title: Use of combination antihypertensive therapy initiation in older Americans without prevalent cardiovascular disease.
abstract: OBJECTIVE
  To describe new users of antihypertensive medications and identify predictors of combination therapy initiation in older Americans.
  
  
  METHODS
  Retrospective observational cohort study.
  
  
  METHODS
  Population-based study using U.S. Medicare fee-for-service healthcare claims (2007-2010).
  
  
  METHODS
  Medicare beneficiaries aged 65 and older with no recent diagnoses, procedures, or medications for cardiovascular disease who newly initiated an antihypertensive therapy (n = 275,493; 210,605 initiated monotherapy, 64,888 initiated combination therapy).
  
  
  METHODS
  Multivariable Poisson regression was used to assess factors associated with initiation of combination therapy versus monotherapy, including participant characteristics, prescriber characteristics, and participant encounters with the healthcare system.
  
  
  RESULTS
  Initiation of combination therapy increased from 21.9% in 2007 to 24.7% in 2010. The most frequently initiated combinations were angiotensin-converting enzyme inhibitors with thiazide (29.7%) and angiotensin II receptor antagonists with thiazide (18.7%). Blacks (prevalence ratio (PR) = 1.48, 95% confidence interval (CI) = 1.45-1.51 vs. whites), individuals seeing a generalist (PR = 1.10, 95% CI = 1.07-1.14), individuals seeing more than one doctor (PR = 3.38, 95% CI = 3.33-3.44), and participants with no pharmacy claims in the previous 6 months (PR = 1.34, 95% CI = 1.30-1.37 vs. ≥3 unique drug classes) were more likely to initiate combination therapy, whereas those who had more outpatient visits in the previous 12 months were less likely to initiate combination therapy (per five visits, PR = 0.82, 95% CI = 0.80-0.83).
  
  
  CONCLUSIONS
  Nearly one in four new users of antihypertensive medications aged 65 and older started treatment with combination therapy. Blacks, individuals living in the south, and those with fewer outpatient physician office visits were more likely to initiate combination therapy. Further research is needed to determine whether this approach to managing hypertension is being well targeted to individuals who will require combination treatment.
authors.affiliation: Department of Epidemiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Li
authors.forename: Wendy
authors.initials: W
authors.lastname: Camelo Castillo
authors.forename: Til
authors.initials: T
authors.lastname: Stürmer
authors.forename: Virginia
authors.initials: V
authors.lastname: Pate
authors.forename: Christine L
authors.initials: CL
authors.lastname: Gray
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Simpson
authors.forename: Soko
authors.initials: S
authors.lastname: Setoguchi
authors.forename: Laura C
authors.initials: LC
authors.lastname: Hanson
authors.forename: Michele
authors.initials: M
authors.lastname: Jonsson Funk
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D057911:Angiotensin Receptor Antagonists / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D044383:Black People / Q000706:statistics & numerical data; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology; D004359:Drug Therapy, Combination / Q000706:statistics & numerical data; D004562:Electrocardiography / Q000706:statistics & numerical data; D005260:Female; D058005:General Practitioners; D006801:Humans; D006949:Hyperlipidemias / Q000453:epidemiology; D008297:Male; D006278:Medicare; D015999:Multivariate Analysis; D009819:Office Visits / Q000706:statistics & numerical data; D012189:Retrospective Studies; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use; D014481:United States / Q000453:epidemiology; D001741:Black or African American
chemical_list: D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D049993:Sodium Chloride Symporter Inhibitors
keywords: Medicare beneficiaries; antihypertensive agents; combination therapy; epidemiology; initial treatment
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