Association between health literacy and medication adherence in chronic diseases: a recent systematic review.

Abstract

Poor medication adherence is a serious barrier to successful chronic disease management. Previous reviews reported that low health literacy could be associated with medication non-adherence but conclusions were uncertain. The aim of this systematic review was to clarify the relationship between health literacy and medication adherence in adults with chronic diseases. A secondary objective was to identify the factors that influence medication adherence. Publications analyzing the relationship between health literacy and adherence in adults with chronic diseases were identified through 6 databases between 2015 and 2020. A quality assessment was conducted in order to improve the interpretation of the relationship between health literacy and medication adherence. A narrative synthesis was then performed to describe the relationship between health literacy and medication adherence. The factors influencing medication adherence were then analyzed as a secondary outcome. Among the 27 studies, 17 and 10 were considered to be of good and medium methodological quality, respectively. Concerning the relationship between health literacy and adherence, 14 reported a positive relationship, 1 study suggested a negative relationship, 3 found mixed results, and 9 reported not finding a relationship. Patient-related factors such as medication beliefs, self-efficacy, or medication knowledge, as well as demographic factors such as ethnic minority and incomes influence medication adherence. The present review confirms an unclear relationship between health literacy and medication adherence. Although health literacy plays a substantial role in medication adherence, other factors must be taken into account when addressing non-adherence.