Is interview a reliable method to verify the compliance with antihypertensive therapy? An international central-European study

Abstract

Non-compliance with prescribed antihypertensive medication is an important contributor to the failure of antihypertensive therapy. To assess the validity of a short questionnaire in the identification of non-compliant patients. In three central-European countries, work-site screening for hypertension was conducted. Blood pressure was measured using an automatic electronic blood pressure measuring device (BpTRU). Respondents were interviewed by trained personnel and a short questionnaire focused on blood pressure awareness and treatment compliance was completed. A total of 2812 persons were screened: 841(29.9%) respondents were hypertensive, and out of these the total number of treated hypertensive subjects was 359 (42.6%). Mean systolic blood pressure and diastolic blood pressure were significantly lower in the compliant group than the non-compliant group (systolic blood pressure, 139.4 and 146.2 mmHg, respectively, P = 0.002; and diastolic blood pressure, 89.2 and 92.3 mmHg, respectively, P < 0.01). The non-compliant group was younger than the compliant group (mean age, 46.7 versus 48.9 years, respectively, P = 0.01). Females, patients on combined therapy and non-smokers were more compliant than males, those on mono-therapy and smokers (P = 0.01, P = 0.004 and P = 0.005, respectively). Patients reporting strict compliance with prescribed drug therapy have significantly lower systolic blood pressure and diastolic blood pressure than those who admit even an occasional lapse in taking medication. A properly formulated questionnaire can identify non-compliant patients.