Author Affiliations: Department of Medicine, Rush University Medical Center, Chicago, Illinois (Dr McNutt); and Division of Gastrointestinal and Endocrine Surgery, University of Texas Southwestern Medical Center, Dallas (Dr Livingston). Drs McNutt and Livingston are Contributing Editors, JAMA.
What if a patient—after diagnostic tests have been performed and there is no more certainty to obtain—still has a 1 in 100 chance of having venous thromboembolism (VTE)? Should the patient's physician engage the patient in a discussion of the harm and benefit of anticoagulation? What if the chance of VTE was 1 in 20? Or even 1 in 10?
Most clinicians may have difficulty answering these questions because of the need for judgment about treatment when certainty is impossible. This judgment has to balance the absolute benefit against the absolute harm for treating a disease when there is uncertainty that the disease exists. This concept reflects a treatment threshold1 representing the probability of a disease, such as VTE, above which treatment would provide more benefit than harm, and below which treatment would produce more harm than benefit. If this probability is not known, and if variations in the individual patient's probabilities after testing is completed are not considered within the clinical practice context, physicians will have difficulty applying evidence-based medicine to patient care.
McNutt RA, Livingston EH. Evidence-Based Medicine Requires Appropriate Clinical Context. JAMA. 2010;303(5):454-455. doi:10.1001/jama.2010.47