1. The Research Question
Does changing prescription medication labels to conform to the United States Pharmacopeia (USP) patient-centered, more understandable, prescription medication label standards increase medication adherence?

2. Research Design and Method
Part of evaluation of a project to pilot test implementing prescription medication label changes to USP standards
8 pharmacy sites
Pharmacy claims data for Medicaid adults with children
Medication possession ratio (MPR) of 3 classes of medications: ) asthma controllers; 2) anti-hypertensives; 3) contraceptives
MPR = sum of days' supply for all fills of a drug in a time period, divided by the number of days, expressed as percent
1,157 patients had 12,566 total of all prescriptions
Study Design: This is a cohort study comparing fill rates for medications intended to be taken continuously during 15 months pre-label change and 13 months post-label change.
Setting/Dataset: Pharmacy claims data for one pharmacy organization (8 sites) extracted from a health plan serving urban Wisconsin Medicaid patients with children.
Patients: Inclusion criteria: 1) age 0-64; 2) both genders; 3) Medicaid eligible for at least 24 of 28 months; and 4) prescription filled at any of the 8 pharmacy organization sites.
Intervention: Medication labels were modified to comply with the USP standards and implemented at each pharmacy site.
Main Outcome Measures: Medication possession ratio (MPR) of 3 classes of medications: 1) asthma controller; 2) anti-hypertensive; and 3) contraceptive. MPR = sum of days' supply for all fills of a drug in a time period, divided by the number of days in the time period, expressed as percent. MPR values during the time period before and after the label change were compared to examine any association of the label change with MPR.

3. What the Research Found
Results: 1157 patients had 12,566 prescriptions filled that met inclusion criteria.
Mean age: 23 years; 70% female.
re/post MPRs (N):
asthma controller- 88%(726)/94%(459) p<0.0001;
anti-hypertensive 89%(195)/96%(174) p<0.0001; and
contraceptive 89%(150)/97%(85) p<
The proportion of all contraceptive patients with MPRs 51-80% decreased from 20% in the pre-period and to 2% in the post-period and with MPRs 0-50% from 4% to 0%, respectively
Note asthma controller med patients are a paired sample- these are the same people before and after the label changes. The other 2 groups had numbers too low to analyze a paired sample.
Significant decrease in MPR in low and medium groups

4. What this means for Clinical Practice
Widespread implementation of the USP patient-centered, more understandable, medication label standards has a very strong potential to increase adherence in Medicaid populations and improve medical outcomes.
Potential for decreased frequencies of:
Asthma controllers: hospitalizations, ED and urgent care visits
Antihypertensives: cardiac events, strokes and renal failure
Contraceptives: unintended pregnancies, iron deficient anemia
Other unintended outcomes due to incomplete treatment
ED = Emergency Department