Fundamentally, patient safety refers to freedom from accidental or preventable injuries produced by medical care. Thus, practices or interventions that improve patient safety are those that reduce the occurrence of preventable adverse events.

See Primer. The vast majority of health care takes place in the outpatient, or ambulatory, setting, and a growing body of research has identified and characterized factors that influence safety in office practice, the types of errors commonly encountered in ambulatory care, and potential strategies for improving ambulatory safety.

Originally created by the Agency for Healthcare Quality and Research (AHRQ), the Patient Safety Indicators (PSIs) reflect the quality of inpatient care as well as the rate of preventable complications and iatrogenic events.

Patient Safety Officers are individuals assigned to lead patient safety efforts in health care organizations, and who are responsible for the management of the patient safety program. They are accountable for assessing the organization’s patient safety measures, ensuring staff are trained, promoting actions to identify and respond to patient safety events, and ensuring that senior leadership is knowledgeable about the status of the patient safety events and overall status of the program.

Patient Safety Organizations (PSOs) were established through the Patient Safety and Quality Improvement Act that authorized the Department of Health and Human Services (HHS) to establish a voluntary system of reporting and analyzing data to evaluate and improve patient safety. PSOs work with healthcare providers (e.g., hospitals, nursing homes, dialysis centers) to assist them with their patient safety programs by analyzing the data submitted and providing feedback on ways to improve patient safety. AHRQ is the agency responsible for the oversight of the PSO program.

Pay for performance, sometimes abbreviated as P4P, refers to the general strategy of promoting quality improvement by rewarding providers (meaning individual clinicians or, more commonly, clinics or hospitals) who meet certain performance expectations with respect to health care quality or efficiency.

Performance can be defined in terms of patient outcomes but is more commonly defined in terms of processes of care (e.g., the percentage of eligible diabetics who have been referred for annual retinal examinations, the percentage of children who have received immunizations appropriate for their age, patients admitted to the hospital with pneumonia who receive antibiotics within 6 hours). Pay-for-performance initiatives reflect the efforts of purchasers of health care—from the federal government to private insurers—to use their purchasing power to encourage providers to develop whatever specific quality improvement initiatives are required to achieve the specified targets. Thus, rather than committing to a specific quality improvement strategy, such as a new information system or a disease management program, which may have variable success in different institutions, pay for performance creates a climate in which provider groups will be strongly incentivized to find whatever solutions will work for them.

See Primer. Long and unpredictable work hours have been a staple of medical training for centuries. However, little attention was paid to the patient safety effects of fatigue among residents until March 1984, when Libby Zion died due to a medication-prescribing error while under the care of residents in the midst of a 36-hour shift. In 2003, the Accreditation Council for Graduate Medical Education (ACGME) implemented new rules limiting work hours for all residents, with the key components being that residents should work no more than 80 hours per week or 24 consecutive hours on duty, should not be "on-call" more than every third night, and should have 1 day off per week.

Commonly referred to as PDSA, refers to the cycle of activities advocated for achieving process or system improvement. The cycle was first proposed by Walter Shewhart, one of the pioneers of statistical process control (see run charts) and popularized by his student, quality expert W. Edwards Deming. The PDSA cycle represents one of the cornerstones of continuous quality improvement (CQI). The components of the cycle are briefly described below:

PDSA can seem like a simple way to tackle quality problems. In practice, though, many omit key steps or do not perform sufficient cycles. PDSA aims to foster rapid change, with frequent tests of improvement, so relying on, for example, quarterly data to assess the effects of the efforts to date is usually not adequate. Another way in which practice deviates from theory for PDSA is the way in which the cycles play out. PDSA cycles are typically depicted as a smooth progression, with each cycle seamlessly and iteratively building on the previous. As the number of cycles increases, their effectiveness and overall cumulative effect strengthens. In practice, this type of work involves frequent false starts, backtracking, regroupings, backsliding, and overlapping scenarios within the process. Well-executed PDSA cycles in practice involve a more complex tangle of related improvement efforts talking different aspects of the target problem.

A potential adverse drug event is a medication error or other drug-related mishap that reached the patient but happened not to produce harm (eg, a penicillin-allergic patient receives penicillin but happens not to have an adverse reaction). In some studies, potential ADEs refer to errors or other problems that, if not intercepted, would be expected to cause harm. Thus, in some studies, if a physician ordered penicillin for a patient with a documented serious penicillin allergy, the order would be characterized as a potential ADE, on the grounds that administration of the drug would carry a substantial risk of harm to the patient.

Preventability in the context of patient safety is the extent to which a patient safety adverse event or harm is preventable. Preventable adverse events occur because of an error or failure to apply strategies for error prevention. One in 10 patients are harmed while receiving inpatient care in hospitals and four in 10 patients are harmed in primary and outpatient care. This harm is caused by a range of adverse events, and 50%-80% of these events are preventable. In terms of prevalence, preventable patient safety events are most frequently related to diagnosis, prescription, or medication delivery processes.

The pressure to put quantity of output—for a product or a service—ahead of safety. This pressure is seen in its starkest form in the line speed of factory assembly lines, famously demonstrated by Charlie Chaplin in Modern Times, as he is carried away on a conveyor belt and into the giant gears of the factory by the rapidly moving assembly line.

In health care, production pressure refers to delivery of services—the pressure to run hospitals at 100% capacity, with each bed filled with the sickest possible patients who are discharged at the first sign that they are stable, or the pressure to leave no operating room unused and to keep moving through the schedule for each room as fast as possible. In a survey of anesthesiologists, half of respondents stated that they had witnessed at least one case in which production pressure resulted in what they regarded as unsafe care. Examples included elective surgery in patients without adequate preoperative evaluation and proceeding with surgery despite significant contraindications.

Production pressure produces an organizational culture in which frontline personnel (and often managers) are reluctant to suggest any course of action that compromises productivity, even temporarily. For instance, in the survey of anesthesiologists, respondents reported pressure by surgeons to avoid delaying cases through additional patient evaluation or canceling cases, even when patients had clear contraindications to surgery.

Psychological safety is the belief that speaking up will not result in negative consequences for oneself, such as punishment or humiliation. Psychological safety within health care teams fosters patient safety by allowing team members to feel accepted, respected, and able to share their ideas, questions, concerns and mistakes.