Clinical Review & Education
From The JAMA Network
The Need to Revisit VTE Quality Measures Christine V. Kinnier, MD; Cindy Barnard, MBA, MSJS, CPHQ; Karl Y. Bilimoria, MD, MS
JAMA OTOLARYNGOLOGY–HEAD & NECK SURGERY Prospective Study of Venous Thromboembolism in Patients With Head and Neck Cancer After Surgery: Interim Analysis Daniel Clayburgh, MD, PhD; Will Stott, BS; Teresa Kochanowski, ANP-C; Renee Park, MD; Kara Detwiller, MD; Maria Buniel, MD; Paul Flint, MD; Joshua Schindler, MD; Peter Andersen, MD; Mark Wax, MD; Neil D. Gross, MD OBJECTIVES To prospectively determine the incidence of venous thromboembolism (VTE) following major head and neck surgery. At the midpoint of enrollment, an interim analysis was performed to determine if it was ethical to continue this study as an observational study without routine anticoagulation. DESIGN Prospective, observational cohort study. SETTING Academic surgical center. PATIENTS The interim analysis comprised 47 subjects. MAIN OUTCOME MEASURE The total number of new cases of VTE (superficial and deep) identified within 30 days of surgery and confirmed on diagnostic imaging. These cases were further categorized as clinically relevant and nonclinically relevant. Clinically relevant VTEs were those requiring more than 6 weeks of anticoagulation or were
Postoperative venous thromboembolism (VTE) is an important cause of surgical morbidity and mortality. Approximately 1% of all surgicalpatientswilldevelopaVTE,definedaseitheradeepvenousthrombosis (DVT) or pulmonary embolism (PE), in the 30 days after an operation, but this rate can reach 6% after high-risk surgeries.1 To reduce postoperative VTE events, quality measures have been developed to drive improvement in perioperative VTE prophylaxis. As currently designed, however, these measures fail to promote optimal VTE prophylaxis due to (1) narrow patient eligibility, (2) penalties for VTE diagnosis, and (3) limited prophylaxis dosing and duration requirements. Two current quality measures used in surgical populations include a process measure to monitor VTE prevention practices and an outcome measure of VTE event rates. The Surgical Care Improvement Project VTE-2 (SCIP-VTE-2) measures the proportion of “eligible” patients who receive VTE chemoprophylaxis within 24 hours of surgery.2 A separate VTE outcome measure, Patient Safety Indicator 12 (PSI-12), measures the risk-adjusted incidence of VTE in postoperative patients.3 Both measures are publicly reported and used in pay-for-performance programs. Multiple surgical populations are excluded from one or both of these measures because the risk-benefit ratio for VTE prophylaxis 286
associated with any negative impact on clinical course. On postoperative day 2 or 3, subjects were clinically examined and received duplex ultrasonography. Subjects with negative findings from examination and ultrasonography were followed up clinically; subjects with evidence of deep venous thrombus or pulmonary embolism were given therapeutic anticoagulation. Subjects with superficial VTE received repeated ultrasonography on postoperative days 4 to 6. Subjects were monitored for 30 days after surgery. RESULTS Three subjects (6%) were identified as having clinically significant VTE: 2 cases of deep venous thrombus and 1 case of pulmonary embolism. Two additional subjects had lower extremity superficial VTE without clinical findings, which were detected by ultrasonography alone. No statistically significant differences were seen between patients with VTE and those without VTE. CONCLUSIONS This interim analysis of the first prospective study of the incidence of VTE in patients with head and neck cancer showed a VTE rate slightly higher than previously estimated in retrospective studies. There have been no unexpected serious adverse events and no rationale for early termination of the study. JAMA Otolaryngol Head Neck Surg. 2013;139(2):161-167. doi:10.1001/jamaoto.2013.1372.
is unknown. In head and neck surgery, for example, clinicians remain concerned that prophylaxis-exacerbated bleeding in the neck may lead to airway compromise while the VTE incidence in the population is unclear. Similarly, many neurosurgeries, orthopedic surgeries, and burn surgeries are also excluded from SCIP-VTE-2 because of concerns that prophylaxis-exacerbated bleeding may have devastating consequences. These concerns, however, are neither new nor unique to these surgical populations. Twenty years ago, many abdominal surgeons feared that VTE chemoprophylaxis would lead to life-threatening postoperative hemorrhage. Since then, a wealth of high-quality research and the introduction of VTE quality measures have transformed VTE chemoprophylaxis into the standard of care after most abdominal surgeries.1 These issues are illuminated by a recent study of VTE rates in head and neck surgical patients by Clayburgh et al,4 reported in JAMA Otolaryngology–Head & Neck Surgery. Although a small interim analysis, the study suggests that concerns regarding potential bleeding in surgical patients with complex head and neck cancer may be inflated while risks of VTE may be underestimated. The authors identified 2 VTE events among the 47 patients studied. In contrast, only
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7 patients in the cohort received VTE chemoprophylaxis, but these patients developed neither VTE nor bleeding complications. Similar risk-benefit ratios for VTE chemoprophylaxis are reported in neurosurgery,5 orthopedic surgery,1 and burn surgery.1 Rather than categorically exclude entire patient populations, process measures should exclude patients based on specific risk factors such as active bleeding or severe thrombocytopenia. In addition, implementation of computerized clinical decision-support tools could help ensure appropriate populations are receiving prophylaxis.6 Where evidence is limited, studies should be undertaken to better quantify the risk-benefit ratio for VTE prophylaxis. Although patient care would benefit from a revision of SCIP-VTE-2 to include a broader range of surgical patients, the PSI-12 measure rests on a less stable foundation. First, PSI-12 flags all postoperative VTE events as presumably preventable, regardless of whether a patient received risk-appropriate VTE prophylaxis. Second, mounting evidence suggests that PSI-12 is significantly vulnerable to a surveillance bias: hospitals that look for more VTEs find more VTEs, thus worsening a hospital’s apparent VTE performance.7 In the study by Clayburgh et al,4 asymptomatic, superficial venous thromboses were diagnosed after routinely screening patients for DVT on the second or third postoperative day. Consequently, when used as a performance measure, PSI-12 effectively penalizes hospitals that provide optimal VTE prophylaxis and have a low threshold to evaluate symptomatic patients for VTE. Rather than these hospitals being penalized for VTEs that occur despite practitioners’ best efforts, all practitioners should be encouraged to provide optimal VTE prophylaxis when the risk-benefit ratio is appropriate. Optimal prevention could be more effectively encouraged using a process measure that measures the percentage of patients who receive all recommended doses of VTE chemoprophylaxis during the postoperative period at the correct dose and timing interval. A second process measure might monitor the percentage of low-risk patients who ambulate and receive mechanical prophylaxis (ie, nonchemical VTE prophylaxis such as sequential ARTICLE INFORMATION Author Affiliations: Surgical Outcomes and Quality Improvement Center, Department of Surgery, Feinberg School of Medicine, Northwestern University and Northwestern Memorial Hospital, Chicago, Illinois (Kinnier, Bilimoria); Department of Surgery, Massachusetts General Hospital, Boston (Kinnier); Department of Quality Strategies, Northwestern Memorial Hospital, Chicago, Illinois (Barnard, Bilimoria). Corresponding Author: Karl Y. Bilimoria, MD, MS, Surgical Outcomes and Quality Improvement Center, Department of Surgery, Feinberg School of Medicine, Northwestern Memorial Hospital, 676 St Clair St, Arkes Pavilion Ste 6-650, Chicago, IL 60611 ([email protected]). Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Bilimoria reported having received unrelated scientific grants, with all payments going to his institution, from the National Institutes of Health, Agency for Healthcare Research and Quality, American Cancer Society, American College of Surgeons, National Comprehensive Cancer
compression devices). These interventions would significantly improve optimal VTE prophylaxis rates without penalizing hospitals for VTE events beyond their control. Finally, neither SCIP-VTE-2 nor PSI-12 addresses VTE chemoprophylaxis duration beyond hospital care. In the study by Clayburgh et al,4 most patients were ambulatory during the 30-day postoperative time frame. Nevertheless, 2 of 47 patients developed a DVT or PE within 30 days of surgery. These data emphasize that ambulation alone is not sufficient VTE prophylaxis in high-risk postoperative patients. After most major surgery, however, VTE chemoprophylaxis is routinely discontinued at the time of hospital discharge. There is no evidence that readiness for discharge correlates with a sudden decline in VTE risk. Prospective randomized trials demonstrate that abdominal and pelvic cancer surgery patients8 and orthopedic surgery patients9 have lower VTE rates when they receive VTE chemoprophylaxis through the 28th postoperative day. Routine postdischarge VTE chemoprophylaxis remains the exception rather than the norm. If significant reductions in perioperative VTE morbidity and mortality are to occur, the duration of postoperative VTE chemoprophylaxis must be reconsidered, and process measures should be modified or developed to encourage postdischarge VTE prophylaxis. The standard of care for VTE prophylaxis has changed substantially in the last 20 years, and VTE quality measures helped promote that change. Current measures, however, do not reflect optimal VTE prophylaxis. Process measures like SCIP-VTE-2 should be modified to broadly include most surgeries; exclude patients with specific risk factors for postoperative bleeding; and mandate riskappropriate chemoprophylaxis dosing, timing, and duration. The PSI-12 outcome measure is inadequately constructed for use as a performance measure because it fails to reflect a hospital’s VTE prevention efforts and to promote improvements in clinical practice. With expansion and revision of VTE process measures, incentive systems can effectively encourage improved VTE prevention practices and reduce a significant risk of surgical patient care.
Network, and Blue Cross Blue Shield of Illinois. No other disclosures were reported.
5. Raslan AM, Fields JD, Bhardwaj A. Prophylaxis for venous thrombo-embolism in neurocritical care. Neurocrit Care. 2010;12(2):297-309.
REFERENCES
6. Haut ER, Lau BD, Kraenzlin FS, et al. Improved prophylaxis and decreased rates of preventable harm with the use of a mandatory computerized clinical decision support tool for prophylaxis for venous thromboembolism in trauma. Arch Surg. 2012;147(10):901-907.
1. Guyatt GH, Akl EA, Crowther M, et al. Executive summary: Antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines [published correction appears in Chest. 2012;142(6):1698]. Chest. 2012;141(2)(suppl):7S-47S. 2. Surgical care improvement project: VTE prophylaxis. National Quality Measures Clearinghouse. http://www.qualitymeasures.ahrq .gov/content.aspx?id=46458. February 10, 2014. 3. Postoperative pulmonary embolism or DVT rates. National Quality Measures Clearinghouse. http://www.qualitymeasures.ahrq.gov/content .aspx?id=38522&search=psi+12. Accessed February 10, 2014. 4. Clayburgh D, Stott W, Kochanowski T, et al. Prospective study of venous thromboembolism in patients with head and neck cancer after surgery: interim analysis. JAMA Otolaryngol Head Neck Surg. 2013;139(2):161-167.
7. Bilimoria KY, Chung J, Ju MH, et al. Evaluation of surveillance bias and the validity of the venous thromboembolism quality measure. JAMA. 2013; 310(14):1482-1489. 8. Bergqvist D, Agnelli G, Cohen AT, et al; ENOXACAN II Investigators. Duration of prophylaxis against venous thromboembolism with enoxaparin after surgery for cancer. N Engl J Med. 2002;346 (13):975-980. 9. Hull RD, Pineo GF, Stein PD, et al. Extended out-of-hospital low-molecular-weight heparin prophylaxis against deep venous thrombosis in patients after elective hip arthroplasty: a systematic review. Ann Intern Med. 2001;135(10):858-869.
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From The JAMA Network
The Need to Revisit VTE Quality Measures Christine V. Kinnier, MD; Cindy Barnard, MBA, MSJS, CPHQ; Karl Y. Bilimoria, MD, MS
JAMA OTOLARYNGOLOGY–HEAD & NECK SURGERY Prospective Study of Venous Thromboembolism in Patients With Head and Neck Cancer After Surgery: Interim Analysis Daniel Clayburgh, MD, PhD; Will Stott, BS; Teresa Kochanowski, ANP-C; Renee Park, MD; Kara Detwiller, MD; Maria Buniel, MD; Paul Flint, MD; Joshua Schindler, MD; Peter Andersen, MD; Mark Wax, MD; Neil D. Gross, MD OBJECTIVES To prospectively determine the incidence of venous thromboembolism (VTE) following major head and neck surgery. At the midpoint of enrollment, an interim analysis was performed to determine if it was ethical to continue this study as an observational study without routine anticoagulation. DESIGN Prospective, observational cohort study. SETTING Academic surgical center. PATIENTS The interim analysis comprised 47 subjects. MAIN OUTCOME MEASURE The total number of new cases of VTE (superficial and deep) identified within 30 days of surgery and confirmed on diagnostic imaging. These cases were further categorized as clinically relevant and nonclinically relevant. Clinically relevant VTEs were those requiring more than 6 weeks of anticoagulation or were
Postoperative venous thromboembolism (VTE) is an important cause of surgical morbidity and mortality. Approximately 1% of all surgicalpatientswilldevelopaVTE,definedaseitheradeepvenousthrombosis (DVT) or pulmonary embolism (PE), in the 30 days after an operation, but this rate can reach 6% after high-risk surgeries.1 To reduce postoperative VTE events, quality measures have been developed to drive improvement in perioperative VTE prophylaxis. As currently designed, however, these measures fail to promote optimal VTE prophylaxis due to (1) narrow patient eligibility, (2) penalties for VTE diagnosis, and (3) limited prophylaxis dosing and duration requirements. Two current quality measures used in surgical populations include a process measure to monitor VTE prevention practices and an outcome measure of VTE event rates. The Surgical Care Improvement Project VTE-2 (SCIP-VTE-2) measures the proportion of “eligible” patients who receive VTE chemoprophylaxis within 24 hours of surgery.2 A separate VTE outcome measure, Patient Safety Indicator 12 (PSI-12), measures the risk-adjusted incidence of VTE in postoperative patients.3 Both measures are publicly reported and used in pay-for-performance programs. Multiple surgical populations are excluded from one or both of these measures because the risk-benefit ratio for VTE prophylaxis 286
associated with any negative impact on clinical course. On postoperative day 2 or 3, subjects were clinically examined and received duplex ultrasonography. Subjects with negative findings from examination and ultrasonography were followed up clinically; subjects with evidence of deep venous thrombus or pulmonary embolism were given therapeutic anticoagulation. Subjects with superficial VTE received repeated ultrasonography on postoperative days 4 to 6. Subjects were monitored for 30 days after surgery. RESULTS Three subjects (6%) were identified as having clinically significant VTE: 2 cases of deep venous thrombus and 1 case of pulmonary embolism. Two additional subjects had lower extremity superficial VTE without clinical findings, which were detected by ultrasonography alone. No statistically significant differences were seen between patients with VTE and those without VTE. CONCLUSIONS This interim analysis of the first prospective study of the incidence of VTE in patients with head and neck cancer showed a VTE rate slightly higher than previously estimated in retrospective studies. There have been no unexpected serious adverse events and no rationale for early termination of the study. JAMA Otolaryngol Head Neck Surg. 2013;139(2):161-167. doi:10.1001/jamaoto.2013.1372.
is unknown. In head and neck surgery, for example, clinicians remain concerned that prophylaxis-exacerbated bleeding in the neck may lead to airway compromise while the VTE incidence in the population is unclear. Similarly, many neurosurgeries, orthopedic surgeries, and burn surgeries are also excluded from SCIP-VTE-2 because of concerns that prophylaxis-exacerbated bleeding may have devastating consequences. These concerns, however, are neither new nor unique to these surgical populations. Twenty years ago, many abdominal surgeons feared that VTE chemoprophylaxis would lead to life-threatening postoperative hemorrhage. Since then, a wealth of high-quality research and the introduction of VTE quality measures have transformed VTE chemoprophylaxis into the standard of care after most abdominal surgeries.1 These issues are illuminated by a recent study of VTE rates in head and neck surgical patients by Clayburgh et al,4 reported in JAMA Otolaryngology–Head & Neck Surgery. Although a small interim analysis, the study suggests that concerns regarding potential bleeding in surgical patients with complex head and neck cancer may be inflated while risks of VTE may be underestimated. The authors identified 2 VTE events among the 47 patients studied. In contrast, only
JAMA July 16, 2014 Volume 312, Number 3
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://jama.jamanetwork.com/ by a Simon Fraser University User on 06/07/2015
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From The JAMA Network Clinical Review & Education
7 patients in the cohort received VTE chemoprophylaxis, but these patients developed neither VTE nor bleeding complications. Similar risk-benefit ratios for VTE chemoprophylaxis are reported in neurosurgery,5 orthopedic surgery,1 and burn surgery.1 Rather than categorically exclude entire patient populations, process measures should exclude patients based on specific risk factors such as active bleeding or severe thrombocytopenia. In addition, implementation of computerized clinical decision-support tools could help ensure appropriate populations are receiving prophylaxis.6 Where evidence is limited, studies should be undertaken to better quantify the risk-benefit ratio for VTE prophylaxis. Although patient care would benefit from a revision of SCIP-VTE-2 to include a broader range of surgical patients, the PSI-12 measure rests on a less stable foundation. First, PSI-12 flags all postoperative VTE events as presumably preventable, regardless of whether a patient received risk-appropriate VTE prophylaxis. Second, mounting evidence suggests that PSI-12 is significantly vulnerable to a surveillance bias: hospitals that look for more VTEs find more VTEs, thus worsening a hospital’s apparent VTE performance.7 In the study by Clayburgh et al,4 asymptomatic, superficial venous thromboses were diagnosed after routinely screening patients for DVT on the second or third postoperative day. Consequently, when used as a performance measure, PSI-12 effectively penalizes hospitals that provide optimal VTE prophylaxis and have a low threshold to evaluate symptomatic patients for VTE. Rather than these hospitals being penalized for VTEs that occur despite practitioners’ best efforts, all practitioners should be encouraged to provide optimal VTE prophylaxis when the risk-benefit ratio is appropriate. Optimal prevention could be more effectively encouraged using a process measure that measures the percentage of patients who receive all recommended doses of VTE chemoprophylaxis during the postoperative period at the correct dose and timing interval. A second process measure might monitor the percentage of low-risk patients who ambulate and receive mechanical prophylaxis (ie, nonchemical VTE prophylaxis such as sequential ARTICLE INFORMATION Author Affiliations: Surgical Outcomes and Quality Improvement Center, Department of Surgery, Feinberg School of Medicine, Northwestern University and Northwestern Memorial Hospital, Chicago, Illinois (Kinnier, Bilimoria); Department of Surgery, Massachusetts General Hospital, Boston (Kinnier); Department of Quality Strategies, Northwestern Memorial Hospital, Chicago, Illinois (Barnard, Bilimoria). Corresponding Author: Karl Y. Bilimoria, MD, MS, Surgical Outcomes and Quality Improvement Center, Department of Surgery, Feinberg School of Medicine, Northwestern Memorial Hospital, 676 St Clair St, Arkes Pavilion Ste 6-650, Chicago, IL 60611 ([email protected]). Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Bilimoria reported having received unrelated scientific grants, with all payments going to his institution, from the National Institutes of Health, Agency for Healthcare Research and Quality, American Cancer Society, American College of Surgeons, National Comprehensive Cancer
compression devices). These interventions would significantly improve optimal VTE prophylaxis rates without penalizing hospitals for VTE events beyond their control. Finally, neither SCIP-VTE-2 nor PSI-12 addresses VTE chemoprophylaxis duration beyond hospital care. In the study by Clayburgh et al,4 most patients were ambulatory during the 30-day postoperative time frame. Nevertheless, 2 of 47 patients developed a DVT or PE within 30 days of surgery. These data emphasize that ambulation alone is not sufficient VTE prophylaxis in high-risk postoperative patients. After most major surgery, however, VTE chemoprophylaxis is routinely discontinued at the time of hospital discharge. There is no evidence that readiness for discharge correlates with a sudden decline in VTE risk. Prospective randomized trials demonstrate that abdominal and pelvic cancer surgery patients8 and orthopedic surgery patients9 have lower VTE rates when they receive VTE chemoprophylaxis through the 28th postoperative day. Routine postdischarge VTE chemoprophylaxis remains the exception rather than the norm. If significant reductions in perioperative VTE morbidity and mortality are to occur, the duration of postoperative VTE chemoprophylaxis must be reconsidered, and process measures should be modified or developed to encourage postdischarge VTE prophylaxis. The standard of care for VTE prophylaxis has changed substantially in the last 20 years, and VTE quality measures helped promote that change. Current measures, however, do not reflect optimal VTE prophylaxis. Process measures like SCIP-VTE-2 should be modified to broadly include most surgeries; exclude patients with specific risk factors for postoperative bleeding; and mandate riskappropriate chemoprophylaxis dosing, timing, and duration. The PSI-12 outcome measure is inadequately constructed for use as a performance measure because it fails to reflect a hospital’s VTE prevention efforts and to promote improvements in clinical practice. With expansion and revision of VTE process measures, incentive systems can effectively encourage improved VTE prevention practices and reduce a significant risk of surgical patient care.
Network, and Blue Cross Blue Shield of Illinois. No other disclosures were reported.
5. Raslan AM, Fields JD, Bhardwaj A. Prophylaxis for venous thrombo-embolism in neurocritical care. Neurocrit Care. 2010;12(2):297-309.
REFERENCES
6. Haut ER, Lau BD, Kraenzlin FS, et al. Improved prophylaxis and decreased rates of preventable harm with the use of a mandatory computerized clinical decision support tool for prophylaxis for venous thromboembolism in trauma. Arch Surg. 2012;147(10):901-907.
1. Guyatt GH, Akl EA, Crowther M, et al. Executive summary: Antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines [published correction appears in Chest. 2012;142(6):1698]. Chest. 2012;141(2)(suppl):7S-47S. 2. Surgical care improvement project: VTE prophylaxis. National Quality Measures Clearinghouse. http://www.qualitymeasures.ahrq .gov/content.aspx?id=46458. February 10, 2014. 3. Postoperative pulmonary embolism or DVT rates. National Quality Measures Clearinghouse. http://www.qualitymeasures.ahrq.gov/content .aspx?id=38522&search=psi+12. Accessed February 10, 2014. 4. Clayburgh D, Stott W, Kochanowski T, et al. Prospective study of venous thromboembolism in patients with head and neck cancer after surgery: interim analysis. JAMA Otolaryngol Head Neck Surg. 2013;139(2):161-167.
7. Bilimoria KY, Chung J, Ju MH, et al. Evaluation of surveillance bias and the validity of the venous thromboembolism quality measure. JAMA. 2013; 310(14):1482-1489. 8. Bergqvist D, Agnelli G, Cohen AT, et al; ENOXACAN II Investigators. Duration of prophylaxis against venous thromboembolism with enoxaparin after surgery for cancer. N Engl J Med. 2002;346 (13):975-980. 9. Hull RD, Pineo GF, Stein PD, et al. Extended out-of-hospital low-molecular-weight heparin prophylaxis against deep venous thrombosis in patients after elective hip arthroplasty: a systematic review. Ann Intern Med. 2001;135(10):858-869.
jama.com
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Copyright 2014 American Medical Association. All rights reserved.
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