A mathematical approach to medical diagnosis. Application to congenital heart disease.

An equation of conditional probability is derived to express the logical process used by a clinician in making a diagnosis from clinical data. Solutions of this equation take the form of a differential diagnosis. The probability that each disease represents the correct diagnosis in any particular patient may be calculated. Sufficient statistical data regarding the incidence of clinical signs, symptoms, and electrocardiographic findings in patients with congenital heart disease have been assembled to allow application of this approach to differential diagnosis in this field. This approach provides a means by which electronic computing equipment may be used to advantage in clinical medicine.