Carl van Walraven

Summary

Affiliation: Ottawa Health Research Institute
Country: Canada

Publications

  1. ncbi request reprint The Kaiser Permanente inpatient risk adjustment methodology was valid in an external patient population
    Carl van Walraven
    Ottawa Health Research Institute, A581 003 Carling Ave, Ottawa, Ontario K1Y 4E9, Canada
    J Clin Epidemiol 63:798-803. 2010
  2. pmc Effect of discharge summary availability during post-discharge visits on hospital readmission
    Carl van Walraven
    Department of Medicine, University of Ottawa, Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, ON, Canada
    J Gen Intern Med 17:186-92. 2002
  3. pmc The Procedural Index for Mortality Risk (PIMR): an index calculated using administrative data to quantify the independent influence of procedures on risk of hospital death
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Hospital Research Institute, 1053 Carling Avenue, Ottawa, K1Y 4E9, Canada
    BMC Health Serv Res 11:258. 2011
  4. doi request reprint The influence of incidental abdominal aortic aneurysm monitoring on patient outcomes
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    J Vasc Surg 54:1290-1297.e2. 2011
  5. ncbi request reprint Incidence, follow-up, and outcomes of incidental abdominal aortic aneurysms
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ontario, Canada
    J Vasc Surg 52:282-9.e1-2. 2010
  6. doi request reprint The independent association of provider and information continuity on outcomes after hospital discharge: implications for hospitalists
    Carl van Walraven
    Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
    J Hosp Med 5:398-405. 2010
  7. pmc Radiographic monitoring of incidental abdominal aortic aneurysms: a retrospective population-based cohort study
    Carl van Walraven
    University of Ottawa, Canada
    Open Med 5:e67-76. 2011
  8. pmc LACE+ index: extension of a validated index to predict early death or urgent readmission after hospital discharge using administrative data
    Carl van Walraven
    Ottawa Hospital Research Institute, Administrative Services Building, Room 1003, 1053 Carling Avenue, Ottawa, ON K1Y 4E9, Canada
    Open Med 6:e80-90. 2012
  9. pmc Derivation and validation of a diagnostic score based on case-mix groups to predict 30-day death or urgent readmission
    Carl van Walraven
    Ottawa Hospital Research Institute, Administrative Services Building, Room 1003, 1053 Carling Avenue, Ottawa, ON K1Y 4E9, Canada
    Open Med 6:e90-e100. 2012
  10. ncbi request reprint A prospective cohort study found that provider and information continuity was low after patient discharge from hospital
    Carl van Walraven
    Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
    J Clin Epidemiol 63:1000-10. 2010

Detail Information

Publications100

  1. ncbi request reprint The Kaiser Permanente inpatient risk adjustment methodology was valid in an external patient population
    Carl van Walraven
    Ottawa Health Research Institute, A581 003 Carling Ave, Ottawa, Ontario K1Y 4E9, Canada
    J Clin Epidemiol 63:798-803. 2010
    ..This study assessed the Kaiser Permanente inpatient risk adjustment methodology for hospital mortality in a patient population distinct from that used for its derivation...
  2. pmc Effect of discharge summary availability during post-discharge visits on hospital readmission
    Carl van Walraven
    Department of Medicine, University of Ottawa, Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, ON, Canada
    J Gen Intern Med 17:186-92. 2002
    ..To determine if the delivery of hospital discharge summaries to follow-up physicians decreases the risk of hospital readmission...
  3. pmc The Procedural Index for Mortality Risk (PIMR): an index calculated using administrative data to quantify the independent influence of procedures on risk of hospital death
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Hospital Research Institute, 1053 Carling Avenue, Ottawa, K1Y 4E9, Canada
    BMC Health Serv Res 11:258. 2011
    ..This study derived and internally validated an index that can be calculated using administrative data to quantify the independent risk of hospital death after a procedure...
  4. doi request reprint The influence of incidental abdominal aortic aneurysm monitoring on patient outcomes
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    J Vasc Surg 54:1290-1297.e2. 2011
    ..These are common, and many undergo incomplete radiological monitoring. The association between monitoring completeness and population-based outcomes has not been studied...
  5. ncbi request reprint Incidence, follow-up, and outcomes of incidental abdominal aortic aneurysms
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ontario, Canada
    J Vasc Surg 52:282-9.e1-2. 2010
    ..Incidental AAAs are important findings because they require monitoring and surgical treatment, when indicated, to prevent rupture. The prevalence of incidental AAAs and their management has not been extensively studied...
  6. doi request reprint The independent association of provider and information continuity on outcomes after hospital discharge: implications for hospitalists
    Carl van Walraven
    Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
    J Hosp Med 5:398-405. 2010
    ..To determine how this influenced patient outcomes, we examined the independent association of several physician continuity and information continuity measures on death or urgent readmission after discharge from hospital...
  7. pmc Radiographic monitoring of incidental abdominal aortic aneurysms: a retrospective population-based cohort study
    Carl van Walraven
    University of Ottawa, Canada
    Open Med 5:e67-76. 2011
    ..No population-based studies have assessed the management of incidental AAAs. The objective of this study was to measure the completeness of radiographic monitoring of incidental AAAs by means of a population-based analysis...
  8. pmc LACE+ index: extension of a validated index to predict early death or urgent readmission after hospital discharge using administrative data
    Carl van Walraven
    Ottawa Hospital Research Institute, Administrative Services Building, Room 1003, 1053 Carling Avenue, Ottawa, ON K1Y 4E9, Canada
    Open Med 6:e80-90. 2012
    ....
  9. pmc Derivation and validation of a diagnostic score based on case-mix groups to predict 30-day death or urgent readmission
    Carl van Walraven
    Ottawa Hospital Research Institute, Administrative Services Building, Room 1003, 1053 Carling Avenue, Ottawa, ON K1Y 4E9, Canada
    Open Med 6:e90-e100. 2012
    ..In this study, we derived and validated a score summarizing the influence of acute hospital diagnoses and procedures on death or urgent readmission within 30 days...
  10. ncbi request reprint A prospective cohort study found that provider and information continuity was low after patient discharge from hospital
    Carl van Walraven
    Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
    J Clin Epidemiol 63:1000-10. 2010
    ..This study is a detailed examination of continuity of care in patients discharged from hospital that simultaneously measured separate components of continuity over time or determined the factors with which they are associated...
  11. pmc Continuity of care and patient outcomes after hospital discharge
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    J Gen Intern Med 19:624-31. 2004
    ..Transfer of information between physicians can be poor. We determined whether early postdischarge outcomes changed when patients were seen after discharge by physicians who treated them in the hospital...
  12. doi request reprint Effect of age on stroke prevention therapy in patients with atrial fibrillation: the atrial fibrillation investigators
    Carl van Walraven
    University of Ottawa and Ottawa Health Research Institute Canada, Ottawa, Canada
    Stroke 40:1410-6. 2009
    ....
  13. pmc Derivation and validation of an index to predict early death or unplanned readmission after discharge from hospital to the community
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa Hospital, and the Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario
    CMAJ 182:551-7. 2010
    ..We sought to derive and validate an index to predict the risk of death or unplanned readmission within 30 days after discharge from hospital to the community...
  14. ncbi request reprint Effect of a nurse team coordinator on outcomes for hospitalized medicine patients
    Alan J Forster
    Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    Am J Med 118:1148-53. 2005
    ..We do not know if adding a clinical nurse specialist (CNS) to physician teams in hospitals that already have discharge planning services makes a difference...
  15. ncbi request reprint Burden of potentially avoidable anticoagulant-associated hemorrhagic and thromboembolic events in the elderly
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Health Research Institute, Ottawa Hospital, Civic Campus, 1053 Carling Avenue, Ottawa, Ontario, Canada
    Chest 131:1508-15. 2007
    ..However, not all anticoagulation-associated events are attributable to poor anticoagulation control, nor do all hemorrhagic or thromboembolic events occur in anticoagulated patients...
  16. pmc Adverse events following an emergency department visit
    Alan J Forster
    Ottawa Health Research Institute Clinical Epidemiology Program, Ottawa, Ontario, Canada
    Qual Saf Health Care 16:17-22. 2007
    ..Many studies demonstrate a high rate of treatment-related adverse outcomes or adverse events. No studies have prospectively evaluated adverse events in patients discharged home from the emergency department (ED)...
  17. doi request reprint Addition of time-dependent covariates to a survival model significantly improved predictions for daily risk of hospital death
    Jenna Wong
    Department of Clinical Epidemiology, Ottawa Hospital Research Institute, Ottawa, ON, Canada
    J Eval Clin Pract 19:351-7. 2013
    ..RATIONAL, AIMS AND OBJECTIVES: The study aims to determine the extent to which the addition of post-admission information via time-dependent covariates improved the ability of a survival model to predict the daily risk of hospital death...
  18. ncbi request reprint Oral anticoagulants vs. aspirin for stroke prevention in patients with non-valvular atrial fibrillation: the verdict is in
    Carl van Walraven
    Clinical Epidemiology Unit Ottawa Health Research Institute, Ottawa, Ontario, Canada
    Card Electrophysiol Rev 7:374-8. 2003
    ..Since high-risk AF patients appear to benefit most from OAC, determining stroke risk in AF patients is very important...
  19. pmc Anticoagulation intensity and outcomes among patients prescribed oral anticoagulant therapy: a systematic review and meta-analysis
    Natalie Oake
    Department of Medicine, University of Ottawa, and the Clinical Epidemiology Program, Ottawa Health Research Institute, Ottawa, Ont
    CMAJ 179:235-44. 2008
    ..We sought to determine the association between anticoagulation intensity and the risk of hemorrhagic and thromboembolic events. We also sought to determine how under-or overanticoagulation would influence patient outcomes...
  20. pmc Effect of an interactive voice response system on oral anticoagulant management
    Natalie Oake
    Clinical Epidemiology Program, Ottawa Health Research Institute, The Ottawa Hospital, Ottawa, ON K1Y 4E9
    CMAJ 180:927-33. 2009
    ..Monitoring oral anticoagulants is logistically challenging for both patients and medical staff. We evaluated the effect of adding an interactive voice response system to computerized decision support for oral anticoagulant management...
  21. ncbi request reprint Elective, major noncardiac surgery on the weekend: a population-based cohort study of 30-day mortality
    Daniel I McIsaac
    Department of Anesthesiology, University of Ottawa Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON
    Med Care 52:557-64. 2014
    ..The generalizability of this association and effect size is unknown...
  22. pmc Validation of a discharge summary term search method to detect adverse events
    Alan J Forster
    FRCPC, C406 1053 Carling Avenue, Ottawa, ON, Canada K1Y 4E9
    J Am Med Inform Assoc 12:200-6. 2005
    ..We performed this study to validate a previously derived method of adverse event detection using term searching in physician-dictated discharge summaries...
  23. doi request reprint Long-term outcomes and resource utilization of endovascular versus open repair of abdominal aortic aneurysms in Ontario
    Prasad Jetty
    Division of Vascular Surgery, The Ottawa Hospital, University of Ottawa, Ontario, Canada
    J Vasc Surg 51:577-83, 583.e1-3. 2010
    ..Despite these data, the use of EVAR continues to increase in North America. Currently, there are very limited adjusted population-based data examining long-term outcomes and resource utilization...
  24. ncbi request reprint The effect of hospitalization on oral anticoagulation control: a population-based study
    Carl van Walraven
    Department of Medicine, University of Ottawa, Clinical Epidemiology Program, Ottawa Health Research Institute, C405, Ottawa Hospital, Civic Campus, 1053 Carling Avenue, Ottawa ON, K1Y 4E9, Canada
    Thromb Res 119:705-14. 2007
    ..Previous studies examining OAC control may not generalize because the patient population was select or INR capture was incomplete...
  25. pmc The impact of adverse events in the intensive care unit on hospital mortality and length of stay
    Alan J Forster
    Department of Medicine, University of Ottawa, Ottawa, Canada
    BMC Health Serv Res 8:259. 2008
    ..We performed this study to measure the independent influence of intensive care unit (ICU) based AEs on in-hospital mortality and hospital length of stay...
  26. pmc Does adding risk-trends to survival models improve in-hospital mortality predictions? A cohort study
    Jenna Wong
    Clinical Epidemiology Program, Ottawa Hospital Research Institute, 1053 Carling Avenue, Ottawa, K1Y 4E9, Canada
    BMC Health Serv Res 11:171. 2011
    ..In this study, we used a unique approach to measure trends in patient hospital death risk and determined whether the incorporation of these trend measures into a survival model improved the accuracy of its risk predictions...
  27. ncbi request reprint Interactive voice response systems for improving delivery of ambulatory care
    Natalie Oake
    Clinical Epidemiology Program, Ottawa Health Research Institute, 1053 Carling Ave, Ottawa, Ontario K1Y 4E9, Canada
    Am J Manag Care 15:383-91. 2009
    ..To comprehensively describe the populations, interventions, and outcomes of interactive voice response system (IVRS) clinical trials...
  28. doi request reprint Influence of neighborhood household income on early death or urgent hospital readmission
    Carl van Walraven
    Ottawa Hospital Research Institute and Institute for Clinical Evaluative Sciences, Ottawa, Canada
    J Hosp Med 8:261-6. 2013
    ..The relationship of socioeconomic status (SES) with hospital readmissions is unclear...
  29. doi request reprint A modification of the Elixhauser comorbidity measures into a point system for hospital death using administrative data
    Carl van Walraven
    Ottawa Health Research Institute, Ottawa, Ontario, Canada
    Med Care 47:626-33. 2009
    ..However, the Elixhauser classification system requires 30 binary variables, making its use for reporting and analysis of comorbidity cumbersome...
  30. doi request reprint Changes in surrogate outcomes can be translated into clinical outcomes using a Monte Carlo model
    Carl van Walraven
    Ottawa Health Research Institute, University of Ottawa, Ontario, Canada
    J Clin Epidemiol 62:1306-15. 2009
    ..Formulae to do this are uncommon because they require primary data from multiple randomized trials that measure both the surrogate and clinical outcome...
  31. pmc Information exchange among physicians caring for the same patient in the community
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Health Research Institute, ASB1 003, Ottawa Hospital, Civic Campus, 1053 Carling Ave, Ottawa, ONK1Y4E9
    CMAJ 179:1013-8. 2008
    ..This study determined the probability that patient information from previous visits with other physicians was available for a current physician visit...
  32. ncbi request reprint A clinical prediction rule to identify patients with atrial fibrillation and a low risk for stroke while taking aspirin
    Carl van Walraven
    Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa Hospital, Ontario, Canada
    Arch Intern Med 163:936-43. 2003
    ....
  33. doi request reprint The effect of hospital-acquired Clostridium difficile infection on in-hospital mortality
    Natalie Oake
    Clinical Quality and Performance Management, Ottawa Hospital, Ottawa, Ontario, Canada
    Arch Intern Med 170:1804-10. 2010
    ..We conducted this study to determine the independent impact of hospital-acquired CDI on in-hospital mortality after adjusting for the time-varying nature of CDI and baseline mortality risk at hospital admission...
  34. doi request reprint Incidence and contributors to potential drug-drug interactions in hospitalized patients
    Leanne Reimche
    Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
    J Clin Pharmacol 51:1043-50. 2011
    ..27 [2.23-2.30] for logarithm), and patient service (adjusted rate ratio, 1.49 [1.46-1.52] for surgical vs medical service). Potential DDIs were present during one fifth of hospitalization time...
  35. doi request reprint The usefulness of administrative databases for identifying disease cohorts is increased with a multivariate model
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Hospital Research Institute, F660 1053 Carling Avenue, Ottawa, Ontario, Canada
    J Clin Epidemiol 63:1332-41. 2010
    ..This would allow the accurate identification of a disease cohort in an administrative database...
  36. pmc Reliability of the peer-review process for adverse event rating
    Alan J Forster
    The Ottawa Hospital, Ottawa, Ontario, Canada
    PLoS ONE 7:e41239. 2012
    ..Their identification requires the peer-review of poor outcomes, which may be unreliable. Combining physician ratings might improve the accuracy of adverse event classification...
  37. pmc Identifying patients with post-discharge care problems using an interactive voice response system
    Alan J Forster
    Department of Medicine, University of Ottawa, Ottawa, Canada
    J Gen Intern Med 24:520-5. 2009
    ..We designed an interactive voice response system (IVRS) with the intent of identifying patients who might be experiencing an AE following discharge or were at risk of developing one...
  38. doi request reprint Administrative database research infrequently used validated diagnostic or procedural codes
    Carl van Walraven
    Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
    J Clin Epidemiol 64:1054-9. 2011
    ..Measure the proportion of ADR studies using diagnostic or procedural codes that measured or referenced code accuracy...
  39. doi request reprint Correlation between serial tests made disease probability estimates erroneous
    Carl van Walraven
    Ottawa Health Research Institute, Ontario, Canada
    J Clin Epidemiol 62:1301-5. 2009
    ..The probability of a disease, given the result of two diagnostic tests, can be calculated by multiplying the odds of disease after the first test by the likelihood ratio of the second test...
  40. doi request reprint Using the Johns Hopkins Aggregated Diagnosis Groups (ADGs) to predict mortality in a general adult population cohort in Ontario, Canada
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Department of Health Management, Policy and Evaluation, University of Ottawa, Ottawa, Ontario, Canada
    Med Care 49:932-9. 2011
    ..There are limited validated methods for risk adjustment in ambulatory populations using administrative healthcare databases...
  41. pmc Incidence of potentially avoidable urgent readmissions and their relation to all-cause urgent readmissions
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Ont
    CMAJ 183:E1067-72. 2011
    ..Urgent, unplanned hospital readmissions are increasingly being used to gauge the quality of care. We reviewed urgent readmissions to determine which were potentially avoidable and compared rates of all-cause and avoidable readmissions...
  42. pmc Frequency of adverse events in patients with poor anticoagulation: a meta-analysis
    Natalie Oake
    Department of Medicine, University of Ottawa, Ottawa, Ont
    CMAJ 176:1589-94. 2007
    ..To gauge the potential effect of improved anticoagulation control, we undertook to determine the proportion of anticoagulant-associated events that occur when INRs are outside the therapeutic range...
  43. pmc Anticoagulation control in the peri-hospitalization period
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Health Research Institute C404, Ottawa Hospital, Civic Campus, 1053 Carling Avenue, Ottawa, ON, K1Y 4E9, Canada
    J Gen Intern Med 22:727-35. 2007
    ..Anticoagulated patients discharged after medical hospitalizations could be targeted for improved anticoagulation control...
  44. doi request reprint A meta-analysis of hospital 30-day avoidable readmission rates
    Carl van Walraven
    University of Ottawa, Ottawa, Ontario, Canada
    J Eval Clin Pract 18:1211-8. 2012
    ..In this study, we generated a literature-based estimate for the proportion of 30-day urgent readmissions deemed avoidable for hospitals to use to gauge their performance in avoidable readmissions...
  45. pmc Comparing methods to calculate hospital-specific rates of early death or urgent readmission
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    CMAJ 184:E810-7. 2012
    ..Hospital-specific readmission rates have been reported as a quality-of-care indicator. However, the extent to which these measures vary with different calculation methods is uncertain...
  46. pmc Ottawa Hospital Patient Safety Study: incidence and timing of adverse events in patients admitted to a Canadian teaching hospital
    Alan J Forster
    Ottawa Health Research Institute, Ottawa, Ont
    CMAJ 170:1235-40. 2004
    ..We evaluated characteristics of adverse events affecting patients admitted to a Canadian teaching hospital, paying particular attention to timing...
  47. ncbi request reprint Using an interactive voice response system to improve patient safety following hospital discharge
    Alan J Forster
    Department of Medicine, University of Ottawa, Ottawa, ON, Canada
    J Eval Clin Pract 13:346-51. 2007
    ..Patients often experience complications when transitioning from hospital to home. These complications are frequently related to poor monitoring. An interactive voice response system (IVRS) could improve post-discharge monitoring...
  48. pmc Proportion of hospital readmissions deemed avoidable: a systematic review
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Ont
    CMAJ 183:E391-402. 2011
    ..We conducted a systematic review of studies that measured the proportion of readmissions deemed avoidable. We examined how such readmissions were measured and estimated their prevalence...
  49. doi request reprint Association of diagnostic radiation exposure and second abdominal-pelvic malignancies after testicular cancer
    Carl van Walraven
    University of Ottawa, Ottawa, Ontario, Canada
    J Clin Oncol 29:2883-8. 2011
    ..Men recovering from low-grade testicular cancer frequently undergo serial abdominal-pelvic computerized tomography (CT) scanning to monitor for recurrent disease...
  50. ncbi request reprint Survival trends in ESRD patients compared with the general population in the United States
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Canada Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada Health Services Research Facility, University of Ottawa, Ottawa, Canada Electronic address
    Am J Kidney Dis 63:491-9. 2014
    ..In this study, we examined survival trends in the United States in patients with ESRD receiving renal replacement therapy with long-term dialysis or transplantation relative to the general population...
  51. pmc The use of quality indicators to promote accountability in health care: the good, the bad, and the ugly
    Alan J Forster
    Performance Measurement, The Ottawa Hospital, Ottawa, Ontario, Canada
    Open Med 6:e75-9. 2012
    ..To meet these recommendations the health system needs to increased investment in performance measurement systems...
  52. doi request reprint Patient-level factors associated with methicillin-resistant Staphylococcus aureus carriage at hospital admission: a systematic review
    Alan J Forster
    Performance Measurement, The Ottawa Hospital, Ottawa, ON, Canada
    Am J Infect Control 41:214-20. 2013
    ..To characterize high-risk populations, we conducted this systematic review to identify patient-level factors associated with MRSA carriage at hospital admission...
  53. doi request reprint Urgent readmission rates can be used to infer differences in avoidable readmission rates between hospitals
    Carl van Walraven
    Medicine, University of Ottawa, Ottawa Health Research Institute, Toronto, Canada
    J Clin Epidemiol 65:1124-30. 2012
    ..Most of the urgent readmissions are unavoidable. This study developed a method that used observed urgent readmission rates to compare the latent avoidable readmission rates between the two hospitals...
  54. doi request reprint Influence of house-staff experience on teaching-hospital mortality: the "July phenomenon" revisited
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ontario, Canada
    J Hosp Med 6:389-94. 2011
    ..Previous quantitative studies of new house-staff and increased mortality have been limited primarily by a focused patient population and the use of limited data to adjust for severity of patient illness...
  55. pmc A systematic review to evaluate the accuracy of electronic adverse drug event detection
    Alan J Forster
    Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
    J Am Med Inform Assoc 19:31-8. 2012
    ..Electronic detection of ADEs is a promising method to identify ADEs. We performed this systematic review to characterize established electronic detection systems and their accuracy...
  56. ncbi request reprint Automated patient assessments after outpatient surgery using an interactive voice response system
    Alan J Forster
    Department of Medicine, University of Ottawa, Ontario, Canada
    Am J Manag Care 14:429-36. 2008
    ..To test the feasibility and utility of an interactive voice response system (IVRS) for monitoring patients after outpatient surgery...
  57. doi request reprint The association between continuity of care and outcomes: a systematic and critical review
    Carl van Walraven
    Department of Medicine, University of Ottawa, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
    J Eval Clin Pract 16:947-56. 2010
    ..Studies doing so must actually measure continuity. If continuity and outcomes are measured concurrently, their association can only be determined with time-dependent methods...
  58. pmc Adverse events among medical patients after discharge from hospital
    Alan J Forster
    Clinical Epidemiology Program, Ottawa Health Research Institute, Ottawa, Ontario, Canada
    CMAJ 170:345-9. 2004
    ..However, few data describe AEs after hospital discharge. We determined the incidence, severity, preventability and ameliorability of AEs in patients discharged from the general internal medicine service of a Canadian hospital...
  59. pmc Using prospective clinical surveillance to identify adverse events in hospital
    Alan J Forster
    The Ottawa Hospital, ON, Canada
    BMJ Qual Saf 20:756-63. 2011
    ..These findings suggest that institutions will need to evaluate service-specific safety problems to set priorities and design improvement strategies...
  60. ncbi request reprint Effect of study setting on anticoagulation control: a systematic review and metaregression
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Health Research Institute, C405, Ottawa Hospital, Civic Campus, 1053 Carling Ave, Ottawa, ON, K1Y 4E9 Canada
    Chest 129:1155-66. 2006
    ..The effect of study-level factors, especially study setting, on anticoagulation control is unknown...
  61. ncbi request reprint The effect of a hepatitis serology testing algorithm on laboratory utilization
    Carl van Walraven
    Institute for Clinical Evaluative Sciences, Toronto, Canada
    J Eval Clin Pract 8:327-32. 2002
    ..Since over-utilization of hepatitis serological tests was suspected, a hepatitis serology testing algorithm was initiated in Ontario, Canada. This study determined the effects of this algorithm on utilization...
  62. ncbi request reprint Did publication of a clinical practice guideline recommendation to screen for type 2 diabetes in women with gestational diabetes change practice?
    Heather D Clark
    Ottawa Health Research Institute, Ontario, Canada
    Diabetes Care 26:265-8. 2003
    ..To determine whether women with previous gestational diabetes mellitus (GDM) were screened postpartum for type 2 diabetes according to the Canadian Diabetes Association (CDA) guidelines...
  63. pmc Predicting potential survival benefit of renal transplantation in patients with chronic kidney disease
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ont
    CMAJ 182:666-72. 2010
    ..To facilitate decision-making about treatment options for patients with end-stage renal disease considering kidney transplantation, we sought to develop an index for clinical prediction of risk for death...
  64. ncbi request reprint The effect of hospital occupancy on emergency department length of stay and patient disposition
    Alan J Forster
    Departments of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    Acad Emerg Med 10:127-33. 2003
    ..Emergency department (ED) overcrowding is a common problem. Despite a widespread belief that low hospital bed availability contributes to ED overcrowding, there are few data demonstrating this effect...
  65. pmc Risk of subsequent thromboembolism for patients with pre-eclampsia
    Carl van Walraven
    Ottawa Health Research Institute, Ottawa, Canada K1Y 4E9
    BMJ 326:791-2. 2003
  66. pmc Dissemination of discharge summaries. Not reaching follow-up physicians
    Carl van Walraven
    Can Fam Physician 48:737-42. 2002
    ..To discover how often hospital discharge summaries were available to physicians seeing patients for follow-up visits after hospitalization...
  67. ncbi request reprint Effect of provider continuity on test repetition
    Carl van Walraven
    Network of Eastern Ontario Medical Laboratories NEO MeL, Ottawa, ONT Canada
    Clin Chem 52:2219-28. 2006
    ..A perceived benefit of PC is decreased test repetition. Repeat tests make up a significant proportion of overall laboratory utilization. This study determined whether test repetition increases when PC decreases...
  68. ncbi request reprint The effect of participation in a weight loss programme on short-term health resource utilization
    Carl van Walraven
    Department of Medicine, Institute for Clinical Evaluative Sciences, University of Ottawa, Ottawa, Ontario, Canada
    J Eval Clin Pract 8:37-44. 2002
    ..Further study is required to determine if patients who maintain their weight loss experience a decrease in health utilization...
  69. pmc Adverse events following 12 and 18 month vaccinations: a population-based, self-controlled case series analysis
    Kumanan Wilson
    Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada
    PLoS ONE 6:e27897. 2011
    ..Live vaccines have distinct safety profiles, potentially causing systemic reactions one to 2 weeks after administration. In the province of Ontario, Canada, live MMR vaccine is currently recommended at age 12 months and 18 months...
  70. ncbi request reprint Time-dependent bias was common in survival analyses published in leading clinical journals
    Carl van Walraven
    Department of Medicine, University of Ottawa, Ottawa Hospital, Civic Campus, 1053 Carling Avenue, F 660, Ottawa, ON K1Y 4E9, Canada
    J Clin Epidemiol 57:672-82. 2004
    ..Time-dependent bias can occur if such variables are not analyzed appropriately. This study sought to determine the prevalence of such time-dependent bias in highly-cited medical journals...
  71. ncbi request reprint Diabetic patients with prior specialist care have better glycaemic control than those with prior primary care
    Baiju R Shah
    Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
    J Eval Clin Pract 11:568-75. 2005
    ..To compare glycaemic control, as reflected in the A1c level, of diabetic patients with primary care vs. with specialist care...
  72. pmc Improving patient safety: moving beyond the "hype" of medical errors
    Alan J Forster
    Department of Medicine and the Ottawa Health Research Institute, University of Ottawa, Ottawa, Ont
    CMAJ 173:893-4. 2005
  73. pmc Risk of death or readmission among people discharged from hospital on Fridays
    Carl van Walraven
    Clinical and Epidemiology Unit, Ottawa Health Research Institute, Ottawa Hospital, ON
    CMAJ 166:1672-3. 2002
  74. ncbi request reprint Adverse events detected by clinical surveillance on an obstetric service
    Alan J Forster
    Ottawa Health Research Institute, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    Obstet Gynecol 108:1073-83. 2006
    ..We performed this study to estimate the rate of adverse events and potential adverse events-errors that have a high likelihood of causing patient harm-occurring during obstetric care...
  75. doi request reprint When projecting required effectiveness of interventions for hospital readmission reduction, the percentage that is potentially avoidable must be considered
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa Hospital Research Institute, ASB1 003 1053 Carling Avenue, Ottawa, Ontario K1Y 4E9, Canada
    J Clin Epidemiol 66:688-90. 2013
    ..In this study, we determined how effective interventions must be to attain specific reductions in hospital readmission rates...
  76. doi request reprint Administrative database research has unique characteristics that can risk biased results
    Carl van Walraven
    Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario K1Y 4E9, Canada
    J Clin Epidemiol 65:126-31. 2012
    ....
  77. ncbi request reprint Combining ratings from multiple physician reviewers helped to overcome the uncertainty associated with adverse event classification
    Alan J Forster
    Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    J Clin Epidemiol 60:892-901. 2007
    ..We performed this study to quantify the misclassification rate obtained using current AE detection methods and to evaluate the effect of combining physician AE ratings...
  78. ncbi request reprint Oral anticoagulants vs aspirin in nonvalvular atrial fibrillation: an individual patient meta-analysis
    Carl van Walraven
    Clinical Epidemiology Unit, Ottawa Health Research Institute, F 6, Ottawa Hospital, Civic Campus, 1053 Carling Ave, Ottawa, Ontario, Canada K1Y 4E9
    JAMA 288:2441-8. 2002
    ..Patients with nonvalvular atrial fibrillation (AF) have an increased risk of stroke and other vascular events...
  79. pmc Derivation and validation of a MEDLINE search strategy for research studies that use administrative data
    Carl van Walraven
    Ottawa Hospital Research Institute, Institute for Clinical Evaluative Sciences, ASB 1 003 1053 Carling Avenue, Ottawa, ON
    Health Serv Res 45:1836-45. 2010
    ..To derive and validate a search strategy that identifies administrative database research (ADR) in the MEDLINE database...
  80. doi request reprint Coding accuracy of abdominal aortic aneurysm repair procedures in administrative databases - a note of caution
    Prasad Jetty
    Division of Vascular Surgery, The Ottawa Hospital and University of Ottawa, Ottawa, ON, Canada
    J Eval Clin Pract 17:91-6. 2011
    ..This requires the use of procedural codes whose accuracy has not been established. In this study we measured the accuracy of procedural codes for open AAA repair and endovascular aneurysm repair (EVAR) in administrative databases...
  81. ncbi request reprint Mycophenolate mofetil dose reduction and the risk of acute rejection after renal transplantation
    Greg A Knoll
    Division of Nephrology, Kidney Research Centre, and Department of Medicine, University of Ottawa, and Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, Ontario, Canada
    J Am Soc Nephrol 14:2381-6. 2003
    ..Clinicians need to be aware of the rejection risk when the MMF dose is reduced and maintain close surveillance on such patients...
  82. ncbi request reprint Population-based study of repeat laboratory testing
    Carl van Walraven
    Clinical Epidemiology Program, Ottawa Health Research Institute, C405, Ottawa Hospital, Civic Campus, 1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada
    Clin Chem 49:1997-2005. 2003
    ..Laboratory test repetition has not been rigorously studied at a population-based level. Our objective was to determine the prevalence of, and charges associated with, repetition of eight common laboratory tests...
  83. ncbi request reprint How far is the sternal angle from the mid-right atrium?
    Ratika Seth
    Department of Medicine, University of Ottawa, Ontario, Canada
    J Gen Intern Med 17:852-6. 2002
    ..Classical clinical teaching quotes this distance as 5 cm, invariable between patients, and invariable with changes in the elevation of the patient's head. The validity of these JVP characteristics has been questioned...
  84. pmc Prevalence of information gaps in the emergency department and the effect on patient outcomes
    Andrew Stiell
    Clinical Epidemiology Unit, Ottawa Health Research Institute, ON
    CMAJ 169:1023-8. 2003
    ..In this study we measured the prevalence of physician-reported information gaps for patients presenting to an emergency department at a teaching hospital...
  85. pmc Restricted driver licensing for medical impairments: does it work?
    Shawn C Marshall
    Department of Medicine, University of Ottawa, Ont
    CMAJ 167:747-51. 2002
    ....
  86. doi request reprint When laboratories report estimated glomerular filtration rates in addition to serum creatinines, nephrology consults increase
    Arsh K Jain
    Division of Nephrology, Department of Medicine, University of Western Ontario, London, Ontario, Canada
    Kidney Int 76:318-23. 2009
    ..However, it remains to be seen whether the routine reporting of eGFR results in improved treatment and outcomes for those with chronic kidney disease...
  87. ncbi request reprint Renin-angiotensin system blockade and the risk of hyperkalemia in chronic hemodialysis patients
    Greg A Knoll
    Division of Nephrology, Department of Medicine, Kidney Research Centre, The Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
    Am J Med 112:110-4. 2002
    ....
  88. pmc Utilization and outcomes of HbA1c testing: a population-based study
    Graham Woodward
    CMAJ 174:327-9. 2006
  89. ncbi request reprint Additive role of plasma von Willebrand factor levels to clinical factors for risk stratification of patients with atrial fibrillation
    Gregory Y H Lip
    Haemostasis, Thrombosis and Vascular Biology Unit, University Department of Medicine, City Hospital, Birmingham, England
    Stroke 37:2294-300. 2006
    ..This study determined the additive role of plasma vWf levels to clinical factors for risk stratification in patients with AF...
  90. pmc Maternal age and risk of stillbirth: a systematic review
    Ling Huang
    Health Surveillance and Epidemiology Division, Centre for Health Promotion, Public Health Agency of Canada, Ottawa, Ont
    CMAJ 178:165-72. 2008
    ..In this systematic review we explored whether older maternal age is associated with an increased risk of stillbirth...
  91. ncbi request reprint Effect of follow-up physician visits on emergency readmissions
    Carl van Walraven
    Am J Med 113:347; author reply 347. 2002
  92. ncbi request reprint Identifying individuals with a reduced GFR using ambulatory laboratory database surveillance
    Amit X Garg
    Division of Nephrology, University of Western Ontario, London Kidney Clinical Research Unit, Room A01, Westminster Tower, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 4G5, Canada
    J Am Soc Nephrol 16:1433-9. 2005
    ..Whether such identification leads to improved health outcomes warrants further study...
  93. ncbi request reprint Clinical inertia in response to inadequate glycemic control: do specialists differ from primary care physicians?
    Baiju R Shah
    Institute for Clinical Evaluative Sciences, G106 2075 Bayview Ave, Toronto, ON, Canada M4N 3M5
    Diabetes Care 28:600-6. 2005
    ..Failure to do so can be termed "clinical inertia." Because data suggest that specialist care results in better control than primary care, we evaluated whether specialists demonstrated less clinical inertia than primary care physicians...
  94. pmc Impact of specialist follow-up in outpatients with congestive heart failure
    Justin A Ezekowitz
    Division of Cardiology, University of Alberta, Edmonton, Alta
    CMAJ 172:189-94. 2005
    ..Our objective was to determine the impact of physician specialty on outcomes in outpatients with new-onset congestive heart failure...
  95. ncbi request reprint Selecting patients with atrial fibrillation for anticoagulation: stroke risk stratification in patients taking aspirin
    Brian F Gage
    Division of General Medical Sciences, Washington University School of Medicine Campus Box 8005, 660 S Euclid Ave, St Louis, MO 63110, USA
    Circulation 110:2287-92. 2004
    ..This prospective cohort study tested the predictive accuracy of 5 stroke risk stratification schemes...
  96. ncbi request reprint Quantifying the impact of survivor treatment bias in observational studies
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Eval Clin Pract 12:601-12. 2006
    ..Survivor treatment bias can arise when the time dependent nature of treatment exposure is ignored since patients who survived to receive treatment may be healthier than patients who died prior to receipt of treatment...
  97. pmc Bias in revascularization study
    Carl van Walraven
    CMAJ 176:1125; author reply 1125. 2007
  98. ncbi request reprint Effect of a controlled feedback intervention on laboratory test ordering by community physicians
    Peter S Bunting
    Gamma Dynacare Medical Laboratories, Brampton, Ontario, Canada
    Clin Chem 50:321-6. 2004
    ..We determined whether laboratory test utilization by community physicians could be reduced by a multifaceted program of education and feedback...
  99. ncbi request reprint Practice guidelines and practicing physicians-who's guiding whom?
    Carl van Walraven
    Clin Chem 48:9-10. 2002