Effect of standardized, patient-centered label instructions to improve comprehension of prescription drug use.

OBJECTIVE: To evaluate the effectiveness of standardized, patient-centered label (PCL) instructions to improve comprehension of prescription drug use compared with typical instructions.
METHODS: A total of 500 adult patients recruited from 2 academic and 2 community primary care clinics in Chicago, IL and Shreveport, LA were assigned to receive as follows: (1) standard prescription instructions written as times per day (once, twice 3 times per day) (usual care), (2) PCL instructions that specify explicit timing with standard intervals (morning, noon, evening, bedtime) (PCL), or (3) PCL instructions with a graphic aid to visually depict dose and timing of the medication (PCL + Graphic). The outcome was correct interpretation of label instructions.
RESULTS: Instructions with the PCL format were more likely to be correctly interpreted compared with standard instructions (adjusted relative risk [RR]: 1.33, 95% confidence interval [CI]: 1.25-1.41). Inclusion of the graphic aid (PCL + Graphic) decreased rates of correct interpretation compared with PCL instructions alone (RR: 0.93; 95% CI: 0.89-0.97). Patients with low literacy were better able to interpret PCL instructions (low literacy: RR: 1.39; 95% CI: 1.14-1.68; P = 0.001).
CONCLUSION: The PCL approach could improve patients' understanding and use of their medication regimen.