title: Prevalence of atrial fibrillation and warfarin use in older patients receiving hemodialysis.
abstract: BACKGROUND
  Little is known about the use of warfarin in hemodialysis (HD) patients with atrial fibrillation (AF). We studied temporal trends of AF among older HD patients, and of warfarin use among those with AF.
  
  
  METHODS
  We linked US Medicare and prescription claims from older patients undergoing HD in 2 Eastern US states. We established annual cohorts of prevalent HD patients; AF was ascertained from >2 claims (>7 days apart) in the same year, with a diagnosis code indicating AF. Among those with AF, we defined current and past warfarin use. Demographic and clinical characteristics were also ascertained for each cohort. We used repeated-measures logistic regression to define the odds of AF and of current or past versus absence of warfarin use.
  
  
  RESULTS
  Of 6,563 unique patients, 2,185 were determined to have AF. The prevalence of AF increased from 26% in 1998 to 32% in 2005. In 2005, current warfarin use was present in 24% of AF patients and past use in 25%; 51% had no evidence of any warfarin use. No significant trends in utilization were observed from 1998 through 2005. Patients aged =85 years and nonwhites were less likely to have received warfarin; most comorbidities were not associated with warfarin use except for patients with past pulmonary embolism or deep venous thrombosis who were more likely than those without such history.
  
  
  CONCLUSIONS
  While the prevalence of AF has been increasing among older HD patients, warfarin use was low and unchanged over time, perhaps reflecting the lack of evidence supporting its use.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. wcw1@stanford.edu
authors.forename: Wolfgang C
authors.initials: WC
authors.lastname: Winkelmayer
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Patrick
authors.forename: Soko
authors.initials: S
authors.lastname: Setoguchi
authors.forename: Niteesh K
authors.initials: NK
authors.lastname: Choudhry
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000453:epidemiology; D011307:Drug Prescriptions; D004363:Drug Utilization; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000628:therapy*; D016015:Logistic Models; D006278:Medicare; D015999:Multivariate Analysis; D009515:New Jersey / Q000453:epidemiology; D016017:Odds Ratio; D010414:Pennsylvania / Q000453:epidemiology; D015995:Prevalence; D006435:Renal Dialysis / Q000706:statistics & numerical data; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin