Communication to promote and support physical distancing for COVID-19 prevention and control

BACKGROUND

This review is an update of a rapid review undertaken in 2020 to identify relevant, feasible and effective communication approaches to promote acceptance, uptake and adherence to physical distancing measures for COVID-19 prevention and control. The rapid review was published when little was known about transmission, treatment or future vaccination, and when physical distancing measures (isolation, quarantine, contact tracing, crowd avoidance, work and school measures) were the cornerstone of public health responses globally. This updated review includes more recent evidence to extend what we know about effective pandemic public health communication. This includes considerations of changes needed over time to maintain responsiveness to pandemic transmission waves, the (in)equities and variable needs of groups within communities due to the pandemic, and highlights again the critical role of effective communication as integral to the public health response.

OBJECTIVES

To update the evidence on the question 'What are relevant, feasible and effective communication approaches to promote acceptance, uptake and adherence to physical distancing measures for COVID-19 prevention and control?', our primary focus was communication approaches to promote and support acceptance, uptake and adherence to physical distancing.

SECONDARY OBJECTIVE

to explore and identify key elements of effective communication for physical distancing measures for different (diverse) populations and groups.

SEARCH METHODS

We searched MEDLINE, Embase and Cochrane Library databases from inception, with searches for this update including the period 1 January 2020 to 18 August 2021. Systematic review and study repositories and grey literature sources were searched in August 2021 and guidelines identified for the eCOVID19 Recommendations Map were screened (November 2021).

SELECTION CRITERIA

Guidelines or reviews focusing on communication (information, education, reminders, facilitating decision-making, skills acquisition, supporting behaviour change, support, involvement in decision-making) related to physical distancing measures for prevention and/or control of COVID-19 or selected other diseases (sudden acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza, Ebola virus disease (EVD) or tuberculosis (TB)) were included. New evidence was added to guidelines, reviews and primary studies included in the 2020 review.

DATA COLLECTION AND ANALYSIS

Methods were based on the original rapid review, using methods developed by McMaster University and informed by Cochrane rapid review guidance. Screening, data extraction, quality assessment and synthesis were conducted by one author and checked by a second author. Synthesis of results was conducted using modified framework analysis, with themes from the original review used as an initial framework.

MAIN RESULTS

This review update includes 68 studies, with 17 guidelines and 20 reviews added to the original 31 studies. Synthesis identified six major themes, which can be used to inform policy and decision-making related to planning and implementing communication about a public health emergency and measures to protect the community. Theme 1: Strengthening public trust and countering misinformation: essential foundations for effective public health communication Recognising the key role of public trust is essential. Working to build and maintain trust over time underpins the success of public health communications and, therefore, the effectiveness of public health prevention measures. Theme 2: Two-way communication: involving communities to improve the dissemination, accessibility and acceptability of information Two-way communication (engagement) with the public is needed over the course of a public health emergency: at first, recognition of a health threat (despite uncertainties), and regularly as public health measures are introduced or adjusted. Engagement needs to be embedded at all stages of the response and inform tailoring of communications and implementation of public health measures over time. Theme 3: Development of and preparation for public communication: target audience, equity and tailoring Communication and information must be tailored to reach all groups within populations, and explicitly consider existing inequities and the needs of disadvantaged groups, including those who are underserved, vulnerable, from diverse cultural or language groups, or who have lower educational attainment. Awareness that implementing public health measures may magnify existing or emerging inequities is also needed in response planning, enactment and adjustment over time. Theme 4: Public communication features: content, timing and duration, delivery Public communication needs to be based on clear, consistent, actionable and timely (up-to-date) information about preventive measures, including the benefits (whether for individual, social groupings or wider society), harms (likewise) and rationale for use, and include information about supports available to help follow recommended measures. Communication needs to occur through multiple channels and/or formats to build public trust and reach more of the community. Theme 5: Supporting behaviour change at individual and population levels Supporting implementation of public health measures with practical supports and services (e.g. essential supplies, financial support) is critical. Information about available supports must be widely disseminated and well understood. Supports and communication related to them require flexibility and tailoring to explicitly consider community needs, including those of vulnerable groups. Proactively monitoring and countering stigma related to preventive measures (e.g. quarantine) is also necessary to support adherence. Theme 6: Fostering and sustaining receptiveness and responsiveness to public health communication Efforts to foster and sustain public receptiveness and responsiveness to public health communication are needed throughout a public health emergency. Trust, acceptance and behaviours change over time, and communication needs to be adaptive and responsive to these changing needs. Ongoing community engagement efforts should inform communication and public health response measures.

AUTHORS' CONCLUSIONS

Implications for practice Evidence highlights the critical role of communication throughout a public health emergency. Like any intervention, communication can be done well or poorly, but the consequences of poor communication during a pandemic may mean the difference between life and death. The approaches to effective communication identified in this review can be used by policymakers and decision-makers, working closely with communication teams, to plan, implement and adjust public communications over the course of a public health emergency like the COVID-19 pandemic. Implications for research Despite massive growth in research during the COVID-19 period, gaps in the evidence persist and require high-quality, meaningful research. This includes investigating the experiences of people at heightened COVID-19 risk, and identifying barriers to implementing public communication and protective health measures particular to lower- and middle-income countries, and how to overcome these.

Equity issues rarely addressed in the development of COVID-19 formal recommendations and good practice statements: a cross-sectional study

BACKGROUND AND OBJECTIVE

To identify COVID-19 actionable statements (e.g., recommendations) focused on specific disadvantaged populations in the living map of COVID-19 recommendations (eCOVIDRecMap) and describe how health equity was assessed in the development of the formal recommendations.

METHODS

We employed the place of residence, race or ethnicity or culture, occupation, gender or sex, religion, education, socio-economic status, and social capital-Plus framework to identify statements focused on specific disadvantaged populations. We assessed health equity considerations in the evidence to decision frameworks (EtD) of formal recommendations for certainty of evidence and impact on health equity criteria according to the Grading of Recommendations, Assessment, Development, and Evaluations criteria.

RESULTS

We identified 16% (124/758) formal recommendations and 24% (186/819) good practice statements (GPS) that were focused on specific disadvantaged populations. Formal recommendations (40%, 50/124) and GPS (25%, 47/186) most frequently focused on children. Seventy-six percent (94/124) of the recommendations were accompanied with EtDs. Over half (55%, 52/94) of those considered indirectness of the evidence for disadvantaged populations. Considerations in impact on health equity criterion most frequently involved implementation of the recommendation for disadvantaged populations (17%, 16/94).

CONCLUSION

Equity issues were rarely explicitly considered in the development COVID-19 formal recommendations focused on specific disadvantaged populations. Guidance is needed to support the consideration of health equity in guideline development during health emergencies.

Which actionable statements qualify as good practice statements In Covid-19 guidelines? A systematic appraisal

OBJECTIVES

To evaluate the development and quality of actionable statements that qualify as good practice statements (GPS) reported in COVID-19 guidelines.

DESIGN AND SETTING

Systematic review . We searched MEDLINE, MedSci, China National Knowledge Infrastructure (CNKI), databases of Grading of Recommendations Assessment, Development and Evaluation (GRADE) Guidelines, NICE, WHO and Guidelines International Network (GIN) from March 2020 to September 2021. We included original or adapted recommendations addressing any COVID-19 topic.

MAIN OUTCOME MEASURES

We used GRADE Working Group criteria for assessing the appropriateness of issuing a GPS: (1) clear and actionable; (2) rationale necessitating the message for healthcare practice; (3) practicality of systematically searching for evidence; (4) likely net positive consequences from implementing the GPS and (5) clear link to the indirect evidence. We assessed guideline quality using the Appraisal of Guidelines for Research and Evaluation II tool.

RESULTS

253 guidelines from 44 professional societies issued 3726 actionable statements. We classified 2375 (64%) as GPS; of which 27 (1%) were labelled as GPS by guideline developers. 5 (19%) were labelled as GPS by their authors but did not meet GPS criteria. Of the 2375 GPS, 85% were clear and actionable; 59% provided a rationale necessitating the message for healthcare practice, 24% reported the net positive consequences from implementing the GPS. Systematic collection of evidence was deemed impractical for 13% of the GPS, and 39% explained the chain of indirect evidence supporting GPS development. 173/2375 (7.3%) statements explicitly satisfied all five criteria. The guidelines' overall quality was poor regardless of the appropriateness of GPS development and labelling.

CONCLUSIONS

Statements that qualify as GPS are common in COVID-19 guidelines but are characterised by unclear designation and development processes, and methodological weaknesses.

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: January 2022 update on the use of therapeutic-intensity anticoagulation in acutely ill patients

BACKGROUND

COVID-19-related acute illness is associated with an increased risk of venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation in patients with COVID-19.

METHODS

ASH formed a multidisciplinary guideline panel that included patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process and performed systematic evidence reviews (through November 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 as part of the living phase of these guidelines.

RESULTS

The panel made one additional recommendation. The panel issued a conditional recommendation in favor of therapeutic-intensity over prophylactic-intensity anticoagulation in patients with COVID-19-related acute illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of risk of thrombosis and bleeding. The panel also noted that heparin (unfractionated or low molecular weight) may be preferred because of a preponderance of evidence with this class of anticoagulants.

CONCLUSION

This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation in patients with COVID-19-related acute illness.

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis for patients with COVID-19: March 2022 update on the use of anticoagulation in critically ill patients

BACKGROUND

COVID-19-related critical illness is associated with an increased risk of venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for patients with COVID-19.

METHODS

ASH formed a multidisciplinary guideline panel, including 3 patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process, including performing systematic evidence reviews (up to January 2022). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the GRADE approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 and May 2021 as part of the living phase of these guidelines.

RESULTS

The panel made 1 additional recommendation: a conditional recommendation for the use of prophylactic-intensity over therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of thrombotic and bleeding risk.

CONCLUSIONS

This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation for patients with COVID-19-related critical illness.

Good or best practice statements: proposal for the operationalisation and implementation of GRADE guidance

An evidence-based approach is considered the gold standard for health decision-making. Sometimes, a guideline panel might judge the certainty that the desirable effects of an intervention clearly outweigh its undesirable effects as high, but the body of supportive evidence is indirect. In such cases, the application of the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach for grading the strength of recommendations is inappropriate. Instead, the GRADE Working Group has recommended developing ungraded best or good practice statement (GPS) and developed guidance under which circumsances they would be appropriate.Through an evaluation of COVID-1- related recommendations on the eCOVID Recommendation Map (COVID-19.recmap.org), we found that recommendations qualifying a GPS were widespread. However, guideline developers failed to label them as GPS or transparently report justifications for their development. We identified ways to improve and facilitate the operationalisation and implementation of the GRADE guidance for GPS.Herein, we propose a structured process for the development of GPSs that includes applying a sequential order for the GRADE guidance for developing GPS. This operationalisation considers relevant evidence-to-decision criteria when assessing the net consequences of implementing the statement, and reporting information supporting judgments for each criterion. We also propose a standardised table to facilitate the identification of GPS and reporting of their development. This operationalised guidance, if endorsed by guideline developers, may palliate some of the shortcomings identified. Our proposal may also inform future updates of the GRADE guidance for GPS.

American Society of Hematology 2021 guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19)-related critical illness and acute illness are associated with a risk of venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for thromboprophylaxis for patients with COVID-19-related critical illness and acute illness who do not have confirmed or suspected VTE.

METHODS

ASH formed a multidisciplinary guideline panel and applied strict management strategies to minimize potential bias from conflicts of interest. The panel included 3 patient representatives. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic evidence reviews (up to 19 August 2020). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 2 recommendations. The panel issued conditional recommendations in favor of prophylactic-intensity anticoagulation over intermediate-intensity or therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness or acute illness who do not have confirmed or suspected VTE.

CONCLUSIONS

These recommendations were based on very low certainty in the evidence, underscoring the need for high-quality, randomized controlled trials comparing different intensities of anticoagulation. They will be updated using a living recommendation approach as new evidence becomes available.

American Society of Hematology 2021 guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19)-related critical illness and acute illness are associated with a risk of venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for thromboprophylaxis for patients with COVID-19-related critical illness and acute illness who do not have confirmed or suspected VTE.

METHODS

ASH formed a multidisciplinary guideline panel and applied strict management strategies to minimize potential bias from conflicts of interest. The panel included 3 patient representatives. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic evidence reviews (up to 19 August 2020). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 2 recommendations. The panel issued conditional recommendations in favor of prophylactic-intensity anticoagulation over intermediate-intensity or therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness or acute illness who do not have confirmed or suspected VTE.

CONCLUSIONS

These recommendations were based on very low certainty in the evidence, underscoring the need for high-quality, randomized controlled trials comparing different intensities of anticoagulation. They will be updated using a living recommendation approach as new evidence becomes available.

Perineural and intravenous dexamethasone and dexmedetomidine: network meta-analysis of adjunctive effects on supraclavicular brachial plexus block

Both perineural and intravenous dexamethasone and dexmedetomidine are used as local anaesthetic adjuncts to enhance peripheral nerve block characteristics. However, the effects of dexamethasone and dexmedetomidine based on their administration routes have not been directly compared, and the relative extent to which each adjunct prolongs sensory blockade remains unclear. This network meta-analysis sought to compare and rank the effects of perineural and intravenous dexamethasone and dexmedetomidine as supraclavicular block adjuncts. We sought randomised trials investigating the effects of adding perineural and intravenous dexamethasone or dexmedetomidine to long-acting local anaesthetics on supraclavicular block characteristics, including time to block onset and durations of sensory, motor and analgesic blockade. Data were compared and ranked according to relative effectiveness for each outcome. Our primary outcome was sensory block duration, with a 2-h difference considered clinically important. We performed a frequentist analysis, using the GRADE framework to appraise evidence. One-hundred trials (5728 patients) were included. Expressed as mean (95%CI), the control group (local anaesthetic alone) had a duration of sensory block of 401 (366-435) min, motor block duration of 369 (330-408) min and analgesic duration of 435 (386-483) min. Compared with control, sensory block was prolonged most by intravenous dexamethasone [mean difference (95%CI) 477 (160-795) min], followed by perineural dexamethasone [411 (343-480) min] and perineural dexmedetomidine [284 (235-333) min]. Motor block was prolonged most by perineural dexamethasone [mean difference (95%CI) 294 (236-352) min], followed by intravenous dexamethasone [289 (129-448)min] and perineural dexmedetomidine [258 (212-304)min]. Analgesic duration was prolonged most by perineural dexamethasone [mean difference (95%CI) 518 (448-589) min], followed by intravenous dexamethasone [478 (277-679) min] and perineural dexmedetomidine [318 (266-371) min]. Intravenous dexmedetomidine did not prolong sensory, motor or analgesic block durations. No major network inconsistencies were found. The quality of evidence for intravenous dexamethasone, perineural dexamethasone and perineural dexmedetomidine for prolongation of supraclavicular sensory block duration was 'low', 'very low' and 'low', respectively. Regardless of route, dexamethasone as an adjunct prolonged the durations of sensory and analgesic blockade to a greater extent than dexmedetomidine. Differences in block characteristics between perineural and intravenous dexamethasone were not clinically important. Intravenous dexmedetomidine did not affect block characteristics.

Ventilation Techniques and Risk for Transmission of Coronavirus Disease, Including COVID-19: A Living Systematic Review of Multiple Streams of Evidence

BACKGROUND

Mechanical ventilation is used to treat respiratory failure in coronavirus disease 2019 (COVID-19).

PURPOSE

To review multiple streams of evidence regarding the benefits and harms of ventilation techniques for coronavirus infections, including that causing COVID-19.

DATA SOURCES

21 standard, World Health Organization-specific and COVID-19-specific databases, without language restrictions, until 1 May 2020.

STUDY SELECTION

Studies of any design and language comparing different oxygenation approaches in patients with coronavirus infections, including severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), or with hypoxemic respiratory failure. Animal, mechanistic, laboratory, and preclinical evidence was gathered regarding aerosol dispersion of coronavirus. Studies evaluating risk for virus transmission to health care workers from aerosol-generating procedures (AGPs) were included.

DATA EXTRACTION

Independent and duplicate screening, data abstraction, and risk-of-bias assessment (GRADE for certainty of evidence and AMSTAR 2 for included systematic reviews).

DATA SYNTHESIS

123 studies were eligible (45 on COVID-19, 70 on SARS, 8 on MERS), but only 5 studies (1 on COVID-19, 3 on SARS, 1 on MERS) adjusted for important confounders. A study in hospitalized patients with COVID-19 reported slightly higher mortality with noninvasive ventilation (NIV) than with invasive mechanical ventilation (IMV), but 2 opposing studies, 1 in patients with MERS and 1 in patients with SARS, suggest a reduction in mortality with NIV (very-low-certainty evidence). Two studies in patients with SARS report a reduction in mortality with NIV compared with no mechanical ventilation (low-certainty evidence). Two systematic reviews suggest a large reduction in mortality with NIV compared with conventional oxygen therapy. Other included studies suggest increased odds of transmission from AGPs.

LIMITATION

Direct studies in COVID-19 are limited and poorly reported.

CONCLUSION

Indirect and low-certainty evidence suggests that use of NIV, similar to IMV, probably reduces mortality but may increase the risk for transmission of COVID-19 to health care workers.

PRIMARY FUNDING SOURCE

World Health Organization. (PROSPERO: CRD42020178187).

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. We aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.

METHODS

We did a systematic review and meta-analysis to investigate the optimum distance for avoiding person-to-person virus transmission and to assess the use of face masks and eye protection to prevent transmission of viruses. We obtained data for SARS-CoV-2 and the betacoronaviruses that cause severe acute respiratory syndrome, and Middle East respiratory syndrome from 21 standard WHO-specific and COVID-19-specific sources. We searched these data sources from database inception to May 3, 2020, with no restriction by language, for comparative studies and for contextual factors of acceptability, feasibility, resource use, and equity. We screened records, extracted data, and assessed risk of bias in duplicate. We did frequentist and Bayesian meta-analyses and random-effects meta-regressions. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. This study is registered with PROSPERO, CRD42020177047.

FINDINGS

Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] -10·2%, 95% CI -11·5 to -7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD -14·3%, -15·9 to -10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12-16-layer cotton masks; pinteraction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD -10·6%, 95% CI -12·5 to -7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings.

INTERPRETATION

The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

FUNDING

World Health Organization.

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. We aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.

METHODS

We did a systematic review and meta-analysis to investigate the optimum distance for avoiding person-to-person virus transmission and to assess the use of face masks and eye protection to prevent transmission of viruses. We obtained data for SARS-CoV-2 and the betacoronaviruses that cause severe acute respiratory syndrome, and Middle East respiratory syndrome from 21 standard WHO-specific and COVID-19-specific sources. We searched these data sources from database inception to May 3, 2020, with no restriction by language, for comparative studies and for contextual factors of acceptability, feasibility, resource use, and equity. We screened records, extracted data, and assessed risk of bias in duplicate. We did frequentist and Bayesian meta-analyses and random-effects meta-regressions. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. This study is registered with PROSPERO, CRD42020177047.

FINDINGS

Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] -10·2%, 95% CI -11·5 to -7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; p_interaction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD -14·3%, -15·9 to -10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12-16-layer cotton masks; p_interaction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD -10·6%, 95% CI -12·5 to -7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings.

INTERPRETATION

The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

FUNDING

World Health Organization.

Safe management of bodies of deceased persons with suspected or confirmed COVID-19: a rapid systematic review

INTRODUCTION

Proper strategies to minimise the risk of infection in individuals handling the bodies of deceased persons infected with 2019 novel coronavirus (2019-nCoV) are urgently needed. The objective of this study was to systematically review the literature to scope and assess the effects of specific strategies for the management of the bodies.

METHODS

We searched five general, three Chinese and four coronavirus disease (COVID-19)-specific electronic databases. We searched registries of clinical trials, websites of governmental and other relevant organisations, reference lists of the included papers and relevant systematic reviews, and Epistemonikos for relevant systematic reviews. We included guidance documents providing practical advice on the handling of bodies of deceased persons with suspected or confirmed COVID-19. Then, we sought primary evidence of any study design reporting on the efficacy and safety of the identified strategies in coronaviruses. We included evidence relevant to contextual factors (ie, acceptability). A single reviewer extracted data using a pilot-tested form and graded the certainty of the evidence using the GRADE approach. A second reviewer verified the data and assessments.

RESULTS

We identified one study proposing an uncommon strategy for autopsies for patients with severe acute respiratory syndrome. The study provided very low-certainty evidence that it reduced the risk of transmission. We identified 23 guidance documents providing practical advice on the steps of handling the bodies: preparation, packing, and others and advice related to both the handling of the dead bodies and the use of personal protective equipment by individuals handling them. We did not identify COVID-19 evidence relevant to any of these steps.

CONCLUSION

While a substantive number of guidance documents propose specific strategies, we identified no study providing direct evidence for the effects of any of those strategies. While this review highlights major research gaps, it allows interested entities to build their own guidance.

Antithrombotic treatment after coronary artery bypass graft surgery: systematic review and network meta-analysis

OBJECTIVE

To assess the effects of different oral antithrombotic drugs that prevent saphenous vein graft failure in patients undergoing coronary artery bypass graft surgery.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Medline, Embase, Web of Science, CINAHL, and the Cochrane Library from inception to 25 January 2019. ELIGIBILITY CRITERIA: for selecting studies Randomised controlled trials of participants (aged ≥18) who received oral antithrombotic drugs (antiplatelets or anticoagulants) to prevent saphenous vein graft failure after coronary artery bypass graft surgery.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was saphenous vein graft failure and the primary safety endpoint was major bleeding. Secondary endpoints were myocardial infarction and death.

RESULTS

This review identified 3266 citations, and 21 articles that related to 20 randomised controlled trials were included in the network meta-analysis. These 20 trials comprised 4803 participants and investigated nine different interventions (eight active and one placebo). Moderate certainty evidence supports the use of dual antiplatelet therapy with either aspirin plus ticagrelor (odds ratio 0.50, 95% confidence interval 0.31 to 0.79, number needed to treat 10) or aspirin plus clopidogrel (0.60, 0.42 to 0.86, 19) to reduce saphenous vein graft failure when compared with aspirin monotherapy. The study found no strong evidence of differences in major bleeding, myocardial infarction, and death among different antithrombotic therapies. The possibility of intransitivity could not be ruled out; however, between-trial heterogeneity and incoherence were low in all included analyses. Sensitivity analysis using per graft data did not change the effect estimates.

CONCLUSIONS

The results of this network meta-analysis suggest an important absolute benefit of adding ticagrelor or clopidogrel to aspirin to prevent saphenous vein graft failure after coronary artery bypass graft surgery. Dual antiplatelet therapy after surgery should be tailored to the patient by balancing the safety and efficacy profile of the drug intervention against important patient outcomes.

STUDY REGISTRATION

PROSPERO registration number CRD42017065678.

Erratum to pre-operative use of aspirin in patients undergoing coronary artery bypass grafting: a systematic review and updated meta-analysis

[This corrects the article DOI: 10.21037/jtd.2018.05.187.].

Pre-operative use of aspirin in patients undergoing coronary artery bypass grafting: a systematic review and updated meta-analysis

Background

Aspirin therapy improves saphenous vein graft (SVG) patency in patients undergoing coronary artery bypass graft (CABG), however, its use in the pre-operative period remains controversial. Therefore, we conducted a systematic review and meta-analysis of randomized-controlled trials (RCTs) to update the evidence about risk and benefits of pre-operative aspirin therapy in patients undergoing CABG.

Methods

Electronic databases (Medline, Embase, PubMed, Cochrane Library, and Scopus) were searched to identify RCTs evaluating the effect of aspirin versus placebo/control before CABG. Two investigators independently and in duplicate screened citations and extracted data and rated the risk of bias. The strength of evidence was appraised using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Meta-analysis was performed using a random-effects model. The main outcomes of interest were 30-day mortality, peri-operative myocardial infarction (MI), chest tube drainage and SVG occlusion.

Results

A total of 13 RCTs involving 4,377 participants (2,266/2,111 pre-operative aspirin/control) met the inclusion criteria. Pre-operative aspirin reduced the risk of SVG occlusion [risk ratio (RR): 0.69, 95% confidence interval (CI): 0.49-0.97, P=0.03, I²=16%], but no differences in mortality (RR: 1.41, 95% Cl: 0.73-2.74, I²=0%) and MI (RR: 0.84, 95% CI: 0.69-1.03, I²=0%) were found. However, pre-operative aspirin increased chest tube drainage (MD: 100.40 mL, 95% CI: 24.32-176.47 mL, P=0.01, I²=84%) and surgical re-exploration (RR: 1.52, 95% CI: 1.02-2.27, P=0.04, I²=8%), with no significant difference in RBC transfusion (RR: 1.06, 95% CI: 0.90-1.25, I²=35%).

Conclusions

Based on trials where the rated body of evidence was of low to very-low quality, pre-operative aspirin improves SVG patency but increases chest tube drainage and need for surgical re-exploration.

Antithrombotic therapy in patients receiving saphenous vein coronary artery bypass grafts: a protocol for a systematic review and network meta-analysis

INTRODUCTION

The current evidence for the prevention of saphenous vein graft failure (SVGF) after coronary artery bypass graft (CABG) surgery consists of direct head-to-head comparison of treatments (including placebo) in randomised-controlled trials (RCTs) and observational studies. However, summarising the evidence using traditional pairwise meta-analyses does not allow the inclusion of data from treatments that have not been compared head to head. Exclusion of such comparisons could impact the precision of pooled estimates in a meta-analysis. Hence, to address the challenge of whether aspirin alone or in addition to another antithrombotic agent is a more effective regimen to improve SVG patency, a network meta-analysis (NMA) is necessary. The objectives of this study are to synthesise the available evidence on antithrombotic agents (or their combination) and estimate the treatment effects among direct and indirect treatment comparisons on SVGF and major adverse cardiovascular events, and to generate a treatment ranking according to their efficacy and safety outcomes.

METHODS

We will perform a systematic review of RCTs evaluating antithrombotic agents in patients undergoing CABG. A comprehensive English literature search will be conducted using electronic databases and grey literature resources to identify published and unpublished articles. Two individuals will independently and in duplicate screen potential studies, assess the eligibility of potential studies and extract data. Risk of bias and quality of evidence will also be evaluated independently and in duplicate. We will investigate the data to ensure its suitability for NMA, including adequacy of the outcome data and transitivity of treatment effects. We plan to estimate the pooled direct, indirect and the mixed effects for all antithrombotic agents using a NMA.

ETHICS AND DISSEMINATION

Due to the nature of the study, there are no ethical concerns nor informed consent required. We anticipate that this NMA will be the first to simultaneously assess the relative effects of multiple antithrombotic agents in patients undergoing CABG. The results of this NMA will inform clinicians, patients and guideline developers the best available evidence on comparative effects benefits of antithrombotic agents after CABG while considering the side effect profile to support future clinical decision-making. We will disseminate the results of our systematic review and NMA through a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42017065678.

Resistant Atherosclerosis

Background and Purpose—

Recent studies indicate that patients with lower levels of low-density lipoprotein cholesterol (LDL-C) have greater regression of coronary plaque. In 2002, we found that carotid plaque progression doubled cardiovascular risk. In 2003, we therefore implemented a new approach, treating arteries instead of risk factors. Since then, we have seen many patients with carotid plaque progression despite very low levels of LDL-C, suggesting other causes of atherosclerosis. We studied the relationship of achieved LDL-C and change in LDL-C to progression/regression of atherosclerosis, before and after 2003.

Methods—

All 4512 patients in our clinic database with at least 2 measurements of LDL-C and carotid total plaque area approximately a year apart and complete data for analyses (n=2025 before and 2487 after December 31, 2003) were included in the study.

Results—

Baseline total plaque area was significantly higher after 2003 (129.56±134.32 versus 113.33±121.52 mm 2 ; P <0.0001), and plaque progression was significantly less after 2003 (2.94±37.11 versus 12.62±43.24 mm 2 ; P <0.0001). Many patients with LDL-C <1.8 mm had plaque progression (47.5%), and change in LDL-C was not correlated with plaque progression/regression. Increasing age and serum creatinine contributed to resistant atherosclerosis.

Conclusions—

Many patients have Resistant Atherosclerosis, failing to achieve regression of atherosclerosis despite low levels of LDL-C. Instead of relying on LDL-C, measuring plaque burden may be a more useful way of assessing individual response to therapy, particularly in resistant atherosclerosis.

Cerebral Embolic Protection Devices During Transcatheter Aortic Valve Implantation

Background and Purpose—

Silent ischemic embolic lesions are common after transcatheter aortic valve implantation (TAVI). The use of embolic protection devices (EPD) may reduce the occurrence of these embolic lesions. Thus, a quantitative overview and credibility assessment of the literature was necessary to draw a robust message about EPD. Therefore, the aim of this meta-analysis was to study whether the use of EPD reduces silent ischemic and clinically evident cerebrovascular events associated with TAVI.

Methods—

We conducted a comprehensive search to identify studies that evaluated patients undergoing TAVI with or without EPD. Random-effects meta-analyses were performed to estimate the effect of EPD compared with no-EPD during TAVI using aggregate data.

Results—

Sixteen studies involving 1170 patients (865/305 with/without EPD) fulfilled the inclusion criteria. The EPD delivery success rate was reported in all studies and was achieved in 94.5% of patients. Meta-analyses evaluating EPD versus without EPD strategies could not confirm or exclude any differences in terms of clinically evident stroke (relative risk, 0.70; 95% confidence interval [CI], 0.38–1.29; P =0.26) or 30-day mortality (relative risk, 0.58; 95% CI, 0.20–1.64; P =0.30). There were no significant differences in new-single, multiple, or total number of lesions. The use of EPD was associated with a significantly smaller ischemic volume per lesion (standardized mean difference, −0.52; 95% CI, −0.85 to −0.20; P =0.002) and smaller total volume of lesions (standardized mean difference, −0.23; 95% CI, −0.42 to −0.03; P =0.02). Subgroup analysis by type of valve showed an overall trend toward significant reduction in new lesions per patient using EPD (standardized mean difference, −0.41; 95% CI, −0.82 to 0.00; P =0.05), driven by self-expanding devices.

Conclusions—

The use of EPD during TAVI may be associated with smaller volume of silent ischemic lesions and smaller total volume of silent ischemic lesions. However, EPD may not reduce the number of new-single, multiple, or total number of lesions. There was only very low quality of evidence showing no significant differences between patients undergoing TAVI with or without EPD with respect to clinically evident stroke and mortality.