ABSTRACT
Objective: Assess the impact of allocation concealment and blinding on the results of trials addressing COVID-19 therapeutics. Data sources: World Health Organization (WHO) COVID-19 database and the Living Overview of the Evidence (L-OVE) COVID-19 platform by the Epistemonikos Foundation (up to February 4th 2022) Methods: We included trials that compared drug treatments, antiviral antibodies and cellular therapies with placebo or standard care. For the five most commonly reported outcomes, if sufficient data were available, we performed random-effects meta-regression comparing the results of trials with and without allocation concealment and trials in which both healthcare providers and patients were blinded with trials in which healthcare providers and/or patients were aware of the intervention. A ratio of odds ratios (ROR) > 1 or a difference in mean difference (DMD) > 0 indicates that trials without allocation concealment or open-label trials produced larger effects than trials with allocation concealment or blinded trials. Results: As of February 4th 2022, we have identified 488 trials addressing COVID-19 drug treatments and antiviral antibodies and cellular therapies. Of these, 436 trials reported on one or more of our outcomes of interest and were included in our analyses. We found that trials without allocation concealment probably overestimate mortality (ROR 1.14 [95% CI 0.92 to 1.41]), need for mechanical ventilation (ROR 1.26 [95% CI 0.97 to 1.64]), admission to hospital (ROR 1.93 [95% CI 0.83 to 4.48]), duration of hospitalization (DMD 1.94 [95% CI 0.86 to 3.02]), and duration of mechanical ventilation (DMD 2.64 [95% CI -0.90 to 6.18]), but results were imprecise. We did not find compelling evidence that double-blind and open-label trials produce consistently different results for mortality (ROR 1.00 [95% CI 0.87 to 1.15]), need for mechanical ventilation (ROR 1.03 [95% CI 0.84 to 1.26]), and duration of hospitalization (DMD 0.47 days [95% CI -0.38 to 1.32]). We found that open-label trials may overestimate the beneficial effects of interventions for hospitalizations (ROR 1.87 [95% CI 0.95 to 3.67] and duration of mechanical ventilation (DMD 1.02 days [95% CI -1.30 to 3.35]), but results were imprecise. Conclusion: We found compelling evidence that, compared to trials with allocation concealment, trials without allocation concealment may overestimate the beneficial effects of treatments. We did not find evidence that trials without blinding addressing COVID-19 interventions produce consistently different results from trials with blinding. Our results suggest that consideration of blinding status may not be sufficient to judge risk of bias due to imbalances in co-interventions. Evidence users may consider evidence of differences in co-interventions between trial arms when judging the trustworthiness of open-label trials. We suggest, however, evidence users to remain skeptical of trials without allocation concealment.
Subject(s)
COVID-19 , Kidney DiseasesABSTRACT
Rationale: The COVID-19 pandemic disrupted non-COVID critical care trials globally as intensive care units (ICUs) prioritized patient care and COVID-specific research. The international randomized controlled trial CYCLE (Critical Care Cycling to Improve Lower Extremity Strength) was forced to halt recruitment at all sites in March 2020, creating immediate challenges. We applied the CONSERVE (CONSORT and SPIRIT Extension for RCTs Revised in Extenuating Circumstance) guidance to report the impact of the pandemic on CYCLE and describe our mitigation approaches.Methods On March 23, 2020, the CYCLE Methods Centre distributed a standardized email to determine the number of patients still in-hospital and those requiring imminent 90-day endpoint assessments. We assessed protocol fidelity by documenting attempts to provide the in-hospital randomized intervention (cycling or routine physiotherapy), collect the primary outcome (physical function 3-days post-ICU discharge), and 90-day outcomes. We advised sites to prioritize data for the study’s primary outcome. We sought feedback on pandemic barriers related to trial procedures.Results As of March 17, 2020, 197 patients (of 360 planned) had been randomized; 26 (13.2%) remained in hospital or were pending 90-day assessments. From 15 active sites (12 Canada, 2 US, 1 Australia), we identified 5 patients still receiving the study intervention in ICUs, 6 requiring primary outcomes, and 17 requiring 90-day assessments. All ICU interventions (5/5, 100%), 5/6 (83%) of primary outcomes, and all (17/17, 100%) 90-day assessments were attempted. Out of the 6 primary outcomes, one site was unable to attempt due to a temporary institutional ban on direct patient contact for non-COVID research, 2 were attempted but not completed due to reasons unrelated to the pandemic, and 3 were completed. Our main mitigation strategies included identifying patients at risk for protocol deviations, communicating early and frequently with sites, monitoring patient progress, data entry, and validation, and providing guidance for conducting some research activities remotely.Conclusions We retained all enrolled patients with minimal missing data using several time-sensitive strategies. Although CONSERVE recommends reporting only major modifications incurred by extenuating circumstances, we suggest that there are other benefits to reporting mitigation strategies with the goal of improving research transparency and trial management.Trial Registration: NCT03471247
Subject(s)
COVID-19ABSTRACT
Objective: To compare the effects of interleukin-6 (IL-6) receptor blockers, with or without corticosteroids, on mortality in patients with COVID-19. Design: Systematic review and network meta-analysis Data sources: WHO COVID-19 database, a comprehensive multilingual source of global covid-19 literature, and two prospective meta-analyses Study selection: Trials in which people with suspected, probable, or confirmed COVID-19 were randomized to IL-6 receptor blockers (with or without corticosteroids), corticosteroids, placebo, or standard care. Results: We assessed the risk of bias of included trials using a modification of the Cochrane risk of bias 2.0 tool. We performed a Bayesian fixed effect network meta-analysis and assessed the certainty of evidence using the GRADE approach. We identified 45 eligible trials (20,650 patients), 36 (19,350 patients) of which could be included in the network meta-analysis. 27 of 36 trials were rated at high risk of bias, primarily due to lack of blinding. Tocilizumab (20 more per 1000, 15 fewer to 59 more; low certainty) and sarilumab (11 more per 1000, 38 fewer to 55 more; low certainty) alone may not reduce the risk of death. Tocilizumab, in combination with corticosteroids, probably reduces the risk of death compared to corticosteroids alone (35 fewer per 1000, 52 fewer to 18 more; moderate certainty) and sarilumab, in combination with corticosteroids, may reduce the risk of death compared to corticosteroids alone (43 fewer, 73 fewer to 12 more; low certainty). Tocilizumab and sarilumab, both in combination with corticosteroids, may have similar effects (8 more per 1000, 20 fewer to 35 more; low certainty). Conclusion: IL-6 receptor blockers, when added to standard care that includes corticosteroids, in patients with severe or critical COVID-19, probably reduce mortality. Tocilizumab and sarilumab may have similar effectiveness.
Subject(s)
COVID-19 , DeathABSTRACT
Objective To determine and compare the effects of drug prophylaxis on severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (covid-19). Design Living systematic review and network meta-analysis. Data sources WHO covid-19 database, a comprehensive multilingual source of global covid-19 literature to 19 January 2021, and six additional Chinese databases to 20 January 2021. Study selection Randomized trials in which people at risk of covid-19 were randomized to drug prophylaxis or no prophylaxis (standard care or placebo). Pairs of reviewers independently screened potentially eligible articles. Methods After duplicate data abstraction, we conducted random-effects bayesian network meta-analysis. We assessed risk of bias of the included studies using a modification of the Cochrane risk of bias 2.0 tool and assessed the certainty of the evidence using the grading of recommendations assessment, development and evaluation (GRADE) approach. Results The first iteration of this living network meta-analysis includes nine randomized trials: six addressing hydroxychloroquine (6,059 participants), one addressing ivermectin combined with iota-carrageenan (234 participants) and two addressing ivermectin alone (540 participants), all compared to standard care or placebo. Hydroxychloroquine has no important effect on admission to hospital (risk difference (RD) 1 fewer per 1,000, 95% credible interval (CrI) 3 fewer to 4 more, high certainty) or mortality (RD 1 fewer per 1,000, 95% CrI 2 fewer to 3 more, high certainty). Hydroxychloroquine probably has no important effect on laboratory-confirmed infection (RD 2 more per 1,000, 95% CrI 18 fewer to 28 more, moderate certainty), probably increases adverse effects leading to drug discontinuation (RD 19 more per 1,000, 95% CrI 1 fewer to 70 more, moderate certainty) and may have no important effect on suspected, probable or laboratory-confirmed infection (RD 15 fewer per 1,000, 95% CrI 64 fewer to 41 more, low certainty). Due to serious risk of bias and very serious imprecision, and thus very low certainty evidence, the effects of ivermectin combined with iota-carrageenan on laboratory-confirmed infection (RD 52 fewer per 1,000, 95% CrI 58 fewer to 37 fewer), and ivermectin alone on laboratory-confirmed infection (RD 50 fewer per 1,000, 95% CrI 59 fewer to 16 fewer) and suspected, probable or laboratory-confirmed infection (RD 159 fewer per 1,000, 95% CrI 165 fewer to 144 fewer) remain uncertain. Conclusion Hydroxychloroquine prophylaxis does not have an important effect on hospital admission and mortality, probably increases adverse effects, and probably does not have an important effect on laboratory-confirmed SARS-CoV-2 infection. Because of serious risk of bias and very serious imprecision, we are highly uncertain whether ivermectin combined with iota-carrageenan and ivermectin alone reduce the risk of SARS-CoV-2 infection. Systematic review registration This review was not registered. The protocol established a priori is included as a supplement. Funding This study was supported by the Canadian Institutes of Health Research (grant CIHR-IRSC:0579001321). Reader note This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication.
Subject(s)
Coronavirus Infections , Laboratory Infection , COVID-19ABSTRACT
SARS-CoV-2 enters cells by binding to angiotensin-converting enzyme 2 (ACE2), and COVID-19 infection may therefore induce changes in the renin-angiotensin system (RAS). To determine the effects of COVID-19 on plasma RAS components, we measured plasma ACE, ACE2, and angiotensins I, (1-7), and II in 46 adults with COVID-19 at hospital admission and on days 2, 4, 7 and 14, compared to 50 blood donors (controls). We compared survivors vs. non-survivors, males vs. females, ventilated vs. not ventilated, and angiotensin receptor blocker (ARB) and angiotensin-converting enzyme (ACE) inhibitor-exposed vs. not exposed. At admission, COVID-19 patients had higher plasma levels of ACE (p=0.012), ACE2 (p=0.001) and angiotensin-(1-7) (p<0.001) than controls. Plasma ACE and ACE2 remained elevated for 14 days in COVID-19 patients, while plasma angiotensin-(1-7) decreased after 7 days. In adjusted analyses, plasma ACE was higher in males vs. females (p=0.042), and plasma angiotensin I was significantly lower in ventilated vs. non-ventilated patients (p=0.001). In summary, plasma ACE and ACE2 are increased for at least 14 days in patients with COVID-19 infection. Angiotensin-(1-7) levels are also elevated, but decline after 7 days. The results indicate dysregulation of the RAS with COVID-19, with increased circulating ACE2 throughout the course of infection.Clinical Trial Registration: https://clinicaltrials.gov/ Unique Identifier: NCT04510623
Subject(s)
COVID-19ABSTRACT
Background: The coronavirus disease (Covid-19) pandemic has produced a large number of clinical trial reports with unprecedented rapidity, raising concerns about methodological quality and potential for research waste. Objectives: To describe the characteristics of randomized clinical trials (RCTs) investigating prophylaxis or treatment of Covid-19 infection and examine the effect of trial characteristics on whether the study reported a statistically significant effect on the primary outcome(s). Study Design: Meta-epidemiological study of Covid-19 treatment and prophylaxis RCTs. Eligibility criteria: English-language RCTs (peer-reviewed or preprint) that evaluated pharmacologic agents or blood products compared to standard care, placebo, or an active comparator among participants with suspected or confirmed Covid-19 or at risk for Covid-19. We excluded trials of vaccines or traditional herbal medicines. Information sources: We searched 25 databases in the US Centre for Disease Control Downloadable Database from January 1 to October 21, 2020. Trial appraisal and synthesis methods: We extracted trial characteristics including number of centres, funding sources (industry versus non-industry), and sample size. We assessed risk of bias (RoB) using the modified Cochrane RoB 2.0 Tool. We used descriptive statistics to summarize trial characteristics and logistic regression to evaluate the association between RoB due to the randomization process, centre status (single vs. multicentre), funding source, and sample size, and statistically significant effect in the primary outcome. Results: We included 91 RCTs (46,802 participants) evaluating Covid-19 therapeutic drugs (n = 76), blood products (n = 9) or prophylactic drugs (n = 6). Of these, 40 (44%) were single-centre, 23 (25.3%) enrolled < 50 patients, and 28 (30.8%) received industry funding. RoB varied across trials, with high or probably high overall RoB in 75 (82.4%) trials, most frequently due to deviations from the intended protocol (including blinding) and randomization processes. Thirty-eight trials (41.8%) found a statistically significant effect in the primary outcome. RoB due randomization (odds ratio [OR] 3.77, 95% confidence interval [CI], 1.47 to 9.72) and single centre trials (OR 3.15, 95% CI, 1.25 to 7.97) were associated with higher likelihood of finding a statistically significant effect. Conclusions: There was high variability in RoB amongst Covid-19 trials. RoB attributed to the randomization process and single centre status were associated with a three-fold increase in the odds of finding a statistically significant effect. Researchers, funders, and knowledge users should remain cognizant of the impact of study characteristics, including RoB, on trial results when designing, conducting, and appraising Covid-19 trials. Registration number: CRD42020192095