Developmentand Validation of a Questionnaire about Patient Knowledge of Adverse Effects of Statins

Abstract

Statins are drugs that are well tolerated, but considering their extensive use, there are still concerns regarding their safety. Knowledge of patients about the side effects of statins has not been adequately studied, although timely recognition of the AES is of vital importance for improving the quality of patient care and reducing morbidity and suffering. The aim of this study was to develop and test a questionnaire for measuring the knowledge of patients about statin therapy about adverse effects of statins (AES). This two-center cross-sectional study was conducted during the period from March 1, 2015 to April 1, 2016, taking place in pharmacies from the city of Belgrade and at the Department of Internal Medicine, Clinical Center in Kragujevac, Serbia. The study included 300 patients and 20 pharmacists. The questionnaire showed satisfactory internal consistency, with Cronbach's alpha of 0.898, good construction and homogeneity of questions. After splitting the questionnaire to two parts at random, Cronbach's alphas were 0.834 and 0.842 for the both parts, respectively. Exploratory factorial analysis revealed two domains. The patients rated their knowledge of the side effects of statins 52.7±19.9 on the visual analogue scale. Based on the results of this study, we believe that this questionnaire could be a useful tool for testing the knowledge of patients about adverse effects of statins and help physicians to identify patients with insufficient knowledge who should be additionally informed about it.