title: Impact of antihypertensive medication adherence on blood pressure control in hypertension: the COMFORT study.
abstract: BACKGROUND
  It has not been fully elucidated whether antihypertensive medication adherence affects blood pressure (BP) control in hypertension cases.
  
  
  OBJECTIVE
  To investigate the association of adherence to antihypertensive drug regimens and BP control using data from the Combination Pill of Losartan Potassium and Hydrochlorothiazide for Improvement of Medication Compliance Trial (COMFORT) study.
  
  
  METHODS
  An observational analysis from a randomized controlled trial.
  
  
  METHODS
  A total of 203 hypertensive subjects were randomly assigned to a daily regimen of a combination pill (losartan 50 mg/hydrochlorothiazide 12.5 mg) or two pills, an angiotensin II receptor blocker and a thiazide diuretic. Medication adherence calculated based on pill counts and BPs was evaluated at 1, 3 and 6 months after randomization.
  
  
  RESULTS
  The subjects were divided into three groups according to their adherence, i.e. relatively low-adherence (<90%; n = 19), moderate-adherence (90-99%; n = 71) and high-adherence (100%; n = 113) groups. Clinical characteristics of the subjects including BP, sex, randomized treatments and past medical history did not differ significantly among the three groups. Achieved follow-up BPs over the 6-month treatment period, which were adjusted for age, sex, baseline BP and randomized treatment, were significantly higher in the low-adherence group (135/78 mmHg) compared with the high-adherence (130/74 mmHg; P = 0.02/0.02) and the moderate-adherence (128/74 mmHg; P = 0.003/0.02) groups.
  
  
  CONCLUSIONS
  Low adherence to an antihypertensive-drug regimen was associated with poor BP control.
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan. matsumk@intmed2.med.kyushu-u.ac.jp.
authors.forename: K
authors.initials: K
authors.lastname: Matsumura
authors.forename: H
authors.initials: H
authors.lastname: Arima
authors.forename: M
authors.initials: M
authors.lastname: Tominaga
authors.forename: T
authors.initials: T
authors.lastname: Ohtsubo
authors.forename: T
authors.initials: T
authors.lastname: Sasaguri
authors.forename: K
authors.initials: K
authors.lastname: Fujii
authors.forename: M
authors.initials: M
authors.lastname: Fukuhara
authors.forename: K
authors.initials: K
authors.lastname: Uezono
authors.forename: Y
authors.initials: Y
authors.lastname: Morinaga
authors.forename: Y
authors.initials: Y
authors.lastname: Ohta
authors.forename: T
authors.initials: T
authors.lastname: Otonari
authors.forename: J
authors.initials: J
authors.lastname: Kawasaki
authors.forename: I
authors.initials: I
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Tsuchihashi
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000191:economics / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D007564:Japan / Q000453:epidemiology; D019808:Losartan / Q000191:economics / Q000627:therapeutic use; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010353:Patient Education as Topic; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; D004338:Drug Combinations; C505809:hydrochlorothiazide, losartan drug combination; D006852:Hydrochlorothiazide; D019808:Losartan