Final Research Plan
Cardiovascular Disease Risk: Screening With Electrocardiography
July 14, 2016
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 will be 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 from May 5 until June 1, 2016 at 8:00 p.m., ET.
* Includes adults regardless of their CVD risk (those with low, intermediate, or high risk are eligible) as assessed by traditional risk factors (those included in Framingham risk models): male sex, older age, cigarette smoking, hypertension, dyslipidemia (high total cholesterol, high low-density lipoprotein cholesterol, or low high-density lipoprotein cholesterol), and diabetes.
† This systematic review does not include KQs about the benefits and harms of preventive medications to reduce cardiovascular risk (i.e., aspirin and lipid-lowering therapy) or the benefits and harms of lifestyle counseling because these have been addressed in other systematic reviews for the USPSTF.
Abbreviations: CVD = cardiovascular disease; ECG = electrocardiography; KQ = key question.
This figure is the analytic framework depicting the three key questions that will guide the evidence review outlined in this research plan. In general, the figure illustrates the overarching question (KQ 1) of whether screening with resting or exercise ECG in asymptomatic adults leads to improved health outcomes compared to traditional CVD risk factor assessment alone. Health outcomes include all-cause mortality, cardiovascular mortality, and cardiovascular events. The framework starts on the left with the patient population of interest: adults without symptoms and a diagnosis of CVD. Moving from left to right, the figure depicts the ability of adding screening with resting or exercise ECG to traditional CVD risk factor assessment alone to accurately reclassify persons into different risk groups (KQ2). There are potential harms of screening with resting or exercise ECG (KQ3). Following reclassification, persons at increased risk of CVD may receive preventive medications or lifestyle counseling, which may lead to improved health outcomes.
- Does the addition of screening with resting or exercise electrocardiography (ECG) improve health outcomes compared to traditional cardiovascular disease (CVD) risk factor assessment alone in asymptomatic adults?
- Does improvement in health outcomes vary for subgroups defined by baseline CVD risk (e.g., low, intermediate, or high risk), age, sex, or race/ethnicity?
- Does the addition of screening with resting or exercise ECG to traditional CVD risk factor assessment accurately reclassify persons into different risk groups (e.g., high-, intermediate-, and low-risk groups) or improve measures of calibration and discrimination?
- What are the harms of screening with resting or exercise ECG, including harms of subsequent procedures or interventions initiated as a result of screening?
- Do the harms of screening vary for subgroups defined by baseline CVD risk (e.g., low, intermediate, or high risk), age, sex, or race/ethnicity?
Contextual questions will not be systematically reviewed and are not shown in the Analytic Frameworks.
1a. What medications (i.e., aspirin, lipid-lowering therapy) are recommended for persons in each CVD risk category (or strata)?
b. What is the fidelity to prescribing and taking the recommended medications?
2. What are the harms and benefits of revascularization procedures in adults without symptoms or a prior diagnosis of CVD?
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).
| Include | Exclude | |
|---|---|---|
| Populations | Adults age ≥18 years without symptoms or a diagnosis of CVD; studies of mixed populations of asymptomatic and symptomatic persons are eligible if results are reported separately for asymptomatic persons or <10% of the sample is symptomatic | Persons with a history of atherosclerotic disease or symptoms suggesting coronary heart disease; children and adolescents |
| Screening tests | Resting ECG, exercise ECG | Radiology tests (e.g., thallium scan, scintigraphy, computed tomography), echocardiography, and vectorcardiography* |
| Comparisons | All KQs: Screened vs. nonscreened groups (i.e., risk stratification using ECG plus traditional risk factors vs. risk stratification using traditional risk factors alone)
KQ 2: CVD risk assessment models that include ECG findings compared to those that do not KQ 3: For harms of subsequent procedures/interventions, studies that compare the procedure/intervention to no procedure/intervention are also eligible. For studies reporting rates of harms from exercise ECG or subsequent procedures/interventions, large registries or multicenter studies without a control group that report rates of harms for asymptomatic persons are also eligible |
No comparison, nonconcordant historical control, comparative studies with other novel risk factors (e.g., comparing ECG vs. C-reactive protein); studies that compare the risk for subsequent events between persons with and without ECG abnormalities and report associations (e.g., prospective cohort studies that report hazard ratios for outcomes associated with baseline T-wave abnormalities) |
| Outcomes | KQ 1: All-cause mortality, cardiovascular mortality, and cardiovascular events (myocardial infarction, angina, stroke, congestive heart failure, composite cardiovascular outcomes)
KQ 2: Reclassification, calibration (the degree to which predicted and observed risk estimates agree, goodness-of-fit statistics), and discrimination (c-statistic/area under the curve) KQ 3: Mortality, arrhythmia, cardiovascular events, or injuries from exercise ECG; anxiety; labeling; harms of subsequent procedures or interventions initiated as a result of screening (e.g., subsequent angiography or revascularization procedures resulting in harm) |
KQ 2: Studies assessing the association between ECG findings and outcomes (e.g., with adjusted hazard ratios) |
| Study designs | All KQs: Randomized, controlled trials or controlled clinical trials
KQs 2, 3: Prospective cohort studies are also eligible KQ 3: Well-designed large retrospective cohort studies and well-designed case-control studies (only for rare events) are also eligible |
All other designs, narrative reviews, systematic reviews,† case reports, case series, editorials, letters, cross-sectional studies |
| Setting | Studies performed in primary care or occupational medicine settings, studies that recruit participants from the general population | Studies performed in specialty settings, studies of patients undergoing preoperative evaluation |
| Country | Studies conducted in countries categorized as “Very High” on the 2014 Human Development Index (as defined by the United Nations Development Program) | |
| Language | English | Non-English |
| Study quality | Good or fair | Poor (according to design-specific USPSTF criteria) |
* Vectorcardiography is a method of recording the magnitude and direction of the electrical forces that are generated by the heart by means of a continuous series of vectors that form curving lines around a central point.
† We will not abstract data from systematic reviews and will not include them in the results, but we will conduct separate searches for systematic reviews and search the references lists of all potentially relevant systematic reviews to identify relevant primary studies that our electronic searches did not identify.
The draft Research Plan was posted for public comment on the USPSTF Web site from May 5, 2016 to June 1, 2016. Several comments suggested evaluating some of the KQs for subpopulations defined by differences in risk category, age, sex, or race/ethnicity. In response, the USPSTF added new sub-KQs to explore whether findings vary for these subgroups. In response to comments, the USPSTF replaced the term “cerebral vascular accident” with “stroke,” “cardioembolic stroke,” or “hemorrhagic stroke,” as appropriate.