Does knowledge matter?: intentional medication nonadherence among middle-aged Korean Americans with high blood pressure.

AIM: To examine predictors of intentional and unintentional nonadherence to antihypertensive medication regimens and their relationships to blood pressure outcomes.

BACKGROUND: Although poor adherence to medical regimens is a major concern in the care of patients with high blood pressure (HBP), our understanding of the complex behavior related to adherence is limited. Moreover, few studies have been devoted to understanding adherence issues in ethnic minority groups, such as the interplay between cultural beliefs and HBP medication-taking behaviors.

DESIGN: A cross-sectional analysis was performed to assess the factors affecting nonadherence to antihypertensive medication regimens.

METHODS: The data used in this analysis came from an ongoing HBP intervention trial involving middle-aged (40-64 years) Korean Americans with HBP. A total of 445 Korean Americans with HBP was enrolled in the trial at baseline. Of these, 208 participants who were on antihypertensive medication were included in the analysis. Using multivariate logistic regression, we examined theoretically selected variables to assess their relationships to intentional and unintentional nonadherence in this sample.

RESULTS: Approximately 53.8% of the subjects endorsed 1 or more types of nonadherent behaviors. After controlling for demographic variables, multivariate analysis revealed that a greater number of side effects from the medication (adjusted odds ratio [OR], 1.19; 95% confidence interval [CI], 1.07 to 1.33) and a lower level of HBP knowledge (adjusted OR, 0.89; 95% CI, 0.79 to 0.99) were significantly associated with intentional nonadherence. Unintentional nonadherence was less strongly associated with the study variables examined in the analysis.

CONCLUSION: Our findings indicate that intentional nonadherence to antihypertensive medication that stems from incomplete knowledge of HBP treatment is prevalent among middle-aged Korean Americans with HBP. The results highlight the strong need for an intervention that focuses on increasing patient knowledge about HBP, including the benefits and side effects of antihypertensive medication. This type of focused intervention may help reduce intentional nonadherence to antihypertensive medications and ultimately result in achieving adequate BP control in this high-risk group.