title: Risk factors associated with antihypertensive medication nonadherence in a statewide Medicaid population.
abstract: BACKGROUND
  This study seeks to determine the most important patient factors and health care exposures available through administrative databases associated with antihypertensive nonadherence.
  
  
  METHODS
  This is a cross-sectional analysis of Medicaid hypertensive patients of Tennessee enrolled for 3 to 7 years from 1994 to 2000. Demographic characteristics, comorbidity and health care utilization were assessed during a 2-year period. The primary outcome was antihypertensive medication refill nonadherence. Subjects were categorized as adherent or nonadherent using an 80% cutoff criteria. Associations with nonadherence were assessed using logistic regression modeling.
  
  
  RESULTS
  Of 49,479 subjects, 60.6% (n = 29,970) were classified as nonadherent and 39.4% (n = 19,509) as adherent. Significant predictors of nonadherence in multivariate analysis (P < 0.05) included male sex (odds ratio [OR] 1.12), black race (OR 1.67), urban residence (OR 1.12), obesity (OR 1.10), mental illness (OR 1.08) and substance abuse (OR 1.43). Significant protective factors included age (OR 0.97), disability (OR 0.62), diabetes (OR 0.76), hypercholesterolemia (OR 0.72) and Charlson index (OR 0.97). When health care utilization was considered, increased outpatient visits were associated with decreased nonadherence. Emergency department visits (OR 1.07) and hospital visits (OR 1.12) were associated with increased nonadherence.
  
  
  CONCLUSIONS
  This cross-sectional study suggests that substance abuse, black race, emergency department visits and hospitalizations are risk factors associated with nonadherence. Outpatient visits are associated with a small decrease in nonadherence. Further studies are needed to determine the characteristics of outpatient visits that most improve adherence.
authors.affiliation: Division of General Internal Medicine, Department of Medicine (JEB, MH, BS, JT, MMR), and Department of Preventive Medicine (JEB, JYW), University of Tennessee Health Science Center, Memphis, Tennessee.
authors.forename: James E
authors.initials: JE
authors.lastname: Bailey
authors.forename: Mohammed
authors.initials: M
authors.lastname: Hajjar
authors.forename: Bushra
authors.initials: B
authors.lastname: Shoib
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.forename: Mario M
authors.initials: MM
authors.lastname: Ray
authors.forename: Jim Y
authors.initials: JY
authors.lastname: Wan
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D044383:Black People / Q000208:ethnology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006760:Hospitalization / Q000639:trends; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy* / Q000208:ethnology*; D008297:Male; D008484:Medicaid / Q000639:trends; D055118:Medication Adherence / Q000208:ethnology*; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000208:ethnology; D013714:Tennessee / Q000208:ethnology; D014481:United States / Q000208:ethnology; D055815:Young Adult; D001741:Black or African American
chemical_list: D000959:Antihypertensive Agents