**2. Methodology**

#### **2.1. Study design**

The cross-sectional design based on patients self-reporting was used in the current study to determine the incidence of dysphagia and its concurrent symptoms. The reason this study was carried out at the Cardiac Clinic of Penang General Hospital was because polypharmacy is more detectable in cardiac patients as a result of their treatment by chronic and multiple therapies. There were 576 cardiac outpatients involved in the current study. Approval for this study was granted by the Ministry of Health of Malaysia and consent forms were collected from patients. All patients involved in the current study were aged 18 years or above, used medications dispensed from the pharmacy of the hospital, and were able to understand and fill in the questionnaire form in Standard Malay (Bahasa Malaysia) or English.

#### **2.2. Self-reporting questionnaire and assessment of polypharmacy**

The self-reporting questionnaire used in the current study had the purpose of counting the incidence and severity of dysphagia and its symptoms. The validity of the questionnaire was established after conducting language, panel, and statistical validity, after conducting a pilot study, and after settling on an appropriate coefficient of reliability (Cronbach's α = 0.92). Statistical advanced logistic regression was used to measure the specificity and sensitivity of dysphagia and its symptoms, which had fixed in the questionnaire form. Patients were asked to answer "yes" or "no" to questions about the existence of dysphagia and its symptoms. Patients were also asked to report the severity of the symptoms as "mild", "moderate", or "severe". Mild referred to symptoms that did not bother the patient who had no need for assistance. Moderate referred to patients who were bothered by symptoms but had no need for assistance. Severe referred to patients who were seriously bothered by these symptoms and had urgent need for assistance. Other information such as demographic data, medical history, and concurrent medications and diseases were taken from the progress files of patients.

The patients included in this study were classified into three groups: (1) patients taking no medications who were referred from other clinics for a follow-up; (2) patients already known to the department taking fewer than 5 medications and (3) patients known to the department taking 5 or more medications. All patients on medication had been in chronic therapy for at least one year.

#### **2.3. Statistical analysis**

blockers; (2) medications reducing esophageal sphincter pressure such as nitrates and atropine; (3) medications inducing xerostomia such as antihypertensive agents and antiarrhythmics; and (4) medications inducing esophageal injury such as aspirin and non-steroidal anti-

Polypharmacy is defined as patient use of five or more medications [9]. Polypharmacy contributes to the high incidence of adverse effects as a consequence of possible drug interactions between medications [10, 11]. Although some studies state that polypharma‐ cy should be considered a significant predictor for dysphagia [2, 12], they have weakness‐ es in that they were either case reports or mainly dealt with specific dysphagia type. Thus, the aims of the current study are, first, to describe the incidence, severity, and predictors of dysphagia; second, to determine the relationship between polypharmacy and dyspha‐ gia; and, third, to describe the association between types of dysphagia (depending on

The cross-sectional design based on patients self-reporting was used in the current study to determine the incidence of dysphagia and its concurrent symptoms. The reason this study was carried out at the Cardiac Clinic of Penang General Hospital was because polypharmacy is more detectable in cardiac patients as a result of their treatment by chronic and multiple therapies. There were 576 cardiac outpatients involved in the current study. Approval for this study was granted by the Ministry of Health of Malaysia and consent forms were collected from patients. All patients involved in the current study were aged 18 years or above, used medications dispensed from the pharmacy of the hospital, and were able to understand and

The self-reporting questionnaire used in the current study had the purpose of counting the incidence and severity of dysphagia and its symptoms. The validity of the questionnaire was established after conducting language, panel, and statistical validity, after conducting a pilot study, and after settling on an appropriate coefficient of reliability (Cronbach's α = 0.92). Statistical advanced logistic regression was used to measure the specificity and sensitivity of dysphagia and its symptoms, which had fixed in the questionnaire form. Patients were asked to answer "yes" or "no" to questions about the existence of dysphagia and its symptoms. Patients were also asked to report the severity of the symptoms as "mild", "moderate", or "severe". Mild referred to symptoms that did not bother the patient who had no need for assistance. Moderate referred to patients who were bothered by symptoms but had no need for assistance. Severe referred to patients who were seriously bothered by these symptoms and had urgent need for assistance. Other information such as demographic data, medical

fill in the questionnaire form in Standard Malay (Bahasa Malaysia) or English.

**2.2. Self-reporting questionnaire and assessment of polypharmacy**

inflammatory medications.

42 Seminars in Dysphagia

**2. Methodology**

**2.1. Study design**

concurrent symptoms) and polypharmacy.

The Statistical Package for the Social Sciences (SPSS) software program was used to analyze the results of the current study. The incidence and severity of dysphagia and its symptoms were measured descriptively. The correlation between dysphagia and its symptoms was tested using Spearman's rank correlation. Multiple logistic regression was used, first, to find out the effect of predictors' interaction on the incidence of dysphagia; second, to discover how polypharmacy impacted dysphagia; and, third, to determine the association between poly‐ pharmacy and type of dysphagia (oropharyngeal and esophageal). All the results of this study were considered significant if their *p* values were less than 0.05.
