Resources Repository
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ArticlePublication 2021Racial and Ethnic Inequities in the Early Distribution of U.S. COVID-19 Testing Sites and Mortality
In 2020, U.S. COVID-19 testing sites were pivotal not just for diagnosis but also to …
In 2020, U.S. COVID-19 testing sites were pivotal not just for diagnosis but also to provide data that would contribute to understanding transmission. This research explored how these sites were distributed in relation to racial and ethnic demographics and its connection to observed disparities in COVID-19 outcomes. Data from mid-April to late May 2020 revealed that testing sites were not equally distributed among racial groups. Specifically, there was an overrepresentation of testing sites in areas…
Test Performance | Health/Medicine | Culture/Society | Health Outcomes | Infectious Diseases | Social Determinants | Policy/Regulation | Science/Technology | North America -
ArticlePublication 2022Comparison of Home Antigen Testing With RT-PCR and Viral Culture During the Course of SARS-CoV-2 Infection
As the availability of at-home self-collected antigen tests for SARS-CoV-2 increases, understanding their efficacy is …
As the availability of at-home self-collected antigen tests for SARS-CoV-2 increases, understanding their efficacy is crucial. A study in San Diego and Denver between January and May 2021 assessed the reliability of these tests against standard RT-PCR tests and viral cultures. Of the 225 participants with confirmed infections, the antigen test sensitivity was found to be 50% during the infectious period, 64% against the same-day RT-PCR, and 84% against the same-day cultures. Sensitivity was highest…
Test Performance | Health/Medicine | Culture/Society | Infectious Diseases | Clinical Care | Science/Technology -
ArticlePublication 2020Testing for SARS-CoV-2 Antibodies
Antibody testing can determine previous exposure to SARS-CoV-2 virus. Recently, the UK government has made …
Antibody testing can determine previous exposure to SARS-CoV-2 virus. Recently, the UK government has made antibody testing available to anyone wanting it, even if there is no clinical indication. The purpose of this article is to provide guidance for when to consider antibody testing in individuals with and without symptoms suggestive of current or past SARS-CoV-2 infection. Key points made by the authors include: (1) antibody testing is likely to be most useful 2 weeks…
Probability/Bayes | Test Performance | Health/Medicine | Technology Assessment | Infectious Diseases | Clinical Care -
ArticlePublication 2020Bayes' Theorem, COVID-19, and Screening Tests
This article reviews the implications of increased testing for COVID-19 using reverse transcriptase polymerase chain …
This article reviews the implications of increased testing for COVID-19 using reverse transcriptase polymerase chain reaction (rRT-PCR) through the application of Bayes’ Theorem for three hypothetical, stylized case scenarios. The scenarios involve three patients with a low, moderate, and high pre-test probability of COVID-19 infection. The category of low probability would include "asymptomatic individuals in a presumed low prevalence environment" and might vary from 10 to 20%. The category of moderate probability would include "individuals…
Probability/Bayes | Test Performance | Health/Medicine | Infectious Diseases | Clinical Care -
ArticlePublication 2020Interpreting COVID-19 Test Results: A Bayesian Approach
This article considers the following question with respect to interpreting the results of polymerase chain reaction …
This article considers the following question with respect to interpreting the results of polymerase chain reaction (PCR) assays from nasal and pharyngeal swabs for COVID-19 to inform clinical decision making: "While a positive result in an acutely ill patient is straightforward, how should physicians interpret negative tests in patients with suspected COVID-19 infection?" Using an assumption of near-perfect specificity of PCR assays for COVID-19, the authors acknowledge the uncertainty of test sensitivity. They consider two clinical scenarios…
Probability/Bayes | Test Performance | Health/Medicine | Infectious Diseases | Science/Technology | Global -
ArticlePublication 2020Clinical Decision Making: Using a Diagnostic Test
This article is part of a 6-part series on clinical decision making. The authors use …
This article is part of a 6-part series on clinical decision making. The authors use two clinical examples to review the principles of interpreting diagnostic test results. They outline an approach that can be used to determine how to select and apply tests and their results to the practice of internal medicine. Topics covered in the two case studies include sensitivity and specificity, positive predictive and negative predictive value of tests, and how to estimate…
Probability/Bayes | Test Performance | Health/Medicine | Clinical Care -
ArticlePublication 2013Contribution of H. Pylori and Smoking to US Incidence of Gastric Adenocarcinoma: A Microsimulation Model
Although gastric cancer has declined dramatically in the US, the disease remains the second leading …
Although gastric cancer has declined dramatically in the US, the disease remains the second leading cause of cancer mortality worldwide. This analysis estimates the contribution of risk factor trends on past and future intestinal-type non-cardia gastric adenocarcinoma (NCGA) incidence. The authors developed a population-based microsimulation model of intestinal-type NCGA and calibrated it to U.S. epidemiologic data on precancerous lesions and cancer. The model explicitly incorporated the impact of Helicobacter pylori and smoking on disease natural history, for which…
Calibration/Validation | Health/Medicine | Culture/Society | Microsimulation | Chronic Disease/Risk | Social Determinants | North America -
ArticlePublication 2023Simulation-Based Comparative Effectiveness Analysis of Policies to Improve Global Maternal Health Outcomes
The Sustainable Development Goals include a target to reduce the global maternal mortality ratio (MMR) …
The Sustainable Development Goals include a target to reduce the global maternal mortality ratio (MMR) to less than 70 maternal deaths per 100,000 live births by 2030, with no individual country exceeding 140. However, on current trends the goals are unlikely to be met. The authors used an empirically calibrated Global Maternal Health microsimulation model, which simulates individual women in 200 countries and territories to evaluate the impact of different interventions and strategies from 2022…
Calibration/Validation | Health/Medicine | Health Outcomes | Mathematical Models | Microsimulation | Maternal/Reproductive Health | Health Systems | Clinical Care | Global -
ArticlePublication 2023Simulation-Based Estimates and Projections of Global, Regional and Country-Level Maternal Mortality by Cause, 1990-2050
While progress has been made globally to reduce maternal deaths, measurement remains a challenge given …
While progress has been made globally to reduce maternal deaths, measurement remains a challenge given the many causes and frequent underreporting of maternal deaths. The authors developed a structural microsimulation model of Global Maternal Health (GMatH) for 200 countries and territories using demographic, epidemiologic, clinical and health system data synthesized from the medical literature, Civil Registration Vital Statistics systems and Demographic and Health Survey data. The model was calibrated to empirical data from 1990 to…
Calibration/Validation | Health/Medicine | Health Outcomes | Evidence Synthesis | Microsimulation | Maternal/Reproductive Health | Health Systems | Clinical Care | Global