Hypertension Control

Name	Description	Numerator	Denominator	Source	Reference
Hypertension Control	Percentage of patients 18 to 85 years of age with a diagnosis of hypertension (HTN) and whose blood pressure (BP) was adequately controlled (<140/90) during the measurement year	Patients from the denominator with last blood pressure measurement with systolic blood pressure less than 140 mm Hg and the diastolic blood pressure less than 90 mm Hg	All patients 18 to 85 years of age with a diagnosis of hypertension (HTN) during the measurement year	NQF/NCQA/ CMS-PQRI 2008	National Committee for Quality Assurance

Part 1: Introduction

Part 2: Characteristics for Success: Hypertension Control

Part 3: Implementation of Quality Measure: Hypertension Control

Part 4: Improvement Strategies: Hypertension Control

Part 5: Holding the Gains and Spreading Improvement

Part 6: Supporting Information

Part 1: Introduction 

Hypertension is one of the most common worldwide diseases afflicting humans. The most widely-used definition of hypertension was published by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure in its Seventh Report (JNC VII 2003 ). Based on its recommendations, the classification of blood pressure, which is the average of two or more readings each taken at two or more visits after initial screening for adults aged 18 years or older, is as follows:

• Normal—systolic blood pressure (SBP) is lower than 120 mm Hg; diastolic blood pressure (DPB) is lower than 80 mm Hg
• Pre-hypertension—SBP is 120 to139 mm Hg; DBP is 80 to 99 mm Hg
• Stage 1—SBP is 140 to159 mm Hg; DBP is 90 to 99 mm Hg
• Stage 2—SBP is equal to or more than 160 mm Hg; DBP is equal to or more than 100 mm Hg

The JNC VII report also clarified a couple of helpful facts about blood pressure. Normal blood pressure (BP) with respect to cardiovascular risk is less than 120/80 mm Hg; however, unusually low readings should be evaluated for clinical significance. A new category of pre-hypertension was defined, emphasizing those patients with pre-hypertension are at risk for progression to hypertension, and lifestyle modifications are important preventive strategies.

Hypertension may be either essential or secondary. Essential hypertension is diagnosed in the absence of an identifiable secondary cause, including coarctation of the aorta, renal disease, pheochromocytoma, and Cushing's syndrome. Approximately 95 percent of American adults have essential hypertension, while secondary hypertension accounts for fewer than 5 percent of the cases.

Hypertension has been described as the most important modifiable risk factor for coronary heart disease (leading cause of death in the United States), stroke (third leading cause), congestive heart failure, and end-stage renal disease. Over 50 million Americans have high blood pressure warranting some form of treatment, and in 2006, there were 44,879 million physician office visits for hypertension.⁽¹⁾

Data from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 ⁽²⁾ summarized in the January 2008 issue of the National Center for Health Statistics, NCHS Data Brief, shows that ⁽³⁾:

• Twenty-nine percent of all United States adults aged 18 years or older have hypertension
• The prevalence of hypertension increases with age, from 7 percent among individuals aged 18 to 39 years to 67 percent in those 60 years of age or older
• Non-Hispanic Blacks had a significantly higher prevalence (41 percent) compared with non-Hispanic Whites (28 percent) and Mexican Americans (22 percent)
• Overall, 37 percent of adults had pre-hypertension (SBP 120 to 139 mm Hg or DBP 80 to 89 mm Hg) and were not taking antihypertensive medication
• The prevalence of pre-hypertension also increased with age and was higher in men (43 percent) than women (39 percent)

Layered on this high prevalence, is the fact that the impact of hypertension on cardiovascular morbidity and mortality is significant, and it continues to be a public health challenge. Death from ischemic heart disease (IHD) and stroke increases linearly from blood pressure levels as low as 115/75 mm Hg. For every 20 mm Hg systolic or 10 mm Hg diastolic increase in blood pressure, mortality from both IHD and stroke doubles. ⁽⁴⁾ It was estimated that the direct and indirect costs of high blood pressure would be $73.4 billion in the year 2009. ⁽⁵⁾

Hypertension continues to be one of those diseases in which significant disparities still exist. It is more common, more severe, develops at an earlier age, and leads to more clinical sequelae in Blacks than in age-matched non-Hispanic Whites. ⁽⁶⁾ Additionally, Mexican Americans and Native Americans have lower control rates than non-Hispanic Whites and Blacks. ^(7,8)

Measuring performance allows an organization to document how well care is currently provided and lay the foundation for improvement. The  Hypertension Control clinical quality measure is designed to measure the effectiveness of the care and management of patients diagnosed with hypertension. Blood pressure reduction has been shown to reduce the risk for developing complications from hypertension, including myocardial infarction and stroke; hence, hypertension control is defined as an intermediate or outcome measure, or one of the proxy measures for assessing cardiovascular health in a community.

Consider the characteristics of a good performance measure and the Institute of Medicine (IOM) framework, Envisioning the National Healthcare Quality Report:

• Relevance: Does the performance measure relate to a frequently-occurring condition or have a great impact on patients at an organization's facility?
• Measurability: Can the performance measure realistically and efficiently be quantified given the facility's finite resources?
• Accuracy: Is the performance measure based on accepted guidelines or developed through formal group decision-making methods?
• Feasibility: Can the performance rate associated with the performance measure realistically be improved given the limitations of the clinical services and patient population?

To ensure that a performance measure has these characteristics, it is often based on, or aligned with, an organization's existing and proven measures.

The Hypertension Control measure aligns with measures endorsed by the National Committee for Quality Assurance (NCQA) and similar performance metrics used by HRSA grantees and programs. The measure also aligns with those adapted by the Office of Regional Operations (ORO) and is similar to the one used by the Bureau of Primary Health Care (BPHC) in the clinical portion of its Uniform Data Systems (UDS) process. Similar measures also exist in the national measure set for Healthy People 2020.

 Hypertension Control Clinical Quality Measure

Measure Description 

Name	Description	Numerator	Denominator	Source	Reference
Hypertension Control	Percentage of patients 18 to 85 years of age with a diagnosis of hypertension (HTN) and whose blood pressure (BP) was adequately controlled (<140/90) during the measurement year	Patients from the denominator with last blood pressure measurement with systolic blood pressure less than 140 mm Hg and the diastolic blood pressure less than 90 mm Hg	All patients 18 to 85 years of age with a diagnosis of hypertension (HTN) during the measurement year	NQF/NCQA/CMS-PQRI 2008	National Committee for Quality Assurance

As with all performance measures, there are essential inclusions, exclusions, and clarifications that are required to ensure that an organization collects and reports data in the same way. This allows an organization using the measure to compare itself with others. Detailed specifications for the measure, with descriptions of inclusion and exclusion criteria, are found in the section, Part 3: Data Infrastructure: Hypertension Control.

Improvement Experience: Hypertension Control

For more than three decades, the National Heart, Lung, and Blood Institute (NHBLI) has administered the National Blood Pressure Education Program Coordinating Committee, a coalition of major professional, public, and voluntary organizations and Federal agencies. An important function has been to increase awareness, prevention, treatment, and control of hypertension.

Through its efforts, considerable progress has been made toward achieving the goals of the program. As Table 1.1: Trends in Awareness, Treatment, and Control of High Blood Pressure indicates:

• Awareness of hypertension among Americans has improved from 51 to 70 percent over two decades
• Percentage of patients with hypertension receiving treatment has increased from 31 to 59 percent in the same period
• Percentage of person with high blood pressure controlled to below 140/90 has increased from 10 to 34 percent

Table 1.1: Trends in Awareness, Treatment, and Control of High Blood Pressure (1976-2000)

Adapted from the National Health and Nutrition Examination Survey 

These improvements are significant in individual and societal value since modest improvements in blood pressure have been shown to reduce morbidity and mortality. As presented in Figure 1.1: Systolic Blood Pressure Distributions, it is estimated that a five mm Hg reduction of SBP in the population would result in: ⁽⁹⁾

• Fourteen percent overall reduction in mortality due to stroke
• Nine percent reduction in mortality due to coronary heart disease (CHD)
• Seven percent decrease in all-cause mortality