Final Research Plan

Hypertension in Adults: Screening

October 04, 2018

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 Review will form the basis of the USPSTF Recommendation Statement on this topic.

The draft Research Plan was available for comment on the USPSTF Web site from June 7 to July 5, 2018.

Figure 1 is the analytic framework that depicts the four Key Questions to be addressed in the systematic review. The figure illustrates how primary care screening for high blood pressure in adults may result in improved health outcomes, including all-cause mortality, cardiovascular disease mortality and events, heart failure, end-stage renal disease, symptomatic peripheral arterial disease, quality of life, and vascular dementia (KQ1). Additionally, the figure illustrates the accuracy of office-based blood pressure measurements in an initial screening for high blood pressure compared with the reference standard (ambulatory blood pressure measurement) (KQ2), and the accuracy of confirmatory blood pressure measurements in adults who initially screen positive for high blood pressure compared with the reference standard (KQ3). Lastly, the figure illustrates what harms may be associated with screening for high blood pressure in adults (KQ4).

Abbreviations: BP = blood pressure; CVD = cardiovascular disease; ESRD = end-stage renal disease; HF = heart failure; QoL = quality of life; PAD = peripheral artery disease.

  1. Does screening for high blood pressure in adults improve health outcomes?
  2. What is the accuracy of office-based blood pressure measurement during a single encounter as initial screening for high blood pressure compared with the reference standard (ambulatory blood pressure measurement [ABPM])?
    1. What screening protocol characteristics define the best diagnostic accuracy?
  3. What is the accuracy of confirmatory blood pressure measurement in adults who initially screen positive for high blood pressure compared with the reference standard (ABPM)?
    1. What confirmation protocol characteristics define the best diagnostic accuracy?
  4. What are the harms of screening for high blood pressure in adults?

Contextual questions are not systematically reviewed and are not shown in the Analytic Framework.

  1. What is the clinically appropriate rescreening interval for patients who have previously been screened and found to have normal blood pressure?
  2. What is the prevalence and prognosis of “masked hypertension”? Have practical methods for identifying masked hypertension been evaluated in primary care or community settings?
  3. What is the prevalence and prognosis of “white coat hypertension”? Have practical methods for identifying white coat hypertension been evaluated in primary care or community settings?

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 Review. Criteria are overarching as well as specific to each of the key questions (KQs).

  Included Excluded
Aim KQs 1, 2, 4: Screening for high blood pressure in a primary care setting

KQ 3: Measuring blood pressure to confirm diagnosis of hypertension

Studies measuring blood pressure for reasons other than screening or confirmation of a hypertension diagnosis; mathematical transformation of blood pressure results (e.g., pulse pressure, variability) or diurnal variations (e.g., morning surge, dipping) for use as additional diagnostic criteria, predicting risk, or both
Population KQs 1, 2, 4: 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

  • Pregnant women, children (age <18 years), inpatients, persons in institutions, patients with secondary hypertension, and highly selected groups of patients (e.g., those with chronic kidney disease or renal transplant) who do not represent a primary screening population
  • Patients treated for hypertension with medication
Intervention KQs 1, 2, 4: Clinic-based, noninvasive brachial blood pressure measurement (manual or automated) using any common device or screening protocol during a single encounter

KQ 3: Any clinic-based or out-of-office noninvasive blood pressure measurement used to confirm an initial elevated blood pressure result (i.e., manual or automated office-based blood pressure, home blood pressure, or kiosk blood pressure measurement)

KQ 3a: ABPM screening protocol that differs from the comparator ABPM protocol (e.g., 12- vs. 24-hour ABPM, daytime vs. nighttime ABPM)

Blood pressure measurement with wrist and finger monitors, forearm cuffs, or ankle and toe measures; any method not commonly used in routine blood pressure screening (e.g., invasive methods, noninvasive method of central blood pressure measurement); Osler’s maneuver
Comparator KQs 1, 4: No blood pressure measurement

KQs 2, 3: ABPM (any protocol)

KQs 2, 3: Within-class comparative effectiveness of devices (e.g., automated vs. automated; random zero vs. standard sphygmomanometer) with identical screening protocols; validation and accuracy studies of devices compared with standards or using specific protocols (e.g., British Hypertension Society, Association for the Advancement of Medical Instrumentation)
Outcomes KQ 1:
  • Mortality (all-cause and cardiovascular)
  • Cardiovascular disease events, including: myocardial infarction, sudden cardiac death, stroke, heart failure, and hospitalization for coronary heart disease
  • End-stage renal disease (i.e., kidney disease requiring dialysis)
  • Quality of life

KQs 2, 3: Sensitivity, specificity, and positive and negative predictive values

KQ 4: Harms of screening (e.g., labeling, absenteeism, quality of life measures, tolerability of ABPM devices)

KQs 1, 3: Cardiovascular symptoms (e.g., palpitations), angina pectoris (chest pain), revascularization, carotid intima-media thickness, left ventricular hypertrophy, or patient satisfaction

KQs 2, 3: Studies that do not provide enough data to create 2×2 tables or to calculate sensitivity and specificity; studies designed to assess devices vs. blood pressure measurement standards

Timing of outcome assessment No restrictions No restrictions
Setting KQs 1, 2, 4: Eligible primary care settings must have personnel trained in blood pressure measurement, established blood pressure measurement protocols, and ongoing documentation procedures

KQ 3: Primary care settings (see above for definition) and out-of-office settings (e.g., home, pharmacy, kiosks in other settings)

All KQs: Inpatient/residential facilities

KQs 1, 2, 4: Settings not generalizable to primary care
Study design KQ 1: RCTs or CCTs

KQs 2, 3: Diagnostic accuracy studies, RCTs, and CCTs

KQ 4: RCTs, CCTs, and cohort studies

All KQs: Before-after studies, time series, case series, case reports, case-control studies, and simulation studies

KQ 3: Studies with a sample size <100

KQ 4: Cross-sectional studies
Country Studies conducted in countries categorized as “very high” on the 2015 Human Development Index (as defined by the United Nations Development Programme) Studies conducted in countries not categorized as “very high” on the 2015 Human Development Index
Language English Other languages than English
Study quality Fair or good Poor, according to design-specific USPSTF criteria

Abbreviations: ABPM = ambulatory blood pressure measurement; CCT = controlled clinical trial; RCT = randomized, controlled trial.

The draft Research Plan was posted for public comment on the USPSTF Web site from June 7 to July 5, 2018. The USPSTF received comments regarding the selection of outcomes, the importance of addressing the prevalence and prognosis of both masked and white coat hypertension, and the categories of blood pressure identified in the Analytic Framework. In response, the USPSTF added symptomatic peripheral artery disease and vascular dementia as health outcomes, and retained end-stage renal disease as the renal outcome. The USPSTF also added a contextual question about the prevalence and prognosis of white coat hypertension. One organization suggested that additional categories of blood pressure classification be added to the Analytic Framework. The USPSTF kept the dichotomous classifications of “normal” and “elevated blood pressure,” referring to the initial office-based screening step, without limiting included studies to specific thresholds. For the purposes of inclusivity, reported thresholds from eligible diagnostic accuracy studies for KQs 2 and 3 will be abstracted and reported in the evidence review.