Resources Repository
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ArticlePublication 2021New Microsimulation Models to Inform Cervical Cancer Control
Health decision models consider the lifetime natural history of human papillomavirus (HPV) infection and pathogenesis …
Health decision models consider the lifetime natural history of human papillomavirus (HPV) infection and pathogenesis of cervical cancer, and estimate the long-term impact of preventive interventions. We propose a new health decision modeling framework that de-emphasizes previously used cytologic-colposcopic-histologic diagnoses, which are subjective and lack reproducibility, relying instead on HPV type and duration of infection as the major determinants of model transition probabilities. We posit that new model health states and corollary transitions are universal,…
Microsimulation | Infectious Diseases | Mathematical Models | Calibration/Validation | Decision Analysis | Cost-Effectiveness Analysis | Global -
ArticlePublication 2022Early HPV Natural History Transitions
Microsimulation models used to evaluate the cost-effectiveness of novel cervical cancer screening technologies rely on …
Microsimulation models used to evaluate the cost-effectiveness of novel cervical cancer screening technologies rely on accurate transition risks for human papillomavirus (HPV) infection, persistence (or absence of HPV clearance), progression to precancerous lesions, and invasion. To inform the refinement of such models, we compared the early natural history of HPV types using prospective data from immunocompetent women in the Guanacaste Natural History Study, the ASCUS-LSIL Triage Study, and the Costa Rica HPV Vaccine Trial. We…
Microsimulation | Infectious Diseases | Mathematical Models | Cost-Effectiveness Analysis | North America | Latin America & Caribbean -
ArticlePublication 2021Impact of COVID-19 on Cancer Diagnosis and Survival in Chile
This paper estimates the impact of the COVID-19 pandemic on delays in cancer diagnosis in …
This paper estimates the impact of the COVID-19 pandemic on delays in cancer diagnosis in Chile, using a microsimulation model of five cancers: breast, cervix, colorectal, prostate, and stomach. The model simulates cancer incidence and progression, as well as stage-specific cancer detection and survival probabilities, and was calibrated to empirical data on monthly detected cases, stage at diagnosis, and 5-year net survival. The analysis accounted for the impact of COVID-19 on month-by-month excess mortality and…
Microsimulation | Infectious Diseases | Health Outcomes | Calibration/Validation | Chronic Disease/Risk | Latin America & Caribbean -
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…
Test Performance | Infectious Diseases | Probability/Bayes | Technology Assessment | Clinical Care | Health/Medicine -
ToolInteractive 2020COVID-19 Antibody Tests: Calculator for Interpreting Test Results
Antibody testing can determine previous exposure to SARS-CoV-2 virus. This interactive calculator, linked to the article …
Antibody testing can determine previous exposure to SARS-CoV-2 virus. This interactive calculator, linked to the article below* on antibody testing for SARS-CoV-2 virus, allows users to vary the prior probability of infection, the sensitivity of SARS-CoV-2 antibody testing, and the specificity of SARS-CoV-2 antibody testing. Key points made in the article accompanying the interactive include: (1) antibody testing is likely to be most useful 2 weeks after infection, (2) sensitivity and specificity will vary over time and…
Test Performance | Infectious Diseases | Probability/Bayes | Technology Assessment | Clinical Care | Health/Medicine | Science/Technology -
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 | Infectious Diseases | Probability/Bayes | 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…
Test Performance | Infectious Diseases | Probability/Bayes | Health/Medicine | Science/Technology | Global -
ArticlePublication 2019Decision-Making for Universal Access to Tuberculosis Diagnosis In India
The authors evaluated the costs of centralized and decentralized testing for tuberculosis with Xpert MTB/RIF …
The authors evaluated the costs of centralized and decentralized testing for tuberculosis with Xpert MTB/RIF (Xpert), a WHO-endorsed test. They used an agent-based simulation of TB transmission in a hypothetical representative region in India to assess the impact and cost-effectiveness of various strategies to provide universal access to diagnosis and drug susceptibility testing (DST) for tuberculosis. The authors found that decentralization was most favorable compared to centralized testing when volume at decentralized facilities was high,…
Microsimulation | Infectious Diseases | Cost-Effectiveness Analysis | Health/Medicine | Asia & Pacific -
ArticlePublication 2019POC Diagnosis of TB With Truenat Assay: CEA for India's Public Sector
Using a microsimulation model, the authors compared four TB diagnostic strategies for HIV-negative adults with …
Using a microsimulation model, the authors compared four TB diagnostic strategies for HIV-negative adults with presumptive TB in order to evaluate the potential cost-effectiveness of strategies that incorporate Truenat, a molecular assay that rapidly detects TB and rifampicin-resistance. They projected life expectancy, costs, incremental cost-effectiveness ratios (ICERs), and 5-year budget impact of deploying Truenat POC in India's public sector. Used at the point-of-care in India, Truenat for TB diagnosis should improve linkage-to-care, increase life expectancy,…
Microsimulation | Infectious Diseases | Cost-Effectiveness Analysis | Health/Medicine | Asia & Pacific