Sutton's Law: A Lesson in Decision-Analysis from the Past…and Present

In 1960, Dr. William Dock, visiting professor at Yale, discussed the case of a young girl with an unknown liver disease. Dock recommended biopsy, invoking bank robber Willie Sutton's words "that's where the money is." Drs. Petersdorf and Beeson, in attendance that day, included the following in their 1961 publication on fever of unexplained origin, "We are indebted to Dr. William Dock for the term Sutton's Law. It recommends proceeding immediately to the diagnostic test most likely to provide a diagnosis, and deplores the tendency to carry out a battery of 'routine' examinations in conventional sequence." Thereafter, Sutton's Law became an acclaimed aphorism advocating pursuit of tissue, because of its specificity for achieving diagnostic certainty. However, its popularity was fleeting, as formal medical decision-analysis (FMDA) became the standard. In the 1940s and 1950s, pioneers in the field laid the groundwork, and by the 1980s, clinician researchers had introduced the science into everyday clinical practice. The original version of Sutton's Law neglected the reality that FMDA is more than specificity, tissue, and absolute certainty. The newer version encourages clinicians to employ and prioritize their "routine" interview questions, physical examination assessments, and laboratory tests that provide clarity to differentiate between disease and no disease, to influence favorably the patient's management, and to discard those evaluations more likely to provide misleading results. Dock, Petersdorf, and Beeson may not have spoken the language of FMDA, but they were adept at applying its principles. Without them, and the unknown medical student who made the diagnosis of schistosomiasis, there would be no Sutton's Law. For many, it is an obsolete and apocryphal aphorism valuable solely for touting the importance of specificity in tissue diagnosis. For others, it has evolved, remaining relevant as an authentic lesson in decision-analysis, past and present.