# \#covid-19

**URL:** https://discourse.datamethods.org/tag/covid-19/146.md

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## [French target trial using obs data of HCQ vs not in SARS-CoV-2 infection](https://discourse.datamethods.org/t/french-target-trial-using-obs-data-of-hcq-vs-not-in-sars-cov-2-infection/3206)

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**Author:** [@filipb](https://discourse.datamethods.org/u/filipb)\
**Replies:** 10\
**Last updated:** [August 5, 2026, 11:36am UTC](https://discourse.datamethods.org/t/french-target-trial-using-obs-data-of-hcq-vs-not-in-sars-cov-2-infection/3206 "2026-08-05T11:36:40Z")

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I have read through this observational data emulated target trial and would be interested in what the methodologists here think of the study. I personally like it and only found small quibbles with it. I think the conclu…

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## [Determining post-test probability of Covid-19](https://discourse.datamethods.org/t/determining-post-test-probability-of-covid-19/4723)

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**Author:** [@samw235711](https://discourse.datamethods.org/u/samw235711)\
**Replies:** 38\
**Last updated:** [January 12, 2024, 12:07am UTC](https://discourse.datamethods.org/t/determining-post-test-probability-of-covid-19/4723 "2024-01-12T00:07:51Z")

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I did this for myself this weekend. I could not find anything online that provided the plot I do here. I wanted to post this somewhere in case someone else was in a similar situation, but I hoped to run it by the folks…

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## [Is it the numerator or denominator which explains variations of a ratio?](https://discourse.datamethods.org/t/is-it-the-numerator-or-denominator-which-explains-variations-of-a-ratio/5600)

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**Author:** [@marcusbendtsen](https://discourse.datamethods.org/u/marcusbendtsen)\
**Replies:** 1\
**Last updated:** [May 11, 2022, 10:44am UTC](https://discourse.datamethods.org/t/is-it-the-numerator-or-denominator-which-explains-variations-of-a-ratio/5600 "2022-05-11T10:44:32Z")

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We are studying a collection of reports which account for the number of diagnosed cases of a disease at different hospitals pre- and during the Covid-19 pandemic. Cases are counted over comparable time intervals (for ins…

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## [First RCT of Lopinavir–Ritonavir on SARS-CoV2](https://discourse.datamethods.org/t/first-rct-of-lopinavir-ritonavir-on-sars-cov2/3105)

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**Author:** [@martinmodrak](https://discourse.datamethods.org/u/martinmodrak)\
**Replies:** 38\
**Last updated:** [October 8, 2021, 12:51pm UTC](https://discourse.datamethods.org/t/first-rct-of-lopinavir-ritonavir-on-sars-cov2/3105 "2021-10-08T12:51:37Z")

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https://www.nejm.org/doi/full/10.1056/NEJMoa2001282 The abstract: Methods We conducted a randomized, controlled, open-label trial involving hospitalized adult patients with confirmed SARS-CoV-2 infection, which causes…

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## [How to update a prognostic model of COVID-19 for the effect of vaccination](https://discourse.datamethods.org/t/how-to-update-a-prognostic-model-of-covid-19-for-the-effect-of-vaccination/4623)

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**Author:** [@Elias\_Eythorsson](https://discourse.datamethods.org/u/Elias_Eythorsson)\
**Replies:** 3\
**Last updated:** [August 7, 2021, 9:26pm UTC](https://discourse.datamethods.org/t/how-to-update-a-prognostic-model-of-covid-19-for-the-effect-of-vaccination/4623 "2021-08-07T21:26:36Z")

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We have just put up uploaded a pre-print (https://www.medrxiv.org/content/10.1101/2021.07.19.21260759v1) that describes the derivation and validation of a prognostic model for Covid-19 severity in a cohort of undifferent…

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## [Fully sequential Bayesian clinical trial design for in-hospital treatment of COVID-19](https://discourse.datamethods.org/t/fully-sequential-bayesian-clinical-trial-design-for-in-hospital-treatment-of-covid-19/3129)

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**Author:** [@f2harrell](https://discourse.datamethods.org/u/f2harrell)\
**Replies:** 23\
**Last updated:** [June 7, 2021, 5:38pm UTC](https://discourse.datamethods.org/t/fully-sequential-bayesian-clinical-trial-design-for-in-hospital-treatment-of-covid-19/3129 "2021-06-07T17:38:52Z")

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Our Research Methods Program of the Vanderbilt Institute for Clinical and Translational Research and Vanderbilt Department of Biostatistics have created a fully sequential design and analysis plan for the COVID ordinal …

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## [Corticosteroid Timing for COVD-19](https://discourse.datamethods.org/t/corticosteroid-timing-for-covd-19/4057)

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**Author:** [@llynn](https://discourse.datamethods.org/u/llynn)\
**Replies:** 3\
**Last updated:** [January 17, 2021, 5:33pm UTC](https://discourse.datamethods.org/t/corticosteroid-timing-for-covd-19/4057 "2021-01-17T17:33:34Z")

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Early guidelines reccommended against corticosteroids in COVID-19 but the NEJM RECOVERY trial showed significant benefit (approx 10% absolute reduction in mortality) when dexamethasone was given to patients receiving eit…

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## [Covid-19 vaccine Phase 3 trials](https://discourse.datamethods.org/t/covid-19-vaccine-phase-3-trials/3925)

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**Author:** [@RGNewcombe](https://discourse.datamethods.org/u/RGNewcombe)\
**Replies:** 2\
**Last updated:** [November 25, 2020, 3:58pm UTC](https://discourse.datamethods.org/t/covid-19-vaccine-phase-3-trials/3925 "2020-11-25T15:58:45Z")

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Great to see such encouraging interim headline results for efficacy of the Pfizer and Moderna vaccines! With what is admittedly the great benefit of hindsight - apparently it would have been better to randomise between a…

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## [Observational Study of Convalescent Plasma and FDA Response](https://discourse.datamethods.org/t/observational-study-of-convalescent-plasma-and-fda-response/3667)

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**Author:** [@f2harrell](https://discourse.datamethods.org/u/f2harrell)\
**Replies:** 17\
**Last updated:** [September 1, 2020, 7:43pm UTC](https://discourse.datamethods.org/t/observational-study-of-convalescent-plasma-and-fda-response/3667 "2020-09-01T19:43:23Z")

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In the preprint Effect of Convalescent Plasma on Mortality among Hospitalized Patients with COVID-19: Initial Three-Month Experience from Mayo Clinic by Joyner et al, an observational study of the use of convalescent pla…

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## [A JAMA paper on School Closing Timing and Covid-19 prevalence and mortality](https://discourse.datamethods.org/t/a-jama-paper-on-school-closing-timing-and-covid-19-prevalence-and-mortality/3634)

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**Author:** [@LauraRK](https://discourse.datamethods.org/u/LauraRK)\
**Replies:** 1\
**Last updated:** [August 7, 2020, 12:01pm UTC](https://discourse.datamethods.org/t/a-jama-paper-on-school-closing-timing-and-covid-19-prevalence-and-mortality/3634 "2020-08-07T12:01:13Z")

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So a friend sent me a blog that referenced the paper linked below https://jamanetwork.com/journals/jama/fullarticle/2769034 given there are only 50 states and rather noisy measures, I was shocked to see the substandard …

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## [Open-label RCT of triple combination (LPV/r, Ribavirin, Interferon) on SARS-CoV2](https://discourse.datamethods.org/t/open-label-rct-of-triple-combination-lpv-r-ribavirin-interferon-on-sars-cov2/3294)

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**Author:** [@Raj](https://discourse.datamethods.org/u/Raj)\
**Replies:** 1\
**Last updated:** [May 15, 2020, 5:49pm UTC](https://discourse.datamethods.org/t/open-label-rct-of-triple-combination-lpv-r-ribavirin-interferon-on-sars-cov2/3294 "2020-05-15T17:49:12Z")

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Study: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31042-4/fulltext This study is generating a lot of discussion at the moment. The reported effect sizes are larger than prior sars-cov2 studies, …

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## [SARS-CoV2 Testing: How Does PPV Factor into Discussion of Test Performance?](https://discourse.datamethods.org/t/sars-cov2-testing-how-does-ppv-factor-into-discussion-of-test-performance/3285)

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**Author:** [@tomasbencomo](https://discourse.datamethods.org/u/tomasbencomo)\
**Replies:** 4\
**Last updated:** [May 12, 2020, 6:12pm UTC](https://discourse.datamethods.org/t/sars-cov2-testing-how-does-ppv-factor-into-discussion-of-test-performance/3285 "2020-05-12T18:12:34Z")

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On Twitter I’ve seen lots of discussion on the sensitivity and specificity of tests for SARS-CoV2 (both diagnostic and antibody tests) but not a lot of discussion around the positive and negative predictive value of thes…

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## [COVID-19 Research Methods Resources](https://discourse.datamethods.org/t/covid-19-research-methods-resources/3143)

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**Author:** [@f2harrell](https://discourse.datamethods.org/u/f2harrell)\
**Replies:** 10\
**Last updated:** [May 4, 2020, 5:11am UTC](https://discourse.datamethods.org/t/covid-19-research-methods-resources/3143 "2020-05-04T05:11:17Z")

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This is a place where researchers can post links to resources under development, or the materials themselves, that would help other researchers, and also obtain feedback for those posting the material. This topic is a…

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## [Illness Severity among Non-COVID patients](https://discourse.datamethods.org/t/illness-severity-among-non-covid-patients/3185)

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**Author:** [@DanLane911](https://discourse.datamethods.org/u/DanLane911)\
**Replies:** 11\
**Last updated:** [April 19, 2020, 11:31pm UTC](https://discourse.datamethods.org/t/illness-severity-among-non-covid-patients/3185 "2020-04-19T23:31:02Z")

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Background Since the beginning of the pandemic, several anecdotal reports of Non-COVID patients presenting to Emergency services (both prehospital and hospital) with more severe disease have been received. The concern i…

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## [Visualization for Benefit of COVID-19 Testing for Decreasing Provider Risk During Intubation](https://discourse.datamethods.org/t/visualization-for-benefit-of-covid-19-testing-for-decreasing-provider-risk-during-intubation/3164)

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**Author:** [@dr.vancleve](https://discourse.datamethods.org/u/dr.vancleve)\
**Replies:** 1\
**Last updated:** [April 2, 2020, 12:33pm UTC](https://discourse.datamethods.org/t/visualization-for-benefit-of-covid-19-testing-for-decreasing-provider-risk-during-intubation/3164 "2020-04-02T12:33:37Z")

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Datamethods Colleagues - I am an anesthesiologist, and our largest professional society recently recommended that healthcare workers trained to place breathing tubes consider wearing a specialized, increasingly rare res…

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## [Power calculations for cluster-RCT in hospital infection control (PPE for Covid19)](https://discourse.datamethods.org/t/power-calculations-for-cluster-rct-in-hospital-infection-control-ppe-for-covid19/3161)

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**Author:** [@Raj](https://discourse.datamethods.org/u/Raj)\
**Replies:** 6\
**Last updated:** [April 1, 2020, 3:14pm UTC](https://discourse.datamethods.org/t/power-calculations-for-cluster-rct-in-hospital-infection-control-ppe-for-covid19/3161 "2020-04-01T15:14:29Z")

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Given the current COVID19 pandemic, having an RCT that could evaluate efficacy of PPE (personal protective equipment) would be of value to determine safety needs of Health care workers. However, previous sample calculat…

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## [COVID-19 Death Prediction Modeling Strategy Discussion](https://discourse.datamethods.org/t/covid-19-death-prediction-modeling-strategy-discussion/3153)

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**Author:** [@dr.vancleve](https://discourse.datamethods.org/u/dr.vancleve)\
**Replies:** 0\
**Last updated:** [March 29, 2020, 3:01pm UTC](https://discourse.datamethods.org/t/covid-19-death-prediction-modeling-strategy-discussion/3153 "2020-03-29T15:01:43Z")

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I’m very curious to hear the thoughts of this community on the modeling strategy employed by the IHME here: This twitter thread has some comments, but I’m more interested in the thoughts of the Bayesians in this commu…

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## ["Impressive" or "anecdotal"? Hydroxychloroquine + Azithromycin vs COVID-19 preprint](https://discourse.datamethods.org/t/impressive-or-anecdotal-hydroxychloroquine-azithromycin-vs-covid-19-preprint/3118)

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**Author:** [@davidcnorrismd](https://discourse.datamethods.org/u/davidcnorrismd)\
**Replies:** 4\
**Last updated:** [March 22, 2020, 2:27pm UTC](https://discourse.datamethods.org/t/impressive-or-anecdotal-hydroxychloroquine-azithromycin-vs-covid-19-preprint/3118 "2020-03-22T14:27:00Z")

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Discussed yesterday at both the highest and lowest levels … https://www.nytimes.com/video/us/politics/100000007046134/trump-fauci.html … this study \[1\] apparently dichotomized a PCR cycle threshold C\_t such that C\_t \\ge…

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## [Imperial College Paper on Interventions to Reduce COVID-19 Population Level Impact](https://discourse.datamethods.org/t/imperial-college-paper-on-interventions-to-reduce-covid-19-population-level-impact/3107)

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**Author:** [@MSchwartz](https://discourse.datamethods.org/u/MSchwartz)\
**Replies:** 0\
**Last updated:** [March 19, 2020, 12:40pm UTC](https://discourse.datamethods.org/t/imperial-college-paper-on-interventions-to-reduce-covid-19-population-level-impact/3107 "2020-03-19T12:40:43Z")

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Hi All, I was initially thinking about adding this as a comment to the thread on prediction models for COVID-19, but that is focused on prospective predictions for individuals, whereas this paper from Ferguson et al at …