Resources Repository
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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 | Technology Assessment | Infectious Diseases | Clinical Care | Health/Medicine -
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 -
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 -
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…
Evidence Synthesis | Test Performance | Health Systems | Clinical Care | Health/Medicine -
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 2017Benefit and Harm of Intensive Blood Pressure Treatment: Derivation and Validation of Risk Models Using Data from the Sprint and Accord Trials
Intensive blood pressure (BP) treatment can avert cardiovascular disease (CVD) events but can cause some …
Intensive blood pressure (BP) treatment can avert cardiovascular disease (CVD) events but can cause some serious adverse events. The authors sought to create risk calculators to estimate individual patients’ chances of benefit and harm from intensive treatment. They developed statistical models of cardiovascular events and serious adverse events from individual participant data from the Systolic Blood Pressure Intervention Trial (SPRINT) of intensive blood pressure treatment (N = 9,069 with complete covariate data) and validated them…
Evidence Synthesis | Probability/Bayes | Health Outcomes | Chronic Disease/Risk -
ArticlePublication 2015A Conceptual Model for Breast, Cervical, and Colorectal Cancer Screening
General frameworks of the cancer screening process are available, but none directly compare the process …
General frameworks of the cancer screening process are available, but none directly compare the process in detail across different organ sites. This limits the ability of medical and public health professionals to develop and evaluate coordinated screening programs that apply resources and population management strategies available for one cancer site to other sites. This paper presents a conceptual model that incorporates a single screening episode for breast, cervical, and colorectal cancers into a unified framework based…
Evidence Synthesis | Test Performance | Preferences/Values | Health Outcomes | Microsimulation | Cost-Effectiveness Analysis | Chronic Disease/Risk | Health Systems | Clinical Care | Health/Medicine | Science/Technology | North America -
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…
Evidence Synthesis | Health Outcomes | Microsimulation | Calibration/Validation | Maternal/Reproductive Health | Health Systems | Clinical Care | Health/Medicine | Global -
ArticlePublication 2010Alternative Strategies to Reduce Maternal Mortality in India: A Cost-Effectiveness Analysis
This article, published in PLoS Medicine, conducted a cost-effectiveness analysis of strategies to improve pregnancy …
This article, published in PLoS Medicine, conducted a cost-effectiveness analysis of strategies to improve pregnancy and childbirth safety in India. Country- and region-specific data were synthesized using a computer-based model that simulates the natural history of pregnancy and pregnancy-associated complications in individual women, and considers delivery location, attendant, and facility level. Model validation compared projected maternal indicators with empiric data. Strategies consisted of improving coverage of effective interventions that could be provided individually or packaged…
Evidence Synthesis | Mathematical Models | Microsimulation | Cost-Effectiveness Analysis | Maternal/Reproductive Health | Economics/Finance | Health/Medicine | Global | Asia & Pacific