Modified labels for long-term medications: influences on adherence, comprehension and preferences in Malaysia

BACKGROUND: Inability to read instructions on drug labels has been identified among the Malaysian population since 1990's.
OBJECTIVE: To assess the impact of font-enlarged and pictogram-incorporated labels used for long-term medications on patients' adherence, comprehension and preferences.
SETTING: Outpatient pharmacy in one of the major general hospitals across Northern Malaysia.
METHOD: This was a three-arm, randomized controlled trial. Outpatients with refill prescriptions of selected oral antihypertensive or antidiabetic medications were screened for eligibility. They were randomly allocated with standard (n = 35), font-enlarged (n = 40) or pictogram-incorporated (n = 35) labels. Assessment of baseline adherence scores using the 8-item Morisky Medication Adherence Scale, comprehension scores using a structured questionnaire and preferences was conducted upon recruitment. Follow-up telephone interviews were conducted after 4 weeks.
MAIN OUTCOME MEASURE: The changes of patients' adherence and comprehension scores and their preferences.
RESULTS: Within-group comparisons demonstrated an increase of total adherence scores after 4 weeks in all three groups (mean changes 0.35, 0.58 and 0.67; p = 0.029, 0.013 and 0.011, respectively). The repeatedly measured total comprehension score of pictogram-incorporated label group was significantly higher than baseline (mean change 0.37, p = 0.010). Two intervention groups obtained significantly higher scores for few items in both adherence and comprehension measurements after 4 weeks as compared with baselines. As indicated by F tests, three groups did not significantly differ in the changes of both total adherence and comprehension scores (p = 0.573 and 0.069, respectively) with the subjects' age adjusted. Elderlies and those with a higher number of morbidity preferred pictogram-incorporated label over font-enlarged label.
CONCLUSION: We did not find a significant change of both adherence and comprehension levels after the introduction of modified medication labels. However, on the basis of within-group comparisons, they may have positive influences on certain aspects of patients' adherence and comprehension. Variations in preferences may reflect the unique need of different subgroups in receiving written medication instructions.
Study site: Outpatient pharmacy, Sultanah Bahiyah Hospital, Alor Setar, Kedah, Malaysia