Beliefs, social normative influences, and compliance with antihypertensive medication.

We explored the relationship between beliefs and social normative influences and self-reported hypertension medication compliance using questionnaire items based on the belief intention model of Ajzen and Fishbein. Persons for whom antihypertensive medication had been prescribed were asked to agree or disagree with statements about taking their medicine. Respondents were a subset of participants in a 1980 survey of risk factors for heart disease in two Pennsylvania counties. Highly significant differences between compliant and noncompliant individuals were observed for all items except one referring to cost. A stepwise multiple logistic regression analysis was performed with age, sex, and the belief and social normative items as independent variables, and reported compliance as the dependent variable. Three variables, age, "taking my blood pressure medicine as the doctor told me would not be necessary when my blood pressure is normal," and "your family wants you to take your blood pressure medicine as the doctor told you," entering into the equation in that order, significantly improved discrimination between compliant and noncompliant persons. The questionnaire's success may have resulted from moving beyond assessing participant's knowledge or beliefs about hypertension in the abstract to ascertaining the direct relevance of these beliefs to their taking their medicine.