Researchers evaluated how changes in USP labeling standards have affected adherence across multiple classes of drugs.
Patient-centered prescription medication labels can help increase medication adherence among patients, according to the findings of a study published in the Journal of the American Pharmacists Association.1
Medication nonadherence is a significant issue among patients, with an estimated 30% to 50% of medications taken by adults to treat chronic illnesses not taken as prescribed; 125,000 deaths and 10% of hospitalizations each year may be attributed to poor medication adherence, the researchers noted. Per-person disease-specific costs associated with medication nonadherence range from $949 to $44,190.
Current medication labels often hinder safe and appropriate use of medicines. Prescription labels frequently use small fonts and vague terminology and include information needed by the pharmacist, not the patient—such as the National Drug Code number and manufacturer. Of note, previous research showed that 46% of patients misunderstood 1 or more dosing instructions and 56% of patients misunderstood 1 or more auxiliary warnings related to using the medication.
In 2013, the United States Pharmacopeia (USP) released voluntary standards to revise medication labels to minimize confusion among patients and combat nonadherence. These new standards emphasized information important to patients, improved readability, gave explicit instructions including purpose for use, limited auxiliary information, and addressed other issues that patients may have, such as limited English proficiency and visual impairment.
To study the impact of these suggested revisions, researchers conducted a retrospective pre-post cohort study using prescription fill claims data from a community health plan serving Medicaid patients. Medication possession ratios (MPRs) and proportion of days covered (PDC) were calculated for medications used for contraception, asthma, hypertension, and depression from 15 months before to 13 months after labels were changed. Data were collected from 1 independent community pharmacy organization with 8 retail sites.
The study cohort included 1157 men and women (mean age, 23±15.6 years; 70% women) who fi lled 12,566 prescriptions. Mean medication possession ratio increased from 0.894±0.009 before the intervention to 0.945±0.023 after the intervention. Mean PDC increased from 0.765±0.0709 to 0.884±0.049 during the same period. Results of a t test results identified significant increases in mean medication possession ratio for asthma control medications, antihypertensives, and contraceptives.
Investigators also conducted paired and unpaired χ2 and Fisher exact tests to evaluate patient distribution differences in terms of both mean medication possession ratio and proportion of days covered in both the pre- and postintervention periods for each therapeutic category. Paired analyses included those who fi lled prescriptions during both study periods.
Findings from these additional analyses showed signifi cant di! erences in medication possession ratio with contraceptive and antihypertensive medications. Results of analyses with both paired and unpaired patients indicated “significant differences in proportions of patients” in PDC groups for both asthma controller and contraceptive medications.
Ultimately, investigators found an increase in adherence to asthma control, antihypertensive, and contraceptive medications after pharmacies implemented the use of prescription medication labels that followed USP patient-centered labeling standards. However, they said additional research is needed “to elucidate the impact of patient-centered labeling across different classes of medication.”
Study limitations include the research design, a lack of control group, and a lack of generalizability to patients not covered by a Medicaid health plan.
“We found an association between a change to more patient-centered prescription medication labels…among a population of Medicaid recipients, a group more vulnerable to misunderstanding prescription medication labels,” the researchers concluded. “Adherence improved most in patients with low and medium MPR and PDC values before the label change, suggesting possible improvements in intended benefits from medications and lower health care costs due to untoward medication effects due to medication nonadherence.”
1. Young HN, Pathan FS, Hudson S, Mott D, Smith PD, Schellhase KG, Impactof patient-centered prescription medication labels on adherence in community pharmacy. J Am Pharm Assoc. Published online January 5, 2023. doi:10.1016/j.japh.2023.01.004