The application of myocardial perfusion scintigraphy to patient care in the era of health care cost containment is a difficult issue. The traditional diagnosis based approach to testing, although effective, is incompletely applied, as evidenced by the number of low likelihood of coronary artery disease patients referred for testing. A prognosis- or risk-based testing approach may be applied to both patients with or without known coronary artery disease by utilizing clinical and scan information to estimate the projected risk of adverse outcomes (cardiac death or myocardial infarction) and planning subsequent patient strategy based upon this estimate. Patients at high risk for these events are more likely to benefit from referral to catheterization while those patients at lower risk may benefit from medical therapy alone. Irrespective of the approach utilized to evaluate testing, consideration of patient population selection and its implications must be considered when reviewing the results of testing or published literature. Further, scrutiny of both the statistical methods used for evaluation of the value of testing and the economic implications of testing in particular patient subgroups are of importance.