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Objectives: Minimal important difference (MID), the smallest change or difference that patients perceive as important, aids interpretation of change in patient-reported outcome measure (PROM) scores. A credibility instrument that assesses the methodological rigor of an anchor-based MID includes one core item addressing the correlation between the PROM and the anchor. However, the majority of MID studies in the literature fail to report the correlation. To address this issue, we extended the anchor-based MID credibility instrument by adding an item addressing construct proximity as an alternative to the correlation item. Study Design and Setting: Informed by an MID methodological survey, we added an alternative item—a subjective assessment of similarity of the constructs (i.e., construct proximity) between PROM and anchor—to the correlation item and generated principles for the assessment. We sampled 101 MIDs and analyzed the assessments performed by each pair of raters. By calculating weighted Cohen's kappa, we assessed the reliability of the assessments. Results: Construct proximity assessment is based on the anticipated association between the anchor and PROM constructs: the closer the anticipated association, the higher the rating. Our detailed principles address the most frequently used anchors: transition ratings, measures of satisfaction, other PROMs, and clinical measures. The assessments showed acceptable agreement (weighted kappa 0.74, 95% CI 0.55–0.94) between raters. Conclusion: In the absence of a reported correlation coefficient, construct proximity assessment provides a useful alternative in the credibility assessment of anchor-based MID estimates.

To evaluate reporting of minimal important difference (MID) estimates using anchor-based methods for patient-reported outcome measures (PROMs), and the association with reporting deficiencies on their credibility.Systematic survey of primary studies empirically estimating MIDs. We searched Medline, EMBASE, PsycINFO, and the Patient-Reported Outcome and Quality of Life Instruments Database until October 2018. We evaluated study reporting, focusing on participants' demographics, intervention(s), characteristics of PROMs and anchors, and MID estimation method(s). We assessed the impact of reporting issues on credibility of MID estimates.In 585 studies reporting on 5,324 MID estimates for 526 distinct PROMs, authors frequently failed to adequately report key characteristics of PROMs and MIDs, including minimum and maximum values of PROM scale, measure of variability accompanying the MID estimate and number of participants included in the MID calculation. Across MID estimates (n = 5,324), the most serious reporting issues impacting credibility included infrequent reporting of the correlation between the anchor and PROM (66%), inadequate details to judge precision of MID point estimate (13%), and insufficient information about the threshold used to ascertain MIDs (16%).Serious issues of incomplete reporting in the MID literature threaten the optimal use of MID estimates to inform the magnitude of effects of interventions on PROMs.

Objective: Assess the impact of allocation concealment and blinding on the results of COVID-19 trials. Data sources: World Health Organization (WHO) COVID-19 database (up to February 2022) Methods: We included randomized trials that compared drug therapeutics with placebo or standard care in patients with COVID-19. We performed random-effects meta-regressions comparing the results of trials with and without allocation concealment and blinding of healthcare providers and patients. Results: We identified 488 trials. We found that, compared to trials with allocation concealment, trials without allocation concealment may estimate treatments to be more beneficial for mortality, mechanical ventilation, hospital admission, duration of hospitalization, and duration of mechanical ventilation, but results were imprecise. We did not find compelling evidence that, compared to trials with blinding, trials without blinding produce consistently different results for mortality, mechanical ventilation, and duration of hospitalization. We found that trials without blinding may estimate treatments to be more beneficial for hospitalizations and duration of mechanical ventilation. Conclusion: We did not find compelling evidence that COVID-19 trials in which healthcare providers and patients are blinded produce different results from trials without blinding but trials without allocation concealment estimate treatments to be more beneficial compared to trials with allocation concealment. What’s new? Additional information: For decades, allocation concealment (the concealment of the randomization sequence from personnel enrolling participants) and blinding (the concealment of the arm to which participants have been randomized from one or more individuals involved in a trial) have been important considerations in the assessment of risk of bias of trials. Previous studies have produced conflicting results with regards to the associations of blinding and allocation concealment and none have investigated the associations of allocation concealment and blinding in the context of COVID-19. Implications: Our study suggests that lack of blinding may not always bias results but that evidence users should remain skeptical of trials without allocation concealment.

OBJECTIVE To compare the relative efficacy and safety of pharmacologic antiinflammatory interventions for gout flares. METHODS We searched Ovid Medline, Embase, and Cochrane library for randomized controlled trials (RCTs) that compared pharmacologic antiinflammatory treatment of gout flares. We conducted a network meta-analysis (NMA) using a frequentist framework and assessed the certainty of evidence and made conclusions using the Grading of Recommendations Assessment, Development, and Evaluation for NMA. RESULTS In the 30 eligible RCTs, canakinumab provided the highest pain reduction at day 2 and at longest follow-up (mean difference relative to acetic acid derivative nonsteroidal antiinflammatory drugs [NSAIDs] -41.12 [95% confidence interval (95% CI) -53.36, -29.11] on a 0-100 scale at day 2, and mean difference -12.84 [95% CI -20.76, -4.91] at longest follow-up; both moderate certainty; minimum important difference -19). Intravenous or intramuscular corticosteroids were inferior to canakinumab but may be better than the other commonly used interventions (low to very low certainty). For joint tenderness, canakinumab may be the most effective intervention at day 2. Acetic acid derivative NSAIDs improved joint swelling better than ibuprofen NSAIDs at day 2 (mean difference -0.29 [95% CI -0.56, -0.02] on a 0-4 scale; moderate certainty) and improved patient global assessment (PtGA) greater than ibuprofen NSAIDs at the longest follow-up (mean difference -0.44 [95% CI -0.86, -0.02]; moderate). CONCLUSION Canakinumab may be superior to other alternatives and intravenous or intramuscular corticosteroids may be the second best in pain reduction. Acetic acid derivative NSAIDs may be superior to ibuprofen NSAIDs in improving joint swelling and PtGA.

Objectives The objective of the study was to develop an inventory summarizing all anchor-based minimal important difference (MID) estimates for patient-reported outcome measures (PROMs) available in the medical literature. Study Design and Setting We searched MEDLINE, EMBASE, CINAHL, PsycINFO, and the Patient-Reported Outcome and Quality of Life Instruments Database internal library (January 1989–October 2018). We included primary studies empirically calculating an anchor-based MID estimate for any PROM in adults and adolescents. Pairs of reviewers independently screened and selected studies, extracted data, and evaluated the credibility of the MIDs. Results We identified 585 eligible studies, the majority conducted in Europe (n = 211) and North America (n = 179), reporting 5,324 MID estimates for 526 distinct PROMs. Investigators conducted their studies in the context of patients receiving surgical (n = 105, 18%), pharmacological (n = 85, 15%), rehabilitation (n = 65, 11%), or a combination of interventions (n = 194, 33%). Of all MID estimates, 59% (n = 3,131) used a global rating of change anchor. Major credibility limitations included weak correlation (n = 1,246, 23%) or no information regarding the correlation (n = 3,498, 66%) between the PROM and anchor and imprecision in the MID estimate (n = 2,513, 47%). Conclusion A large number of MIDs for assisting in the interpretation of PROMs exist. The MID inventory will facilitate the use of MID estimates to inform the interpretation of the magnitude of treatment effects in clinical research and guideline development.

Purpose: To assess the trustworthiness and impact of preprint trial reports during the COVID-19 pandemic. Data sources: WHO COVID-19 database and the L-OVE COVID-19 platform by the Epistemonikos Foundation (up to August 3rd, 2021) Design: We compare the characteristics of COVID-19 trials with and without preprints, estimate time to publication of COVID-19 preprint reports, describe discrepancies in key methods and results between preprint and published trial reports, report the number of retracted preprints and publications, and assess whether including versus excluding preprint reports affects meta-analytic estimates and the certainty of evidence. For the effects of eight therapies on mortality and mechanical ventilation, we performed meta-analyses including preprints and excluding preprints at 1 month, 3 months, and 6 months after the first trial addressing the therapy became available either as a preprint or publication (120 meta-analyses in total). Results: We included 356 trials, 101 of which are only available as preprints, 181 as journal publications, and 74 as preprints first and subsequently published in journals. Half of all preprints remain unpublished at six months and a third at one year. There were few important differences in key methods and results between trial preprints and their subsequent published reports. We identified four retracted trials, three of which were published in peer-reviewed journals. With two exceptions (2/60; 3.3%), point estimates were consistent between meta-analyses including versus excluding preprints as to whether they indicated benefit, no appreciable effect, or harm. There were nine comparisons (9/60; 15%) for which the rating of the certainty of evidence differed when preprints were included versus excluded, for four of these comparisons the certainty of evidence including preprints was higher and for five of these comparisons the certainty of evidence including preprints was lower. Limitations: The generalizability of our results is limited to COVID-19. Preprints that are subsequently published in journals may be the most rigorous and may not represent all trial preprints. Conclusion: We found no compelling evidence that preprints provide less trustworthy results than published papers. We show that preprints remain the only source of findings of many trials for several months, for a length of time that is unacceptable in a health emergency. We show that including preprints may affect the results of meta-analyses and the certainty of evidence. We encourage evidence users to consider data from preprints in contexts in which decisions are being made rapidly and evidence is being produced faster than can be peer-reviewed.

Objective : To systematically survey the literature addressing the reporting of studies estimating anchor-based minimal important differences (MIDs) and choice of optimal MIDs. Study design and Setting : We searched Medline, Embase and PsycINFO from 1987 to March 2020. Teams of two reviewers independently identified eligible publications and extracted quotations addressing relevant issues for reporting and/or selecting anchor-based MIDs. Using a coding list, we assigned the same code to quotations capturing similar or related issues. For each code, we generated an ‘item’, i.e. a specific phrase or sentence capturing the underlying concept. When multiple concepts existed under a single code, the team created multiple items for that code. We clustered codes addressing a broader methodological issue into a ‘category’ and classified items as relevant for reporting, relevant for selecting an anchor-based MID, or both. Results : We identified 136 eligible publications that provided 6 categories (MID definition, anchors, patient-reported outcome measures, generalizability and statistics) and 24 codes. These codes contained 34 items related to reporting MID studies, of which 29 were also related to selecting MIDs. Conclusion : The systematic survey identified items related to reporting of anchor-based MID studies and selecting optimal MIDs. These provide a conceptual framework to inform the design of studies related to MIDs, and a basis for developing a reporting standard and a selection approach for MIDs.

ObjectiveTo compare the effects of interleukin 6 receptor blockers, tocilizumab and sarilumab, with or without corticosteroids, on mortality in patients with covid-19.DesignSystematic review and network meta-analysis.Data sourcesWorld Health Organization covid-19 database, a comprehensive multilingual source of global covid-19 literature, and two prospective meta-analyses (up to 9 June 2021).Review methodsTrials in which people with suspected, probable, or confirmed covid-19 were randomised to interleukin 6 receptor blockers (with or without corticosteroids), corticosteroids, placebo, or standard care. The analysis used a bayesian framework and assessed the certainty of evidence using the GRADE approach. Results from the fixed effect meta-analysis were used for the primary analysis.ResultsOf 45 eligible trials (20 650 patients) identified, 36 (19 350 patients) could be included in the network meta-analysis. Of 36 trials, 27 were at high risk of bias, primarily due to lack of blinding. Tocilizumab, in combination with corticosteroids, suggested a reduction in the risk of death compared with corticosteroids alone (odds ratio 0.79, 95% credible interval 0.70 to 0.88; 35 fewer deaths per 1000 people, 95% credible interval 52 fewer to 18 fewer per 1000; moderate certainty of evidence), as did sarilumab in combination with corticosteroids, compared with corticosteroids alone (0.73, 0.58 to 0.92; 43 fewer per 1000, 73 fewer to 12 fewer; low certainty). Tocilizumab and sarilumab, each in combination with corticosteroids, appeared to have similar effects on mortality when compared with each other (1.07, 0.86 to 1.34; eight more per 1000, 20 fewer to 35 more; low certainty). The effects of tocilizumab (1.12, 0.91 to 1.38; 20 more per 1000, 16 fewer to 59 more; low certainty) and sarilumab (1.07, 0.81 to 1.40; 11 more per 1000, 38 fewer to 55 more; low certainty), when used alone, suggested an increase in the risk of death.ConclusionThese findings suggest that in patients with severe or critical covid-19, tocilizumab, in combination with corticosteroids, probably reduces mortality, and that sarilumab, in combination with corticosteroids, might also reduce mortality. Tocilizumab and sarilumab, in combination with corticosteroids, could have similar effectiveness. Tocilizumab and sarilumab, when used alone, might not be beneficial.

Objective To evaluate the efficacy and safety of antiviral antibody therapies and blood products for the treatment of novel coronavirus disease 2019 (covid-19). Design Living systematic review and network meta-analysis, with pairwise meta-analysis for outcomes with insufficient data. Data sources WHO covid-19 database, a comprehensive multilingual source of global covid-19 literature, and six Chinese databases (up to 21 July 2021). Study selection Trials randomising people with suspected, probable, or confirmed covid-19 to antiviral antibody therapies, blood products, or standard care or placebo. Paired reviewers determined eligibility of trials independently and in duplicate. Methods After duplicate data abstraction, we performed random effects bayesian meta-analysis, including network meta-analysis for outcomes with sufficient data. We assessed risk of bias using a modification of the Cochrane risk of bias 2.0 tool. The certainty of the evidence was assessed using the grading of recommendations assessment, development, and evaluation (GRADE) approach. We meta-analysed interventions with ≥100 patients randomised or ≥20 events per treatment arm. Results As of 21 July 2021, we identified 47 trials evaluating convalescent plasma (21 trials), intravenous immunoglobulin (IVIg) (5 trials), umbilical cord mesenchymal stem cells (5 trials), bamlanivimab (4 trials), casirivimab-imdevimab (4 trials), bamlanivimab-etesevimab (2 trials), control plasma (2 trials), peripheral blood non-haematopoietic enriched stem cells (2 trials), sotrovimab (1 trial), anti-SARS-CoV-2 IVIg (1 trial), therapeutic plasma exchange (1 trial), XAV-19 polyclonal antibody (1 trial), CT-P59 monoclonal antibody (1 trial) and INM005 polyclonal antibody (1 trial) for the treatment of covid-19. Patients with non-severe disease randomised to antiviral monoclonal antibodies had lower risk of hospitalisation than those who received placebo: casirivimab-imdevimab (odds ratio (OR) 0.29 (95% CI 0.17 to 0.47); risk difference (RD) −4.2%; moderate certainty), bamlanivimab (OR 0.24 (0.06 to 0.86); RD −4.1%; low certainty), bamlanivimab-etesevimab (OR 0.31 (0.11 to 0.81); RD −3.8%; low certainty), and sotrovimab (OR 0.17 (0.04 to 0.57); RD −4.8%; low certainty). They did not have an important impact on any other outcome. There was no notable difference between monoclonal antibodies. No other intervention had any meaningful effect on any outcome in patients with non-severe covid-19. No intervention, including antiviral antibodies, had an important impact on any outcome in patients with severe or critical covid-19, except casirivimab-imdevimab, which may reduce mortality in patients who are seronegative. Conclusion In patients with non-severe covid-19, casirivimab-imdevimab probably reduces hospitalisation; bamlanivimab-etesevimab, bamlanivimab, and sotrovimab may reduce hospitalisation. Convalescent plasma, IVIg, and other antibody and cellular interventions may not confer any meaningful benefit. Systematic review registration This review was not registered. The protocol established a priori is included as a data supplement. Funding This study was supported by the Canadian Institutes of Health Research (grant CIHR- IRSC:0579001321). Readers’ note This article is a living systematic review that will be updated to reflect emerging evidence. Interim updates and additional study data will be posted on our website ( www.covid19lnma.com ).

ObjectiveTo assess the trustworthiness (ie, complete and consistent reporting of key methods and results between preprint and published trial reports) and impact (ie, effects of preprints on meta-analytic estimates and the certainty of evidence) of preprint trial reports during the covid-19 pandemic.DesignRetrospective review.Data sourcesWorld Health Organization covid-19 database and the Living Overview of the Evidence (L-OVE) covid-19 platform by the Epistemonikos Foundation (up to 3 August 2021).Main outcome measuresComparison of characteristics of covid-19 trials with and without preprints, estimates of time to publication of covid-19 preprints, and description of differences in reporting of key methods and results between preprints and their later publications. For the effects of eight treatments on mortality and mechanical ventilation, the study comprised meta-analyses including preprints and excluding preprints at one, three, and six months after the first trial addressing the treatment became available either as a preprint or publication (120 meta-analyses in total, 60 of which included preprints and 60 of which excluded preprints) and assessed the certainty of evidence using the GRADE framework.ResultsOf 356 trials included in the study, 101 were only available as preprints, 181 as journal publications, and 74 as preprints first and subsequently published in journals. The median time to publication of preprints was about six months. Key methods and results showed few important differences between trial preprints and their subsequent published reports. Apart from two (3.3%) of 60 comparisons, point estimates were consistent between meta-analyses including preprints versus those excluding preprints as to whether they indicated benefit, no appreciable effect, or harm. For nine (15%) of 60 comparisons, the rating of the certainty of evidence was different when preprints were included versus being excluded—the certainty of evidence including preprints was higher in four comparisons and lower in five comparisons.ConclusionNo compelling evidence indicates that preprints provide results that are inconsistent with published papers. Preprints remain the only source of findings of many trials for several months—an unsuitable length of time in a health emergency that is not conducive to treating patients with timely evidence. The inclusion of preprints could affect the results of meta-analyses and the certainty of evidence. Evidence users should be encouraged to consider data from preprints.

ObjectiveTo compare the effects of interleukin-6 (IL-6) receptor blockers, with or without corticosteroids, on mortality in patients with COVID-19.DesignSystematic review and network meta-analysisData sourcesWHO COVID-19 database, a comprehensive multilingual source of global covid-19 literature, and two prospective meta-analysesStudy selectionTrials 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.ResultsWe assessed the risk of bias of included trials using a modification of the Cochrane risk of bias 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).ConclusionIL-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.Systematic review registrationNAWhat is already known on this topic?IL-6 receptor blockers have immunosuppressive effects that may be important in COVID-19 patients with immune system dysfunction and inflammationCorticosteroids reduce the risk of death in patients with severe or critical COVID-19What this study addsOur systematic review and network meta-analysis provides a comprehensive review of the evidence addressing the effects of IL-6 receptor blockers, alone or in combination with corticosteroids, in COVID-19IL-6 receptor blockers when added to a standard care that includes corticosteroids, in patients with severe or critical COVID-19, probably reduce mortality.Tocilizumab and sarilumab in combination with corticosteroids may have similar effectiveness for reducing mortality.

ObjectiveTo 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).DesignLiving systematic review and network meta-analysis.Data sourcesWHO 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 selectionRandomized 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.MethodsAfter 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.ResultsThe 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.ConclusionHydroxychloroquine 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 registrationThis review was not registered. The protocol established a priori is included as a supplement.FundingThis study was supported by the Canadian Institutes of Health Research (grant CIHR-IRSC:0579001321).Readers’ noteThis 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.

Background Many studies have assessed the quality of news reports about the effects of health interventions, but there has been no systematic review of such studies or meta-analysis of their results. We aimed to fill this gap (PROSPERO ID: CRD42018095032). Methods We included studies that used at least one explicit, prespecified and generic criterion to assess the quality of news reports in print, broadcast, or online news media, and specified the sampling frame, and the selection criteria and technique. We assessed criteria individually for inclusion in the meta-analyses, excluding inappropriate criteria and criteria with inadequately reported results. We mapped and grouped criteria to facilitate evidence synthesis. Where possible, we extracted the proportion of news reports meeting the included criterion. We performed meta-analyses using a random effects model to estimate such proportions for individual criteria and some criteria groups, and to characterise heterogeneity across studies. Results We included 44 primary studies in the qualitative summary, and 18 studies and 108 quality criteria in the meta-analyses. Many news reports gave an unbalanced and oversimplified picture of the potential consequences of interventions. A limited number mention or adequately address conflicts of interest (22%; 95% CI 7%-49%) (low certainty), alternative interventions (36%; 95% CI 26%-47%) (moderate certainty), potential harms (40%; 95% CI 23%-61%) (low certainty), or costs (18%; 95% CI 12%-28%) (moderate certainty), or quantify effects (53%; 95% CI 36%-69%) (low certainty) or report absolute effects (17%; 95% CI 4%-49%) (low certainty). Discussion There is room for improving health news, but it is logically more important to improve the public’s ability to critically appraise health information and make judgements for themselves.

Clinical question What is the role of drugs in preventing covid-19? Why does this matter? There is widespread interest in whether drug interventions can be used for the prevention of covid-19, but there is uncertainty about which drugs, if any, are effective. Recommendations The second version of this living guideline reiterates the previous strong recommendation against the use of hydroxychloroquine and includes a new conditional recommendation against the use of tixagevimab-cilgavimab in individuals who do not have covid-19. How this guideline was created This living guideline is from the World Health Organization (WHO) and provides up to date covid-19 guidance to inform policy and practice worldwide. Magic Evidence Ecosystem Foundation (MAGIC) provides methodological support. A living systematic review with network analysis informs the recommendations. An international guideline development group (GDG) of content experts, clinicians, patients, an ethicist and methodologists produces recommendations following standards for trustworthy guideline development using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Understanding the recommendations The living network meta-analysis informing this guideline included 12 trials (8379 participants) comparing hydroxychloroquine to standard care/placebo, and one trial (5197 participants) comparing tixagevimab-cilgavimab to standard care/placebo. When moving from evidence to the continued strong recommendation against the use of hydroxychloroquine, the GDG emphasised additional evidence suggesting no or little effect on mortality and hospital admission, and an increased risk of adverse effects. For the new conditional recommendation against the use of tixagevimab-cilgavimab, the GDG emphasised in vitro evidence reducing the applicability of available trial data. While trial results demonstrated modest reduction in the occurrence of laboratory confirmed symptomatic covid-19, lack of in vitro neutralisation of new SARS-CoV-2 sub-lineages was considered to have rendered these results obsolete. Updates This is a living guideline. New recommendations will be published in this article and signposted by update notices to this guideline. Readers note This is the second version of the living guideline for drugs to prevent covid-19. It complements the WHO living guideline on drugs to treat covid-19 and living guidance regarding covid-19 related clinical management. When citing this article, please consider adding the update number and date of access for clarity.

Objective To compare the effects of treatments for 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, up to 1 March 2021 and six additional Chinese databases up to 20 February 2021. Studies identified as of 12 February 2021 were included in the analysis. Study selection Randomised clinical trials in which people with suspected, probable, or confirmed covid-19 were randomised to drug treatment or to standard care or placebo. Pairs of reviewers independently screened potentially eligible articles. Methods After duplicate data abstraction, a bayesian network meta-analysis was conducted. Risk of bias of the included studies was assessed using a modification of the Cochrane risk of bias 2.0 tool, and the certainty of the evidence using the grading of recommendations assessment, development, and evaluation (GRADE) approach. For each outcome, interventions were classified in groups from the most to the least beneficial or harmful following GRADE guidance. Results 196 trials enrolling 76 767 patients were included; 111 (56.6%) trials and 35 098 (45.72%) patients are new from the previous iteration; 113 (57.7%) trials evaluating treatments with at least 100 patients or 20 events met the threshold for inclusion in the analyses. Compared with standard care, corticosteroids probably reduce death (risk difference 20 fewer per 1000 patients, 95% credible interval 36 fewer to 3 fewer, moderate certainty), mechanical ventilation (25 fewer per 1000, 44 fewer to 1 fewer, moderate certainty), and increase the number of days free from mechanical ventilation (2.6 more, 0.3 more to 5.0 more, moderate certainty). Interleukin-6 inhibitors probably reduce mechanical ventilation (30 fewer per 1000, 46 fewer to 10 fewer, moderate certainty) and may reduce length of hospital stay (4.3 days fewer, 8.1 fewer to 0.5 fewer, low certainty), but whether or not they reduce mortality is uncertain (15 fewer per 1000, 30 fewer to 6 more, low certainty). Janus kinase inhibitors may reduce mortality (50 fewer per 1000, 84 fewer to no difference, low certainty), mechanical ventilation (46 fewer per 1000, 74 fewer to 5 fewer, low certainty), and duration of mechanical ventilation (3.8 days fewer, 7.5 fewer to 0.1 fewer, moderate certainty). The impact of remdesivir on mortality and most other outcomes is uncertain. The effects of ivermectin were rated as very low certainty for all critical outcomes, including mortality. In patients with non-severe disease, colchicine may reduce mortality (78 fewer per 1000, 110 fewer to 9 fewer, low certainty) and mechanical ventilation (57 fewer per 1000, 90 fewer to 3 more, low certainty). Azithromycin, hydroxychloroquine, lopinavir-ritonavir, and interferon-beta do not appear to reduce risk of death or have an effect on any other patient-important outcome. The certainty in effects for all other interventions was low or very low. Conclusion Corticosteroids and interleukin-6 inhibitors probably confer important benefits in patients with severe covid-19. Janus kinase inhibitors appear to have promising benefits, but certainty is low. Azithromycin, hydroxychloroquine, lopinavir-ritonavir, and interferon-beta do not appear to have any important benefits. Whether or not remdesivir, ivermectin, and other drugs confer any patient-important benefit remains uncertain. Systematic review registration This review was not registered. The protocol is publicly available in the supplementary material. Readers’ 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. This is the fourth version of the original article published on 30 July 2020 ( BMJ 2020;370:m2980), and previous versions can be found as data supplements. When citing this paper please consider adding the version number and date of access for clarity.

To provide guidance for the management of gout, including indications for and optimal use of urate-lowering therapy (ULT), treatment of gout flares, and lifestyle and other medication recommendations.Fifty-seven population, intervention, comparator, and outcomes questions were developed, followed by a systematic literature review, including network meta-analyses with ratings of the available evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, and patient input. A group consensus process was used to compose the final recommendations and grade their strength as strong or conditional.Forty-two recommendations (including 16 strong recommendations) were generated. Strong recommendations included initiation of ULT for all patients with tophaceous gout, radiographic damage due to gout, or frequent gout flares; allopurinol as the preferred first-line ULT, including for those with moderate-to-severe chronic kidney disease (CKD; stage3); using a low starting dose of allopurinol (≤100 mg/day, and lower in CKD) or febuxostat (40 mg/day); and a treat-to-target management strategy with ULT dose titration guided by serial serum urate (SU) measurements, with an SU target of6 mg/dl. When initiating ULT, concomitant antiinflammatory prophylaxis therapy for a duration of at least 3-6 months was strongly recommended. For management of gout flares, colchicine, nonsteroidal antiinflammatory drugs, or glucocorticoids (oral, intraarticular, or intramuscular) were strongly recommended.Using GRADE methodology and informed by a consensus process based on evidence from the current literature and patient preferences, this guideline provides direction for clinicians and patients making decisions on the management of gout.

Genetic predisposition to obesity presents a paradox: how do genetic variants with a detrimental impact on human health persist through evolutionary time? Numerous hypotheses, such as the thrifty genotype hypothesis, attempt to explain this phenomenon yet fail to provide a justification for the modern obesity epidemic. In this critical review, we appraise existing theories explaining the evolutionary origins of obesity and explore novel biological and sociocultural agents of evolutionary change to help explain the modern-day distribution of obesity-predisposing variants. Genetic drift, acting as a form of 'blind justice,' may randomly affect allele frequencies across generations while gene pleiotropy and adaptations to diverse environments may explain the rise and subsequent selection of obesity risk alleles. As an adaptive response, epigenetic regulation of gene expression may impact the manifestation of genetic predisposition to obesity. Finally, exposure to malnutrition and disease epidemics in the wake of oppressive social systems, culturally mediated notions of attractiveness and desirability, and diverse mating systems may play a role in shaping the human genome. As an important first step towards the identification of important drivers of obesity gene evolution, this review may inform empirical research focused on testing evolutionary theories by way of population genetics and mathematical modelling.

Objectives To identify credible anchor-based minimal important differences (MIDs) for patient-reported outcome measures (PROMs) relevant to a BMJ Rapid Recommendations addressing subacromial decompression surgery for shoulder pain. Design Systematic review. Outcome measures Estimates of anchor-based MIDs, and their credibility, for PROMs judged by the parallel BMJ Rapid Recommendations panel as important for informing their recommendation (pain, function and health-related quality of life (HRQoL)). Data sources MEDLINE, EMBASE and PsycINFO up to August 2018. Study selection and review methods We included original studies of any intervention for shoulder conditions reporting estimates of anchor-based MIDs for relevant PROMs. Two reviewers independently evaluated potentially eligible studies according to predefined selection criteria. Six reviewers, working in pairs, independently extracted data from eligible studies using a predesigned, standardised, pilot-tested extraction form and independently assessed the credibility of included studies using an MID credibility tool. Results We identified 22 studies involving 5562 patients that reported 74 empirically estimated anchor-based MIDs for 10 candidate instruments to assess shoulder pain, function and HRQoL. We identified MIDs of high credibility for pain and function outcomes and of low credibility for HRQoL. We offered median estimates for the systematic review team who applied these MIDs in Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence summaries and in their interpretations of results in the linked systematic review addressing the effectiveness of surgery for shoulder pain. Conclusions Our review provides anchor-based MID estimates, as well as a rating of their credibility, for PROMs for patients with shoulder conditions. The MID estimates inform the interpretation for a linked systematic review and guideline addressing subacromial decompression surgery for shoulder pain, and could also prove useful for authors addressing other interventions for shoulder problems. PROSPERO registration number CRD42018106531.

ObjectivesTo identify credible anchor-based minimal important differences (MIDs) for patient-reported outcome measures (PROMs) relevant to aBMJRapid Recommendations addressing subacromial decompression surgery for shoulder pain.DesignSystematic review.Outcome measuresEstimates of anchor-based MIDs, and their credibility, for PROMs judged by the parallelBMJRapid Recommendations panel as important for informing their recommendation (pain, function and health-related quality of life (HRQoL)).Data sourcesMEDLINE, EMBASE and PsycINFO up to August 2018.Study selection and review methodsWe included original studies of any intervention for shoulder conditions reporting estimates of anchor-based MIDs for relevant PROMs. Two reviewers independently evaluated potentially eligible studies according to predefined selection criteria. Six reviewers, working in pairs, independently extracted data from eligible studies using a predesigned, standardised, pilot-tested extraction form and independently assessed the credibility of included studies using an MID credibility tool.ResultsWe identified 22 studies involving 5562 patients that reported 74 empirically estimated anchor-based MIDs for 10 candidate instruments to assess shoulder pain, function and HRQoL. We identified MIDs of high credibility for pain and function outcomes and of low credibility for HRQoL. We offered median estimates for the systematic review team who applied these MIDs in Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence summaries and in their interpretations of results in the linked systematic review addressing the effectiveness of surgery for shoulder pain.ConclusionsOur review provides anchor-based MID estimates, as well as a rating of their credibility, for PROMs for patients with shoulder conditions. The MID estimates inform the interpretation for a linked systematic review and guideline addressing subacromial decompression surgery for shoulder pain, and could also prove useful for authors addressing other interventions for shoulder problems.PROSPERO registration numberCRD42018106531.

The association between rare coding loss-of-function (LOF) mutations in the melanocortin receptor 3 (MC3R) gene and human obesity is controversial. To fill this gap of knowledge, we performed a systematic review and meta-analysis of genetic association studies in all ages and ethnicities. Two reviewers independently performed risk of bias assessment and extracted data. We searched Medline, Embase, Web of Science Core Collection, BIOSIS Preview, CINAHL, ProQuest Dissertations & Theses, and reference lists of relevant studies. All case-control, cross-sectional, prospective, and retrospective studies that evaluated prevalence of rare (less than 1% frequency) coding partial/complete LOF mutations in MC3R among individuals with obesity and normal weight were included. Our systematic search identified 1925 references relevant to the present review. Six studies were deemed eligible. Meta-analysis of 2969 individuals with obesity and 2572 with normal weight showed a positive association between rare heterozygous coding partial/complete LOF mutations in MC3R and obesity in children and adults of European, North African, and Asian ancestries (odds ratio = 3.07; 95% CI, 1.48-7.00; P = 4.2 × 10-3 ). Our data demonstrates that rare partial/complete LOF mutations in the coding region of MC3R confer three-time increased risk of obesity in humans, and implies that rare genetic variants with intermediate effects contribute to the missing heritability of obesity.

Objective To determine and compare the effects of drug prophylaxis on SARS-CoV-2 infection and covid-19. Design Living systematic review and network meta-analysis. Data sources World Health Organization covid-19 database, a comprehensive multilingual source of global covid-19 literature to 25 March 2021, and six additional Chinese databases to 20 February 2021. Study selection Randomised trials of people at risk of covid-19 who were assigned to receive prophylaxis or no prophylaxis (standard care or placebo). Pairs of reviewers independently screened potentially eligible articles. Methods Random effects bayesian network meta-analysis was performed after duplicate data abstraction. Included studies were assessed for risk of bias using a modification of the Cochrane risk of bias 2.0 tool, and certainty of evidence was assessed using the grading of recommendations assessment, development, and evaluation (GRADE) approach. Results The first iteration of this living network meta-analysis includes nine randomised trials—six of hydroxychloroquine (n=6059 participants), one of ivermectin combined with iota-carrageenan (n=234), and two of ivermectin alone (n=540), all compared with standard care or placebo. Two trials (one of ramipril and one of bromhexine hydrochloride) did not meet the sample size requirements for network meta-analysis. Hydroxychloroquine has trivial to no effect on admission to hospital (risk difference 1 fewer per 1000 participants, 95% credible interval 3 fewer to 4 more; high certainty evidence) or mortality (1 fewer per 1000, 2 fewer to 3 more; high certainty). Hydroxychloroquine probably does not reduce the risk of laboratory confirmed SARS-CoV-2 infection (2 more per 1000, 18 fewer to 28 more; moderate certainty), probably increases adverse effects leading to drug discontinuation (19 more per 1000, 1 fewer to 70 more; moderate certainty), and may have trivial to no effect on suspected, probable, or laboratory confirmed SARS-CoV-2 infection (15 fewer per 1000, 64 fewer to 41 more; low certainty). Owing to serious risk of bias and very serious imprecision, and thus very low certainty of evidence, the effects of ivermectin combined with iota-carrageenan on laboratory confirmed covid-19 (52 fewer per 1000, 58 fewer to 37 fewer), ivermectin alone on laboratory confirmed infection (50 fewer per 1000, 59 fewer to 16 fewer) and suspected, probable, or laboratory confirmed infection (159 fewer per 1000, 165 fewer to 144 fewer) remain very uncertain. Conclusions Hydroxychloroquine prophylaxis has trivial to no effect on hospital admission and mortality, probably increases adverse effects, and probably does not reduce the risk of SARS-CoV-2 infection. Because of serious risk of bias and very serious imprecision, it is 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. Readers’ 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.

Objective To develop an instrument to evaluate the credibility of anchor based minimal important differences (MIDs) for outcome measures reported by patients, and to assess the reliability of the instrument. Design Instrument development and reliability study. Data sources Initial criteria were developed for evaluating the credibility of anchor based MIDs based on a literature review (Medline, Embase, CINAHL, and PsycInfo databases) and the experience of the authors in the methodology for estimation of MIDs. Iterative discussions by the team and pilot testing with experts and potential users facilitated the development of the final instrument. Participants With the newly developed instrument, pairs of masters, doctoral, or postdoctoral students with a background in health research methodology independently evaluated the credibility of a sample of MID estimates. Main outcome measures Core credibility criteria applicable to all anchor types, additional criteria for transition rating anchors, and inter-rater reliability coefficients were determined. Results The credibility instrument has five core criteria: the anchor is rated by the patient; the anchor is interpretable and relevant to the patient; the MID estimate is precise; the correlation between the anchor and the outcome measure reported by the patient is satisfactory; and the authors select a threshold on the anchor that reflects a small but important difference. The additional criteria for transition rating anchors are: the time elapsed between baseline and follow-up measurement for estimation of the MID is optimal; and the correlations of the transition rating with the baseline, follow-up, and change score in the patient reported outcome measures are satisfactory. Inter-rater reliability coefficients (ĸ) for the core criteria and for one item from the additional criteria ranged from 0.70 to 0.94. Reporting issues prevented the evaluation of the reliability of the three other additional criteria for the transition rating anchors. Conclusions Researchers, clinicians, and healthcare policy decision makers can consider using this instrument to evaluate the design, conduct, and analysis of studies estimating anchor based minimal important differences.