The point has been well made that while most of the patient safety literature focuses on hospital errors, most healthcare is delivered in office settings. Consider this: for every one hospitalized patient, 28 people visit a physician’s office.1 Nevertheless, the early emphasis on patient safety in the hospital was natural: the stakes are higher, errors are more visible, and the resources to research safety problems and implement solutions are all greater there.

The scope of potential errors is also broader in the hospital. Although both settings are beset by medication and laboratory errors, and both inpatient and outpatient errors center on transitions of care and communication problems, the ambulatory setting will see fewer surgical errors (although the rapid increase in outpatient surgery makes these a growing problem) and healthcare-associated infections, pressure ulcers, and blood clots are lesser concerns. Moreover, the research focus on hospital safety also reflects the disproportionate emphasis by academic health centers on hospital care.

But interest in ambulatory safety is growing rapidly, accompanied by a number of new research and practice initiatives. Recent studies have shown that nearly 10% of adverse events occur in physician offices;2 adverse drug events and diagnostic errors are particularly common.3,4 Growing experience from outpatient-based patient safety networks indicates that ambulatory practices should focus on two main risky areas: prescription medications and the processing of lab, x-ray, and diagnostic tests.5,6 Both areas will likely be transformed by the implementation of ambulatory electronic health records and computerized prescribing, presently being driven in the United States by incentive payments to office practitioners who implement information technology (IT) systems that meet certain standards of functionality and interoperability.7,8

Sarkar et al. have proposed a model for ambulatory safety9 modified from the Chronic Care Model described by Wagner et al.10 It encompasses the three interrelated roles and relationships that influence outpatient safety:

• The role of the community and health system
  
• The relationship between patients and providers
  
• The role of patient and caregiver behaviors

The model emphasizes that ambulatory safety involves more than simply improving the flow of laboratory tests and consultations (as important as it is to fix the many problems in these systems). Errors and adverse events may relate to problems in each of these areas, and the patient’s role is particularly important. Far more than in the hospital, in the ambulatory setting some patients may become unwitting participants in the genesis of errors, while others may assume some degree of responsibility for catching mistakes (Chapter 21).

This chapter highlights some of the emerging literature on ambulatory safety and reflects on some of the differences between the hospital and the clinic that may impact efforts to improve safety in the latter setting.11

In the ambulatory world, the pace is slower and the rhythm more predictable (generally driven by a patient visit schedule) than in the hospital. The average error in the office is less consequential, because patients are less fragile and their medications and procedures are less potent (although the cumulative impact of errors may be surprisingly large because the volume is so high). In the hospital, much of the “action” centers on the patient’s room—when the patient travels, the distances are relatively short (to the operating room, to the radiology department) and the patient remains within the same system. In the ambulatory environment, on the other hand, the patient may travel many miles to obtain a test or see a specialist, often traversing practices that use different information systems and have vastly different clinical and operational cultures and policies (Chapter 8).

The structural and organizational differences may be even more important than the clinical ones. In all but the tiniest hospital, the scale is such that it is possible to have individuals on staff who specialize in safety-related tasks (Chapter 22). For example, even a modest-sized hospital is likely to have a quality officer, a compliance officer, a risk manager, and several IT experts. A larger hospital will have armies of people in these departments, and may even employ a human factors specialist and a patient safety officer. In the average small office practice, a physician (or nurse or practice administrator) will wear all of these hats. Moreover, because none of these specialized staff members generate patient care revenue, the ability of a small practice to support them is far more limited than in the hospital (of course, they don’t produce revenue in the hospital either, but they can be cross-subsidized by lucrative activities that do).

There are other important policy and cultural differences that influence ambulatory safety. Office practice is less highly regulated, and, because most of the care takes place behind closed doors (with just doctor and patient in the room), it is easier for errors to avoid the light of day. Even the cultural issues (Chapters 9 and 15) have a very different flavor. For example, consider programs that aim to improve physician–nurse relationships and dampen the steep authority gradients that are often present in healthcare settings. In American hospitals (where the physician is usually self-employed while the nurse works for the hospital), the shape of such programs is likely to be very different from the office, where the doctor is frequently the nurse’s employer.

Many of these differences would appear to favor the hospital as an environment to establish a flourishing patient safety enterprise. However, the ambulatory setting also has unique advantages. First, simplification, standardization, and the implementation of IT may yield more palpable efficiency advantages. When a single clerk or nurse is working with three physicians in an office practice, the impact of implementing a standard procedure for following up lab results is often profound. And the office space freed up by converting to a paperless medical record system can yield major economic advantages for a practice. Second, efforts to engage patients in helping to ensure their own safety are more likely to be productive (Chapter 21), because ambulatory patients are less apt to be mentally slowed by their disease or medications or distracted by anxiety. In addition, ambulatory patients are better able to intervene (because there are fewer tests and procedures and the pace is slower) when they see something amiss.

The previously mentioned organizational structure of most American outpatient practices can become another advantage. In many hospitals, the doctors are not particularly invested in the safety enterprise (because they use the hospital to provide care but don’t own the organization), whereas most office practices in the United States are owned by the physicians themselves. The old saying “nobody ever washes a rented car” helps explain the challenge faced by those who try to engage office-based or other nonemployed physicians in hospital safety efforts (Chapter 22).

The implications of these ambulatory versus hospital differences will be important as we turn our attention to outpatient safety. Most clinics will be able to identify a relatively small number of common but risky practices on which to focus their safety efforts, such as medication prescribing, follow-up of laboratory and x-ray test results, and communication with referring physicians and hospital providers. Gordon Schiff, in a far-reaching discussion of a delayed diagnosis of a renal mass, highlights a number of Swiss cheese–related (Chapter 2) problems, along with the many opportunities for improvement in ambulatory test follow-up (Table 12-1).12