Journal of General Internal Medicine

, Volume 21, Issue 12, pp 1215–1221 | Cite as

Factors associated with medication refill adherence in cardiovascular-related diseases

A focus on health literacy
  • Julie A. GazmararianEmail author
  • Sunil Kripalani
  • Michael J. Miller
  • Katharina V. Echt
  • Junling Ren
  • Kimberly Rask
Original Articles


BACKGROUND: The factors influencing medication adherence have not been fully elucidated. Inadequate health literacy skills may impair comprehension of medical care instructions, and thereby reduce medication adherence.

OBJECTIVES: To examine the relationship between health literacy and medication refill adherence among Medicare managed care enrollees with cardiovascular-related conditions.

RESEARCH DESIGN: Prospective cohort study.

SUBJECTS: New Medicare enrollees from 4 managed care plans who completed an in-person survey and were identified through administrative data as having coronary heart disease, hypertension, diabetes mellitus, and/or hyperlipidemia (n=1,549).

MEASURES: Health literacy was determined using the short form of the Test of Functional Health Literacy in Adults (S-TOFHLA). Prospective administrative data were used to calculate the cumulative medication gap (CMG), a valid measure of medication refill adherence, over a 1-year period. Low adherence was defined as CMG ≥ 20%.

RESULTS: Overall, 40% of the enrollees had low refill adherence. Bivariate analyses indicated that health literacy, race/ethnicity, education, and regimen complexity were each related to medication refill adherence (P<.05). In unadjusted analysis, those with inadequate health literacy skills had increased odds (odds ratio [OR]=1.37, 95% confidence interval [CI]: 1.08 to 1.74) of low refill adherence compared with those with adequate health literacy skills. However, the OR for inadequate health literacy and low refill adherence was not statistically significant in multivariate analyses (OR=1.23, 95% CI: 0.92 to 1.64).

CONCLUSIONS: The present study suggests, but did not conclusively demonstrate, that low health literacy predicts poor refill adherence. Given the prevalence of both conditions, future research should continue to examine this important potential association.

Key words

elderly health literacy adherence 


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Copyright information

© the Society of General Internal Medicine 2006

Authors and Affiliations

  • Julie A. Gazmararian
    • 1
    Email author
  • Sunil Kripalani
    • 2
  • Michael J. Miller
    • 3
  • Katharina V. Echt
    • 2
    • 4
  • Junling Ren
    • 1
  • Kimberly Rask
    • 1
    • 2
  1. 1.Emory Center on Health Outcomes and Quality, Department of Health Policy and Management, Rollins School of Public HealthEmory UniversityAtlanta
  2. 2.Emory University School of MedicineAtlantaUSA
  3. 3.College of Pharmacy and Health SciencesDrake UniversityDes MoinesUSA
  4. 4.Atlanta Veterans Affairs Rehabilitation Research and Development CenterAtlantaUSA

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