Resources Repository
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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 | Infectious Diseases | Clinical Care | Health/Medicine -
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 | Test Performance | Infectious Diseases | Clinical Care | Health/Medicine | 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 | Test Performance | Infectious Diseases | Health/Medicine | Science/Technology | Global -
Resource PackPublication, Teaching Resource 2020Resource Pack: Cost-Effectiveness of SSB Excise Taxes
The use of fiscal instruments, such as taxes or subsidies, to promote healthier dietary behavior …
The use of fiscal instruments, such as taxes or subsidies, to promote healthier dietary behavior has been of increasing interest in the last decade as the evidence-base builds for the health and economic consequences of obesity, overweight, and unhealthy eating. The motivation for using fiscal instruments in nutrition policy is to make the unhealthy option less affordable and less economically attractive by increasing the price via a tax, and therefore reduce the incentive to consume…
Mathematical Models | Health Outcomes | Evidence Synthesis | Microsimulation | Cost-Effectiveness Analysis | Child/Nutrition | Chronic Disease/Risk | Policy/Regulation | Business/Industry | Economics/Finance | Food/Agriculture | Government/Law | Health/Medicine | North America | Latin America & Caribbean | Europe | Oceania -
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 | Clinical Care | Health/Medicine -
ArticlePublication 2020Equity & Distributional Impact on Stunting of a Nutritional Package, Children Aged 6-36 Months in China: Modeling Study Findings
This article evaluates the potential impact of rolling out the Ying Yang Bao (YYB) nutritional …
This article evaluates the potential impact of rolling out the Ying Yang Bao (YYB) nutritional package on child stunting across provinces and wealth groups in China, focusing on equity. Utilizing data from the China Family Panel Studies and extended cost-effectiveness analysis methods, the study estimates the distributional impact of a 12-month YYB program for children aged 6-36 months across 25 provinces and two wealth groups. Results indicate that a 75% coverage of YYB could avert…
Mathematical Models | Health Outcomes | Cost-Effectiveness Analysis | Child/Nutrition | Health/Medicine | Asia & Pacific -
ArticlePublication 2018Equity Impact Vaccines May Have on Averting Deaths and Medical Impoverishment
In this analysis, authors estimated the number of deaths averted and the number of cases …
In this analysis, authors estimated the number of deaths averted and the number of cases of medical impoverishment averted of ten antigens and their corresponding vaccines across income quintiles for forty-one low- and middle-income countries. The study found that vaccines administered between 2016 and 2030 would prevent 36 million deaths. Vaccines will have the greatest impact on reducing cases of poverty caused by hepatitis B, helping an estimated 14 million people avoid medical impoverishment. An…
Mathematical Models | Health Outcomes | Priority Setting/Ethics | Costing Methods | Cost-Effectiveness Analysis | Infectious Diseases | Child/Nutrition | Global Governance | Economics/Finance | Health/Medicine | Science/Technology | Sub-Saharan Africa | Middle East & North Africa | Asia & Pacific -
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 | Test Performance | Decision Analysis | Environmental Health | Health/Medicine | 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 | Test Performance | Decision Analysis | Child/Nutrition | Health/Medicine | College | Graduate | Doctoral | Professional | Critical Thinking/Analysis | Graphics/Visualization | Quantitative Literacy