Deciding without data.

Introduction: Physician decisions drive most of the increases in health care expenditures, yet virtually no published literature has sought to understand the types of evidence used by physicians as they make decisions in real time.

Methods: Ten pediatric cardiologists recorded every clinically significant decision made during procedures, test interpretation, or delivery of inpatient and outpatient care during 5 full days and 5 half days of care delivery. The basis for each decision was assigned to one of 10 predetermined categories, ranging from arbitrary and anecdotal, to various qualities of published studies, to parental preference and avoiding a lawsuit.

Results: During the 7.5 days, 1188 decisions (158/day) were made. Almost 80% of decisions were deemed by the physicians to have no basis in any prior published data and fewer than 3% of decisions were based on a study specific to the question at hand.

Conclusions: In this pilot study, physicians were unable to cite a formal evidence source for most of their real-time clinical decision making, including those that consumed medical resources. Novel approaches to building an evidence base produced from real-time clinical decisions may be essential for health care reform based on data.