- Email: [email protected]
Thromboprophylaxis for patients at high risk of VTE – Authors' reply
Correspondence
Officer’s guidance3 advises VTE prophylaxis only in patients whose length of stay is predicted as likely to be more than 4 days. We feel that this recommendation adds uncertainty into clinical decisions. The admitting physicians were only able to predict a length of stay in 47% of the 135 patients, who otherwise met thromboprophylaxis guidelines. We have now changed our admission proforma to include VTE risk assessment as a matter of routine in all patients admitted with an acute illness, and hope that this improves the rate of VTE prophylaxis. We declare that we have no conflict of interest.
*Stephen Wallis, Sunku Guptha [email protected] Department of Medicine for the Elderly, Peterborough & Stamford Hospitals NHS Foundation Trust, Thorpe Road, Peterborough PE3 6DA, UK 1
2
3
Cohen AT, Tapson VF, Bergmann JF, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Cohen AT, Alikhan R, Arcelus J, et al. Assessment of venous thromboembolism risk and the benefits of thromboprophylaxis in medical patients. Thromb Haemost 2005; 94: 750–59. Department of Health. Report of the independent expert working group on the prevention of venous thromboembolism in hospitalised patients. London: Staionery Office, 2007. http://www.dh.gov.uk/en/Publica tionsandstatistics/Publications/Publications PolicyAndGuidance/DH_073944 (accessed Feb 4, 2008).
Alexander Cohen and colleagues1 show that 42% of at-risk surgical patients did not receive venous thromboembolism (VTE) prophylaxis as recommended by the American College of Chest Physicians (ACCP). It is a wonder that so many surgeons did follow ACCP (or equivalent) guidelines, because, at least from a surgeon’s perspective, they are effectively buried in Chest.2 We hazard a guess that most surgeons have probably never heard of, let alone read, this journal. ACCP guidelines have formed the basis of our departmental VTE prevention policy for 7 years, but only because, when developing our own guidelines, we 1912
approached a friendly haematologist for advice on best practice. In the VTE prevention guidelines published by the UK’s National Institute for Health and Clinical Excellence,3 the ACCP guidelines are mentioned only as the 189th citation in more than 580 references (and do not feature by name in the text). Hardly a place of prominence for the most cited standard for the prevention of VTE disease. It is a truism that guidelines are only of value if doctors know about them, and are worthless if not heavily publicised, but Cohen and colleagues pay only scant attention to the issue of guideline dissemination as a possible explanation for their findings. We declare that we have no conflict of interest.
*Howard Marsh, John Reynard [email protected] Churchill Hospital, Oxford OX3 7LJ, UK 1
2
3
Cohen AT, Tapson VF, Bergmann J-F, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Geerts WH, Pineo GF, Heit JA, et al. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126 (suppl 3): 338S–400S. National Institute for Health and Clinical Excellence. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in inpatients undergoing surgery. NICE clinical guideline no 46. London: NICE, 2007. http://www.nice. org.uk/CG046 (accessed May 12, 2008).
Authors’ reply D Graham Mackenzie and colleagues, like many others, have been misled by the SIGN guidelines.1 These guidelines report that aspirin has not been shown to reduce total mortality or all vascular deaths in the surgical setting or in patients with hip fracture. Most patients included in the clinical trials cited in the SIGN guidelines were given aspirin in addition to standard therapy (mechanical and anticoagulant prophylaxis); however, unsupported conclusions relating to aspirin use alone are commonly made. The PEP trial,2 which contributed most
of the patients considered within the SIGN recommendations, showed that the reduction in deaths related to pulmonary embolism (PE) in patients on aspirin was counterbalanced by the increase in other vascular-related deaths. Despite this finding, the SIGN guidelines erroneously state that “Aspirin also reduces cardiovascular events in acute myocardial infarction and acute ischaemic stroke”.1 Although aspirin might reduce the risk of PE to a clinically significant degree in high-risk patients, it minimally affects the risk of deep-vein thrombosis, with only a 34% odds reduction3 compared with a 67% odds reduction reported for heparin-based prophylaxis.4 The PEP study also showed that aspirin led to a significant increase in gastrointestinal bleeding, an outcome that was “diluted” by the method of analysis. Finally, the PEP study and SIGN guidelines concluded that antiplatelet therapy made little or no difference to outcomes related to venous thromboembolism (VTE) in elective hip and knee surgery, respectively. In the surgical setting, anticoagulants have been shown to reduce mortality related to PE by two-thirds and total mortality by more than 20%.4 In orthopaedic surgery, a two-thirds reduction in VTE and VTE-related death has been shown.4 We agree that the data relating to hip fracture are limited and that recommendations require looking at the wider area of orthopaedic surgery. However, patients with hip fracture made up only 2·5% of our population and hence their outcomes do not change our overall conclusion. Furthermore, we would not recommend drawing conclusions on antithrombotic therapy solely from the audit mentioned.5 We acknowledge that the association between increased age and VTE risk is important and should guide treatment provision, as commented by Bruno Caramelli. We have additional data for this subject, which is to be included in a future publication. www.thelancet.com Vol 371 June 7, 2008
VTE risk is the single commonest risk factor for all hospital-related illness. We agree with Stephen Wallis and Sunku Guptha that risk assessment of all patients is essential at admission, irrespective of the presumed length of stay, which can be difficult to predict. Howard Marsh and John Reynard make a valid argument that guidelines should be disseminated more widely, and perhaps we should have given this more attention. We also agree that the NICE guidelines failed to recognise the importance and findings of the internationally recognised ACCP guidelines. NICE might therefore provide a potentially unbalanced view of the published work that is neither evidence-based nor commensurate with local or international practice, as shown by the ENDORSE findings. We declare that we have no conflict of interest other than that stated in the original paper.
*A T Cohen, V F Tapson, F A Anderson, on behalf of the ENDORSE Steering Committee and Investigators [email protected] King’s College Hospital, London SE5 9RS, UK (ATC); Duke University Medical Center, Durham, NC, USA (VFT); and Center for Outcomes Research, University of Massachusetts Medical School, Worcester, MA, USA (FAA) 1
2
3
4
5
Scottish Intercollegiate Guidelines Network. Prophylaxis of venous thromboembolism. Edinburgh: SIGN, 2002. http://www.sign. ac.uk/guidelines/fulltext/62/index.html (accessed May 12, 2008). Pulmonary Embolism Prevention (PEP) trial Collaborative Group. Prevention of pulmonary embolism and deep vein thrombosis with low dose aspirin: Pulmonary Embolism Prevention (PEP) trial. Lancet 2000; 355: 1295–302. Antiplatelet Trialists’ Collaboration. Collaborative overview of randomised trials of antiplatelet therapy—III: reduction in venous thrombosis and pulmonary embolism by antiplatelet prophylaxis among surgical and medical patients. BMJ 1994; 308: 235–46. Collins R, Scrimgeour A, Yusuf S, Peto R. Reduction in fatal pulmonary embolism and venous thrombosis by perioperative administration of subcutaneous heparin. Overview of results of randomized trials in general, orthopedic, and urologic surgery. N Engl J Med 1988; 318: 1162–73. Handoll HHG, Farrar MJ, McBirnie J, Tytherleigh-Strong G, Milne AA, Gillespie WJ. Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures. Cochrane Database Syst Rev 2002; 4: CD000305.
www.thelancet.com Vol 371 June 7, 2008
Prospects for healthsystems research
serve to achieve greater focus and commitment, so as to finally deliver on this long overdue agenda?
We welcome the Viewpoint by Michael Reich and colleagues (March 8, p 865)1 on the need to strengthen health systems and the opportunity presented by the G8 summit in Toyako to move this agenda along. In particular we endorse Reich and colleagues’ call for more investment in research on health systems. But this call has been made many times before. The WHO Advisory Committee on Medical Research first discussed this need in the 1970s; in 2004, the call was repeated by the participants in the Mexico Summit on Health Research, and the WHO Task Force on Health Systems Research.2 So what will turn these various appeals into a reality? One issue not addressed by the Viewpoint is that of capacity. A concerted initiative to develop greater capacity for health-systems research in low-income and middle-income countries is necessary to ensure that additional investment in healthsystems research benefits researchers, policy makers, and populations. Second, health-systems research knowledge needs to be packaged in ways that make it easily accessible to policy makers. Systematic reviews and summaries of systematic reviews are critical in this regard. Such reviews also help us to document existing evidence better, and identify future research priorities. There are significant opportunities on the horizon with regard to a focus on health-systems research. Certainly the G8 could be important, but so are the Inter-governmental Working Group on Public Health, Innovation and Intellectual Property, the Ministerial Forum in Bamako on Health Research later this year, and WHO’s own research strategy with its strong emphasis on strengthening the evidence base for policy recommendations. Is it too much to hope that this time, these processes will
We declare that we have no conflict of interest.
*Sara Bennett, Andy Oxman, Andy Haines [email protected] Alliance for Health Policy and Systems Research, WHO, 1211 Geneva 27, Switzerland (SB); Norwegian Satellite of the Cochrane Effective Practice and Organisation of Care Group, Norwegian Knowledge Centre for the Health Services, Oslo, Norway (AO); and London School of Hygiene and Tropical Medicine, London, UK (AH) 1
2
The printed journal includes an image merely for illustration
Reich MR, Takemi K, Roberts MJ, Hsiao WC. Global action on health systems: a proposal for the Toyako G8 summit. Lancet 2008; 371: 865–69. Task Force on Health Systems Research. Informed choices for attaining the Millennium Development Goals: towards an international cooperative agenda for health systems research. Lancet 2004; 364: 997–1003.
Michael Reich and colleagues1 provide a helpful overview of today’s pivotal global health challenge—health systems strengthening. Although we agree with their analysis, our recommendations for the G8 Summit diverge from the three actions they propose. We endorse engagement of community-based organisations, but only if women’s organisations are able to participate fully in policy development and accountability mechanisms. Although we agree that a separate fund for health systems is not appropriate, support from vertical funds will be limited at best. The G8 should also lift International Monetary Fund restrictions on healthsector subsidies and encourage public-private partnerships. It should commit to direct financing of health systems and to universal support for the International Health Partnership that aims to address most of the problems described by Reich and colleagues. The third proposal—enhanced learning, including pilot projects—is important but should not become an excuse for inaction. Pilot projects in particular should be avoided—poor countries are littered with them. 1913
Panos Pictures
Correspondence
Officer’s guidance3 advises VTE prophylaxis only in patients whose length of stay is predicted as likely to be more than 4 days. We feel that this recommendation adds uncertainty into clinical decisions. The admitting physicians were only able to predict a length of stay in 47% of the 135 patients, who otherwise met thromboprophylaxis guidelines. We have now changed our admission proforma to include VTE risk assessment as a matter of routine in all patients admitted with an acute illness, and hope that this improves the rate of VTE prophylaxis. We declare that we have no conflict of interest.
*Stephen Wallis, Sunku Guptha [email protected] Department of Medicine for the Elderly, Peterborough & Stamford Hospitals NHS Foundation Trust, Thorpe Road, Peterborough PE3 6DA, UK 1
2
3
Cohen AT, Tapson VF, Bergmann JF, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Cohen AT, Alikhan R, Arcelus J, et al. Assessment of venous thromboembolism risk and the benefits of thromboprophylaxis in medical patients. Thromb Haemost 2005; 94: 750–59. Department of Health. Report of the independent expert working group on the prevention of venous thromboembolism in hospitalised patients. London: Staionery Office, 2007. http://www.dh.gov.uk/en/Publica tionsandstatistics/Publications/Publications PolicyAndGuidance/DH_073944 (accessed Feb 4, 2008).
Alexander Cohen and colleagues1 show that 42% of at-risk surgical patients did not receive venous thromboembolism (VTE) prophylaxis as recommended by the American College of Chest Physicians (ACCP). It is a wonder that so many surgeons did follow ACCP (or equivalent) guidelines, because, at least from a surgeon’s perspective, they are effectively buried in Chest.2 We hazard a guess that most surgeons have probably never heard of, let alone read, this journal. ACCP guidelines have formed the basis of our departmental VTE prevention policy for 7 years, but only because, when developing our own guidelines, we 1912
approached a friendly haematologist for advice on best practice. In the VTE prevention guidelines published by the UK’s National Institute for Health and Clinical Excellence,3 the ACCP guidelines are mentioned only as the 189th citation in more than 580 references (and do not feature by name in the text). Hardly a place of prominence for the most cited standard for the prevention of VTE disease. It is a truism that guidelines are only of value if doctors know about them, and are worthless if not heavily publicised, but Cohen and colleagues pay only scant attention to the issue of guideline dissemination as a possible explanation for their findings. We declare that we have no conflict of interest.
*Howard Marsh, John Reynard [email protected] Churchill Hospital, Oxford OX3 7LJ, UK 1
2
3
Cohen AT, Tapson VF, Bergmann J-F, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Geerts WH, Pineo GF, Heit JA, et al. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126 (suppl 3): 338S–400S. National Institute for Health and Clinical Excellence. Reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in inpatients undergoing surgery. NICE clinical guideline no 46. London: NICE, 2007. http://www.nice. org.uk/CG046 (accessed May 12, 2008).
Authors’ reply D Graham Mackenzie and colleagues, like many others, have been misled by the SIGN guidelines.1 These guidelines report that aspirin has not been shown to reduce total mortality or all vascular deaths in the surgical setting or in patients with hip fracture. Most patients included in the clinical trials cited in the SIGN guidelines were given aspirin in addition to standard therapy (mechanical and anticoagulant prophylaxis); however, unsupported conclusions relating to aspirin use alone are commonly made. The PEP trial,2 which contributed most
of the patients considered within the SIGN recommendations, showed that the reduction in deaths related to pulmonary embolism (PE) in patients on aspirin was counterbalanced by the increase in other vascular-related deaths. Despite this finding, the SIGN guidelines erroneously state that “Aspirin also reduces cardiovascular events in acute myocardial infarction and acute ischaemic stroke”.1 Although aspirin might reduce the risk of PE to a clinically significant degree in high-risk patients, it minimally affects the risk of deep-vein thrombosis, with only a 34% odds reduction3 compared with a 67% odds reduction reported for heparin-based prophylaxis.4 The PEP study also showed that aspirin led to a significant increase in gastrointestinal bleeding, an outcome that was “diluted” by the method of analysis. Finally, the PEP study and SIGN guidelines concluded that antiplatelet therapy made little or no difference to outcomes related to venous thromboembolism (VTE) in elective hip and knee surgery, respectively. In the surgical setting, anticoagulants have been shown to reduce mortality related to PE by two-thirds and total mortality by more than 20%.4 In orthopaedic surgery, a two-thirds reduction in VTE and VTE-related death has been shown.4 We agree that the data relating to hip fracture are limited and that recommendations require looking at the wider area of orthopaedic surgery. However, patients with hip fracture made up only 2·5% of our population and hence their outcomes do not change our overall conclusion. Furthermore, we would not recommend drawing conclusions on antithrombotic therapy solely from the audit mentioned.5 We acknowledge that the association between increased age and VTE risk is important and should guide treatment provision, as commented by Bruno Caramelli. We have additional data for this subject, which is to be included in a future publication. www.thelancet.com Vol 371 June 7, 2008
VTE risk is the single commonest risk factor for all hospital-related illness. We agree with Stephen Wallis and Sunku Guptha that risk assessment of all patients is essential at admission, irrespective of the presumed length of stay, which can be difficult to predict. Howard Marsh and John Reynard make a valid argument that guidelines should be disseminated more widely, and perhaps we should have given this more attention. We also agree that the NICE guidelines failed to recognise the importance and findings of the internationally recognised ACCP guidelines. NICE might therefore provide a potentially unbalanced view of the published work that is neither evidence-based nor commensurate with local or international practice, as shown by the ENDORSE findings. We declare that we have no conflict of interest other than that stated in the original paper.
*A T Cohen, V F Tapson, F A Anderson, on behalf of the ENDORSE Steering Committee and Investigators [email protected] King’s College Hospital, London SE5 9RS, UK (ATC); Duke University Medical Center, Durham, NC, USA (VFT); and Center for Outcomes Research, University of Massachusetts Medical School, Worcester, MA, USA (FAA) 1
2
3
4
5
Scottish Intercollegiate Guidelines Network. Prophylaxis of venous thromboembolism. Edinburgh: SIGN, 2002. http://www.sign. ac.uk/guidelines/fulltext/62/index.html (accessed May 12, 2008). Pulmonary Embolism Prevention (PEP) trial Collaborative Group. Prevention of pulmonary embolism and deep vein thrombosis with low dose aspirin: Pulmonary Embolism Prevention (PEP) trial. Lancet 2000; 355: 1295–302. Antiplatelet Trialists’ Collaboration. Collaborative overview of randomised trials of antiplatelet therapy—III: reduction in venous thrombosis and pulmonary embolism by antiplatelet prophylaxis among surgical and medical patients. BMJ 1994; 308: 235–46. Collins R, Scrimgeour A, Yusuf S, Peto R. Reduction in fatal pulmonary embolism and venous thrombosis by perioperative administration of subcutaneous heparin. Overview of results of randomized trials in general, orthopedic, and urologic surgery. N Engl J Med 1988; 318: 1162–73. Handoll HHG, Farrar MJ, McBirnie J, Tytherleigh-Strong G, Milne AA, Gillespie WJ. Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures. Cochrane Database Syst Rev 2002; 4: CD000305.
www.thelancet.com Vol 371 June 7, 2008
Prospects for healthsystems research
serve to achieve greater focus and commitment, so as to finally deliver on this long overdue agenda?
We welcome the Viewpoint by Michael Reich and colleagues (March 8, p 865)1 on the need to strengthen health systems and the opportunity presented by the G8 summit in Toyako to move this agenda along. In particular we endorse Reich and colleagues’ call for more investment in research on health systems. But this call has been made many times before. The WHO Advisory Committee on Medical Research first discussed this need in the 1970s; in 2004, the call was repeated by the participants in the Mexico Summit on Health Research, and the WHO Task Force on Health Systems Research.2 So what will turn these various appeals into a reality? One issue not addressed by the Viewpoint is that of capacity. A concerted initiative to develop greater capacity for health-systems research in low-income and middle-income countries is necessary to ensure that additional investment in healthsystems research benefits researchers, policy makers, and populations. Second, health-systems research knowledge needs to be packaged in ways that make it easily accessible to policy makers. Systematic reviews and summaries of systematic reviews are critical in this regard. Such reviews also help us to document existing evidence better, and identify future research priorities. There are significant opportunities on the horizon with regard to a focus on health-systems research. Certainly the G8 could be important, but so are the Inter-governmental Working Group on Public Health, Innovation and Intellectual Property, the Ministerial Forum in Bamako on Health Research later this year, and WHO’s own research strategy with its strong emphasis on strengthening the evidence base for policy recommendations. Is it too much to hope that this time, these processes will
We declare that we have no conflict of interest.
*Sara Bennett, Andy Oxman, Andy Haines [email protected] Alliance for Health Policy and Systems Research, WHO, 1211 Geneva 27, Switzerland (SB); Norwegian Satellite of the Cochrane Effective Practice and Organisation of Care Group, Norwegian Knowledge Centre for the Health Services, Oslo, Norway (AO); and London School of Hygiene and Tropical Medicine, London, UK (AH) 1
2
The printed journal includes an image merely for illustration
Reich MR, Takemi K, Roberts MJ, Hsiao WC. Global action on health systems: a proposal for the Toyako G8 summit. Lancet 2008; 371: 865–69. Task Force on Health Systems Research. Informed choices for attaining the Millennium Development Goals: towards an international cooperative agenda for health systems research. Lancet 2004; 364: 997–1003.
Michael Reich and colleagues1 provide a helpful overview of today’s pivotal global health challenge—health systems strengthening. Although we agree with their analysis, our recommendations for the G8 Summit diverge from the three actions they propose. We endorse engagement of community-based organisations, but only if women’s organisations are able to participate fully in policy development and accountability mechanisms. Although we agree that a separate fund for health systems is not appropriate, support from vertical funds will be limited at best. The G8 should also lift International Monetary Fund restrictions on healthsector subsidies and encourage public-private partnerships. It should commit to direct financing of health systems and to universal support for the International Health Partnership that aims to address most of the problems described by Reich and colleagues. The third proposal—enhanced learning, including pilot projects—is important but should not become an excuse for inaction. Pilot projects in particular should be avoided—poor countries are littered with them. 1913
Panos Pictures
Correspondence