Assessment of adherence to statin therapy in patients with coronary artery disease: comparison of three self-reporting measures.

OBJECTIVES: To investigate adherence to statin therapy using three self-reporting adherence measures in patients with coronary artery disease and to compare the three measures. METHODS: A cross-sectional study was carried out at a multidisciplinary outpatient clinic of cardiology at a teaching hospital in south-eastern Brazil in patients with coronary artery disease who were using statins. The sample consisted of 148 patients who were selected from April 2018 to February 2019. Adherence to statin therapy was determined by the Measure of Adherence to Treatment, Visual Analogue Scale of adherence and 7-day recall. A descriptive analysis and determination of the level of agreement between the adherence scales by the Cohen kappa coefficient were performed. RESULTS: The study included 148 patients (104 (70.3%) men, median age 62 years) diagnosed with coronary artery disease who were using statins. The adherence to statin therapy was 98.6% using the Measure of Adherence to Treatment, 95.9% with the Visual Analogue Scale and 95.3% with 7-day recall. Agreement between the Measure of Adherence to Treatment and the Visual Analogue Scale (0.277) and the Measure of Adherence to Treatment and 7-day recall (0.241) was low. There was a high level of agreement between the Visual Analogue Scale and 7-day recall (0.759). CONCLUSIONS: The adherence Visual Analogue Scale and 7-day recall were shown to be easy to apply, low-cost adherence measures to identify adherence to statins in patients with coronary artery disease. The Measure of Adherence to Treatment may also be used to provide information regarding the specific reasons for non-adherent behaviour.

Medication literacy: A conceptual model.

BACKGROUND: Medication literacy reflects the specific literacy skills necessary to act on medication-related information. A comprehensive and clear conceptual model that reflects medication literacy is lacking. Conceptual models describe the components that represent a construct, allowing for its understanding and providing a rationale for its measurement. OBJECTIVES: To propose a conceptual model to support the development of an instrument to measure medication literacy. METHODS: This is a three-phase methodological study. A literature review was conducted to identify the components that should be part of the preliminary conceptual model. Subsequently, the importance of its components was judged on a Likert-5 scale. Then, the model was refined, and the dimensions and subdimensions of medication literacy were defined. RESULTS: Forty-five experts were included, with a mean age of 39.9 (SD = 10.5) years, most of them females (86.7%) and pharmacists (80%). All components of the preliminary conceptual model were considered important to extremely important by most experts. "Dosing information", "medication name", and "processing the information received about their medication and acting upon medication instructions" were the components considered most important. In the refinement phase, we identified that the construct has four dimensions - functional literacy, communicative literacy, critical literacy, and numeracy, which include the subdimensions to access, understand, evaluate, calculate, and communicate medication-related information. CONCLUSIONS: The conceptual model allowed identifying the components that represent medication literacy, which will support the development of an instrument for measuring the construct in Brazil.