Defensive medicine is aptly named. The term implies both actions to prevent litigation and an untrusting attitude toward patients. Defensive medicine is based on three assumptions: that making more accurate diagnoses will reduce malpractice claims; that tests and procedures improve the probability of a correct diagnosis; and that the use of more technology implies better medical care. [Harris JE. Defensive medicine: it costs, but does it work? JAMA. 1987;257:2801–2802.] These assumptions come from a physician-oriented view of medical care. The problem is that patients, not physicians, bring malpractice lawsuits. Patients are primarily concerned with the outcome and the humanistic aspects of their treatment. It is physicians who care about diagnoses. Patients want to be treated well and successfully. Defensive medicine generates anger and expense, both of which increase the probability that an injured patient will seek legal counsel.

Defensive medicine directly increases the probability of injury when it involves dangerous tests or procedures. For example, intravenous pyelograms (IVPs) pose a significant risk of complications. If an IVP is ordered as a necessary diagnostic test, the risk of the procedure is balanced by the benefit of the diagnostic information that it produces. If an IVP is ordered as a defensive measure, there is no benefit to the patient to offset the risk. Since a defensive test or procedure is, by definition, one that does not have a favorable risk or cost benefit ratio for the patient, the patient may be expected to sue successfully for any major complications of a defensive test or procedure.