Safe but Sound: Patient Safety Meets Evidence-Based Medicine

THE INSTITUTE OF MEDICINE’S SEMINAL REPORT TO ERR Is Human highlighted the risks of medical care in the United States and shocked the sensibilities of many Americans. As one element of a multipronged response, the Agency for Healthcare Research and Quality (AHRQ) commissioned the University of California, San Francisco– Stanford University Evidence-Based Practice Center to develop a compendium of evidence-based patient safety practices, a resource summarizing the literature supporting practices relevant to improving patient safety. Making Health Care Safer: A Critical Analysis of Patient Safety Practices contains the complete results of this collaborative effort. Production of the report involved a commissioned group of 40 researchers across the country, including experts in patient safety, evidence-based medicine, and various areas of clinical medicine, nursing, and pharmacy. The report, which contains concise summaries of the evidence supporting more than 80 safety practices and a detailed description of its methods, has generated a substantial amount of attention (more than 50000 copies have been ordered or downloaded) and some controversy. The latter, elegantly articulated in the accompanying article of this issue of THE JOURNAL by 3 of the dominant figures in the fields of patient safety and quality improvement, largely concerns the tension inherent in applying principles of evidencebased medicine to patient safety practices. The paradigm of evidence-based medicine arose from the realization that health care interventions, no matter how commonsense or physiologically sound, often lack benefit and sometimes even cause harm. Since safety practices also may prove ineffective, wasteful, or even harmful, there is no reason to exempt most safety practices from the scrutiny of an evidence-based approach. Moreover, in the face of limited resources, evidence of effectiveness provides a useful parameter for prioritizing safety practices, just as with other health care interventions. Defining Patient Safety In the evidence report, we defined a patient safety practice as a type of process or structure whose application reduces the probability of adverse events resulting from exposure to the health care system across a range of diseases and procedures. We intentionally avoided explicit reference to “error” in this definition, both because of its negative connotations and the difficulties in specifying what constitutes “medical error.” The patient safety practices that flow from our definition (TABLE) may strike some readers as insufficiently distinct from quality improvement strategies. The same concerns have been raised regarding alternative definitions used by others. Nonetheless, our definition served several useful functions. First, the focus on prevention of adverse events due to medical care led to identification of a much broader pool of safety practices than would have been the case had we focused more narrowly on the prevention of errors. Second, physicians’ judgments regarding the preventability of errors tend to be poorly reproducible. Third, our definition served a pragmatic function by allowing relatively unambiguous identification of practices that “reduce the probability of adverse events resulting from exposure to the health care system”—in other words, practices that make health care safer. Using this definition, we identified 83 distinct safety practices supported by 70 systematic reviews and 293 additional primary investigations meeting our inclusion criteria, a 10fold higher yield than that of a recent systematic review targeting interventions to reduce medical errors. Our definition allowed us to include the usual practices considered under the patient safety rubric, such as computerized physician order entry (CPOE) and strategies to prevent falls among hospitalized elderly patients, as well as practices that have not traditionally been grouped under patient safety (perhaps because they may not result from discrete “errors”) but that clearly seek to prevent complications that fall within the same family of adverse events (Table).