Resources Repository
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EditorialPublication 2020Waiting for Certainty on COVID-19 Antibody Tests — At What Cost?
This perspective anticipates the availability of serologic antibody testing and considers its potential usefulness in mitigation …
This perspective anticipates the availability of serologic antibody testing and considers its potential usefulness in mitigation policy to reduce COVID-19 transmission. For example: Could we screen for serologic antibodies as a proxy for possible immunity and identify people who could return to the workplace with less severe mitigation measures? The authors acknowledge the uncertainties raised by many policy actors, including the WHO, such as, "Do antibodies confer immunity and, if so, for how long? How accurate is…
Probability/Bayes | Health/Medicine | Test Performance | Technology Assessment | Infectious Diseases | Health Systems | Policy/Regulation | Government/Law | Global | North America -
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 | Health/Medicine | Test Performance | Infectious Diseases | Clinical Care -
Tools/ModelsInteractive, Teaching Resource 2020Interactive Graphic: Interpreting a COVID-19 Test Result
Currently, the most common diagnostic test for COVID-19 relies on reverse transcriptase polymerase chain reaction …
Currently, the most common diagnostic test for COVID-19 relies on reverse transcriptase polymerase chain reaction (RT-PCR), and most often uses samples obtained from the respiratory tract by nasopharyngeal swab. This interactive graphic demonstrates the influence of the prior probability of COVID-19, the test sensitivity (i.e., the probability of a positive test conditional on disease presence), and the test specificity (i.e., the probability of a negative test conditional on disease absence) on the post-test probability of…
Probability/Bayes | Health/Medicine | Test Performance | Infectious Diseases | Clinical Care | Science/Technology | High School | College | Graduate | Doctoral | Professional | Graphics/Visualization | Quantitative Literacy -
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 | Health/Medicine | Test Performance | 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 | Health/Medicine | Test Performance | Clinical Care -
Lesson/ModuleVideo, Teaching Resource 2018Estimating Transition Probabilities for a Model
This video is intended to provide a discussion on various methods for deriving probabilities that are …
This video is intended to provide a discussion on various methods for deriving probabilities that are needed for decision models. Presented are the concepts of literature based Odds Ratios and Relative Risks, which need to be transformed into probabilities, how to deal with probability estimates from time frames not relevant to the model in question, and how to derive probabilities from published summary statistics. This lecture is aimed at the researcher who is interested in operationalizing…
Probability/Bayes | Health/Medicine | Evidence Synthesis | Mathematical Models | North America | College | Graduate | Doctoral | Critical Thinking/Analysis | Quantitative Literacy -
Teaching PackPublication, Teaching Resource 2022Teaching Pack: Introduction to Decision Analysis
In this teaching pack on Introduction to Decision Analysis, students are provided a basic introduction to …
In this teaching pack on Introduction to Decision Analysis, students are provided a basic introduction to the field of decision analysis in the context of public health. After differentiating simple "relatively automatic" decisions from those that might require more systematic analysis, students are introduced to the core elements of a decision analysis (e.g., objectives, alternatives, probabilities, and outcomes), and the basic steps of a decision analysis. Materials include an instructor's note, videos, companion slides, a glossary,…
Probability/Bayes | Health/Medicine | Decision Psychology | Preferences/Values | Decision Analysis | Cost-Effectiveness Analysis | Global | College | Graduate | Critical Thinking/Analysis | Quantitative Literacy -
Teaching PackPublication, Teaching Resource 2022Teaching Pack: Probability Revision and Bayes
In this teaching pack on Probability Revision and Bayes, students are introduced to the implications …
In this teaching pack on Probability Revision and Bayes, students are introduced to the implications of imperfect information, acquire a conceptual understanding of Bayes theorem, and gain practical skills in performing probability revision. Materials include an instructor's note, videos, companion slides, a glossary, an annotated bibliography, sample exercises, and additional support. Learning Objectives Demonstrate a conceptual understanding of Bayes’ theorem and probability revision. Differentiate between test characteristics (e.g., probability of positive test given…
Probability/Bayes | Health/Medicine | Test Performance | Decision Analysis | Environmental Health | College | Graduate | Critical Thinking/Analysis | Graphics/Visualization | Quantitative Literacy -
Teaching PackPublication, Teaching Resource 2022Teaching Pack: Using Test Information I
In this teaching pack on Using Test Information I, students review the performance of a …
In this teaching pack on Using Test Information I, students review the performance of a dichotomous test and the relationship between sensitivity and specificity, calculate likelihood ratios to describe test performance, and conduct probability revision using the odds-LR form of Bayes. Materials include an instructor's note, videos, companion slides, a glossary, an annotated bibliography, and sample exercises. Learning Objectives Calculate four conditional probabilities describing the performance of a dichotomous test, and explain the…
Probability/Bayes | Health/Medicine | Test Performance | Decision Analysis | Child/Nutrition | College | Graduate | Doctoral | Professional | Critical Thinking/Analysis | Graphics/Visualization | Quantitative Literacy