The safety and quality of care are two of the central dimensions of health care. It is increasingly clear that both could be much better, and in recent years it has become easier to measure safety and quality. In addition, the public is—with good justification—demanding measurement and accountability, and payment for services increasingly will be based on performance in these areas. Thus, physicians must learn about these two domains, how they can be improved, and the relative strengths and limitations of the current ability to measure them.
Safety and quality are closely related but do not completely overlap. The Institute of Medicine has suggested in a seminal series of reports that safety is the first part of quality and that health care first must guarantee that it will deliver safe care, although quality is also pivotal. In the end, it is likely that more net clinical benefit will be derived from improving quality than from improving safety, though both are important and safety is in many ways more tangible to the public. Accordingly, the first section of this chapter will address issues relating to the safety of care and the second will cover quality of care.
Safety theory clearly points out that individuals make errors all the time. Think of driving home from the hospital; you intend to stop and pick up a quart of milk on the way home but find yourself entering your driveway without realizing how you got there. Everybody uses low-level, semiautomatic behavior for many activities in daily life; this kind of error is called a "slip." Slips occur often during care delivery, e.g., when people intend to write an order but forget because they have to complete another action first. "Mistakes," by contrast, are errors of a higher level; they occur in new or nonstereotypic situations in which conscious decisions are being made. An example would be dosing a medication with which a physician is not familiar. The strategies used to prevent slips and mistakes are often different.
Systems theory suggests that most accidents occur as the result of a series of small failures that happen to line up in an individual instance so that an accident can occur (Fig. 10-1). It also suggests that most individuals in an industry such as health care are trying to do the right thing (e.g., deliver safe care), and most accidents thus can be seen as resulting from defects in the systems. Correspondingly, systems should be designed both to make errors less likely and to identify those which do occur, as some inevitably will.
"Swiss cheese" diagram. Reason has argued that most accidents occur when a series of "latent failures" in a system are present and happen to line up in a given instance, resulting in an accident. Examples of latent failures in the case of a fall might be that the unit was unusually busy that day and that the floor happened to be wet. (Adapted from J Reason: Human error: Models and management. BMJ 320:768–770, 2000; with permission.)
Factors that Increase the Likelihood of Errors
Many factors ubiquitous in health care systems can increase the likelihood of errors, including fatigue, stress, interruptions, complexity, and transitions. The effects of fatigue in other industries are clear, but its effects in health care have been more controversial until recently. For example, the accident rate in truck drivers increases dramatically if they work over a certain number of hours in a week, especially with prolonged shifts. A recent study of house officers in the intensive care unit demonstrated that they were about one-third more likely to make errors when they were on a 24-h shift than when they were on a schedule that allowed them to sleep 8 h the previous night. The American College of Graduate Medical Education (ACGME) has moved to address this issue by putting in place the 80-h workweek. Although this is a step forward, it does not address the most important cause of fatigue-related errors: extended-duty shifts. High levels of stress and workload also can increase error rates. Thus, in extremely high-pressure situations, such as cardiac arrests, errors are more likely to occur. Strategies such as using protocols in these settings can be helpful, as can simply recognizing that the situation is stressful.
Interruptions also increase the likelihood of error and occur frequently in health care delivery. It is common to forget to complete an action when one is interrupted partway through it by a page, for example. Approaches that may be helpful in this area include minimizing the use of interruptions and setting up tools that help define the urgency of an interruption.
In addition, complexity represents a key issue that contributes to errors. Providers are confronted by streams of data, such as laboratory tests and vital signs, many of which provide little useful information but some of which are important and require action or suggest a specific diagnosis. Tools that emphasize specific abnormalities or combinations of abnormalities may be helpful in this area.
Transitions between providers and settings are also common in health care, especially with the advent of the 80-h workweek, and generally represent vulnerabilities. Tools that provide structure in exchanging information, e.g., when transferring care between providers, may be helpful.
The Frequency of Adverse Events in Health Care
Most large studies focusing on the frequency and consequences of adverse events have been performed in the inpatient setting; some data are available for nursing homes, and much less information is available about the outpatient setting. The Harvard Medical Practice Study, one of the largest studies to address this issue, was performed with hospitalized ...