Uncertainty Pervades All Health Care

Abstract Uncertainty in health care dates from antiquity and has been most clearly articulated for two centuries. Clinicians cope with uncertainty in establishing diagnoses, predicting outcomes, and recommending therapies. In all cases, uncertainty is reduced but not necessarily eliminated by education and experience. Technologies are important in aiding all these clinical activities, but technologies themselves have imperfect sensitivity, specificity, and prognostic value. These characteristics can be improved by experience, especially clinical trials. However, health care professionals must always employ new technologies recognizing their limitations; in other words, in most instances, precision may not be perfect. The limitations must be understood by patients and providers alike. The limitations of technologies may not be appreciated for direct-to-consumer testing.