Cognitive Therapy

The purpose of this literature review was to inform development of the conceptual model by identifying definitions and metrics for terms such as medication adherence, persistence, and discontinuation used in published studies based on electronic databases, and the rationale provided by the authors of these studies for selecting definitions and measurement tools. To accomplish this, two authors of the current paper (JLK and MAR) searched published literature to identify EHR, pharmacy dispensing, and pharmacy insurance claims-based studies where medication adherence, persistence, and/or discontinuation was stated as a primary outcome. Although the purpose of this review was narrowly focused and a comprehensive literature review was neither intended nor undertaken, the authors utilized search techniques from the literature on systematic reviews. Retrospective observational studies, randomized controlled trials, and non-randomized comparative studies were included. The National Library of Medicine’s Medical Subject Headings (MeSH) keyword nomenclature developed for MEDLINE^® and adapted for use in other databases was employed. The search was limited to studies published in English from January 1, 2000 through December 15, 2011, and to articles indexed in PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL®), Google Scholar, or the Web of Science. MeSH terms applied during the preliminary search were revised and refined based on expert input from a medical librarian and review of the MeSH terms identified from relevant publication titles retrieved in the preliminary search.
In the medical literature, the word adherence is applied to a broader variety of behaviors and regulatory topics than the focus of this work. Thus, studies that focused on adherence to or compliance with lifestyle, guidelines, exercise, diet, preventative screenings or follow-up, dental screenings/procedures, radiation/imaging, hospitalization/surgery, quality of care recommendations, medication reconciliation, drug administration/efficacy/adverse effects, device use, medical visits recommendations, isolation or hand washing precautions, cognitive/behavioral therapies, vaccination/immunization, and Health Insurance Portability and Accountability Act (HIPAA) regulations were excluded. Moreover, we excluded studies that used the degree of risk factor control as the indicator of adherence, rather than directly measuring medication use or non-use.
The title of each citation retrieved was reviewed and the abstract retrieved if the title indicated adherence or persistence to, or discontinuation of, chronic oral medications was the focus. Abstracts of articles dealing with validation of adherence measures used in electronic database studies were also included. Potentially relevant citations were imported into an electronic database. Abstracts of these citations were reviewed and the full texts of relevant articles were retrieved and read by the two individuals that conducted the literature search (MAR and JLK). As articles were read, the definitions and terminology used for adherence, persistence, and/or discontinuation in the articles were extracted and cataloged.
This literature scan retrieved 2484 articles, 315 (13%) of which utilized electronic data sources that included as the primary outcome chronic oral medication adherence or that evaluated adherence metrics. Studying the definitions and terminology we extracted from these publications confirmed our subjective impression of variation, inconsistency, and confusion in the terminology used. It also demonstrated that terms were used imprecisely and interchangeably to refer to different constructs in different papers. This background work reinforced the fact that a conceptual model of and uniform definitions for the adherence continuum were lacking. It also informed the standardized terminology and definitions we developed (Tables 1 and 2).