Psychometric evaluation of the Polish version of the Adherence to Refills and Medications Scale (ARMS) in adults with hypertension

Background: Only 50%-75% of chronically ill patients take their medication as prescribed. The patient is found to adhere to treatment correctly and optimally if they accomplish 80% or more of the treatment plan. A questionnaire titled the Adherence to Refills and Medications Scale (ARMS) has been used in studies involving various populations and proved to be a simple instrument for measuring adherence, with good psychometric properties. Objective: The aim of this study was to develop a Polish version of the ARMS (ARMS-P), an instrument that identifies levels of adherence in the hypertensive population, and evaluate its psychometric properties. Methods: This cross-sectional study included 279 patients, including 166 females (mean age 66.5 years), hospitalized between September 2016 and March 2017 in the Department of Internal Medicine, Occupational Diseases, and Hypertension of Wroclaw Medical University, Poland. The 12-item ARMS was translated from English into Polish. The 12 items included in the final questionnaire comprise two subscales: adherence to taking medications (eight items) and adherence to refilling prescriptions (four items). Results: Patients in the good-adherence group were younger (P=0.017; P=0.048), more likely to be professionally active (P=0.041), better educated (P=0.037), and more likely to have normal blood pressure (P<0.001). They also measured their blood pressure more often (P<0.001), and took fewer pills in a day (P<0.001). Adherent patients were also more likely to take their medication on their own (P=0.016) and read information leaflets on the medication (P<0.001). The study demonstrated that the ARMS-P questionnaire has good psychometric properties that enable its use for assessing adherence in chronically ill patients, including in particular, patients with hypertension. Conclusion: The psychometric properties of the questionnaire are satisfactory (reliability measured by means of Cronbach's alpha). The ARMS-P questionnaire proved to be suitable for use in the Polish population. The use of this screening tool for the assessment of adherence to treatment is recommended in this population of hypertensive patients.