Final Research Plan
Final Research Plan for High Blood Pressure in Adults: Screening
Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
The final Research Plan is used to guide a systematic review of the evidence by researchers at an Evidence-based Practice Center. The resulting Evidence Report will form the basis of the USPSTF Recommendation Statement on this topic.
The draft Research Plan was available for comment from June 20 until July 17, 2013 at 5:00 p.m., ET.
The figure is an analytic framework that depicts the five Key Questions described in the Research Plan. In general, it illustrates the overarching questions: whether screening for high blood pressure in adults leads to improved health outcomes or potential harms. The analytic framework also illustrates the intermediate steps and Key Questions related to methods and protocols for the initial screening encounter that identifies patients with elevated blood pressure, methods and protocols for confirmation (or no confirmation) of the diagnosis of hypertension at a subsequent encounter, and treatment of patients with identified hypertension leading to improved outcomes. The analytic framework also identifies an interval after which patients with normal blood pressure levels would be rescreened.
*Elevated blood pressure is defined as the threshold for pharmacologic treatment.
Abbreviations: ABPM = ambulatory blood pressure monitoring; BP = blood pressure; CHD = coronary heart disease; CVD = cardiovascular disease; HF = heart failure; ESKD = end-stage kidney disease; HBPM = home blood pressure monitoring.
Key Questions to be Systematically Reviewed
- Does screening for high blood pressure reduce cardiovascular disease and mortality in adults age 18 years or older?
What is the best way to screen for high blood pressure in adults in the primary care setting*?
- How accurate (i.e., sensitivity, specificity, predictive value) are clinic-based blood pressure measurement methods (e.g., manual vs. automated) in diagnosing hypertension within a single visit?
- What screening protocol characteristics within a single encounter (e.g., sitting quietly for 5 minutes, number of readings) define the best diagnostic accuracy?
What is the best way to confirm hypertension in adults who initially screen positive for high blood pressure?
- How well do home and ambulatory blood pressure monitoring methods predict cardiovascular events compared with clinic-based blood pressure measurement methods? What confirmation protocol characteristics define the best prediction of cardiovascular events? Which methods and associated protocols best predict cardiovascular events?
- How accurate are other noninvasive blood pressure measurement methods in establishing or confirming the diagnosis of hypertension compared with these best methods and associated protocols? Does diagnostic accuracy vary by protocol characteristics (i.e., characteristics not reviewed in Key Question 2b, such as the number of visits)?
- Does changing the measurement method from that used during the initial screening improve diagnostic accuracy for some specific patient subgroups (e.g., those with suspected white coat hypertension)?
What is the clinically appropriate rescreening interval for patients who have previously been screened and found to have normal blood pressure?
- What is the shortest interval in which clinically significant, diagnosed hypertension may develop?
- Does the rescreening interval vary by patient characteristics (e.g., age, sex, race/ethnicity, cardiovascular risk, blood pressure level, screening history)?
- What are the adverse effects of screening for high blood pressure in adults?
*For this review, eligible primary care settings must have personnel trained in blood pressure measurement, established blood pressure measurement protocols, and ongoing documentation procedures for each (e.g., internal medicine, family practice, obstetrics/gynecology, school- and military-based health clinics, pharmacies, retail and mobile clinics, dental offices).
Contextual questions will not be systematically reviewed and are not shown in the Analytic Framework.
- What is the diagnostic accuracy of automated and nonautomated blood pressure measurement instruments in the community setting (e.g., grocery store and pharmacy kiosks, community health fairs) that are not associated with an attendant, trained personnel, or established procedures? What are the characteristics of patients for whom these automated kiosks may be acceptable (e.g., non-obese)?
- Is there a valid protocol for identifying patients who are likely to have white coat hypertension?
The Research Approach identifies the study characteristics and criteria that the Evidence-based Practice Center will use to search for publications and to determine whether identified studies should be included or excluded from the Evidence Report. Criteria are overarching as well as specific to each of the key questions (KQs).
KQs 1, 2, 4, 5: Screening for high blood pressure in a primary care setting (alone or as part of a clinical examination)
KQ 3: Measuring blood pressure to confirm diagnosis of hypertension
|Measurement of short-term diet-, exercise-, or drug-induced blood pressure changes; measurement of blood pressure as part of a disease management program for heart failure or weight loss|
KQs 1, 2, 5: Adults age 18 years or older
KQ 3: Adults age 18 years or older with at least one elevated blood pressure measurement (as defined by study) identified by clinic-based screening
KQ 4a: Adults age 18 years or older whose previous clinic-based blood pressure screening was normal or not in the treatable range, or for whom an initial diagnosis of hypertension was not confirmed
Pregnant women, children (age <18 years), inpatients, institutionalized persons, patients with underlying causes of high blood pressure, and highly selected groups of patients (e.g., patients with diabetes, chronic kidney disease, or renal transplant) who do not represent a primary screening population
KQs 1, 2, 3b, 3c, 4, 5:
KQs 1, 2, 4, 5: Clinic-based, noninvasive blood pressure measurement using any commonly used device or screening protocol during a single encounter; blood pressure measurements conducted as part of a multicomponent cardiovascular risk assessment in which blood pressure elevation is the initial and sole factor that determines whether a patient proceeds to additional assessment
KQ 3: Any clinic-based blood pressure measurement confirmed by another clinic-based, home, or ambulatory blood pressure measurement (with any device or measurement protocol). For all ambulatory devices, average 24- or 48-hour, daytime, and nighttime (e.g., daytime to nighttime ratio to capture nighttime dipping) blood pressure measurements are acceptable
|Wrist and finger monitors|
KQs 1, 5: No blood pressure screening
KQ 2: A noninvasive blood pressure measurement method that differs either by device or protocol (e.g., manual vs. automated; clinic-based using one protocol vs. clinic-based using a different protocol)
KQ 3: Any clinic-based blood pressure measurement confirmed by another clinic-based, home, or ambulatory blood pressure measurement (with any device or protocol)
KQ 4a: Time interval for rescreening using the same method
|KQs 2, 3: Within-class comparative effectiveness of devices (e.g., automated vs. automated) with identical screening protocols|
KQs 2, 3b, 3c: Sensitivity, specificity, positive and negative predictive value (or comparable statistics or data that allow calculation of such), concordance for hypertension (e.g., r, r2, p-value for comparison of or difference of means)
KQ 3a: Measures of association of blood pressure and fatal or nonfatal cardiovascular events (as listed above), such as risk ratio or hazard ratio
KQ 4: Change in blood pressure classification (i.e., normal to diagnosis of hypertension) when rescreened at different time intervals (e.g., 1 year, 5 years, 10 years)
KQs 1, 3: Cardiovascular symptoms (e.g., palpitations), angina pectoris (chest pain), revascularization, carotid intima-media thickness, left ventricular hypertrophy, patient satisfaction, quality of life
KQs 2, 3b: Studies that do not provide enough data to create 2×2 tables or calculate sensitivity and specificity; studies that are designed to assess devices versus blood pressure measurement standards
KQ 3a: Studies that do not define composite cardiovascular disease outcomes; composite cardiovascular outcomes that contain excluded outcomes (as listed above)
KQ 4: Studies that report only average change in blood pressure for the entire population
|Timing of outcome assessment||No restrictions||No restrictions|
KQs 1, 2, 4, 5: Eligible primary care settings must have personnel trained in blood pressure measurement, established blood pressure measurement protocols, and ongoing documentation procedures for each (e.g., internal medicine, family practice, obstetrics/gynecology, school- and military-based health clinics, pharmacies, retail and mobile clinics, dental offices)
KQ 3: Primary care settings (see above for definition), home
|Health care or nonhealth care settings (e.g., worksites, school) that do not have personnel trained in blood pressure measurement, do not have established blood pressure measurement protocols, or do not have ongoing documentation procedures for each; inpatient/residential facilities, correctional facilities|
KQ 1: Randomized, controlled trials (RCTs) or controlled clinical trials (CCTs)
KQ 2: Diagnostic accuracy studies, RCTs, CCTs, cohort studies
KQ 3: Diagnostic accuracy studies, RCTs, CCTs, cohort studies, case-control studies
KQ 4a: Longitudinal cohort studies
KQ 5: RCTs, CCTs, cohort studies
|Before-after studies, time series, case series, case reports; studies enrolling treated hypertension patients with less than a 2-week washout period|
|Country||Studies in countries rated as “very high” on the 2013 Human Development Index: Andorra, Argentina, Australia, Austria, Barbados, Belgium, Brunei Darussalam, Canada, Chile, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hong Kong, Hungary, Iceland, Ireland, Israel, Italy, Japan, Korea, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, New Zealand, Norway, Poland, Portugal, Qatar, Seychelles, Singapore, Slovakia, Slovenia, Spain, Sweden, Switzerland, United Arab Emirates, United Kingdom, United States||Studies in countries rated below “very high” on the 2013 Human Development Index|
|Literature search dates||
KQs 1, 5: January 2002 to present (which includes carrying forward any studies included in the previous USPSTF systematic review)
KQs 2, 3: January 1992 to present. The rationale is based on that of Verberk and colleagues1; 1992 was chosen because the first protocol with guidelines for validation of blood pressure monitoring devices was published in 1990, and a lag time of 2 years was added to allow the guidelines to be fully implemented.
KQ 4: January 1965 to present. The rationale is that this is a new KQ that has never been addressed in a USPSTF systematic review
|Language||English||Other languages than English|
|Study quality||Fair or good||
Poor, according to design-specific USPSTF criteria
Response to Public Comments
The draft Research Plan was posted for public comment on the U.S. Preventive Services Task Force (USPSTF) Web site from June 20 to July 17, 2013; 18 individuals and organizations provided comments. The USPSTF received comments suggesting that operational definitions of normal blood pressure, elevated blood pressure, and hypertension be included. In the Analytic Framework, elevated blood pressure is now generally defined as the threshold for pharmacologic treatment. The review will include additional detail noting that this value is derived from guidelines for various populations and that the threshold varies by measurement method. A “high-normal” blood pressure category was added as a third possible result after screening, with lifestyle counseling as a possible intervention before entering the rescreening loop in the Analytic Framework (evidence to be summarized in the review). Key Question 2a (screening) was changed to “provisionally diagnosing hypertension” to remain consistent with wording in Key Question 3b (“establishing or confirming the diagnosis of hypertension”). Minor changes were made to the Research Plan in order to clarify the inclusion and exclusion criteria in response to a variety of comments. Additional comments addressed issues already covered by the Key Questions, treatment questions that this review will not address, minor clarifications, or potentially important contextual issues or discussion points. These comments did not warrant changes to the Research Plan but will be considered in the preparation of the evidence review and report.
Internet Citation: Final Research Plan: High Blood Pressure in Adults: Screening. U.S. Preventive Services Task Force. October 2014.