To the Editor.
—The recent provocative articles dealing with the association between diagnostic testing and therapeutic interventions1-3 highlight an issue of urgent importance that was discussed in each of these communications: although it is clear that diagnostic testing determines further procedures, it is unclear whether "more" or "less" diagnostic testing has a favorable risk-to-benefit ratio. It is obvious in the case of coronary angiography, for instance, that the procedure itself carries a definable risk, as does coronary artery bypass graft surgery. The long-term efficacy of bypass surgery, angioplasty, or both, for prolonging life is clear under only certain, very limited circumstances. It may be satisfactory to await an individual's first myocardial infarction (MI) before performing cardiac catheterization (unless, of course, the first infarct results in sudden death). A meaningful answer to this and related questions can ultimately be obtained only through a randomized clinical trial.We have found a
Crouse JR, Howard G, Toole JF, Pearson TA. Intensity of Testing and Invasive Procedures. JAMA. 1996;276(7):528. doi:10.1001/jama.1996.03540070024022