High prevalence and poor control of hypertension in primary care: cross-sectional study.

OBJECTIVE: To report: (1) on the background, design and methods of the Hypertension and Diabetes Risk Screening and Awareness (HYDRA) study, (2) on the point prevalence of hypertension in primary care and (3) on the proportion of treated, controlled, and uncontrolled hypertension.
DESIGN: Cross-sectional point prevalence study.
SETTING: Representative nationwide sample of 1912 primary care practices in Germany. PARTICIPANTS: A total of 45,125 unselected primary care attendees. MAIN OUTCOME MEASURES: Prevalence of hypertension based on doctor's diagnosis, self-reported diagnosis, and blood pressure (BP) measurements.
RESULTS: A total of 39% of all patients and 67% of patients aged 60 years or older, respectively, were diagnosed by their doctors as having hypertension. Eighty-four percent of diagnosed patients were on antihypertensive medication, 57% of which were rated by the physician as well controlled. When hypertension was defined as either current BP levels > or = 140/90 mmHg and/or current antihypertensive medication, the total point prevalence increased to 50%, while treatment and control rates (BP < 140/90 mmHg) dropped to 64 and 19%, respectively.
CONCLUSIONS: Extrapolation of these findings to the entire primary care patient population seen in the over 20 000 primary care practices in Germany suggests that on an average day, over 700,000 patients with elevated BP are seen by primary care physicians, but that only around 132,000 of these patients are well controlled. Thus, this study not only documents the enormous burden of hypertensive patients in the primary health system, but also highlights the alarming lack of BP control in the vast majority of hypertensive patients.