Motivational Interviewing (MI) Intervention to Improve Adherence

Angiotensin converting enzyme inhibitors (ACEI)/ angiotensin receptor blockers (ARB) are highly recommended for patients with both diabetes (DM) and hypertension (HTN), and their efficacy in reducing macrovascular and microvascular complications of DM is well-documented. Poor adherence remains a significant barrier to achieving full effectiveness and optimal long-term outcomes. This study aims to develop innovative group-based trajectory models to identify patients with similar ACE/ARB medication filling behavior among patients with co-morbid HTN and DM. The proportion of days covered (PDC), often used as an adherence measure, reduces complex patterns of longitudinal observations into a single value that cannot adequately depict different adherence experiences. Group based trajectory models are designed to identify patients with similar longitudinal patterns while capturing the dynamic nature. A motivational interviewing (MI) pharmacy student telephone intervention will then be customized by the identified trajectories and tested to demonstrate effectiveness in enhancing adherence. In pilot work, the investigator's team has demonstrated improvements in adherence through a pharmacy student telephone MI intervention. Pharmacy students have the knowledge base and training to provide comparable services to pharmacists at a lower cost. MI fosters behavior change by setting desired goals and promoting self-efficacy in a supportive, collaborative way. The objectives are to 1. Develop group-based trajectory models to identify patients with similar medication filling behavior patterns among patients enrolled in a Medicare advantage plan and 2. Customize an MI pharmacy student telephone intervention by the adherence patterns identified, and demonstrate the benefit of the customized intervention in improving adherence. Phase 1 of the project will be a retrospective analysis of 12 month refill data to determine patient adherence patterns. Phase 2 will be a prospective study among non-adherent patients to evaluate the effectiveness of the customized intervention (n=500). The students will contact patients assigned to the intervention group and follow a protocol using the Ask-Provide-Ask approach of MI given the patient adherence pattern for a tailored education. Monthly follow-up calls will be carried out for 6 months. Adherence during the 6 and 12 months post-intervention will be evaluated for the intervention and control groups as PDC as well as a categorical variable. Chi-square and t-tests will be used to evaluate the intervention effect. Multivariable multiple and logistic regression will be carried out in case of any significant differences in baseline characteristics. Implementing this project will provide students a unique MI training as a new way of communicating with patients. The training is further strengthened by PhD students trained in research design and statistical analyses to assist in the automated data analysis. The project will formulate a strong adherence research team at University of Houston that will be instrumental in implementing customized innovative interventions to improve medication adherence and subsequent health outcomes.

Inclusion criteria

• Continuous enrollment over the study period July 2016 to December 2018.
• A prescription filled for an ACEI or ARB medication between July 1st, 2017- December 31st, 2017. This will be defined as the index date (for phase 1).
• Diagnosis of both DM and HTN prior to index date, identified through the health plan's medical claims program (CCMS) using the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes only.

Exclusion criteria

• Disenrollment from drug plan.
• Death prior to end of the study.
• Having a diagnosis of dementia in the one-year pre-index period.
• Having an ACEI/ARB contraindication like angioedema, hyperkalemia, and renal artery stenosis in the one-year pre-index period.