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…
Test Performance | Health/Medicine | Probability/Bayes | 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…
Test Performance | Health/Medicine | Probability/Bayes | 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…
Test Performance | Health/Medicine | Probability/Bayes | 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…
Test Performance | Health/Medicine | Probability/Bayes | Infectious Diseases | Science/Technology | Global -
ArticlePublication 2013Nutritional Policy Changes in SNAP: A Microsimulation and Cost-Effectiveness Analysis
This analysis estimated the health effects and cost-effectiveness of banning or taxing sugar-sweetened beverages (SSBs) …
This analysis estimated the health effects and cost-effectiveness of banning or taxing sugar-sweetened beverages (SSBs) or subsidizing fruits and vegetables purchased with SNAP. The target population was adults in the U.S. and the time horizon was 10 years. Results showed that banning SSB purchases using SNAP benefits would be expected to avert 510,000 diabetes person-years and 52,000 deaths from MIs and strokes over the next decade, with a savings of $2900 per QALY saved. A…
Microsimulation | Health/Medicine | Mathematical Models | Cost-Effectiveness Analysis | Chronic Disease/Risk | Policy/Regulation | Economics/Finance | Food/Agriculture | Government/Law | North America -
ArticlePublication 2016Mexico's SSB Tax Policy Impact on Diabetes and Cardiovascular Disease: Modeling Study
In 2014, Mexico instituted a nationwide tax on sugar-sweetened beverages (SSBs) in order to reduce …
In 2014, Mexico instituted a nationwide tax on sugar-sweetened beverages (SSBs) in order to reduce the high level of SSB consumption, a preventable cause of diabetes and cardiovascular disease (CVD). In this analyses, a computer simulation model of CVD was used to project potential long-range health and economic impacts of SSB taxation in Mexico. Two main scenarios were modeled: (1) a 10% reduction in SSB consumption (corresponding to the reduction observed after tax implementation) and…
Microsimulation | Health/Medicine | Mathematical Models | Cost-Effectiveness Analysis | Chronic Disease/Risk | Policy/Regulation | Economics/Finance | Food/Agriculture | Government/Law | Latin America & Caribbean -
ArticlePublication 2019Health Impact and Cost-Effectiveness of SSB Taxes for Reducing Cancer Burden in the U.S.
This analysis evaluated the health outcomes, costs, and cost-effectiveness of a national sugar-sweetened beverage (SSB) …
This analysis evaluated the health outcomes, costs, and cost-effectiveness of a national sugar-sweetened beverage (SSB) tax policy for reducing obesity-related cancer in the U.S. A probabilistic cohort state-transition model, the Diet Cancer Outcome Model (DiCOM), was used to project the effect of a national $0.01 per ounce SSB excise tax on 13 obesity-associated cancers among U.S. adults age 20 and older over their lifetime. Cost-effectiveness was evaluated using both government affordability and societal perspectives. Results showed…
Microsimulation | Health/Medicine | Mathematical Models | Cost-Effectiveness Analysis | Chronic Disease/Risk | Policy/Regulation | Economics/Finance | Government/Law | North America -
ArticlePublication 2020Translating Population Evidence to Individual Patients
In this paper, the authors describe the differences in population level outcomes compared to individual …
In this paper, the authors describe the differences in population level outcomes compared to individual patients and discuss ways that these are differences. The authors cover topics including the difference between relative and absolute risk and benefit. They use an example of the decision to start anticoagulation in new-onset atrial fibrillation to discuss translating population level evidence to treatment of an individual. These options include generalizability, subgroup analysis, prediction rules, following response to therapy, and even…
Test Performance | Health/Medicine | Evidence Synthesis | Health Systems | Clinical Care -
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…
Test Performance | Health/Medicine | Probability/Bayes | Clinical Care