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.

IntroductionWaterpipe tobacco smoking is harmful to health however its prevalence estimates remain uncertain. We aimed to systematically review the medical literature on waterpipe tobacco prevalence and trends.MethodsWe searched Medline, Embase and ISI Web of Science for ‘waterpipe’ and its synonyms, without using language or date restrictions. We included any measure of waterpipe tobacco smoking prevalence in jurisdictionally representative populations. We stratified findings by prevalence measure (past 30 day, ever, regular or occasional, daily, other or unspecified) and age (adults or youth).ResultsWe included 129 studies reporting 355 estimates for 68 countries. In general, prevalence estimates among adults were highest in the Eastern Mediterranean, and among youth were about equal between Eastern Mediterranean and European regions. Past 30 day use was highest among Lebanese youth (37.2% in 2008), ever use was highest among Lebanese youth in 2002 and Lebanese university students in 2005 (both 65.3%), regular or occasional use was highest in among Iranian university students (16.3% in 2005), and daily use was highest among Egyptian youth (10.4% in 2005). Trend data were limited but most studies reported increased use over time, ranging from 0.3–1.0% per year among youth in the US to 2.9% per year among youth in Jordan (both for past 30 day use). Results were similar for ever use trends. Turkey (2.3% in 2008 to 0.8% in 2010) and Iraq (6.3% in 2008 and 4.8% in 2012) both witnessed decreased waterpipe use.ConclusionWaterpipe tobacco smoking is most prevalent in Eastern Mediterranean and European countries, and appears higher among youth than adults. Continued surveillance will be important to assess and inform policy measures to control waterpipe tobacco use.

Background: COVID-19 related acute 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 in patients with COVID-19. Methods: ASH formed a multidisciplinary guideline panel, including patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including performing 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 thrombotic and bleeding risk. 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. 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 in patients with COVID-19-related acute illness.

There may be many predictors of venous thromboembolism (VTE) and bleeding in hospitalized medical patients, but until now, systematic reviews and assessments of the certainty of the evidence have not been published. We conducted a systematic review to identify prognostic factors for VTE and bleeding in hospitalized medical patients and searched Medline and EMBASE from inception through May 2018. We considered studies that identified potential prognostic factors for VTE and bleeding in hospitalized adult medical patients. Reviewers extracted data in duplicate and independently and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. Of 69 410 citations, we included 17 studies in our analysis: 14 that reported on VTE, and 3 that reported on bleeding. For VTE, moderate-certainty evidence showed a probable association with older age; elevated C-reactive protein (CRP), D-dimer, and fibrinogen levels; tachycardia; thrombocytosis; leukocytosis; fever; leg edema; lower Barthel Index (BI) score; immobility; paresis; previous history of VTE; thrombophilia; malignancy; critical illness; and infections. For bleeding, moderate-certainty evidence showed a probable association with older age, sex, anemia, obesity, low hemoglobin, gastroduodenal ulcers, rehospitalization, critical illness, thrombocytopenia, blood dyscrasias, hepatic disease, renal failure, antithrombotic medication, and presence of a central venous catheter. Elevated CRP, a lower BI, a history of malignancy, and elevated heart rate are not included in most VTE risk assessment models. This study informs risk prediction in the management of hospitalized medical patients for VTE and bleeding; it also informs guidelines for VTE prevention and future research.

Background: COVID-19 related acute 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 thromboprophylaxis in patients with COVID-19 who do not have confirmed or suspected VTE. Methods: ASH formed a multidisciplinary guideline panel, including three patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including performing systematic evidence reviews (up to March 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. Results: The panel agreed on one additional recommendation. The panel issued a conditional recommendation against the use of outpatient anticoagulant prophylaxis in patients with COVID-19 being discharged from the hospital who do not have suspected or confirmed VTE or another indication for anticoagulation. Conclusions: This recommendation was based on very low certainty in the evidence, underscoring the need for high-quality, randomized controlled trials assessing the role of post-discharge thromboprophylaxis. Other key research priorities include better evidence on assessing risk of thrombosis and bleeding outcomes in patients with COVID-19 after hospital discharge.

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 thromboprophylaxis in patients with COVID-19-related critical illness who do not have confirmed or suspected VTE. Methods: ASH formed a multidisciplinary guideline panel, including three patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including performing systematic evidence reviews (up to March 5, 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 on guidelines published in February 2021. Results: The panel agreed on one additional recommendation. The panel issued a conditional recommendation in favor of prophylactic-intensity over intermediate-intensity anticoagulation in patients with COVID-19 related-critical illness who do not have confirmed or suspected VTE. Conclusions: This recommendation was based on low certainty in the evidence, underscoring the need for further high-quality, randomized controlled trials comparing different intensities of anticoagulation in critically ill patients. Other key research priorities include better evidence on predictors of thrombosis and bleeding risk in critically ill patients with COVID-19 and the impact of non-anticoagulant therapies (e.g., antiviral agents, corticosteroids) on thrombotic risk.

Values and preferences relate to the importance that patients place on health outcomes (eg, bleeding, having a deep venous thrombosis) and are essential when weighing benefits and harms in guideline recommendations. To inform the American Society of Hematology guidelines for management of venous thromboembolism (VTE) disease, we conducted a systematic review of patients’ values and preferences related to VTE. We searched Medline, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, and the Cumulative Index to Nursing and Allied Health Literature from inception to April of 2018 (PROSPERO-CRD42018094003). We included quantitative and qualitative studies. We followed Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidance for rating the certainty and presenting findings for quantitative research about the relative importance of health outcomes and a grounded theory approach for qualitative thematic synthesis. We identified 14 quantitative studies (2465 participants) describing the relative importance of VTE-related health states in a widely diverse population of patients, showing overall small to important impact on patients’ lives (certainty of the evidence from low to moderate). Additionally, evidence from 34 quantitative studies (6424 participants) and 15 qualitative studies (570 participants) revealed that patients put higher value on VTE risk reduction than on the potential harms of the treatment (certainty of evidence from low to moderate). Studies also suggested a clear preference for oral medication over subcutaneous medication (moderate certainty). The observed variability in health state values may be a result of differences in the approaches used to elicit them and the diversity of included populations rather than true variability in values. This finding highlights the necessity to explore the variability induced by different approaches to ascertain values.

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 in patients with COVID-19. Methods: ASH formed a multidisciplinary guideline panel, including three patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University 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 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 and May 2021 as part of the living phase of these guidelines. Results: The panel made one additional recommendation, a conditional recommendation for the use of prophylactic-intensity over therapeutic-intensity anticoagulation in 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 in patients with COVID-19-related critical illness.