title: Antihypertensive drug class and adherence: an electronic monitoring study.
abstract: BACKGROUND
  Medication adherence is essential to optimizing blood pressure (BP) control. Prior research has demonstrated differences in pharmacy refill patterns according to antihypertensive drug class. No prior study has assessed the association between drug class and day-to-day adherence.
  
  
  METHODS
  Between 2011 and 2014, we enrolled a convenience sample of 149 patients with persistently uncontrolled hypertension from two inner-city clinics and concurrently measured adherence of up to four antihypertensive medications using electronic pillboxes during the interval between two primary care visits. The main outcome was mean percent of days adherent to each drug. Mixed effects regression analyses were used to assess the association between drug class and adherence adjusting for age, gender, race, ethnicity, education, health insurance, coronary artery disease, heart failure, chronic kidney disease, diabetes, number of medications, days monitored, and dosing frequency.
  
  
  RESULTS
  The mean age was 64 years; 72% women, 75% Hispanic, 88% prescribed ≥ 1 BP medication. In unadjusted analyses, adherence was lower for beta-blockers (70.9%) compared to angiotensin receptor blocking agents (75.0%, P = 0.11), diuretics (75.9%, P < 0.001), calcium channel blockers (77.6%, P < 0.001) and angiotensin-converting enzyme inhibitors (78.0%, P < 0.0001). In the adjusted analysis, only dosing frequency (P = 0.0001) but not drug class (P = 0.71) was associated with medication adherence.
  
  
  CONCLUSIONS
  Antihypertensive drug class was not associated with electronically measured adherence after accounting for dosing frequency amongst patients with uncontrolled hypertension. Low adherence to beta-blockers may have been due to the common practice of prescribing multiple daily dosing. Providers may consider using once daily formulations to optimize adherence and should assess adherence among all treated patients with uncontrolled hypertension.
authors.affiliation: Division of General Internal Medicine, Center for Behavioral Cardiovascular Health, Columbia University Medical Center, New York, New York, USA; nm2562@cumc.columbia.edu.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Moise
authors.affiliation: Division of General Internal Medicine, Center for Behavioral Cardiovascular Health, Columbia University Medical Center, New York, New York, USA; Department of Psychiatry and Behavioral Sciences, Stony Brook University, Stony Brook, New York, USA;
authors.forename: Joseph
authors.initials: J
authors.lastname: Schwartz
authors.affiliation: Division of General Internal Medicine, Center for Behavioral Cardiovascular Health, Columbia University Medical Center, New York, New York, USA;
authors.forename: Rachel
authors.initials: R
authors.lastname: Bring
authors.affiliation: Division of General Internal Medicine, Center for Behavioral Cardiovascular Health, Columbia University Medical Center, New York, New York, USA; Division of Cardiology, Columbia University Medical Center, New York, New York, USA.
authors.forename: Daichi
authors.initials: D
authors.lastname: Shimbo
authors.affiliation: Division of General Internal Medicine, Center for Behavioral Cardiovascular Health, Columbia University Medical Center, New York, New York, USA;
authors.forename: Ian M
authors.initials: IM
authors.lastname: Kronish
mesh_terms: D000959:Antihypertensive Agents / Q000145:classification / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D016303:Clinical Pharmacy Information Systems / Q000706:statistics & numerical data; D055695:Electronic Prescribing / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000379:methods; D012959:Socioeconomic Factors; D014481:United States; D016903:Drug Monitoring
chemical_list: D000959:Antihypertensive Agents
keywords: blood pressure; drug class; hypertension; medication adherence.