Alexander M Walker

Summary

Publications

  1. ncbi request reprint The incidence of first provoked and unprovoked seizure in pediatric patients with and without psychiatric diagnoses
    Andrew T McAfee
    i3 Drug Safety, Waltham, Massachusetts 02451, USA
    Epilepsia 48:1075-82. 2007
  2. doi request reprint Identification of esophageal cancer in the General Practice Research Database
    Alexander M Walker
    World Health Information Science Consultants, LLC, Newton, MA 02466, USA
    Pharmacoepidemiol Drug Saf 20:1159-67. 2011
  3. doi request reprint Matching on provider is risky
    Alexander M Walker
    World Health Information Science Consultants, Riverside Center, Suite 2 400, 275 Grove Street, Newton, MA 02466, USA
    J Clin Epidemiol 66:S65-8. 2013
  4. doi request reprint Signal detection for vaccine side effects that have not been specified in advance
    Alexander M Walker
    World Health Information Science Consultants, LLC, Newton, MA, USA
    Pharmacoepidemiol Drug Saf 19:311-7. 2010
  5. doi request reprint Orthogonal predictions: follow-up questions for suggestive data
    Alexander M Walker
    World Health Information Science Consultants, LLC, Newton, MA 02466, USA
    Pharmacoepidemiol Drug Saf 19:529-32. 2010
  6. doi request reprint Coronary heart disease outcomes in patients receiving antidiabetic agents in the PharMetrics database 2000-2007
    Alexander M Walker
    World Health Information Science Consultants LLC, Wellesley, MA 02481, USA
    Pharmacoepidemiol Drug Saf 17:760-8. 2008
  7. ncbi request reprint Coronary heart disease outcomes in patients receiving antidiabetic agents
    Andrew T McAfee
    i3 Drug Safety, Newton, Massachusetts 02451, USA
    Pharmacoepidemiol Drug Saf 16:711-25. 2007
  8. pmc The Zelnorm epidemiologic study (ZEST): a cohort study evaluating incidence of abdominal and pelvic surgery related to tegaserod treatment
    John D Seeger
    Brigham and Women s Hospital and Harvard Medical School, Boston, MA, USA
    BMC Gastroenterol 12:171. 2012
  9. ncbi request reprint Achilles tendon rupture and its association with fluoroquinolone antibiotics and other potential risk factors in a managed care population
    John D Seeger
    i3 Drug Safety, Auburndale, MA, USA
    Pharmacoepidemiol Drug Saf 15:784-92. 2006
  10. ncbi request reprint Paroxetine in the first trimester and the prevalence of congenital malformations
    J Alexander Cole
    i3 Drug Safety, Auburndale, MA, USA
    Pharmacoepidemiol Drug Saf 16:1075-85. 2007

Detail Information

Publications49

  1. ncbi request reprint The incidence of first provoked and unprovoked seizure in pediatric patients with and without psychiatric diagnoses
    Andrew T McAfee
    i3 Drug Safety, Waltham, Massachusetts 02451, USA
    Epilepsia 48:1075-82. 2007
    ..To estimate the rate of new-onset afebrile provoked and unprovoked seizure in a general pediatric population and subgroups of patients with and without psychiatric diagnoses other than attention deficit hyperactivity disorder (ADHD)...
  2. doi request reprint Identification of esophageal cancer in the General Practice Research Database
    Alexander M Walker
    World Health Information Science Consultants, LLC, Newton, MA 02466, USA
    Pharmacoepidemiol Drug Saf 20:1159-67. 2011
    ..The literature on the timing of cancer code appearance in general practice records is scanty but suggests that there may be substantial error by comparison with actual dates of clinical onset...
  3. doi request reprint Matching on provider is risky
    Alexander M Walker
    World Health Information Science Consultants, Riverside Center, Suite 2 400, 275 Grove Street, Newton, MA 02466, USA
    J Clin Epidemiol 66:S65-8. 2013
    ..To illustrate that matching on provider may exacerbate, not remove, bias...
  4. doi request reprint Signal detection for vaccine side effects that have not been specified in advance
    Alexander M Walker
    World Health Information Science Consultants, LLC, Newton, MA, USA
    Pharmacoepidemiol Drug Saf 19:311-7. 2010
    ..The system is potentially much more sensitive to patterns with multiple features than are very large, high-dimension contingency tables...
  5. doi request reprint Orthogonal predictions: follow-up questions for suggestive data
    Alexander M Walker
    World Health Information Science Consultants, LLC, Newton, MA 02466, USA
    Pharmacoepidemiol Drug Saf 19:529-32. 2010
    ..The Universal Data Warehouse will shortly render moot searches for new databases in which to test...
  6. doi request reprint Coronary heart disease outcomes in patients receiving antidiabetic agents in the PharMetrics database 2000-2007
    Alexander M Walker
    World Health Information Science Consultants LLC, Wellesley, MA 02481, USA
    Pharmacoepidemiol Drug Saf 17:760-8. 2008
    ..The risk of coronary heart disease (CHD) in users of antidiabetic agents must be quantified to permit reasoned therapeutic choices...
  7. ncbi request reprint Coronary heart disease outcomes in patients receiving antidiabetic agents
    Andrew T McAfee
    i3 Drug Safety, Newton, Massachusetts 02451, USA
    Pharmacoepidemiol Drug Saf 16:711-25. 2007
    ..There is conflicting evidence on the reduction of cardiovascular risk in diabetic patients treated with oral antidiabetic agents...
  8. pmc The Zelnorm epidemiologic study (ZEST): a cohort study evaluating incidence of abdominal and pelvic surgery related to tegaserod treatment
    John D Seeger
    Brigham and Women s Hospital and Harvard Medical School, Boston, MA, USA
    BMC Gastroenterol 12:171. 2012
    ..We sought to quantify the association between tegaserod use and the occurrence of abdominal or pelvic surgery, including cholecystectomy...
  9. ncbi request reprint Achilles tendon rupture and its association with fluoroquinolone antibiotics and other potential risk factors in a managed care population
    John D Seeger
    i3 Drug Safety, Auburndale, MA, USA
    Pharmacoepidemiol Drug Saf 15:784-92. 2006
    ..We sought to quantify the strength of association between exposure to fluoroquinolone antibiotics and the occurrence of ATR, accounting for other risk factors...
  10. ncbi request reprint Paroxetine in the first trimester and the prevalence of congenital malformations
    J Alexander Cole
    i3 Drug Safety, Auburndale, MA, USA
    Pharmacoepidemiol Drug Saf 16:1075-85. 2007
    ..To refine a preliminary analysis identifying a possibly increased prevalence of malformations among infants born to women exposed to paroxetine in the first trimester...
  11. doi request reprint Risk of Guillain-Barré syndrome after meningococcal conjugate vaccination
    Priscilla Velentgas
    Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA
    Pharmacoepidemiol Drug Saf 21:1350-8. 2012
    ..We conducted a study to assess the risk of GBS after MCV4 vaccination using health plan administrative and claims data together with the review of primary medical records of potential cases...
  12. ncbi request reprint The incidence of abdominal and pelvic surgery among patients with irritable bowel syndrome
    J Alexander Cole
    Department of Epidemiology, Ingenix, Riverside Center 3 120, 275 Grove Street, Auburndale, Massachusetts 02466, USA
    Dig Dis Sci 50:2268-75. 2005
    ..Patients with IBS have an increased risk for abdominopelvic and gallbladder surgery and, thus, an associated risk for experiencing morbidity and mortality associated with these surgical procedures...
  13. doi request reprint Hospitalization for peptic ulcer and bleeding in users of selective COX-2 inhibitors and nonselective NSAIDs with special reference to celecoxib
    M Kay Patterson
    i3 Drug Safety, Waltham, MA, USA
    Pharmacoepidemiol Drug Saf 17:982-8. 2008
    ..To assess the relative incidence of peptic ulcer bleeding and perforation (PUBP) in users of selective cyclooxygenase-2 (COX-2) inhibitors and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs)...
  14. ncbi request reprint Bupropion in pregnancy and the prevalence of congenital malformations
    J Alexander Cole
    i3 Drug Safety, Epidemiology, Auburndale, MA 02466, USA
    Pharmacoepidemiol Drug Saf 16:474-84. 2007
    ..We conducted a study of congenital malformations among infants born to women exposed to bupropion during their first trimester...
  15. ncbi request reprint The comparative safety of rosuvastatin: a retrospective matched cohort study in over 48,000 initiators of statin therapy
    Andrew T McAfee
    i3 Drug Safety, Newton, MA 02466, USA
    Pharmacoepidemiol Drug Saf 15:444-53. 2006
    ..The purpose of this study was to compare incidence rates of hospitalization associated with rhabdomyolysis, myopathy, renal, or hepatic dysfunction, and of in-hospital death, between initiators of rosuvastatin and other statins...
  16. pmc An event-based approach for comparing the performance of methods for prospective medical product monitoring
    Joshua J Gagne
    Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women s Hospital and Harvard Medical School, Boston, MA, USA
    Pharmacoepidemiol Drug Saf 21:631-9. 2012
    ..Little attention has been given to how to compare methods in this setting...
  17. ncbi request reprint Results of multivariable logistic regression, propensity matching, propensity adjustment, and propensity-based weighting under conditions of nonuniform effect
    Tobias Kurth
    Division of Preventive Medicine, Department of Medicine, Brigham and Women s Hospital, Harvard Medical School, Boston, MA, USA
    Am J Epidemiol 163:262-70. 2006
    ..Researchers need to be clear about the population for which an overall treatment estimate is most suitable...
  18. ncbi request reprint Cardiovascular risk of selective cyclooxygenase-2 inhibitors and other non-aspirin non-steroidal anti-inflammatory medications
    Priscilla Velentgas
    Ingenix i3 Drug Safety, Auburndale, MA 02466, USA
    Pharmacoepidemiol Drug Saf 15:641-52. 2006
    ..The purpose of this study was to estimate rates of acute coronary syndrome (ACS), and sudden cardiac death in relation to use of rofecoxib, celecoxib, naproxen, diclofenac, and ibuprofen...
  19. ncbi request reprint Serum potassium monitoring for users of ethinyl estradiol/drospirenone taking medications predisposing to hyperkalemia: physician compliance and survey of knowledge and attitudes
    Patricia Mona Eng
    i3 Drug Safety, Riverside Center 3 120, 275 Grove Street, Auburndale, MA 02466, USA
    Contraception 75:101-7. 2007
    ..Product labeling recommends potassium monitoring in the first month of use for women concurrently receiving medication that may increase serum potassium...
  20. ncbi request reprint Severe vascular events in migraine patients
    Priscilla Velentgas
    Ingenix Epidemiology, Auburndale, MA 02466, USA
    Headache 44:642-51. 2004
    ..To estimate rates of vascular events in relation to dispensing of triptans and ergot alkaloids among migraineurs, and to compare these rates with those of nonmigraineurs...
  21. pmc Active safety monitoring of new medical products using electronic healthcare data: selecting alerting rules
    Joshua J Gagne
    Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women s Hospital and Harvard Medical School, Boston, MA 02120, USA
    Epidemiology 23:238-46. 2012
    ..These systems will rely on algorithms to generate alerts about potential safety concerns...
  22. ncbi request reprint Serious cardiovascular events and mortality among patients with schizophrenia
    Cheryl Enger
    Ingenix Epidemiology, Riverside Center, Suite 3 120, 275 Grove Street, Auburndale, MA 02466, USA
    J Nerv Ment Dis 192:19-27. 2004
    ..This risk was most pronounced in persons with more intense exposure to drugs and appeared to be indistinguishable in users of typical antipsychotics, of atypical products, or of both...
  23. ncbi request reprint More lawyers. More bureaucrats. Less information on drug safety
    Alexander M Walker
    i3 Drug Safety, Riverside Center 3 120, Auburndale, MA 02466, USA
    Pharmacoepidemiol Drug Saf 15:394-5. 2006
  24. ncbi request reprint Posttransplant lymphoproliferative disorder among renal transplant patients in relation to the use of mycophenolate mofetil
    Donnie P Funch
    Ingenix Epidemiology, Auburndale, MA 02466, and Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, USA
    Transplantation 80:1174-80. 2005
    ..This study assessed the risk of PTLD in relation to immunosuppression during a period that saw the introduction and eventual market dominance of mycophenolate mofetil (MMF)...
  25. ncbi request reprint Temporal trends and drug exposures in pulmonary hypertension: an American experience
    Alexander M Walker
    Harvard School of Public Health, Boston, MA, USA
    Am Heart J 152:521-6. 2006
    ..We also studied whether use of anorexigens and other drugs differed among patients with pulmonary hypertension of different etiologies...
  26. doi request reprint Epidemiology and outcomes in patients with atrial fibrillation in the United States
    Alexander M Walker
    World Health Information Science Consultants, Wellesley, Massachusetts, USA
    Heart Rhythm 5:1365-72. 2008
    ..Nonrheumatic atrial fibrillation (AF) is a common cause of embolic stroke. Warfarin therapy can reduce stroke risk by two-thirds in patients with AF, but therapy may not always be used or always be used optimally...
  27. ncbi request reprint The impact of wording in "Dear doctor" letters and in black box labels
    Lisa Bianchi Weatherby
    Epidemiology Division, Ingenix, Newton, MA 02466, USA
    Clin Pharmacol Ther 72:735-42. 2002
    ....
  28. ncbi request reprint Incidence of colonic ischemia, hospitalized complications of constipation, and bowel surgery in relation to use of alosetron hydrochloride
    David P Miller
    Ingenix, Epidemiology Division, Newton, Massachusetts 02466, USA
    Am J Gastroenterol 98:1117-22. 2003
    ..We sought to compare the incidence of colonic ischemia, hospitalized complications of constipation, and bowel surgery among alosetron users and a cohort of patients with IBS who did not use alosetron...
  29. ncbi request reprint Precautions for proactive surveillance
    Alexander M Walker
    Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA
    Pharmacoepidemiol Drug Saf 11:17-20. 2002
    ..The resolution for proactive surveillance is sen/cen: high sensitivity to signals and vigorous censoring to filter out the noise...
  30. ncbi request reprint Studies of diabetes, thiazolidinediones, and coronary heart disease
    Alexander M Walker
    Pharmacoepidemiol Drug Saf 16:1313-4; author reply 1314-6. 2007
  31. doi request reprint Aprotinin during coronary-artery bypass grafting and risk of death
    Sebastian Schneeweiss
    Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women s Hospital and Harvard Medical School, Boston, MA 02120, USA
    N Engl J Med 358:771-83. 2008
    ..Aprotinin (Trasylol) is used to mitigate bleeding during coronary-artery bypass grafting (CABG). Accumulating evidence suggests that this practice increases mortality...
  32. ncbi request reprint Use of propensity score technique to account for exposure-related covariates: an example and lesson
    John D Seeger
    Ingenix i3 Drug Safety, Waltham, Massachusetts, USA
    Med Care 45:S143-8. 2007
    ..Although propensity scores are used increasingly often, their limitations in settings without complete data may not be recognized...
  33. doi request reprint Supplementary data collection with case-cohort analysis to address potential confounding in a cohort study of thromboembolism in oral contraceptive initiators matched on claims-based propensity scores
    P Mona Eng
    Ingenix, i3 Drug Safety, Waltham, MA 02451, USA
    Pharmacoepidemiol Drug Saf 17:297-305. 2008
    ..g., smoking and obesity) not captured in claims data in a claims-based cohort study of thromboembolism among matched oral contraceptive (OC) initiators...
  34. ncbi request reprint Analgesic use and change in kidney function in apparently healthy men
    Tobias Kurth
    Division of Preventive Medicine, Brigham and Women s Hospital, Harvard Medical School, Boston, MA 02215 1204, USA
    Am J Kidney Dis 42:234-44. 2003
    ..Studies using a single creatinine measurement have yielded inconsistent results regarding analgesic use and kidney function...
  35. ncbi request reprint Risk of thromboembolism in women taking ethinylestradiol/drospirenone and other oral contraceptives
    John D Seeger
    i3 Drug Safety, Ingenix, Waltham, Massachusetts 02451, USA
    Obstet Gynecol 110:587-93. 2007
    ..We sought to estimate the association between ethinylestradiol/drospirenone and risk of thromboembolism relative to the association among other oral contraceptives...
  36. ncbi request reprint Risk for respiratory events in a cohort of patients receiving inhaled zanamivir: a retrospective study
    Jeanne E Loughlin
    Epidemiology and Safety Research Division, Ingenix, Inc, Auburndale, Massachusetts 02466, USA
    Clin Ther 24:1786-99. 2002
    ..Inhaled zanamivir is indicated for treatment of uncomplicated acute illness due to influenza A and B viruses in patients aged > or = 12 years who have been symptomatic for no more than 2 days...
  37. ncbi request reprint The effect of zanamivir treatment on influenza complications: a retrospective cohort study
    J Alexander Cole
    Epidemiology and Safety Research Division, Riverside Center, Ingenix, Inc, Auburndale, Massachusetts 02466, USA
    Clin Ther 24:1824-39. 2002
    ..Complications of influenza are a major cause of morbidity and mortality during the influenza season. Clinical trials of zanamivir have reported a reduced incidence of influenza complications among high-risk patients...
  38. ncbi request reprint Inhibition of clinical benefits of aspirin on first myocardial infarction by nonsteroidal antiinflammatory drugs
    Tobias Kurth
    Division of Preventive Medicine, Department of Medicine, Brigham and Women s Hospital, 900 Commonwealth Ave E, Boston, Mass 02215 1204, USA
    Circulation 108:1191-5. 2003
    ..Recent data also suggest that other nonsteroidal anti-inflammatory drugs (NSAIDs) may interfere with this benefit of aspirin...
  39. ncbi request reprint A propensity score-matched cohort study of the effect of statins, mainly fluvastatin, on the occurrence of acute myocardial infarction
    John D Seeger
    Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA
    Am J Cardiol 92:1447-51. 2003
    ..Serum low-density lipoprotein levels were reduced by statin therapy, and there were fewer incidents of AMI in statin initiators than in noninitiators...
  40. ncbi request reprint Benzodiazepine use and hip fractures in the elderly: who is at greatest risk?
    Anita K Wagner
    Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, Boston, MA 02215, USA
    Arch Intern Med 164:1567-72. 2004
    ..It remains unclear whether benzodiazepine use increases hip fracture incidence. We studied this relationship in a large cohort, controlling for multiple potential confounders...
  41. ncbi request reprint An application of propensity score matching using claims data
    John D Seeger
    Ingenix Epidemiology, Auburndale, Massachusetts 02466, USA
    Pharmacoepidemiol Drug Saf 14:465-76. 2005
    ..In such settings, there will typically be many more variables available for control as potential confounders than traditional epidemiologic techniques will allow...
  42. ncbi request reprint Algorithms to identify colonic ischemia, complications of constipation and irritable bowel syndrome in medical claims data: development and validation
    Bruce E Sands
    Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
    Pharmacoepidemiol Drug Saf 15:47-56. 2006
    ..This report describes the development and validation of claims-based algorithms to identify colonic ischemia, hospitalized complications of constipation, and irritable bowel syndrome (IBS)...
  43. ncbi request reprint Persistence and adherence with topical glaucoma therapy
    Beth L Nordstrom
    Ingenix Epidemiology, Auburndale, Massachusetts 02466, USA
    Am J Ophthalmol 140:598-606. 2005
    ..The present study describes the patterns and predictors of treatment persistence and adherence among patients who are diagnosed with glaucoma or as glaucoma suspects (based on claims codes)...
  44. ncbi request reprint Determinants of the differences in LDL-cholesterol after initiation of statin treatment
    Herve Caspard
    Department of US Medical Affairs, Sanofi Aventis, Bridgewater, NJ 08807 0977, USA
    Ann Pharmacother 40:21-6. 2006
    ..Randomized clinical trials may not accurately predict drug benefit in clinical practice because the patients and conditions of therapy almost always differ between those settings...
  45. ncbi request reprint Anemia as a predictor of cardiovascular events in patients with elevated serum creatinine
    Alexander M Walker
    i3 Drug Safety, Auburndale, Massachusetts, Thousand Oaks, California, USA
    J Am Soc Nephrol 17:2293-8. 2006
    ..0 to 12.9 g/dl. The risk for progression to dialysis was only slightly elevated (7 to 34%) in anemic patients. Anemia raises the risk for cardiovascular disease in patients with elevated serum creatinine...
  46. ncbi request reprint Drug copayment and adherence in chronic heart failure: effect on cost and outcomes
    J Alexander Cole
    Division of Epidemiology, i3 Drug Safety, Auburndale, Massachusetts 02466, USA
    Pharmacotherapy 26:1157-64. 2006
    ..To measure the association among prescription copayment, drug adherence, and subsequent health outcomes among patients with chronic heart failure (CHF)...
  47. ncbi request reprint Venous thromboembolism, myocardial infarction, and stroke among transdermal contraceptive system users
    J Alexander Cole
    i3 Drug Safety, Auburndale, Massachusetts, USA
    Obstet Gynecol 109:339-46. 2007
    ....
  48. ncbi request reprint Mortality of stroke patients treated with thrombolysis: analysis of nationwide inpatient sample
    Tobias Kurth
    Neurology 68:710; author reply 711. 2007
  49. ncbi request reprint Dopamine antagonists and the development of breast cancer
    Philip S Wang
    Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women s Hospital, 221 Longwood Ave, Boston, MA 02115, USA
    Arch Gen Psychiatry 59:1147-54. 2002
    ..Although animal studies have raised the possibility that prolactin-elevating dopamine antagonists used to treat psychotic disorders may initiate and promote breast cancers, epidemiologic studies in humans have been limited and inconsistent...