Human Error and Cognitive Functioning by Design

Cognitive psychologists have identified the physical environment as having a significant impact on safety and human performance.^{1, 2} Understanding “the interrelationships between humans, the tools they use, and the environment in which they live and work”³ is basic to any study of the design a health care facility and its effect on the performance of the nurses and other caregivers who interface with the facility and its fixed (e.g., oxygen and suctioning ports on the wall of a patient room) and moveable (e.g., a patient bed) equipment and technology. Humans do not always behave clumsily and humans do not always err, but they are more likely to do so when they work in a badly conceived and designed⁴ health care setting.

Organizational/system factors that can potentially create the conditions conducive for errors are called latent conditions. According to Reason,¹ latent conditions are the inevitable “resident pathogens” that “may lie dormant within the system for a long time, only becoming evident when they combine with other factors to breach the system’s defenses. Latent conditions can be identified and remedied before an adverse event occurs.” Examples of latent conditions are: poorly designed facilities, including the location of technology and equipment; confusing procedures; training gaps; staff shortages or improper staffing patterns; and poor safety culture. A specific example of a latent condition effecting patient safety would be the impact of low lighting levels in the medication dispensing areas that are associated with some medication errors but not others.⁵ These and other conditions occur at what Reason describes as the “blunt end,” where administrators, the work environment, and resources determine the processes of care delivery. Latent conditions are present in all organizations and can be unintentionally created by those who are responsible for designing systems, ensuring adequate staffing, creating and enforcing policies, and so on.

The design of a facility/structure with its fixed and moveable components can have a significant impact on human performance, especially on the health and safety of employees, patients, and families.⁶ In a review of more than 600 articles, researchers found that there was a link between the physical environment (i.e., single-bed or multiple-bed patient rooms) and patient (e.g., fewer adverse events and better health care quality) and staff outcomes (e.g., reduced stress and fatigue and increased effectiveness in delivering care).⁷ Efforts to improve patient and staff outcomes can target latent conditions for clinicians by using evidence-based designs to decrease distractions, standardize locations of equipment and supplies, and ensure adequate space for documentation and work areas. The research done by Reason¹ and Leape² describes the value of practices based on principles designed to compensate for human cognitive failings. Thus, when applied to the health care field, human factors research (i.e., an area of research that includes human performance, technology design, and human-computer interaction; this topic is covered in chapter 5, “A Human Factors Framework,” by Henriksen and colleagues), which has emphasized the need for standardization, simplification, and use of protocols and checklists, can be used to improve health care outcomes.

By targeting human factors through facility design and ensuring that latent conditions and cognitive failures that lead to adverse events are minimized, patient safety will improve. This requires a multifaceted approach, including developing a strong safety culture, redesigning systems or facilities with their equipment and technology, focusing on eliminating the conditions of cognitive errors, and helping caregivers correct/stop an error before it leads to harm or mitigate it if it occurs.^{1, 2}

Factors Influencing the Built Environment

With human factors in mind, there are several aspects of the built environment that should be considered. In a review of the literature by Henriksen and colleagues,⁸ the following design elements were identified as critical in ensuring patient safety and quality care, based on the six quality aims of the Institute of Medicine’s report, Crossing the Quality Chasm: A New Health System for the 21^st Century:⁹

• Patient-centeredness, including

  • using variable-acuity rooms and single-bed rooms
  • ensuring sufficient space to accommodate family members
  • enabling access to health care information
  • having clearly marked signs to navigate the hospital
• Safety, including

  • applying the design and improving the availability of assistive devices to avert patient falls
  • using ventilation and filtration systems to control and prevent the spread of infections
  • using surfaces that can be easily decontaminated
  • facilitating hand washing with the availability of sinks and alcohol hand rubs
  • preventing patient and provider injury
  • addressing the sensitivities associated with the interdependencies of care, including work spaces and work processes
• Effectiveness, including

  • use of lighting to enable visual performance
  • use of natural lighting
  • controlling the effects of noise
• Efficiency, including

  • standardizing room layout, location of supplies and medical equipment
  • minimizing potential safety threats and improving patient satisfaction by minimizing patient transfers with variable-acuity rooms
• Timeliness, by

  • ensuring rapid response to patient needs
  • eliminating inefficiencies in the processes of care delivery
  • facilitating the clinical work of nurses
• Equity, by

  • ensuring the size, layout, and functions of the structure meet the diverse care needs of patients

There have been five other significant reviews of the literature relating to the physical environment and patient outcomes. Nelson and colleagues¹⁰ identified the need to reduce noise pollution and enhance factors that can shorten a patient’s length of stay (e.g., natural lighting, care in new/remodeled units, and access to music and views of nature); according to their study, patients can benefit from the skillful utilization of music and artwork. Ulrich and colleagues⁷ found research that demonstrated that the design of a hospital can significantly improve patient safety by decreasing health care associated infections and medical errors. They also found that facility design can have a direct impact on patient and staff satisfaction, a patient’s stress experience, and organization performance metrics. Three other reviews found that hospital design, particularly when single-bed rooms are employed, can enhance patient safety and create environments that are healthier for patients, families, and staff by preventing injury from falls, infections, and medical errors; minimizing environmental stressors associated with noise and inefficient room and unit layout; and using nature, color, light, and sound to control potential stressors.^11–13

Lessons From Best-Practice Designs

There are several examples of the impact of evidence-based design in acute care settings; a few will be discussed here. Research in the early 1970s found that unit efficiency was determined by the design of the unit, not room size or occupancy.⁵⁰ Research conducted since then has continued to emphasize the importance of designs. One study⁵¹ began with a systematic evaluation of best practices in 19 intensive care units (ICUs), built between 1993 and 2003, that received a design award from the Society of Critical Care Medicine, the American Association of Critical Care Nurses, and the American Institute of Architects. The reviewer found positive characteristics of the ICUs to include single-bed rooms for improved patient care, safety, privacy, and comfort; bed locations that provided easy access for clinicians; hand-washing sinks and waste disposal in the patient rooms; and use of natural lighting. Negative characteristics were found to be renovation projects that posed health and safety hazards during the construction; mixed-service units with safety and staffing problems; overall layout—and layout of work areas for staff—that lacked a common design solution; and family space that was often located outside the unit and provided the family with limited access.

The Pebble Project, supported by the Center for Health Design and funded by the Robert Wood Johnson Foundation, includes several hospitals across the country. As part of this project, evidence-based designs are used and empirical evidence is assessed to measure outcomes such as safety (visit the Center for Health Design’s Web site at www.healthdesign.org). Findings from the Pebble Project are expected to advance the evidence base by increasing our knowledge of design features that can ensure a safe healing environment where the best quality of care can be provided. The project is intended to have a ripple effect and influence other health care facilities nationwide.⁵²

There are several examples of hospitals involved in the Pebble Project, such as Children’s Hospital in San Diego, which opened a long-term, convalescent hospital designed to promote the care needs for permanently disabled children. The design included out-of-sight wheelchair storage in patients’ rooms, private spaces outside the patient rooms for parents to hold their children, and an improved ventilation system to decrease respiratory infections. The Methodist Hospital in Indianapolis opened a 56-bed cardiovascular critical care unit where patients are admitted directly to their rooms from the emergency room, admitting, physicians’ offices, or the Lifeline helicopter. Patient rooms are private and patients are in control of the temperature and light. Each room also has an interior window that can become opaque to increase privacy. The design also enabled nurses to observe patients better, resulting in half as many patient falls, and the need for patient transfers has decreased substantially from 200 per month to an average of 20 per month. Bronson Methodist Hospital in Michigan opened a new facility with private patient rooms and increased patient access to nature (e.g., indoor gardens, natural light, and landscape views) and decreased patient stress using of positive distractions such as music, water sounds, artwork, and daylight. The Barbara Ann Karmanos Cancer Institute renovated several hospital areas to be patient-centered and to provide a more pleasant environment, where patient rooms were made larger and an emphasis was placed on lighting and acoustics. In doing so, administrators and clinicians have seen a decrease in the use of pain medication and medication errors on these units. Thus, by incorporating private rooms into their designs, these four hospitals and patients they have served have experienced successful outcomes in their new and renovated facilities.⁵³

Nurses’ Perspective

Four studies assessed hospital nurses’ perspectives on factors associated with the built environment using cross-sectional surveys. Two surveys intended to assess the work environment and challenges prior to moving forward with specific changes.^{54, 55} When asked about performance obstacles, nurses reported: work environments; distractions from families; hectic and crowded work environments; delays in getting medications from the pharmacy; amount of time spent teaching families; equipment not being available; patient rooms not well stocked; insufficient workspace for completing paperwork; time spent seeking supplies or patients’ charts; receiving many phone calls from families; delays in seeing new medical orders; and misplaced equipment.⁵⁴ When asked about what physical changes were problematic in the layout of the current unit, including patients’ rooms, pediatric nurses reported that they were not satisfied with: the size of residents’ closets, showers, and activity room; the actual size, aesthetics, and location of the break room and dining room; the available space for medical equipment; the available space for charting; and the outdoor recreation area. Not only did nurses share similar concerns with parents, the facility aesthetics and work environment were found to be associated with higher satisfaction and better coworker relationships among nurses.⁵⁵

The other two surveys assessed the perceptions of nurses about single versus multiple bed rooms. A very small sample of nurse managers and unit directors (n = 7) in best-practice ICUs reported the benefits of single-bed rooms as enhanced patient safety, ensured privacy for patients, increased access to patient status information, and more space for family members.⁵⁶ In the other survey, administrative and nursing staff (n = 77) reported that they favored single-occupancy rooms because of their flexibility, being more appropriate for patient examination, improved quality of patient monitoring and scope of patient surveillance, and improved patient comfort level and patient recovery rate. Helpful characteristics of single-occupancy rooms were reported as: the more favorable layout of the room, including the availability of extra space in the room making arrangement of furniture easier and providing storage for clean and dirty supplies in the room; better privacy for patients and more space for family members; and better lighting and temperature control and lower noise levels. A little over half of the respondents believed that health care acquired infections were low or very low in single-occupancy rooms, but that there was no difference in the number of patient falls or the need for pain-reducing or sleep-inducing medications between the two types of rooms. Conversely, helpful characteristics of double-occupancy rooms included proximity to the nursing station. However, being able to see patients for monitoring purposes was reported as problematic for both single and multiple occupancy rooms.⁵⁷

Patients’ Perspective and Impact

Five of the identified studies assessed the perspective of patients who received care in a purposefully built environment within hospitals. Two studies used focus groups to assess the patients’ perspective, one with hospital inpatients,⁵⁸ and the other with patients and family members in ambulatory care, acute care, and long-term care settings.⁵⁹ A consistent theme among these studies was the preference for an environment that offered quality and comfortable personal space, rather than an environment that addressed only medical needs, but none were without some aspect that was not favorable.

Three studies assessed the perspectives of patients and family members in the United States and the United Kingdom. Patients and family members in the United States, across various settings, reported wanting a health care environment that facilitates connections to clinicians; fosters a sense of well-being; and is not dissociated from the world outside the hospital, outpatient setting, or long-term care setting.⁵⁹ Patients in the United Kingdom, hospitalized patients in various units (n = 51) reported feeling a loss of independence and control while hospitalized, but felt safer and at home when they had the TV close by, and were able to walk around. For these patients, the most important factors about the built environment were privacy, a homely environment, considerations for disabilities, and being able to see outside and get outside.⁵⁸ Patients in another study in the United Kingdom reported a relationship between the environment and internal areas of the hospital and how that made them feel comfortable, able to keep a sense of normalcy, and as having a positive affect on their feelings of well-being. Patients further reported that they felt that it was important to have good signage, controllable lighting and temperature, privacy, reduced noise levels, access to the natural environment, safety and security in internal and external areas, internal and external children’s play areas, accommodations for visitors, shops and personal services, good 24-7 catering facilities, and good landscape designs with seating and garden areas.⁶⁰

Patient perceptions were assessed after implementation of a built environment in a hospital. In one study, there were fewer patients who left against medical advice, aggression levels in patients decreased, and levels of benzodiazepine dosing decreased compared to measured occurrences before the new unit opened. It is not known if there was any assessment of patients’ perceptions.⁶¹ Parents (n = 40) in a children’s hospital reported more satisfaction with the structure and facility aesthetics, but were not satisfied with space for showers/baths, the amount of closet space in the patient room, lack of sufficient private areas to be with their child or for outdoor recreation, location of the nurses station, and the low level of natural lighting.⁵⁵

Acuity-Adaptable Rooms

One study investigated the impact of an evidence-based design of 56 new acuity-adaptable rooms for a combined coronary critical care and step-down unit.⁶² Researchers found that two different levels of acute care (intensive care and step-down care) could effectively be merged together into a single patient room by making the room acuity adaptable to accommodate the changing needs of patients. Once in the new single-bed acuity-adaptable unit, researchers found: a large reduction in clinician handoffs and transfers; a 70 percent reduction in medication errors; a reduction in patient falls; improvements in patient satisfaction; decreases in budgeted nursing hours per patient day; and increases in available nursing time for direct care without additional cost. Yet, clinicians felt more isolated by the increased size of the unit and with decentralized nursing stations; then again, the “isolation” gave nurses greater opportunity for autonomous decisionmaking.

Designed ICU

The implementation of a new neonatal intensive care unit, designed to have a more efficient floor plan, provide space for supportive family-centered care, and to use of natural light, used was assessed using multiple methods.⁶³ On this new unit, the majority of nurses were positive about the design features. Nurses reported the new unit as enabling efficiency, in part attributable to being able to move about the unit at a greater velocity, enabling them to spend more time with the infants and less time needed to walk about the unit in the course of their work. The nurses also reported that the new unit was more comforting, clean and quieter, and the new lighting was thought to have a positive impact on the patients. Additionally, nurses reported that they felt that families were utilizing the majority of space designated to them.

Designing for Nursing Care

The first step for the National Learning Lab was an educational program about human error and its causes associated with latent conditions and active failures. The goal of this education was to gain commitment to the need for nurses to be active in the design phase. Then representatives of nursing were elected to a facility design committee. Design teams of nurses were also formed to assure formal input into the design. Mock-ups were also an important feature and prompted more input from the nurses. Many rooms were mocked up, and the medical-surgical room was modified multiple times by the involvement of nurses reviewing every detail to assure a safe design. Nurses’ involvement in equipment and technology planning started immediately with the mock-ups. The interplay between the facility (with its equipment and technology) and nurses and patients creates safe or unsafe interactions, and the result is affected in large part by the facility design.

Once the National Learning Lab was over, St. Joseph’s Hospital began the important process of implementing the Lab’s recommendations. For St. Joseph’s to implement the National Learning Lab’s recommendations, senior leadership knew they needed to involve nurses in the facility design process because of nursing’s essential role in caring for patients, and because nurses interface with all the systems of a hospital at the “sharp end,” including equipment, technology, facilities, and patients—more so then any other care provider in a hospital. Not discounting the role of physicians, other clinicians, and health care staff, nurses provide care 24 hours a day, 7 days a week. As such, nurses providing care are most aware of the best way to design a patient room (for example) so the room design minimizes the potential for human error and harm to patients. St. Joseph’s organized the design process to maximize the involvement of nurses.

Single-Patient Room

In many instances, including the need for patient isolation measures, double or multiple-occupancy rooms were viewed as not being conducive to patient safety and quality care. The floor plan shown in Figure 1 illustrates how a series of standardized single-patient rooms were laid out on both sides of a hallway in St. Joseph’s Hospital. This perspective allows various features of the room to be seen in relation to each other. There are two entrances to the room, one from the hallway (along the lower edge of the picture), and one from the alcove on the right. In that alcove, also entered from the hallway, a desk, computer, and chair are provided for use by staff. The alcove also contains a standardized storage area, so staff can find everything they need for the care of the patient adjacent to the patient room.

Figure 1

Floor Layout of Single-Patient Rooms in St. Joseph’s Hospital

The interior of a single-patient room incorporates many of the recommendations relating to latent conditions and active failures in the design for safety (see Figure 2). The family area of the room is in the right corner of the room, by the window, and includes a couch/pull-out bed, chair, desk with Internet connection, and good natural lighting. The treatment area of the room is on the left side of the bed, with room all around the bed for patient care. It is intentional, also, that the patient is on the nurses’ and other caregivers’ right as that person enters the room from either door, so care can be more efficiently provided. Note that the bathroom is at the head of the patient’s bed, allowing the patient to get to and from the bathroom without impediments, holding onto a rail all the way if necessary. At the head of the bed is the headwall with connections for various gases such as oxygen; on the wall to the left of the bed is a pull-down table the caregiver can use when it is needed. Although it is not shown in the illustration, there will also be a portable cart in each room, with a computer on it. Last but not least, in the lower right-hand corner of the room, between the two doorways, easily visible to the patient, there is a sink—an ever-present and convenient reminder to nurses, all staff, and visitors to wash their hands.

Figure 2

Single-Patient Room in St. Joseph’s Hospital

Applying Knowledge of Active Failures and Latent Conditions to Room Design

The design process for St. Joseph’s Hospital focused on safety, employing broad participation, including nurses, physicians, board members, administration, National Learning Lab participants, expert consultants, other health systems, health care writers, and design teams. The patient room was selected as a good example of how the design plan for the hospital came together in one location. To show how the room design was reached, each of the applicable latent conditions and active failures will be discussed, to explain how they relate to the plan for a single-patient room.

Addressing the Root Causes of Precarious Events

The approaches used by St. Joseph’s to address root causes for other types of at risk areas are described as follows:

Bringing It All Together at St. Joseph’s Community Hospital

The use of failure mode and effects analysis, patient focus groups, mock-ups with employee evaluation, and checklist safety design principles (latent conditions and active failures) helped St. Joseph’s create the safest room they could envision. The patient room evolved over months of design. Over 27 different designs or refinements were made on the patient room. This room is not the only way a patient room can be designed for safety, but it is believed to be a good way, and it exhibits efficient, thoughtful features that meet National Learning Lab expectations.

The 2002 National Learning Lab had a powerful effect on St. Joseph’s and is beginning to influence hospital facility development nationally. St. Joseph’s Hospital implemented the recommendations of the Learning Lab, designing around latent conditions and active failures, and enhancing or creating a safety culture through facility design with its technology and equipment. The importance of nursing leadership in the whole process cannot be overstated. Without the commitment, knowledge, and perseverance of the nursing leadership, along with the chief executive officer, board, medical staff, architects, and the rest of the design teams, a safe design would not have occurred.

The effort of St. Joseph’s is just the tip of the iceberg of the potential for improving safety of patients in hospitals as a result of facility development. The impact of the National Learning Lab recommendations on processes also offers an immense opportunity to improve the safety of patients in hospitals. The work of St. Joseph’s should serve as a model for those health care leaders who share the vision that facilities, including equipment and technology, focused on safety will improve the health and well-being of the patients whom they serve.

The building of the new hospital was completed in 2005, and investigators are currently evaluating the impact of their designs on the frequency of adverse events and patient outcomes. Using innovative architectural and design features to enhance patient safety together with institutionalizing a nonpunitive safety culture can potentially have a greater impact than design features alone. Over the past few years, the National Learning Lab changed St. Joseph’s Hospital and has begun to influence hospitals and health care throughout the country.

Leaders and clinicians at St. Joseph’s found that the project, with its many safety enhancements, resulted in capital expenditures under budget—an important consideration in the business case. The National Learning Lab’s process of identifying and addressing latent conditions was correlated with the Toyota Lean Principles. Standardization, visibility, continuous flow, value stream, minimizing handoffs/transfers will be created as a result of a safely designed facility. This should lead to less human error and potential harm and more efficient operations (process). Yet, one of the major difficulties of translating this efficiency and better outcomes into improved net income is the basic misalignment of financial incentives. Both the fee-for-service and the DRG (diagnosis-related group) introduce perverse incentives. Hospital revenues can actually be reduced as a result of improved safety, and savings can accrue to the insurance companies and not the institutions creating the improvements. Although there is some evidence of changes to improve these misaligned incentives, more dramatic changes are needed to encourage safe process redesign.