Against Diagnosis

The act of diagnosis requires that patients be placed in a binary category of either having or not having a certain disease. Accord-ingly, the diseases of particular concern for industrialized coun-tries—such as type 2 diabetes, obesity, or depression—require that a somewhat arbitrary cut-point be chosen on a continuous scale of measurement (for example, a fasting glucose level 6.9 mmol/L [125 mg/dL] for type 2 diabetes). These cut-points do not ade-quately reflect disease biology, may inappropriately treat patients on either side of the cut-point as 2 homogenous risk groups, fail to incorporate other risk factors, and are invariable to patient prefer-ence. This article discusses risk prediction as an alternative to diag-nosis: Patient risk factors (blood pressure, age) are combined into a single statistical model (risk for a cardiovascular event within 10 years) and the results are used in shared decision making about possible treatments. The authors compare and contrast the diag-nostic and risk prediction approaches and attempt to identify the types of medical problem to which each is best suited. Ann Intern Med. 2008;149:200-203. www.annals.or