Introduction This study aimed to determine the relationships between knowledge, beliefs, and treatment adherence among patients with hypertension. Patients with hypertension do not have adequate knowledge about hypertension and poor perceptions of hypertension and treatment adherence.

Methodology This quantitative, descriptive correlation study was conducted in outpatient clinics from January 2018 to March 2018. Self-report data were collected from patients using the instruments of the Hypertension Knowledge-Level Scale (HK-LS), Commonsense Beliefs and Treatment Adherence Questionnaire for Patients with Hypertension (TAQPH) from 356 patients diagnosed with hypertension who were chosen via convenience sampling. The statistical tests that were applied were the Chi-Square test and Logistic Regression.

Results Three hundred and ten patients participated in this study, with a response rate of 87.1%. Overall, patients had high knowledge, beliefs, and treatment adherence to hypertension. Sociodemographic data significantly related to knowledge, beliefs, and treatment adherence to hypertension. Meanwhile, no significance was found between beliefs and treatment of adherence to hypertension.

Discussion About 45.5% of the patients had poorly defined hypertension, especially regarding systolic and diastolic blood pressure. These terms might have been medical jargon that laypersons could not understand. Those who had higher education or were exposed to hypertension health education might be able to read and interpret the information better. Also, the information could be provided by previous hypertension health education or social media. It was possible that income could influence patients' beliefs from different income groups living in other environments, which might impact how they perceive things. Besides, education level and health education would somehow influence how people perceive things. Systolic and diastolic BP and body mass index were expected to have significant relationships with treatment adherence. As diet control and weight control are poor, which means treatment adherence is poor, the BMI will be uncontrolled as well and leads to uncontrolled BP.

Conclusion Systolic and diastolic blood pressure, BMI, and the number of antihypertensive medications taken daily were the predicting factors for treatment adherence.