title: Predicting blood pressure outcomes using single-item physician-administered measures: a retrospective pooled analysis of observational studies in Belgium.
abstract: BACKGROUND
  Patient adherence is often not monitored because existing methods of evaluating adherence are either burdensome or do not accurately predict treatment outcomes.
  
  
  OBJECTIVE
  To examine whether two simple, single-item physician-administered measures of patient adherence to antihypertensive medication are predictive of blood pressure outcomes.
  
  
  METHODS
  Retrospective database analysis of patients with hypertension treated in Belgian primary care.
  
  
  METHODS
  Using pooled data from five observational studies, a sample was identified of 9725 patients who were assessed using two single-item physician-administered measures of adherence to antihypertensive medication: the first item of the Basel Assessment of Adherence Scale (BAAS) and the Visual Analogue Scale (VAS). These two assessment tools were administered by GPs during regular appointments with patients. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and combined SBP/DBP were measured at baseline and at 90 days.
  
  
  RESULTS
  BAAS-identified adherent patients achieved lower mean SBP and DBP compared with non-adherent patients at 90 days (P<0.001), and had odds ratios of achieving blood pressure control of 0.66 (95% confidence intervals (CI) = 0.61 to 0.73, P<0.001) for SBP, 0.69 (95% CI = 0.62 to 0.76, P<0.001) for DBP, and 0.65 (95% CI = 0.59 to 0.72, P<0.001) for combined SBP/DBP. For VAS-identified adherent patients, the odds ratios of achieving blood pressure control were 0.93 (95% CI = 0.86 to 1.00, P<0.001) for SBP, 0.79 (95% CI = 0.73 to 0.85, P<0.001) for DBP, and 0.91 (95% CI = 0.84 to 0.99, P<0.001) for combined SBP/DBP.
  
  
  CONCLUSIONS
  The first item of the BAAS and the VAS are independent predictors of blood pressure control. These methods can be integrated seamlessly into routine clinical practice by allowing GPs to quickly evaluate a patient's adherence and tailor treatment recommendations accordingly.
authors.affiliation: Faculty of Pharmacy, University of Concepción, Concepción, Chile.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Villa
authors.affiliation: Center for Health Outcomes & PharmacoEconomic Research, College of Pharmacy, The University of Arizona, Tucson, AZ, US.
authors.forename: Diana
authors.initials: D
authors.lastname: Sun
authors.affiliation: Matrix45, Basel, Switzerland.
authors.forename: Kris
authors.initials: K
authors.lastname: Denhaerynck
authors.affiliation: Novartis Pharma, Vilvoorde, Belgium.
authors.forename: Stefaan
authors.initials: S
authors.lastname: Vancayzeele
authors.affiliation: Novartis Pharma, Vilvoorde, Belgium.
authors.forename: Heidi
authors.initials: H
authors.lastname: Brié
authors.affiliation: Novartis Pharma, Vilvoorde, Belgium.
authors.forename: Christine
authors.initials: C
authors.lastname: Hermans
authors.affiliation: Novartis Pharma, Vilvoorde, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Aerts
authors.affiliation: Center for Health Outcomes and PharmacoEconomic Research, The University of Arizona, Tucson, AZ, US.
authors.forename: Michael
authors.initials: M
authors.lastname: Levengood
authors.affiliation: Matrix45, Tucson, AZ, US.
authors.forename: Karen
authors.initials: K
authors.lastname: MacDonald
authors.affiliation: Center for Health Outcomes & PharmacoEconomic Research; Department of Pharmacy Practice & Science, College of Pharmacy; Department of Family and Community Medicine, College of Medicine, The University of Arizona, Tucson, AZ, US.
authors.forename: Ivo
authors.initials: I
authors.lastname: Abraham
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001530:Belgium / Q000453:epidemiology; D001794:Blood Pressure / Q000187:drug effects; D001795:Blood Pressure Determination / Q000379:methods / Q000706:statistics & numerical data; D017281:Cost of Illness; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000523:psychology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011320:Primary Health Care / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D064232:Visual Analog Scale; D016903:Drug Monitoring
chemical_list: D000959:Antihypertensive Agents
keywords: hypertension; medication adherence; patient adherence; primary health care