithms were developed to identify adult DM patients within eleven independent electronic health record or claims databases, totaling over 800 million patients, using the Observational Medical Outcomes Partnership (OMOP) Common Data Model.

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Our study examined the heterogeneity of phenotype algorithms (PA) in literature on Alzheimer's disease (AD), major depressive disorder (MDD), and pulmonary arterial hypertension (PAI), focusing on the impact of PA differences on patient overlap and incidence rate variability across conditions in six observational databases. We reviewed 49 replicated PAs (13 for AD, 23 for MDD, and 13 for PAI) and found significant heterogeneity. These varied PAs identified distinct patient cohorts, resulting in significant incidence rate heterogeneity.

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Objective: To complement and support routine pharmacovigilance, Janssen conducted rapid real-world data analyses for near real-time safety monitoring of the Janssen COVID-19 vaccine and to contextualize potential safety signals.

Methods: Analyses were performed in four U.S.

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Objective: This paper introduces a novel framework for evaluating phenotype algorithms (PAs) using the open-source tool, Cohort Diagnostics.

Materials And Methods: The method is based on several diagnostic criteria to evaluate a patient cohort returned by a PA. Diagnostics include estimates of incidence rate, index date entry code breakdown, and prevalence of all observed clinical events prior to, on, and after index date.

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The Health-Analytics Data to Evidence Suite (HADES) is an open-source software collection developed by Observational Health Data Sciences and Informatics (OHDSI). It executes directly against healthcare data such as electronic health records and administrative claims, that have been converted to the Observational Medical Outcomes Partnership (OMOP) Common Data Model. Using advanced analytics, HADES performs characterization, population-level causal effect estimation, and patient-level prediction, potentially across a federated data network, allowing patient-level data to remain locally while only aggregated statistics are shared.

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Article Synopsis
  • The study focuses on the importance of creating accurate phenotype definitions for reliable safety research, comparing different definitions to see how they affect background incidence rates of adverse events.
  • Using data from 16 sources, the researchers analyzed 13 adverse events and discovered significant variations in incidence rates based on how phenotypes were defined, particularly with different modifications like inpatient settings.
  • The results indicated that requiring an inpatient setting significantly increased the incidence rates, showing the need to carefully evaluate definitions before using them for background rate assessments in a global context.
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  • The study aimed to compare the incidence rates of adverse events of special interest (AESIs) following COVID-19 infection with historical rates in the general population, focusing on 16 specific health outcomes.
  • Researchers conducted a multinational cohort study using diverse health data from 2017 to 2022 and found that post-COVID-19 AESIs were consistently more common, with significant variations based on age and population demographics.
  • The findings indicated that thromboembolic events, like pulmonary embolism, were particularly prevalent after a COVID-19 infection, highlighting the need for further research on long-term complications related to the virus.
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  • This study investigates how different interpretations of an observational study's design can affect the results when independent researchers attempt to reproduce it.
  • The researchers found that out of ten criteria for including patients, teams only agreed, on average, 4 of 10 times, leading to significant variability in the size and characteristics of the resulting patient cohorts.
  • The study concludes that providing open analytical code and a standardized data model can improve reproduction accuracy and consistency in observational research.
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  • The study aimed to measure the background incidence rates of 15 specific adverse events linked to COVID-19 vaccines across various populations.
  • Conducted as a multinational cohort study, it utilized electronic health records from eight countries, analyzing data from over 126 million individuals monitored for at least a year prior to 2017, 2018, or 2019.
  • Findings revealed significant variations in incident rates of adverse events like deep vein thrombosis and myocardial infarction based on database, age, and sex, with some events being more frequent in older adults and others more common in younger individuals.
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  • - Vaccine-induced thrombotic thrombocytopenia (VITT) is a serious but rare side effect linked to COVID-19 vaccines, prompting researchers to study pre-pandemic cases of thrombosis with thrombocytopenia (TWT) using global health data sources.
  • - The study analyzed electronic health records from 2017 to 2019 to determine background rates of TWT, which were found to vary significantly across different demographics and definitions, with incidence rates ranging from 1.62 to 150.65 per 100,000 person-years.
  • - Results indicated that TWT patients tend to be older men with various health issues, and the research suggests challenges in identifying VITT due to inconsistent baseline characteristics compared to
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Article Synopsis
  • The study analyzes how different factors like age, race, sex, and the choice of databases affect background incidence rates in safety studies related to COVID-19 vaccines.
  • It found that background incidence rates can vary significantly (up to 1,000 times) due to these factors, indicating that there’s more complexity than previously understood.
  • Researchers emphasized the importance of careful selection of study parameters, such as time-at-risk duration and starting points, to ensure accurate comparisons of background and observed rates.
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  • The study aimed to develop COVID-19 prediction models using influenza data to quickly and accurately assess risks of hospital admission and death in patients diagnosed with COVID-19.
  • The researchers created three COVID-19 Estimated Risk (COVER) scores that quantify risks related to pneumonia and mortality based on historical data and validated them using a large dataset of COVID-19 patients across multiple countries.
  • They found that seven key health predictors, along with age and sex, effectively distinguished which patients were likely to face severe outcomes, achieving strong performance in model validation.
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Purpose: To assess veteran-specific prostate cancer (PrCA) mortality-to-incidence ratios (MIR) in South Carolina's (SC) veteran population.

Methods: U.S.

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Background: As large-scale immunization programs against COVID-19 proceed around the world, safety signals will emerge that need rapid evaluation. We report population-based, age- and sex-specific background incidence rates of potential adverse events of special interest (AESI) in eight countries using thirteen databases.

Methods: This multi-national network cohort study included eight electronic medical record and five administrative claims databases from Australia, France, Germany, Japan, Netherlands, Spain, the United Kingdom, and the United States, mapped to a common data model.

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  • The COVID-19 vulnerability (C-19) index was developed to predict which patients might need hospitalization for pneumonia related to COVID-19 but is at risk of bias and lacks external validation.
  • The study aimed to externally validate the C-19 index using data from various healthcare settings and target populations to determine its predictive capabilities for hospitalization due to pneumonia.
  • Results showed that while the C-19 index performed moderately well in internal validation, its external validation yielded low predictive accuracy across different countries, suggesting that it may underestimate the actual risk of hospitalization.
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  • Antithrombotic therapies can lead to an increased risk of abnormal uterine bleeding, particularly in women with conditions like venous thromboembolism (VTE) and atrial fibrillation (AF), but data specific to AF patients are limited.
  • This study analyzed real-world data from 2010 to 2018 to compare the incidence of severe uterine bleeding among women taking different anticoagulants, including rivaroxaban, apixaban, dabigatran, and warfarin.
  • Results indicated a low overall incidence of severe uterine bleeding, yet there was a notable risk increase for rivaroxaban compared to warfarin, apixaban, and dabigatran in women with AF,
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  • * A study analyzed 34,128 COVID-19 patients across the US, South Korea, and Spain, revealing differences in gender and age demographics among countries.
  • * Compared to influenza patients hospitalized from 2014-2019, COVID-19 patients tend to be younger, more often male, and have fewer comorbidities and lower medication use, indicating a need for tailored response strategies.
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  • The study investigated the safety of hydroxychloroquine, a drug used for rheumatoid arthritis, particularly considering its controversial use for COVID-19 pneumonia.
  • It compared adverse events in patients starting hydroxychloroquine versus those starting sulfasalazine, analyzing data from multiple countries and focusing on severe events within a 30-day period.
  • Results showed no significant increase in severe adverse events for short-term use of hydroxychloroquine compared to sulfasalazine, but long-term use may be linked to a higher risk of cardiovascular issues.
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Background In this study we phenotyped individuals hospitalised with coronavirus disease 2019 (COVID-19) in depth, summarising entire medical histories, including medications, as captured in routinely collected data drawn from databases across three continents. We then compared individuals hospitalised with COVID-19 to those previously hospitalised with influenza. Methods We report demographics, previously recorded conditions and medication use of patients hospitalised with COVID-19 in the US (Columbia University Irving Medical Center [CUIMC], Premier Healthcare Database [PHD], UCHealth System Health Data Compass Database [UC HDC], and the Department of Veterans Affairs [VA OMOP]), in South Korea (Health Insurance Review & Assessment [HIRA]), and Spain (The Information System for Research in Primary Care [SIDIAP] and HM Hospitales [HM]).

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Background: Racial and socio-economic status (SES) disparities exist in prostate cancer (PrCA) incidence and mortality. Less is known regarding how geographical factors, including neighborhood social vulnerability and distance traveled to receive care, affect PrCA risk. The purpose of this research was to use the Veterans Administration Medical System, which provides a unique means for studying PrCA epidemiology among diverse individuals with ostensibly equal access to healthcare, to determine whether area-level characteristics influence PrCA incidence while accounting for individual-level risk factors.

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Background And Purpose: Hemorrhagic transformation (HT) after cerebral infarction is a complex and multifactorial phenomenon in the acute stage of ischemic stroke, and often results in a poor prognosis. Thus, identifying risk factors and making an early prediction of HT in acute cerebral infarction contributes not only to the selections of therapeutic regimen but also, more importantly, to the improvement of prognosis of acute cerebral infarction. The purpose of this study was to develop and validate a model to predict a patient's risk of HT within 30 days of initial ischemic stroke.

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  • The study aimed to determine if a growth curve derived from prostate-specific antigen (PSA) levels can effectively predict high-risk prostate cancer (PrCA) in men.
  • Researchers analyzed data from over 38,000 men in a cancer screening trial to model PSA growth and then applied this model to a larger dataset of veterans.
  • Results showed that a PSA rate threshold of 0.37 ng/ml/year was highly effective in identifying high-risk PrCA, but different populations, like African-American men, may require further investigation due to lower specificity in the findings.
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Background: The 3 fluoroquinolone (FQ) antibiotics - ciprofoxacin, levofoxacin, and moxifoxacin - are commonly administered to oncology patients. Although these oral antibiotics are approved by the US Food and Drug Administration (FDA) for treatment of urinary tract infections, acute bacterial sinusitis, or bacterial infection in patients with chronic obstructive pulmonary disease, they are commonly prescribed off-label to neutropenic cancer patients for the prevention and treatment of infections associated with febrile neutropenia. New serious FQ-associated safety concerns have been identified through novel collaborations between FQ-treated persons who have developed long-term neuropsychiatric (NP) toxicity, pharmacovigilance experts, and basic scientists.

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Purpose: To test the hypothesis that the pattern of prostate-specific antigen (PSA) change in men diagnosed with high-risk prostate cancer (PrCA) differs from the pattern evident in men diagnosed with low-risk PrCA or those with no evidence of PrCA.

Methods: A retrospective cohort study from which PSA measures were taken before PrCA diagnosis from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Data were fitted using a nonlinear regression model to estimate the adjusted absolute and relative (%) change of PSA.

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