Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.


Health Management and Systems Sciences

Degree Program

Public Health Sciences

Committee Chair

Wainscott, Barry

Committee Co-Chair (if applicable)

Esterhay, Robert

Committee Member

Esterhay, Robert

Committee Member

Furman, Christian

Committee Member

Nesbitt, LaQuandra

Author's Keywords

affordable care act; medication adherence; ACA; coverage gap; diabetes; cost-related nonadherence


This dissertation involves an evaluation of the effect of the Patient Protection and Affordable Care Act (ACA) on diabetic medication adherence for mail order utilizers over 6 years as the Medicare Part D coverage gap begins to close. The study had 3 objectives: 1) to evaluate diabetes medication adherence of health plan members before they reach the coverage gap and then while they are in the coverage gap, 2) to compare diabetes medication adherence between two similar groups with differing benefit structures, one group with a gap in coverage as opposed to a group with no benefit changes within the year and 3) to examine diabetes medication adherence trend over multiple years as the coverage gap is closed. A retrospective, pre-post cohort analysis with control group study design was used to assess the study objectives. The control group consisted of low- income subsidy (LIS) members with no gap in coverage. The results of this study indicate that being in the coverage gap was a significant indicator of a decrease in adherence for health plan members on brand diabetic medications. While the study findings showed a decrease rather than an increase in the treatment group medication adherence year over year, the results did indicate no significant changes in the control group. The expectation would be that once the coverage gap is fully closed in 2020, the treatment group would exhibit similar behavior. Both groups exhibited high adherence overall suggesting the mail order dispensing channel could have an effect on adherence.