title: The relationship between emergency department use and cost-related medication nonadherence among Medicare beneficiaries.
abstract: OBJECTIVE
  The objective of this study was to evaluate the relationship between self-reported cost-related nonadherence to prescription medications and emergency department (ED) utilization among Medicare beneficiaries. We hypothesized that persons who report cost-related medication nonadherence would have subsequent higher ED use.
  
  
  METHODS
  We conducted a retrospective cohort study of continuously enrolled Medicare beneficiaries in 2006 and 2007. We used multivariate logistic regression to evaluate the relationship between ED use and cost-related medication nonadherence. Our principal dependent variable was any ED visit within a 364-day period after an interview assessing cost-related medication nonadherence. Our principal independent variables both denoted cost-related medication nonadherence: mild cost-related medication nonadherence, defined as a reduction in dose or a delay in filling medications because of cost; and severe cost-related medication nonadherence, defined as not filling a medication at all because of cost.
  
  
  RESULTS
  Our sample consisted of 7,177 Medicare Current Beneficiary Survey respondents. Approximately 7.5% of respondents reported mild cost-related medication nonadherence only (n=541) and another 8.2% reported severe cost-related medication nonadherence (n=581). Disabled Medicare beneficiaries with severe cost-related medication nonadherence were more likely to have at least 1 ED visit (1.53; 95% confidence interval 1.03 to 2.26) compared with both disabled Medicare beneficiaries without cost-related medication nonadherence and elderly Medicare beneficiaries in all cost-related medication nonadherence categories.
  
  
  CONCLUSIONS
  Our results show an association between severe cost-related medication nonadherence and ED use. Disabled beneficiaries younger than 65 years who report severe cost-related medication nonadherence were more likely to have at least 1 ED visit, even when adjusting for other factors that affect utilization.
authors.affiliation: Department of Emergency Medicine, George Washington University, Washington, DC. Electronic address: jblanchard@mfa.gwu.edu.
authors.forename: Janice
authors.initials: J
authors.lastname: Blanchard
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA.
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Madden
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Ross-Degnan
authors.affiliation: Department of Health Systems Administration, Georgetown University, Washington, DC.
authors.forename: Carol Roan
authors.initials: CR
authors.lastname: Gresenz
authors.affiliation: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Soumerai
mesh_terms: D000368:Aged; D006233:Persons with Disabilities; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D006278:Medicare / Q000191:economics; D055118:Medication Adherence; D008875:Middle Aged; D011306:Prescription Fees; D012189:Retrospective Studies; D014481:United States