Effects of health literacy and polypharmacy on medication adherence

To determine if health literacy has an effect on medication adherence in patients taking fewer than five prescriptions (no polypharmacy), and those taking five or more prescriptions (polypharmacy).

Retrospective cohort.

The Primary Care Residents' Clinic at Virginia Commonwealth University Health System (VCUHS).

Those who received a Rapid Estimate of Adult Literacy in Medicine-Revised (REALM-R) assessment at the clinic between June 1, 2009, and June 30, 2010, and utilized the VCUHS outpatient pharmacies to fill their prescriptions. A total of 648 individuals were identified.

The degree of health literacy and level of medication adherence were analyzed per patient by accessing the clinic's electronic health records. The number of medications each patient filled was determined using VCUHS outpatient pharmacy databases.

To determine if there are any associations among the degree of health literacy, the level of medication adherence, and the amount of medications a patient is taking.

There was a significant association found between the level of medication adherence and the degree of polypharmacy. We found no association between the degree of health literacy and the level of adherence to a prescribed medication regimen. Additionally, there was no relationship between the degree of polypharmacy and health literacy. Those patients with more medications were also found to have lower levels of medication adherence and vice versa.

Our study does not show an association between health literacy and medication adherence nor between health literacy and polypharmacy. Thus, potential changes to improving health literacy may not have a significant effect on adherence.