Improved Hypertension Control

Abstract

HYPERTENSION HAS LONG BEEN RECOGNIZED AS A MAjor risk factor for cardiovascular diseases. Advances in drug therapy have provided clinicians with the ability to lower blood pressure (BP) to goal levels in most persons with hypertension. In addition, many intervention trials have demonstrated large benefits of BP lowering in reducing the incidence of cardiovascular events independently of age, sex, type or severity of hypertension, or presence of comorbid conditions. Nevertheless, the control of hypertension in the United States and throughout the world has been grossly inadequate. The article by Egan and colleagues in this issue of JAMA provides new information on hypertension awareness, treatment, and control rates compiled from the 2007-2008 National Health and Nutrition Survey (NHANES). Data were derived from a representative sample of individuals aged 18 years or older and compared with the findings from NHANES surveys dating back to 1988. The results suggest considerable improvement in hypertension treatment and control rates in the period since the 1999-2004 survey, with awareness of hypertension increasing from 72% to 81%, treatment from 61% to 73%, and control (defined by systolic BP level of 140 mm Hg and diastolic BP level of 90 mm Hg) from 35% to 50%. The 50% control rate is particularly impressive and meets the Healthy People 2010 objective, which even recently seemed unachievable. The study by Egan et al also indicates a substantial reduction in BP in the hypertension group as a whole, the decrease averaging 7/4 mm Hg between these same periods. The percentage of individuals with the more severe category of stage 2 hypertension also decreased from 21% to 12%. The highest percentage of patients treated and not controlled for hypertension was in the group aged 60 years or older. These NHANES data have some limitations inherent in the study design. The hypertension sample size was relatively small, particularly in the group younger than 40 years. Blood pressures were obtained by a physician on a single visit and not confirmed subsequently; therefore, hypertension prevalence was probably overestimated. Individuals with diabetes were not considered to have hypertension if their BP was less than 140/90 mm Hg; however, they were included in the controlled hypertension group even if they did not receive antihypertensive therapy. Nevertheless, comparison of data between different periods would seem valid for demonstrating trends because the methods used in the different NHANES study periods appear broadly comparable, and appropriate age adjustments of data were made. The reasons for the accelerated improvement in hypertension control rates are unclear. Blood pressure control may be affected by factors such as inadequate access to health care, cost of therapy, poor adherence to medications, drug adverse effects, clinician inertia, disregard of treatment guidelines, inadequate education of clinicians and patients, and unhealthy lifestyles. The magnitude of the changes reported by Egan et al suggests that several factors probably were involved. Major changes toward healthier lifestyles have not occurred in the United States during the periods covered by this study and would not appear responsible for the observed improvement. Importantly, the proportion of individuals with hypertension receiving drug treatment increased substantially in concert with the increased percentage who achieved goal BP levels. The availability of a broad array of effective antihypertensive drugs with excellent tolerability has made treatment easier than in the past. Significant adverse effects are uncommon with many of the drugs, and cost has become less of an issue with the availability of generic preparations for most antihypertensive drug classes. In addition, many combination drugs have been introduced that can facilitate medication adherence for the patient. Other factors that may have been involved include increased use of electronic systems and other approaches to provide feedback reminders to patients and clinicians regarding patient appointments, prescription refills, the need to advance therapy based on existing national guidelines, auditing of records, and adherence to Health Plan Employer Data and Information Set performance standards and their enforcement by insurers and managed care organizations. Likewise, the increased use of nonphysician health care professionals such as nurse cli-