title: Health system factors and antihypertensive adherence in a racially and ethnically diverse cohort of new users.
abstract: BACKGROUND
  The purpose of this study was to identify potential health system solutions to suboptimal use of antihypertensive therapy in a diverse cohort of patients initiating treatment.
  
  
  METHODS
  Using a hypertension registry at Kaiser Permanente Northern California, we conducted a retrospective cohort study of 44 167 adults (age, ≥18 years) with hypertension who were new users of antihypertensive therapy in 2008. We used multivariate logistic regression analysis to model the relationships between race/ethnicity, specific health system factors, and early nonpersistence (failing to refill the first prescription within 90 days) and nonadherence (<80% of days covered during the 12 months following the start of treatment), respectively, controlling for sociodemographic and clinical risk factors.
  
  
  RESULTS
  More than 30% of patients were early nonpersistent and 1 in 5 were nonadherent to therapy. Nonwhites were more likely to exhibit both types of suboptimal medication-taking behavior compared with whites. In logistic regression models adjusted for sociodemographic, clinical, and health system factors, nonwhite race was associated with early nonpersistence (black: odds ratio, 1.56 [95% CI, 1.43-1.70]; Asian: 1.40 [1.29-1.51]; Hispanic: 1.46 [1.35-1.57]) and nonadherence (black: 1.55 [1.37-1.77]; Asian: 1.13 [1.00-1.28]; Hispanic: 1.46 [1.31-1.63]). The likelihood of early nonpersistence varied between Asians and Hispanics by choice of first-line therapy. In addition, racial and ethnic differences in nonadherence were appreciably attenuated when medication co-payment and mail-order pharmacy use were accounted for in the models.
  
  
  CONCLUSIONS
  Racial/ethnic differences in medication-taking behavior occur early in the course of treatment. However, health system strategies designed to reduce patient co-payments, ease access to medications, and optimize the choice of initial therapy may be effective tools in narrowing persistent gaps in the use of these and other clinically effective therapies.
authors.affiliation: Kaiser Permanente Division of Research, Oakland, CA 94612, USA. Alyce.S.Adams@kp.org
authors.forename: Alyce S
authors.initials: AS
authors.lastname: Adams
authors.forename: Connie
authors.initials: C
authors.lastname: Uratsu
authors.forename: Wendy
authors.initials: W
authors.lastname: Dyer
authors.forename: David
authors.initials: D
authors.lastname: Magid
authors.forename: Patrick
authors.initials: P
authors.lastname: O'Connor
authors.forename: Arne
authors.initials: A
authors.lastname: Beck
authors.forename: Melissa
authors.initials: M
authors.lastname: Butler
authors.forename: P Michael
authors.initials: PM
authors.lastname: Ho
authors.forename: Julie A
authors.initials: JA
authors.lastname: Schmittdiel
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D044466:Asian People / Q000706:statistics & numerical data*; D044383:Black People / Q000706:statistics & numerical data*; D015331:Cohort Studies; D016527:Drug Costs; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000208:ethnology* / Q000523:psychology / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013997:Time Factors; D044465:White People / Q000706:statistics & numerical data*
chemical_list: D000959:Antihypertensive Agents