The USPSTF defines certainty as “likelihood that the USPSTF assessment of the net benefit of a preventive service is correct.” The net benefit is defined as benefit minus harm of the preventive service as implemented in a general, primary care population. The USPSTF assigns a certainty level on the basis of the nature of the overall evidence available to assess the net benefit of a preventive service.
sidered low-risk, and those in the 10% to 20% range are considered intermediate-risk.
Screening Tests
Many resting and exercise ECG abnormalities have been associated with an increased risk for CHD events, such as MI and CHD death. Although exercise ECG is considered more sensitive for detecting coronary artery ste- nosis, the magnitude of increased risk for CHD events, as well as the sensitivity of ECG abnormalities for predicting future events, is similar for resting and exercise ECG (1, 2). Performing baseline ECG so that results may be compared with future ECG findings is considered screening by the USPSTF and is not recommended for asymptomatic adults at low risk for CHD; evidence is insufficient about its usefulness in adults at increased risk.
For asymptomatic adults at low risk for CHD events, a resting or exercise ECG is unlikely to provide additional information about CHD risk beyond that obtained with conventional CHD risk factors (that is, Framingham risk factors) and result in changes in risk stratification that would prompt interventions and ultimately reduce CHD- related events. False-positive results may cause harms in low-risk asymptomatic adults; for more information about