The impact of illness perception on adherence to therapeutic regimens of patients with hypertension in Taiwan

Aims. To examine the predictive effects of illness perception on adherence to therapeutic regimens of patients with hypertension. Background. Illness perception is an important predictor for adherence to therapeutic regimens. Hypertension is asymptomatic. How the lay views, especially identity and causal attribution, affect the patients' adherence to therapeutic regimens need to be further explored. Design. A cross-sectional survey. Methods. Purposive sampling was conducted at the cardiovascular clinics of two teaching hospitals in central Taiwan. A sample of 277 patients was included in this study. Guided by the Self Regulation Model, a series of variables including socio-demographic variables, clinical variables, illness representations, identity and causes were evaluated for their relationships with adherence to the antihypertensive regimen and recommendations of self-management. Results. Predictors of adherence to prescribed medications in the hierarchical logistic regressions were treatment control, risk factors and psychological attribution. In the self-management model, we found that symptoms experienced after a hypertension diagnosis, symptoms for blood pressure prediction, personal control, balance and cultural causal attribution were significant predictors of adherence to self-management, adding an additional 21% of the variance. The results of analysis of variance showed that those who were unsure if they had experienced symptoms after a hypertension diagnosis were more likely to self-regulate (increase or decrease) prescribed medications than those without symptoms. Conclusions. The findings suggest that the Self Regulation Model may provide a useful framework for understanding and explaining adherence to therapeutic regimens of patients with hypertension across cultures. Relevance to clinical practice. Factors that affect the patients' adherence to prescribed medications and self-management recommendations differ greatly. Despite its subjectivity, identity showed significantly predictive effects on adherence to self-management. Understanding patients' lay views on hypertension allows health professionals providing effective care for better adherence to therapeutic regimens.