**2. Method**

Cross-sectional with convenient sampling study conducted for volunteer outpatients from the cardiac clinic of Penang Hospital in Pulau Pinang State of Malaysia. Study protocol was approved by Clinical Research Committee of Penang General Hospital, and signed consent forms were obtained from all participants. The patients included in this study were at least 18 years old and voluntarily to participate in this study. They have to used statins and could understand Malay Language (the National Language of Malaysia) or English Language, since Malaysia is a multiracial country. Patients who allergies to statin, pregnant or lactating women, or changing in types or dosage of statin used were excluded from this study. These types of patients excluded because their conditions may affected outcomes of the study. The study period was 5 months, and 1900 patients presented in the cardiac clinic within this study period. Depending on inclusion and exclusion criteria, 500 patients voluntarily agreed to participate in this study. A validated questionnaire form (Cronbach's alpha is 0.853) were used for reporting of ADRs. The patients were asked whether they have experience of common statin-related ADRs while they were on statin therapy and give their answers on the self-report questionnaire forms. This questionnaire form has some questions on demographic data and undesired symptoms that patients had during statin therapy. There were 27 ADRs of statin listed in the questionnaire form. They were required to tick yes or no on these listed ADRs. They can tick more than one ADR. In order to ensure these ADRs really related with statin therapy these patients had to indicate in the questionnaire form that these ADRs occurred while they were receiving statin therapy and these symptoms should continuously occurred at least for 3 months.
