Reproduced with permission from Whelton et al.S4.4-1 Copyright 2017, American College of Cardiology Foundation and the American Heart Association, Inc. CLINICAL STATEMENTS AND GUIDELINES Assessing the value of prevention in appar- ently healthy patients is generally more difficult than evaluating therapy for established disease because the time horizon to the clinical mani- festation of disease is generally long many decades in the young. Thus, it is difficult, per- haps impossible, to assess long-term effective- ness in terms of survival or quality-adjusted life-years (QALYs) or associated costs because of increasing uncertainty about outcome the fur- ther one tries to look into the future. Furthermore, the principle of discounting, which places relative emphasis on current costs and benefits while deemphasizing downstream costs and benefits, creates disadvantages for prevention because costs of- ten accrue in the present while the benefit may only be fully realized long into the future. These methodologi- cal challenges notwithstanding, prior AHA statements have highlighted the public policies, community efforts, and pharmacological interventions that are likely to be cost-effective and, at times, cost-saving prevention tac- tics compared with common benchmarks. For example, robust evidence suggests that both antihypertensive and statin therapy,S5-7 S5-9 particularly with low-cost generic drug formulations, are high-value inter- ventions across a wide spectrum of risk and age strata. The incorporation of the value category into clinical practice guidelines is one of several considerations in medical decision-making and resource allocation. Clini- cians, researchers, and policymakers alike must contin- ue to place cost-effective analyses in the proper context, extracting key value determinations while acknowledg- ing the challenges in fully characterizing and incorpo- rating the downstream benefits of a given therapeutic prevention tactic. 