Over the past decade, the rising cost of health care in the United States has fueled major reforms in the systems by which health care is delivered. Physicians drive many health care costs through their decisions about the use of diagnostic tests and procedures, hospitalization and referral, and management. A number of studies also have shown that physicians—including neurologists—differ in their use of diagnostic tests to evaluate similar patients.<sup>4 Chassin M.R., Brook R., Park R. Variations in the use of medical and surgical services by the Medicare population N Engl J Med 1986 ;  314 : 285-290  [cross-ref]

Cliquez ici pour aller à la section Références, 14 Gifford D.R., Vickrey B.G., Mittman B.S. , et al. Neurologists vary in the diagnostic tests they order to evaluate dementia J Am Geriatric Soc 1995 ;  43 : SA34

Cliquez ici pour aller à la section Références, 27 Hopkins A., Menken M., DeFriese G.H. , et al. Differences in strategies for the diagnosis and treatment of neurologic disease among British and American neurologists Arch Neurol 1989 ;  46 : 1142-1148

Cliquez ici pour aller à la section Références, 46 Ringel S.P., Franklin G.M., DeLapp H.C. , et al. A cross-sectional comparative study of outpatient neurologic practices in Colorado Neurology 1988 ;  38 : 1308-1314

Cliquez ici pour aller à la section Références, 58 Wennberg J., Gestelsohn Small area variations in health care delivery Science 1973 ;  182 : 1102-1108

Cliquez ici pour aller à la section Références</sup> and in their use of treatments for similar clinical presentations,<sup>2 Anderson D.C. How twin cities' neurologists treat ischemic stroke Arch Neurol 1993 ;  50 : 1098-1103

Cliquez ici pour aller à la section Références</sup> particularly when clear standards based on scientific evidence for appropriate care are lacking. Because of this link between the effects of clinical decision making and the costs of health care, and because of concerns about provision of high-quality care, there has been support for research on the nature of clinical decision making and the factors influencing the process and outcomes of decision making by physicians.

This article discusses one key area of clinical decision making—diagnostic reasoning. The diagnostic reasoning process and its characteristics are presented, several of the more important factors influencing physicians' decision-making process are discussed, and some of the tools available to support clinical decisions and overcome some of the barriers to effective and accurate diagnostic reasoning and clinical decision making are highlighted, with attention to the applicability of these studies to neurologists.