Medication adherence in a sample of elderly suffering from hypertension: evaluating the influence of illness perceptions, treatment beliefs, and illness burden.

BACKGROUND: Although many advances in the management of hypertension have been made, success in hypertension control in real-life practice is limited. Control of hypertension is paramount in primary as well as secondary prevention of cardiovascular disease. Poor adherence to antihypertensive medication is one possible reason why success in clinical trials has not been translated into everyday practice. Despite many years of study, questions remain about why patients do or do not take medicines and what can be done to change their behavior. Although trends in adherence patterns across hypertensive patients is briefly documented in the literature, the role of perceived illness burden in addition to illness perceptions and medication beliefs in elderly people with hypertension is unclear.

OBJECTIVE: To assess the collective influence of illness perceptions, medications beliefs, and illness burden on medication adherence of a sample of elderly people suffering from hypertension.

METHODS: A cross-sectional questionnaire survey research design, utilizing convenience sampling strategies and a battery of self-administered health surveys, was adapted to address key study objectives. Previously validated instruments, such as the Brief Illness Perception Questionnaire, Pictorial Representation of Illness and Self Measure Revised II, Beliefs about Medicines Questionnaire, and Morisky Medication Adherence Scale, were utilized to assess illness perceptions, perceived illness burden, medication beliefs, and medication adherence, respectively. Conceptualized associations among the study variables were explored and tested to assess their individual, as well as collective, impact on medication adherence. In addition, combined predictive abilities of key variables in explaining the variations in medication adherence were determined using appropriate bivariate and multivariate statistics.

RESULTS: The majority of the sample was white (76.9%); 52.1% was over aged 65 years of which 47.9% attended some college, while 70.1% accessed adult day care centers. A usable sample of 117 respondents was retained for statistical analysis. From multiple linear regression analysis, it was observed that perceptions about illness, perceived illness burden, and beliefs about medication jointly played a significant role in the prediction of medication adherence (R-squared = 0.328). Significant bivariate correlations among study variables further indicated that threatening view of illness translated into higher levels of self-reported adherence with hypertensive medications (r = 0.332, P < 0.001), which in turn was associated with lower perceived illness burden (r = 0.423, -0.444, P < 0.001). The respondents reported illness-related “Stress” (49.1%) as a primary cause of hypertension in their opinion, followed by “Lifestyle” (43.8%) and “Heredity” (7.1%) factors. Perceived concerns about the benefits of medication played a more significant role in the prediction of adherence and perceived illness burden than the risks associated with their use.

CONCLUSIONS: This study provides insights into how perceptions of illness and burden relate to medication adherence in hypertension. More benign perceptions of illness and greater perceived illness burden translate to lower medication adherence. Positive beliefs regarding medications are also crucial for shaping adherence behavior of elderly hypertensive individuals. Threatening views of illness and stronger beliefs of the necessity of medications contribute substantially to positive medication adherence. Interventions and programs aimed at building adherence in elderly hypertension patients need to recognize the value and importance of patient perceptions of illness and medications in shaping adherence behavior.