Counseling About Physical Activity

Abstract

To the Editor.— In the article entitled Physical Activity Counseling for Healthy Adults as a Primary Preventive Intervention in the Clinical Setting, 1 the authors state that screening asymptomatic persons for occult disease is not economically feasible and subjects them to psychological distress and to a significant risk of morbidity and mortality during further diagnostic workup. Also, it is stated that exercise ECGs [electrocardiograms] produce many false-positive results, estimated at 80% in asymptomatic persons. The authors cite a false-positive rate of 80%, referencing an article by Shepard. 2 This is an error. The actual false-positive rate in Shepard's article was 70%, assuming a 5% prevalence of coronary disease in the population being tested. Also, in the United States, it is more likely that the prevalence of asymptomatic disease is closer to 10% or higher, which would significantly lower the estimated rates of false-positive tests. 3(p369) From a public health standpoint,