Decisions about taking antihypertensive medication as prescribed are likely to be
influenced by patients' beliefs about medication. We assessed the influence of selected
patient beliefs about medication on blood pressure (RR) control in subjects treated
for arterial hypertension.
STAAB is a strictly controlled population-based prospective cohort study in inhabitants
of Würzburg, aged 30 – 79yrs. Inadequately controlled RR was defined as systolic RR
> 140/90 mm/Hg despite antihypertensive medication. We used the BMQ-Specific (Beliefs
about Medicines Questionnaire) to evaluate the specific necessity of prescribed medication (5 items; range 0 – 25) and specific concerns about medications (6 items; range 0 – 30). Higher scores indicate higher levels of concern or necessity. Multivariable logistic
regression, adjusted for sociodemographic status (age, sex, education), body mass
index > 25 kg/m2, and self-reported smoking was used.
Overall, 156 participants free of cardiovascular disease but with hypertension and
on antihypertensive treatment could be analysed: median age 62.2 years, 52.6% women;
inadequately controlled RR in n = 68 (43.6%). Inadequately controlled RR was associated
with lower concerns (OR 0.92, 95%CI 0.85 – 0.99), lower age (OR per decade 0.65, 0.44
– 0.95), and smoking (OR 2.82, 1.01 – 7.87). No significant associations were found
for specific necessity.
In the present study we could not condirm the intuitively attractive association between
inadequately controlled RR and the belief regarding the necessity of prescribed medication.
By contrast, we observe an inverse association between concerns about medication and
inappropriately controlled RR. A possible explanation might be that subjects with
a higher level of concern may be particularly well-informed, thus better adhering
to physician's advice: these subjects may have a stronger inclination to take their
medication as prescribed in order to thereby avoid additional treatment with even
more substance classes.
