Predictors of Medication Self-management Skill in a Low-literacy Population

Background: Patients' ability to manage medications is critical to chronic disease control. Also known as medication management capacity (MMC), it includes the ability to correctly identify medications and describe how they should be taken.

Objective: To evaluate the effects of low literacy, medication regimen complexity, and sociodemographic characteristics on MMC.

Design: Cross-sectional analysis of enrollment data from participants in a randomized trial.

Participants: Patients with coronary heart disease in an inner-city clinic.

Measurements: Medication management capacity was measured with the Drug Regimen Unassisted Grading Scale (DRUGS), which scores subjects' ability to identify, open, describe the dose, and describe the timing of their medications. DRUGS overall and component scores were compared by literacy, Mini Mental State Exam score, regimen complexity (number of prescription medications), and sociodemographic characteristics.

Results: Most of the 152 participants were elderly (mean age 65.4 years), women (54.6%), and African American (94.1%). Approximately half (50.7%) had inadequate literacy skills, and 28.9% had marginal skills. In univariate analysis, MMC was significantly associated with literacy (P<.001), and this effect was driven by the ability to identify medications. In multivariable models, patients with inadequate literacy skills had 10 to 18 times the odds of being unable to identify all of their medications, compared with those with adequate literacy skills (P<.05).

Conclusions: Adults with inadequate literacy skills have less ability to identify their medications. Techniques are needed to better educate low-literacy patients about their medications, as a potential strategy to enhance adherence.