Zero Dollar Drug Co-Pay Program Increases Medication Adherence and Utilization Among Members With Diabetes in Louisiana

Speaker(s)

Tang T1, Winberg D2, Li J3, Stoecker C3, Bazzano A3, Hu G4, Shen Y4, Shao H5, Cong M6, Mohundro B7, Liu M7, Ouyang J7, Nigam S7, Carby M7, Nauman E8, Price-Haywood E9, Shi L3
1Tulane University School of Public Health and Tropical Medicine, metairie, LA, USA, 2Tulane University School of Public Health and Tropical Medicine, Darnestown, MD, USA, 3Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA, 4The Pennington Biomedical Research Center, Baton Rouge, LA, USA, 5University of Florida, College of Pharmacy, Atlanta, GA, USA, 6Blue Cross Blue Shield of Louisiana, lenexa, KS, USA, 7Blue Cross Blue Shield of Louisiana, Baton Rouge, LA, USA, 8Louisiana Public Health Institute, New Orleans, LA, USA, 9Ochsner Health, New Orleans, LA, USA

Presentation Documents

OBJECTIVES: Blue Cross and Blue Shield of Louisiana (BCBSLA) offers a Zero Dollar Copay (ZDC) pharmacy benefit to alleviate financial burdens of medications for eligible members. After the program's early success (2014) in enhancing medication adherence and clinical outcomes, BCBSLA expanded the ZDC-program to its fully insured members. This study aimed to evaluate the effectiveness of the ZDC-program on the beneficiaries’ medication adherence and medication utilization.

METHODS: Medical and pharmacy claims from 2019 – 2021 were used to identify 7,714 continuously enrolled members with diabetes. Of these, 3,125 fully insured members became eligible for the ZDC-program on July 1, 2020, while those with ZDC-opt-out Administrative-Services-Only (ASO) plans served as the control group. The current follow-up period was July 1, 2020 through December 31, 2021. Medication adherence and utilization outcomes were measured using proportion of days covered (PDC), drug counts, and monthly utilization rate (MUR ). MUR is calculated as proportion of members using medications in each group for each month. A difference-in-difference model with inverse propensity treatment weighting (IPTW) was used to estimate effects on monthly outcomes, controlling for individual fixed effects, time fixed effects, age, chronic conditions, drug spending, healthcare utilization, and product type by treatment status linear time trends.

RESULTS: The standardized mean differences of all the covariates and pre-period outcomes were smaller than 0.1 after applying IPTW. The ZDC-program was associated with a 4.33 (p < 0.001) and 5.94 (p < 0.001) percentage points increase in PDC and MUR, and a 0.089 (p < 0.001) increase in drug counts for members using any antidiabetic medications. For members who only used ZDC-eligible antidiabetic medications, the improvements were 5.44 (p < 0.001), 7.48 (p < 0.001), and 0.074 (p < 0.001) for PDC, MUR, and drug counts, respectively.

CONCLUSIONS: The ZDC-program was effective in improving medication adherence and medication utilization.

Code

CO40

Topic

Clinical Outcomes, Economic Evaluation, Health Policy & Regulatory, Patient-Centered Research

Topic Subcategory

Adherence, Persistence, & Compliance, Performance-based Outcomes, Reimbursement & Access Policy

Disease

Diabetes/Endocrine/Metabolic Disorders (including obesity)