Characteristics of patients with uncontrolled hypertension in the United States

Treatment of hypertension is one of the most common clinical responsibilities of U.S. physicians, yet only one fourth of patients with hypertension have their blood pressure adequately controlled.

We analyzed data from the third National Health and Nutrition Examination Survey to assess the role of access to and use of health care in the control of hypertension. We assessed demographic characteristics, clinical data, health insurance status, and awareness and treatment of hypertension in subjects with hypertension (defined as a blood pressure of at least 140/90 mm Hg or the use of antihypertensive medication) and subjects without hypertension.

The study sample consisted of 16,095 adults who were at least 25 years old and for whom blood-pressure values were known. We estimated that 27 percent of the population had hypertension, but only 23 percent of those with hypertension were taking medications that controlled their condition. Among subjects with untreated or uncontrolled hypertension, the pattern was an elevation in the systolic blood pressure with a diastolic pressure of less than 90 mm Hg. The great majority had health insurance. Independent predictors of a lack of awareness of hypertension were an age of at least 65 years, male sex, non-Hispanic black race, and not having visited a physician within the preceding 12 months. The same variables, except for non-Hispanic black race, were independently associated with poor control of hypertension among those who were aware of their condition. An age of at least 65 years accounted for the greatest proportion of the attributable risk of the lack of awareness of hypertension and the lack of control of hypertension among those who were aware of their condition.

Most cases of uncontrolled hypertension in the United States consist of isolated, mild systolic hypertension in older adults, most of whom have access to health care and relatively frequent contact with physicians.