Impact of adherence to antihypertensive agents on clinical outcomes and hospitalization costs

Med Care. 2010 May;48(5):418-25. doi: 10.1097/MLR.0b013e3181d567bd.


Background: Cardiovascular diseases (CVD) represent a heavy economic burden on individuals, health services, and society. Low adherence to antihypertensive (AH) agents is acknowledged as a major contributor to the lack of blood pressure control, and may have a significant impact on clinical outcomes and healthcare costs.

Objectives: To evaluate the impact of low adherence to AH agents on cardiovascular outcomes and hospitalization costs.

Methods: A cohort of 59,647 patients with essential hypertension was reconstructed from the Régie de l'assurance maladie du Québec and Med-Echo databases. Subjects included were between 45 and 85 years of age, without any evidence for symptomatic CVD, newly treated with AH agents between 1999 and 2002 and followed-up for a 3-year period. Adherence to AH agents was categorized as >or=80% or <80%. The adjusted odds ratio (OR) for CVD events between the 2 adherence groups was estimated using a polytomous logistic analysis. A 2-part model was applied for hospitalization costs.

Results: Patients with low adherence were more likely to have coronary disease (OR, 1.07; 95% confidence interval [CI], 1.00-1.13), cerebrovascular disease (OR, 1.13; 95% CI, 1.03-1.25), and chronic heart failure (OR, 1.42; 95% CI, 1.27-1.58) within the 3-year follow-up period. Among hospitalized patients, low adherence to AH therapy was associated with increased costs by approximately $3574 (95% CI, $2897-$4249) per person within a 3-year period.

Conclusions: Low adherence to AH agents is correlated with a higher risk of vascular events, hospitalization, and greater healthcare costs. An increased level of adherence to AH agents should provide a better health status for individuals and a net economic gain.

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Antihypertensive Agents / economics
  • Antihypertensive Agents / therapeutic use*
  • Cardiovascular Diseases / economics*
  • Cardiovascular Diseases / etiology
  • Cerebrovascular Disorders / economics
  • Cerebrovascular Disorders / etiology
  • Cohort Studies
  • Coronary Artery Disease / economics
  • Coronary Artery Disease / etiology
  • Drug Therapy, Combination
  • Female
  • Heart Failure / economics
  • Heart Failure / etiology
  • Hospital Charges / statistics & numerical data*
  • Hospitalization / economics
  • Hospitalization / statistics & numerical data
  • Humans
  • Hypertension / complications
  • Hypertension / drug therapy*
  • Hypertension / economics
  • Insurance Claim Review / statistics & numerical data
  • Male
  • Medication Adherence / statistics & numerical data*
  • Middle Aged
  • Sex Factors
  • Treatment Outcome


  • Antihypertensive Agents