Since its inception in 1994, the Center for Outcomes Research (COR) has served as the scientific coordinating center for a number of national and international disease-focused outcomes registries. Based in the Department of Surgery at UMass Chan Medical School, COR’s projects have ranged from phase-IV post-marketing studies and randomized clinical interventional studies to quality of care initiatives. COR’s responsibilities have included study design, maintenance of patient and physician confidentiality, design of data collection instruments, development of data management systems, and the dissemination of study results through scientific publications and confidential reports to patients, physicians and sponsors. This collection showcases publications about COR activities not related to specific projects.


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Recently Published

  • Occurrence and predictors of recurrence after a first episode of acute venous thromboembolism: population-based Worcester Venous Thromboembolism Study

    Huang, Wei; Goldberg, Robert J.; Anderson, Frederick A. Jr.; Cohen, Alexander T.; Spencer, Frederick A. (Kluwer Academic Publishers, 2016-02-05)
    Venous thromboembolism (VTE) has multiple risk factors and tends to recur. Despite the benefits of anticoagulation, the prevalence of, and case-fatality rate associated with, recurrent VTE remains a concern after an acute episode; it is particularly high during the acute treatment phase. We sought to quantify the magnitude, identify predictors, and develop risk score calculator of recurrence within 3 years after first-time VTE. This was a population-based surveillance study among residents of central Massachusetts (MA), USA, diagnosed with an acute first-time pulmonary embolism and/or lower-extremity deep vein thrombosis from 1999 to 2009 in hospital and ambulatory settings in all 12 central MA hospitals. Medical records were reviewed and validated. The 2989 study patients were followed for 5836 person-years [mean follow-up 23.4 (median 30) months]. Mean age was 64.3 years, 44 % were men, and 94 % were white. The cumulative incidence rate of recurrent VTE within 3 years after an index VTE was 15 % overall, and 25, 13, and 13 % among patients with active cancer, provoked, or unprovoked VTE, respectively. Multivariable regression indicated that active cancer, varicose vein stripping, and inferior vena cava filter placement were independent predictors of recurrence during both 3-month and 3-year follow-up. A risk score calculator was developed based on the 3-month prognostic model. In conclusion, the rate of VTE recurrence over 3 years of follow-up remained high. The risk score calculator may assist clinicians at the index encounter in determining the frequency of clinical surveillance and appropriate outpatient treatment of VTE during the acute treatment phase.
  • The Agency for Healthcare Research and Quality Inpatient Quality Indicator #11 overall mortality rate does not accurately assess mortality risk after abdominal aortic aneurysm repair

    Robinson, William P. III; Huang, Wei; Rosen, Amy K.; Schanzer, Andres; Fang, Hua (Julia); Anderson, Frederick A. Jr.; Messina, Louis M. (Mosby-Year Book, 2014-07-24)
    OBJECTIVE: The Agency for Healthcare Research and Quality (AHRQ) Inpatient Quality Indicator (IQI) #11, abdominal aortic aneurysm (AAA) repair mortality rate, is a measure of hospital quality that is publically reported but has not been externally validated. Because the IQI #11 overall mortality rate includes both intact and ruptured aneurysms and open and endovascular repair, we hypothesized that IQI #11 overall mortality rate does not provide accurate assessment of mortality risk after AAA repair and that AAA mortality cannot be accurately assessed by a single quality measure. METHODS: Using AHRQ IQI software version 4.2, we calculated observed (O) and expected (E) mortality rates for IQI #11 for all hospitals performing more than 10 AAA repairs per year in the Nationwide Inpatient Sample for the years 2007 to 2011. We used Spearman correlation coefficient to compare expected rates as determined by IQI #11 overall mortality rate risk adjustment methodology and observed rates for all AAA repairs in four cohorts stratified by aneurysm stability (ruptured vs intact) and method of repair (open vs endovascular). RESULTS: Among 187,773 AAA repairs performed at 1268 U.S. hospitals, hospitals' IQI #11 overall expected rates correlated poorly with their observed rates (E: 5.0% ± 4.4% vs O: 6.0% ± 9.8%; r = .49). For ruptured AAAs, IQI #11 overall mortality rate methodology underestimated the mortality risk of open repair (E: 34% ± 7.2% vs O: 40.1% ± 38.2%; r = 0.20) and endovascular repair (E: 24.8% ± 9% vs O: 27.3% ± 37.9%; r = 0.08). For intact AAA repair, IQI #11 overall mortality rate methodology underestimated the mortality risk of open repair (E: 4.3% ± 2.4% vs O: 6.3% ± 16.1%; r = .24) but overestimated the mortality risk of endovascular repair (E: 1.3% ± 0.8% vs O: 1.1% ± 3.7%; r = 0.25). Hospitals' observed mortality rates after intact AAA repair were not correlated with their mortality rates after ruptured AAA repair (r = 0.03). CONCLUSIONS: IQI #11 overall mortality rate fails to provide accurate assessment of inpatient mortality risk after AAA repair. Thus, it is inappropriate to use IQI #11 overall mortality rate for quality reporting. The accuracy of separate quality measures that assess mortality risk after repair of ruptured and intact AAAs, stratified by the use of open or endovascular repair, should be examined.
  • Randomized trial of physician alerts for thromboprophylaxis after discharge

    Piazza, Gregory; Anderson, Frederick A. Jr.; Ortel, Thomas L.; Cox, Michael J.; Rosenberg, David J.; Rahimian, Shahram; Pendergast, William J.; McLaren, Gordon D.; Welker, James A.; Akus, Jan J.; et al. (Excerpta Medica, 2013-05-01)
    BACKGROUND: Many hospitalized Medical Service patients are at risk for venous thromboembolism in the months after discharge. We conducted a multicenter randomized controlled trial to test whether a hospital staff member's thromboprophylaxis alert to an Attending Physician before discharge will increase the rate of extended out-of-hospital prophylaxis and, in turn, reduce the incidence of symptomatic venous thromboembolism at 90 days. METHODS: From April 2009 to January 2010, we enrolled hospitalized Medical Service patients using the point score system developed by Kucher et al to identify those at high risk for venous thromboembolism who were not ordered to receive thromboprophylaxis after discharge. There were 2513 eligible patients from 18 study sites randomized by computer in a 1:1 ratio to the alert group or the control group. RESULTS: Patients in the alert group were more than twice as likely to receive thromboprophylaxis at discharge as controls (22.0% vs 9.7%, P <.0001). Based on an intention-to-treat analysis, symptomatic venous thromboembolism at 90 days (99.9% follow-up) occurred in 4.5% of patients in the alert group, compared with 4.0% of controls (hazard ratio 1.12; 95% confidence interval, 0.74-1.69). The rate of major bleeding at 30 days in the alert group was similar to that of the control group (1.2% vs 1.2%, hazard ratio 0.94; 95% confidence interval, 0.44-2.01). CONCLUSIONS: Alerting providers to extend thromboprophylaxis after hospital discharge in Medical Service patients increased the rate of prophylaxis but did not decrease the rate of symptomatic venous thromboembolism.
  • Risk-assessment models for predicting venous thromboembolism among hospitalized non-surgical patients: a systematic review

    Huang, Wei; Anderson, Frederick A. Jr.; Spencer, Frederick A.; Gallus, Alexander S.; Goldberg, Robert J. (Kluwer Academic Publishers, 2012-07-24)
    Venous thromboembolism (VTE) prophylaxis is suboptimal in American hospitals despite long-standing evidence-based recommendations. Data from observational studies indicate a lower uptake of effective prophylaxis in patients hospitalized with medical versus surgical conditions. Reluctance to use prophylaxis in medical patients has been attributed to difficulty in identifying at-risk patients and balancing risks of bleeding against occurrence of VTE. Several risk-assessment models (RAMs) have been proposed to assist physicians in identifying non-surgical patients who need prophylaxis. We conducted a systematic review of published RAMs, based on objective criteria, to determine whether any RAM is validated sufficiently to be employed in clinical practice. We identified 11 RAMs, six derived from primary data and five based on expert opinion. The number, types, and strength of association of VTE risk predictors were highly variable. The variability in methods and outcome measurement precluded pooled estimates of these different models. Published RAMs for VTE lack generalizability and adequate validation. As electronic health records become more ubiquitous, validated dynamic RAMs are needed to assess VTE risk at the point-of-care in real time.
  • Prevention of venous thromboembolism after hip or knee arthroplasty: findings from a 2008 survey of US orthopedic surgeons

    Anderson, Frederick A. Jr.; Huang, Wei; Friedman, Richard J.; Kwong, Louis M.; Lieberman, Jay R.; Pellegrini, Vincent D. Jr.; The Orthopaedic Surgeon's Survey Steering Committee; Ayers, David C.; Franklin, Patricia D. (2012-05-01)
    A survey was mailed to a representative sample of US orthopedic surgeons to assess protocols for the prevention of venous thromboembolism after lower extremity total joint arthroplasty. Practices were examined by type of operation, annual surgical volume, and opinions of consensus guidelines issued by the American Academy of Orthopaedic Surgeons and the American College of Chest Physicians. Although there was near-unanimous agreement that routine thromboprophylaxis should be the standard practice for patients who undergo hip or knee arthroplasty, surgeons were divided as to the exact management approach.