Large Language Model as Unsupervised Health Information Retriever.

Retrieving health information is a task of search for health-related information from a variety of sources. Gathering self-reported health information may help enrich the knowledge body of the disease and its symptoms. We investigated retrieving symptom mentions in COVID-19-related Twitter posts with a pretrained large language model (GPT-3) without providing any examples (zero-shot learning). We introduced a new performance measure of total match (TM) to include exact, partial and semantic matches. Our results show that the zero-shot approach is a powerful method without the need to annotate any data, and it can assist in generating instances for few-shot learning which may achieve better performance.

Renin-Angiotensin System Modulation With Synthetic Angiotensin (1-7) and Angiotensin II Type 1 Receptor-Biased Ligand in Adults With COVID-19: Two Randomized Clinical Trials.

Importance: Preclinical models suggest dysregulation of the renin-angiotensin system (RAS) caused by SARS-CoV-2 infection may increase the relative activity of angiotensin II compared with angiotensin (1-7) and may be an important contributor to COVID-19 pathophysiology. Objective: To evaluate the efficacy and safety of RAS modulation using 2 investigational RAS agents, TXA-127 (synthetic angiotensin [1-7]) and TRV-027 (an angiotensin II type 1 receptor-biased ligand), that are hypothesized to potentiate the action of angiotensin (1-7) and mitigate the action of the angiotensin II. Design, Setting, and Participants: Two randomized clinical trials including adults hospitalized with acute COVID-19 and new-onset hypoxemia were conducted at 35 sites in the US between July 22, 2021, and April 20, 2022; last follow-up visit: July 26, 2022. Interventions: A 0.5-mg/kg intravenous infusion of TXA-127 once daily for 5 days or placebo. A 12-mg/h continuous intravenous infusion of TRV-027 for 5 days or placebo. Main Outcomes and Measures: The primary outcome was oxygen-free days, an ordinal outcome that classifies a patient's status at day 28 based on mortality and duration of supplemental oxygen use; an adjusted odds ratio (OR) greater than 1.0 indicated superiority of the RAS agent vs placebo. A key secondary outcome was 28-day all-cause mortality. Safety outcomes included allergic reaction, new kidney replacement therapy, and hypotension. Results: Both trials met prespecified early stopping criteria for a low probability of efficacy. Of 343 patients in the TXA-127 trial (226 [65.9%] aged 31-64 years, 200 [58.3%] men, 225 [65.6%] White, and 274 [79.9%] not Hispanic), 170 received TXA-127 and 173 received placebo. Of 290 patients in the TRV-027 trial (199 [68.6%] aged 31-64 years, 168 [57.9%] men, 195 [67.2%] White, and 225 [77.6%] not Hispanic), 145 received TRV-027 and 145 received placebo. Compared with placebo, both TXA-127 (unadjusted mean difference, -2.3 [95% CrI, -4.8 to 0.2]; adjusted OR, 0.88 [95% CrI, 0.59 to 1.30]) and TRV-027 (unadjusted mean difference, -2.4 [95% CrI, -5.1 to 0.3]; adjusted OR, 0.74 [95% CrI, 0.48 to 1.13]) resulted in no difference in oxygen-free days. In the TXA-127 trial, 28-day all-cause mortality occurred in 22 of 163 patients (13.5%) in the TXA-127 group vs 22 of 166 patients (13.3%) in the placebo group (adjusted OR, 0.83 [95% CrI, 0.41 to 1.66]). In the TRV-027 trial, 28-day all-cause mortality occurred in 29 of 141 patients (20.6%) in the TRV-027 group vs 18 of 140 patients (12.9%) in the placebo group (adjusted OR, 1.52 [95% CrI, 0.75 to 3.08]). The frequency of the safety outcomes was similar with either TXA-127 or TRV-027 vs placebo. Conclusions and Relevance: In adults with severe COVID-19, RAS modulation (TXA-127 or TRV-027) did not improve oxygen-free days vs placebo. These results do not support the hypotheses that pharmacological interventions that selectively block the angiotensin II type 1 receptor or increase angiotensin (1-7) improve outcomes for patients with severe COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04924660.

Oxygen-Saturation Targets for Critically Ill Adults Receiving Mechanical Ventilation.

BACKGROUND: Invasive mechanical ventilation in critically ill adults involves adjusting the fraction of inspired oxygen to maintain arterial oxygen saturation. The oxygen-saturation target that will optimize clinical outcomes in this patient population remains unknown. METHODS: In a pragmatic, cluster-randomized, cluster-crossover trial conducted in the emergency department and medical intensive care unit at an academic center, we assigned adults who were receiving mechanical ventilation to a lower target for oxygen saturation as measured by pulse oximetry (Spo₂) (90%; goal range, 88 to 92%), an intermediate target (94%; goal range, 92 to 96%), or a higher target (98%; goal range, 96 to 100%). The primary outcome was the number of days alive and free of mechanical ventilation (ventilator-free days) through day 28. The secondary outcome was death by day 28, with data censored at hospital discharge. RESULTS: A total of 2541 patients were included in the primary analysis. The median number of ventilator-free days was 20 (interquartile range, 0 to 25) in the lower-target group, 21 (interquartile range, 0 to 25) in the intermediate-target group, and 21 (interquartile range, 0 to 26) in the higher-target group (P = 0.81). In-hospital death by day 28 occurred in 281 of the 808 patients (34.8%) in the lower-target group, 292 of the 859 patients (34.0%) in the intermediate-target group, and 290 of the 874 patients (33.2%) in the higher-target group. The incidences of cardiac arrest, arrhythmia, myocardial infarction, stroke, and pneumothorax were similar in the three groups. CONCLUSIONS: Among critically ill adults receiving invasive mechanical ventilation, the number of ventilator-free days did not differ among groups in which a lower, intermediate, or higher Spo₂ target was used. (Supported by the National Heart, Lung, and Blood Institute and others; PILOT ClinicalTrials.gov number, NCT03537937.).

Neutralizing COVID-19 Convalescent Plasma in Adults Hospitalized With COVID-19: A Blinded, Randomized, Placebo-Controlled Trial.

BACKGROUND: Convalescent plasma has been one of the most common treatments for COVID-19, but most clinical trial data to date have not supported its efficacy. RESEARCH QUESTION: Is rigorously selected COVID-19 convalescent plasma with neutralizing anti-SARS-CoV-2 antibodies an efficacious treatment for adults hospitalized with COVID-19? STUDY DESIGN AND METHODS: This was a multicenter, blinded, placebo-controlled randomized clinical trial among adults hospitalized with SARS-CoV-2 infection and acute respiratory symptoms for < 14 days. Enrolled patients were randomly assigned to receive one unit of COVID-19 convalescent plasma (n = 487) or placebo (n = 473). The primary outcome was clinical status (disease severity) 14 days following study infusion measured with a seven-category ordinal scale ranging from discharged from the hospital with resumption of normal activities (lowest score) to death (highest score). The primary outcome was analyzed with a multivariable ordinal regression model, with an adjusted odds ratio (aOR) < 1.0 indicating more favorable outcomes with convalescent plasma than with placebo. In secondary analyses, trial participants were stratified according to the presence of endogenous anti-SARS-CoV-2 antibodies ("serostatus") at randomization. The trial included 13 secondary efficacy outcomes, including 28-day mortality. RESULTS: Among 974 randomized patients, 960 were included in the primary analysis. Clinical status on the ordinal outcome scale at 14 days did not differ between the convalescent plasma and placebo groups in the overall population (aOR, 1.04; one-seventh support interval [1/7 SI], 0.82-1.33), in patients without endogenous antibodies (aOR, 1.15; 1/7 SI, 0.74-1.80), or in patients with endogenous antibodies (aOR, 0.96; 1/7 SI, 0.72-1.30). None of the 13 secondary efficacy outcomes were different between groups. At 28 days, 89 of 482 (18.5%) patients in the convalescent plasma group and 80 of 465 (17.2%) patients in the placebo group had died (aOR, 1.04; 1/7 SI, 0.69-1.58). INTERPRETATION: Among adults hospitalized with COVID-19, including those seronegative for anti-SARS-CoV-2 antibodies, treatment with convalescent plasma did not improve clinical outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT04362176; URL: www. CLINICALTRIALS: gov.

Discovery of COVID-19 Symptomatic Experience Reported by Twitter Users.

Since the beginning of the COVID-19 pandemic, patients shared their personal experiences of the viral infection on social media. Gathering their symptomatic experiences reported on Twitter may help better understand the infectious disease and supplement our knowledge of the disease gathered by healthcare workers. In this study, we identified personal experience tweets related to COVID-19 infection using a pre-trained and fine-tuned language model, and annotated the machine-identified tweets in order to extract the information of infection status, symptom concepts, and the days the symptomatic experience occurred. Our result shows that the top 10 most common symptoms mentioned in the collected Twitter data are in line with those published by WHO and CDC. The symptoms along with the day information appear to provide additional insight on how the infection progresses in infected individuals.

Securely sharing DSMB reports to speed decision making from multiple, concurrent, independent studies of similar treatments in COVID-19.

Introduction: As clinical trials were rapidly initiated in response to the COVID-19 pandemic, Data and Safety Monitoring Boards (DSMBs) faced unique challenges overseeing trials of therapies never tested in a disease not yet characterized. Traditionally, individual DSMBs do not interact or have the benefit of seeing data from other accruing trials for an aggregated analysis to meaningfully interpret safety signals of similar therapeutics. In response, we developed a compliant DSMB Coordination (DSMBc) framework to allow the DSMB from one study investigating the use of SARS-CoV-2 convalescent plasma to treat COVID-19 to review data from similar ongoing studies for the purpose of safety monitoring. Methods: The DSMBc process included engagement of DSMB chairs and board members, execution of contractual agreements, secure data acquisition, generation of harmonized reports utilizing statistical graphics, and secure report sharing with DSMB members. Detailed process maps, a secure portal for managing DSMB reports, and templates for data sharing and confidentiality agreements were developed. Results: Four trials participated. Data from one trial were successfully harmonized with that of an ongoing trial. Harmonized reports allowing for visualization and drill down into the data were presented to the ongoing trial's DSMB. While DSMB deliberations are confidential, the Chair confirmed successful review of the harmonized report. Conclusion: It is feasible to coordinate DSMB reviews of multiple independent studies of a similar therapeutic in similar patient cohorts. The materials presented mitigate challenges to DSMBc and will help expand these initiatives so DSMBs may make more informed decisions with all available information.

Oxygen-Free Days as an Outcome Measure in Clinical Trials of Therapies for COVID-19 and Other Causes of New-Onset Hypoxemia.

Mortality historically has been the primary outcome of choice for acute and critical care clinical trials. However, undue reliance on mortality can limit the scope of trials that can be performed. Large sample sizes are usually needed for trials powered for a mortality outcome, and focusing solely on mortality fails to recognize the importance that reducing morbidity can have on patients' lives. The COVID-19 pandemic has highlighted the need for rapid, efficient trials to rigorously evaluate new therapies for hospitalized patients with acute lung injury. Oxygen-free days (OFDs) is a novel outcome for clinical trials that is a composite of mortality and duration of new supplemental oxygen use. It is designed to characterize recovery from acute lung injury in populations with a high prevalence of new hypoxemia and supplemental oxygen use. In these populations, OFDs captures two patient-centered consequences of acute lung injury: mortality and hypoxemic lung dysfunction. Power to detect differences in OFDs typically is greater than that for other clinical trial outcomes, such as mortality and ventilator-free days. OFDs is the primary outcome for the Fourth Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV-4) Host Tissue platform, which evaluates novel therapies targeting the host response to COVID-19 among adults hospitalized with COVID-19 and new hypoxemia. This article outlines the rationale for use of OFDs as an outcome for clinical trials, proposes a standardized method for defining and analyzing OFDs, and provides a framework for sample size calculations using the OFD outcome.

Assessment of Awake Prone Positioning in Hospitalized Adults With COVID-19: A Nonrandomized Controlled Trial.

Importance: Awake prone positioning may improve hypoxemia among patients with COVID-19, but whether it is associated with improved clinical outcomes remains unknown. Objective: To determine whether the recommendation of awake prone positioning is associated with improved outcomes among patients with COVID-19-related hypoxemia who have not received mechanical ventilation. Design, Setting, and Participants: This pragmatic nonrandomized controlled trial was conducted at 2 academic medical centers (Vanderbilt University Medical Center and NorthShore University HealthSystem) during the COVID-19 pandemic. A total of 501 adult patients with COVID-19-associated hypoxemia who had not received mechanical ventilation were enrolled from May 13 to December 11, 2020. Interventions: Patients were assigned 1:1 to receive either the practitioner-recommended awake prone positioning intervention (intervention group) or usual care (usual care group). Main Outcomes and Measures: Primary outcome analyses were performed using a bayesian proportional odds model with covariate adjustment for clinical severity ranking based on the World Health Organization ordinal outcome scale, which was modified to highlight the worst level of hypoxemia on study day 5. Results: A total of 501 patients (mean [SD] age, 61.0 [15.3] years; 284 [56.7%] were male; and most [417 (83.2%)] were self-reported non-Hispanic or non-Latinx) were included. Baseline severity was comparable between the intervention vs usual care groups, with 170 patients (65.9%) vs 162 patients (66.7%) receiving oxygen via standard low-flow nasal cannula, 71 patients (27.5%) vs 62 patients (25.5%) receiving oxygen via high-flow nasal cannula, and 16 patients (6.2%) vs 19 patients (7.8%) receiving noninvasive positive-pressure ventilation. Nursing observations estimated that patients in the intervention group spent a median of 4.2 hours (IQR, 1.8-6.7 hours) in the prone position per day compared with 0 hours (IQR, 0-0.7 hours) per day in the usual care group. On study day 5, the bayesian posterior probability of the intervention group having worse outcomes than the usual care group on the modified World Health Organization ordinal outcome scale was 0.998 (posterior median adjusted odds ratio [aOR], 1.63; 95% credibility interval [CrI], 1.16-2.31). However, on study days 14 and 28, the posterior probabilities of harm were 0.874 (aOR, 1.29; 95% CrI, 0.84-1.99) and 0.673 (aOR, 1.12; 95% CrI, 0.67-1.86), respectively. Exploratory outcomes (progression to mechanical ventilation, length of stay, and 28-day mortality) did not differ between groups. Conclusions and Relevance: In this nonrandomized controlled trial, prone positioning offered no observed clinical benefit among patients with COVID-19-associated hypoxemia who had not received mechanical ventilation. Moreover, there was substantial evidence of worsened clinical outcomes at study day 5 among patients recommended to receive the awake prone positioning intervention, suggesting potential harm. Trial Registration: ClinicalTrials.gov Identifier: NCT04359797.

Standardized two-step testing of antibody activity in COVID-19 convalescent plasma.

The COVID-19 pandemic revealed an urgent need for rapid profiling of neutralizing antibody responses and development of antibody therapeutics. The current Food and Drug Administration-approved serological tests do not measure antibody-mediated viral neutralization, and there is a need for standardized quantitative neutralization assays. We report a high-throughput two-step profiling approach for identifying neutralizing convalescent plasma. Screening and downselection for serum antibody binding to the receptor-binding domain are followed by quantitative neutralization testing using a chimeric vesicular stomatitis virus expressing spike protein of SARS-CoV-2 in a real-time cell analysis assay. This approach enables a predictive screening process for identifying plasma units that neutralize SARS-CoV-2. To calibrate antibody neutralizing activity in serum from convalescent plasma donors, we introduce a neutralizing antibody standard reagent composed of two human antibodies that neutralize SARS-CoV strains, including SARS-CoV-2 variants of concern. Our results provide a framework for establishing a standardized assessment of antibody-based interventions against COVID-19.

Protocol and statistical analysis plan for the Pragmatic Investigation of optimaL Oxygen Targets (PILOT) clinical trial.

INTRODUCTION: Mechanical ventilation of intensive care unit (ICU) patients universally involves titration of the fraction of inspired oxygen to maintain arterial oxygen saturation (SpO2). However, the optimal SpO2 target remains unknown. METHODS AND ANALYSIS: The Pragmatic Investigation of optimaL Oxygen Targets (PILOT) trial is a prospective, unblinded, pragmatic, cluster-crossover trial being conducted in the emergency department (ED) and medical ICU at Vanderbilt University Medical Center in Nashville, Tennessee, USA. PILOT compares use of a lower SpO2 target (target 90% and goal range: 88%-92%), an intermediate SpO2 target (target 94% and goal range: 92%-96%) and a higher SpO2 target (target 98% and goal range: 96%-100%). The study units are assigned to a single SpO2 target (cluster-level allocation) for each 2-month study block, and the assigned SpO2 target switches every 2 months in a randomly generated sequence (cluster-level crossover). The primary outcome is ventilator-free days (VFDs) to study day 28, defined as the number of days alive and free of invasive mechanical ventilation from the final receipt of invasive mechanical ventilation through 28 days after enrolment. ETHICS AND DISSEMINATION: The trial was approved by the Vanderbilt Institutional Review Board. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences. TRIAL REGISTRATION NUMBER: The trial protocol was registered with ClinicalTrials.gov on 25 May 2018 prior to initiation of patient enrolment (ClinicalTrials.gov identifier: NCT03537937).

Passive Immunity Trial for Our Nation (PassITON): study protocol for a randomized placebo-control clinical trial evaluating COVID-19 convalescent plasma in hospitalized adults.

BACKGROUND: Convalescent plasma is being used widely as a treatment for coronavirus disease 2019 (COVID-19). However, the clinical efficacy of COVID-19 convalescent plasma is unclear. METHODS: The Passive Immunity Trial for Our Nation (PassITON) is a multicenter, placebo-controlled, blinded, randomized clinical trial being conducted in the USA to provide high-quality evidence on the efficacy of COVID-19 convalescent plasma as a treatment for adults hospitalized with symptomatic disease. Adults hospitalized with COVID-19 with respiratory symptoms for less than 14 days are eligible. Enrolled patients are randomized in a 1:1 ratio to 1 unit (200-399 mL) of COVID-19 convalescent plasma that has demonstrated neutralizing function using a SARS-CoV-2 chimeric virus neutralization assay. Study treatments are administered in a blinded fashion and patients are followed for 28 days. The primary outcome is clinical status 14 days after study treatment as measured on a 7-category ordinal scale assessing mortality, respiratory support, and return to normal activities of daily living. Key secondary outcomes include mortality and oxygen-free days. The trial is projected to enroll 1000 patients and is designed to detect an odds ratio ≤ 0.73 for the primary outcome. DISCUSSION: This trial will provide the most robust data available to date on the efficacy of COVID-19 convalescent plasma for the treatment of adults hospitalized with acute moderate to severe COVID-19. These data will be useful to guide the treatment of COVID-19 patients in the current pandemic and for informing decisions about whether developing a standardized infrastructure for collecting and disseminating convalescent plasma to prepare for future viral pandemics is indicated. TRIAL REGISTRATION: ClinicalTrials.gov NCT04362176 . Registered on 24 April 2020.

A high-throughput liquid bead array assay confirms strong correlation between SARS-CoV-2 antibody level and COVID-19 severity.

A detailed understanding of the adaptive host response to SARS-CoV-2 infection in humans is urgently needed. We developed a sensitive, high-throughput, and efficient assay using liquid bead array technology. We observed advantages over traditional ELISA for the detection and quantification of binding IgG against the receptor binding domain (RBD) of SARS-CoV-2. To determine whether COVID-19 symptom severity correlates with SARS-CoV-2 IgG, we measured anti-RBD IgG levels from 67 subjects recovered from PCR-confirmed COVID-19. We found that COVID-19 symptom severity strongly correlated with RBD IgG level (p < 0.001). These findings have substantial implications for public policy surrounding assessments of antibody responses and possible immunity, as not all cases of COVID-19 can be assumed to generate a protective antibody response, and mild disease in particular is capable of generating very low-level anti-RBD IgG levels. These findings also have important implications for the selection of donors for convalescent plasma to be used therapeutically.

Equipoise and research in the current COVID-19 pandemic

A review. Equipoise in translational research and in clin. practice means there is essential uncertainty in terms of benefit or risk resulting from the use of a particular therapy. The interplay between equipoise and ethics form one of the essential foundations of clin. research;one notable clin. ethicist succinctly characterized equipoise as "a clin. necessary condition in all cases of clin. research.". In the setting of COVID-19, there are no therapies with known effect. We rely on supportive care only. To be clear: 100% of pharmacol. therapies in use today are not established for this disease and no evidence exists that any treatment is more helpful than harmful, a critical premise underlying the ethical practice of medicine. Fundamentally, a firm evidence base on which to decide the appropriate path for the patients in our care is lacking, and the abundance of anecdote -- normally a hypothesis generation mechanism -- can get in the way of our societal need to understand the risks and benefits of untested therapies through well controlled, randomized trials. The challenges facing us in the current pandemic are undeniably urgent, but do not preclude systematic and thorough evaluation of risk and benefit. This call is echoed by others advocating for design and completion of high-quality trials to evaluate the safety and efficacy of all therapies under consideration for COVID-19.