Predicting blood pressure outcomes using single-item physician-administered measures: A retrospective pooled analysis of observational studies in Belgium

Lorenzo Villa, Diana Sun, Kris Denhaerynck, Stefaan Vancayzeele, Heidi Brié, Christine Hermans, Ann Aerts, Michael Levengood, Karen MacDonald, Ivo Abraham

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5 Scopus citations


Background Patient adherence is often not monitored because existing methods of evaluating adherence are either burdensome or do not accurately predict treatment outcomes. Aim To examine whether two simple, single-item physician-administered measures of patient adherence to antihypertensive medication are predictive of blood pressure outcomes. Design and setting Retrospective database analysis of patients with hypertension treated in Belgian primary care. Method 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 nonadherent 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.

Original languageEnglish (US)
Pages (from-to)e9-e15
JournalBritish Journal of General Practice
Issue number630
StatePublished - Jan 1 2015



  • Hypertension
  • Medication adherence
  • Patient adherence
  • Primary health care

ASJC Scopus subject areas

  • Family Practice

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