Message frame and health literacy: Strategies to improve adherence to antihypertensive medications

Hypertension and prehypertension is prevalent in about half of the total world population. Experts recommend comprehensive medical treatment for people with underlying diseases or at risk for metabolic syndrome. However, previous studies have found that approximately half of all patients with hypertension stopped taking antihypertensive medication within a year, and this phenomenon was closely related to the low perceived benefit and outcome expectation of taking behavior.As the initial perception of medication is greatly influenced by the medication message, this study explored the effect of the gain-loss framing of the message of adherence to antihypertensives. Furthermore, the study analyzed the interaction between health literacy and involvement, which is a characteristic of the message recipient, and the message frame and examined how the message strategy should differ according to individual factors.The quasi-experiment via an online survey was conducted from August 9 to 11, 2021. Participants who had the potential for hypertension but had not yet been diagnosed were selected through screening questions. A total of 1200 participants were randomly assigned to each frame group. Data analysis was conducted using descriptive statistics, analysis of covariance for analysis of main effects and interaction effects between variables, and Bonferroni post-hoc for multiple analyses.Regarding medical adherence intention, the frame did not show a main effect, whereas individual factors showed a main effect. An interaction effect of frame and individual factors were found. Specifically, in the group with low health literacy or low involvement, a significant gain frame advantage effect was observed.This study verified the relationship between medication messages and behavior and provides insight into tailoring messages to antihypertensive adherence; it found that individuals' health literacy and involvement must be considered in health communication message strategies.