Evidence-based design, or EBD, is a field of study emphasizing credible evidence to influence design. This approach has become popular in healthcare to improve patient and staff well-being, patient healing, stress reduction and safety. Evidence-based design is a relatively new field, borrowing terminology and ideas from disciplines such as environmental psychology, architecture, neuroscience and behavioral economics.
Studies have examined how the physical environment can influence well-being, promote healing, relieve patient pain and stress and reduce medical errors, infections and falls. Many hospitals, community health centers and residential care centers are adopting evidence-based design for new construction, expansion and remodeling.
EBD is a process used by architects, interior designers and facility managers in the planning, design, and construction of commercial buildings. An individual using evidence-based design makes decisions based on the best information available from research, project evaluations and evidence gathered from client operations. Critical thinking is required to develop appropriate solutions to design problems, since available information will rarely offer a precise fit to a client's situation. Therefore, research specific to a project's objectives is required. An evidence-based design should result in improvements to an organization's outcomes, economic performance, productivity and customer satisfaction.
The process is particularly suited to healthcare, because of the unusually high stakes and the financial and clinical outcomes that can be impacted by the built environment; however, it may be used in other fields. Its positive effect is demonstrated by patients (who have higher-quality stays) and families; physicians, who practice based on medical evidence, and administrators, who reduce costs and improve organizational effectiveness.
EBD is applicable to many types of commercial building projects. The building itself can help reduce stress experienced by patients, their families and caregivers. The healthcare environment is multifaceted; it is a work environment for staff, a healing environment for patients and families, a business environment and a cultural environment for the organization to fulfill its mission.
Healthcare design may come from many areas:
- Environmental psychologists: Focus on stress reduction:
- Social support (patients, family, staff)
- Control (privacy, choices, escape)
- Positive distractions (artwork, music, entertainment)
- Nature (plants, flowers, water, wildlife, nature sounds)
- Clinicians: Focus on medical and scientific literature:
- Treatment modalities (models of care and technology)
- Quality and safety (infections, errors, falls)
- Exercise (exertion, rehabilitation)
- Administration: Refers to management literature:
- Financial performance (margin, cost per patient day, nursing hours)
- Operational efficiency (transfers, utilization, resource conservation)
- Satisfaction (patient, staff, physician turnover)
- Evidence-based metrics: Includes research tools and methods for practitioners:
- Work measurement (time studies)
- Efficiency designs
- Patient and resource workflow
About 1,200 environmentally-relevant studies have been identified by The Center for Health Design. The primary aim of hospital designers and administrators is to create a healing space which reduces stress, helps health and healing and improves patient and staff safety.
Healing spaces have existed since ancient Greece. People who were ill visited temples in the hope of having a dream in which the god would reveal a cure. In 1860 Florence Nightingale identified fresh air as "the very first canon of nursing," and emphasized the importance of quiet, proper lighting, warmth and clean water. Nightingale applied statistics to nursing, writing "Diagram of the causes of mortality in the army in the East". This statistical study led to advances in sanitation, although the germ theory of disease was not yet fully accepted. A 1984 study by Roger Ulrich found that surgical patients with a view of nature suffered fewer complications, used less pain medication and were discharged sooner than those who looked out on a brick wall. Studies also exist about the psychological effects of lighting, carpeting and noise on critical-care patients, and evidence links physical environment with improvement of patients and staff safety, wellness and satisfaction..
EBD continues research and building practices developed during the 1960s. In the US and UK during the 1970s, architectural researchers studied the impact of hospital layout on staff effectiveness (Clipson & Johnson 1987; Clipson & Wehrer 1973; Medical Architecture Research Unit, 1971–1977) and social scientists studied guidance and wayfinding (Carpman & Grant 1993). Architectural researchers have conducted post-occupancy evaluations (POE) to provide advice on improving building design and quality (Baird, Gray, Isaacs, Kernohan, & McIndoe, 1996; Zimring, 2002). The Center for Health Design focuses on EBD practices, their uses and application to each step of the design process. More than 600 studies with environmental-design relevance have been identified.
Performance-based building design (PBBD)
EBD is closely related to performance-based building design practices. As an approach to design, PBBD tries to create clear statistical relationships between design decisions and satisfaction levels demonstrated by the building systems. Like EBD, PBBD uses research evidence to predict performance related to design decisions.
The decision-making process is non-linear, since the building environment is a complex system. Choices cannot be based on cause-and-effect predictions; instead, they depend on variable components and mutual relationships. Technical systems, such as heating, ventilation and air-conditioning, have interrelated design choices and related performance requirements (such as energy use, comfort and use cycles) are variable components.
Evidence-based medicine (EBM) is a systematic process of evaluating scientific research which is used as the basis for clinical treatment choices (Claridge & Fabian, 2005). Sackett, Rosenberg, Gray, Haynes and Richardson (1996) argue that "evidence-based medicine is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients" (British Medical Journal). It is used in the healthcare industry to convince decision-makers to invest the time and money to build better buildings, realizing strategic business advantages as a result. As medicine has become increasingly evidence-based, healthcare design uses EBD to link hospitals’ physical environments with healthcare outcomes.
Research and accreditation
As EBD is supported by research, many healthcare organizations are adopting its principles with the guidance of evidence-based designers. The Center for Health Design and InformeDesign (a not-for-profit clearinghouse for design and human-behaviour research) have developed the Pebble Project, a joint research effort by CHD and selected healthcare providers on the effect of building environments on patients and staff.
The Evidence Based Design Accreditation and Certification (EDAC) program was introduced in 2009 by The Center for Health Design to provide internationally recognized accreditation and promote the use of EBD in healthcare building projects, making EBD an accepted and credible approach to improving healthcare outcomes. The EDAC identifies those experienced in EBD and teaches about the research process: identifying, hypothesizing, implementing, gathering and reporting data associated with a healthcare project.
EBD may be divided into four steps:
- Reviewing existing research literature, selecting significant findings and recommendations
- Matching referenced findings with data gathered from site visits, survey results and subject-matter experts
- Predicting the outcome of design decisions
- Tracking positive outcomes for design implementation
Other sources provide a specific guide to practical applications of achieving EBD objectives; some are listed below.
In his book Evidence-based Policy: A Realistic Perspective, Ray Pawson (2006) suggests a meta-analysis template which may be applied to EBD. With this protocol, the field will be able to provide designers with a source for evidence-based design.
A systematic review process should follow five steps:
- Formulating the review question
- Identifying and collecting evidence
- Evaluating the quality of the evidence
- Extracting, processing and systematizing data
- Disseminating findings
According to Hamilton ("Four Levels of Evidence-Based Practice", AIA Journal of Architecture, 2006), environmental research is more likely to result in performance guidelines than in prescriptive regulation. A variety of information sources are helpful: literature from psychology, sociology, anthropology, economics, management, engineering and industrial design. The Internet, the press, conferences and exemplary facilities are also good resources. To demonstrate evidence-based practices, the model below illustrates four means of dealing with research and related methods:
- Level 1
- Analysing field literature to follow related environmental research
- Determining the evidence's meaning in relationship to the project
- Level 2
- Predicting expected outcomes of design decisions on general findings
- Measuring results through analysis of implications and construction of a chain of logic from decision to outcome
- Level 3
- Reporting results publicly, moving information beyond design team
- Subjecting methods and results to peer review
- Level 4
- Publishing findings in peer-reviewed journals
- Collaborating with academic and social scientists
The White Paper (series 3/5) from The Center for Health Design presents a working model to help designers implement EBD decision-making. The primary goal is providing a healing environment; positive outcomes depend on three investments:
- Designed infrastructure, including the built environment and technology
- Re-engineered clinical and administrative practices to maximize infrastructure investment
- Leadership to maximize human and infrastructure investments
All three investments depend on existing research.
A white paper from The Center for Health Design identifies ten strategies to aid EBD decision-making:
- Start with problems. Identify the problems the project is trying to solve and for which the facility design plays an important role (for example, adding or upgrading technology, expanding services to meet growing market demand, replacing aging infrastructure)
- Use an integrated multidisciplinary approach with consistent senior involvement, ensuring that everyone with problem-solving tools is included. It is essential to stimulate synergy between different community to maximize efforts, outcomes and interchanges.
- Maintain a patient- and family-centered approach; patient and family experiences are key to defining aims and assessing outcomes.
- Focus on financial operations past the first-cost impact, exploring the cost-effectiveness of design options over time and considering multi-year investment returns.
- Apply disciplined participation and criteria management. These processes use decision-making tools such as SWOT analysis, analytic hierarchy processes and decision trees which may also be used in design (particularly of technical aspects such as structure, fire safety or energy use).
- Establish incentive-linked criteria to increase design-team motivation and involve end users with checklists, surveys and simulations.
- Use strategic partnerships to create new products with hospital-staff expertise and influence.
- Encourage simulation and testing, assuming the patient’s perspective when making lighting and energy models and computer visualizations.
- Use a lifecycle perspective (30–50 years) from planning to product, exploring the lifecycle return on investment of design strategies for safety and workforce outcomes.
- Overcommunicate. Positive outcomes are connected with the involvement of clinical staff and community members with meetings, newsletters, webcams and other tools.
Evidence-based design has been applied to efficacy measurements of a building's design, and is usually done at the post-construction stage as a part of a post-occupancy evaluation (POE). The POE assesses strengths and weaknesses of design decisions in relation to human behaviour in a built environment. Issues include acoustics, odor control, vibration, lighting and user-friendliness, and are binary-choice (acceptable or unacceptable). Other research techniques, such as observation, photography, checklists, interviews, surveys and focus groups, supplement traditional design-research methods. Assessment tools have been developed by The Center for Health Design and the Picker Institute to help healthcare managers and designers gather information on consumer needs, assess their satisfaction and measure quality improvements:
- The Patient Environmental Checklist assesses an existing facility's strong and weak points. Specific environmental features are evaluated by patients and their families on a 5-point scale, and the checklist quickly identifies areas needing improvement.
- The Patient Survey gathers information on patients' experiences with the built environment. The questions range is wide, since patients' priorities may differ significantly from those of administrators or designers.
- Focus Groups with consumers learn about specific needs and generate ideas for future solutions.
- Cama, R., "Patient room advances and controversies: Are you in the evidence-based healthcare design game?", Healthcare Design, March 2009.
- Hall, C.R., "CHD rolls out evidence-based design accreditation and certification", Health Facilities Management, July 2009.
- Kirk, Hamilton D., "Research Informed Design & Outcomes for Healthcare" in Evidence Based Hospital Design Forum, Washington, January 2009.
- Kirk, Hamilton D., "Four Levels of Evidence-Based Practice", AIA Journal of Architecture, November 2006.
- Stankos, M. and Scharz, B., "Evidence-Based Design in Healthcare: A Theoretical Dilemma", IDRP Interdisciplinary Design and Research e-Journal, Volume I, Issue I (Design and Health), January 2007.
- Ulrich, R.S., "Effects of Healthcare Environmental Design on Medical Outcomes" in Design & Health–The therapeutic benefits of design, proceedings of the 2nd Annual International Congress on Design and Health. Karolinska Institute, Stockholm, June 2000.
- Webster, L. and Steinke, C., "Evidence-based design: A new direction for health care". Design Quarterly, Winter 2009
- Sadler, B.L., Dubose, J.R., Malone, E.B. and Zimring, C.M., "The business case for building better hospital through evidence based design". White Paper Series 1/5, Evidence-Based Design Resources for Healthcare Executives, Center for Health Design, September 2008.
- Zimring, C.M., Augenbroe, G.L., Malone, E.B. and Sadler, B.L., "Implementing healthcare excellence: the vital role of the CEO in evidence based design". White Paper Series 3/5, Evidence-Based Design Resources for Healthcare Executives, Center for Health Design, September 2008.
- Ulrich, R.S., Zimring, C.M., Zhu, X., Dubose, J., Seo, H.B., Choi, Y.S., Quan, X. and Joseph, A., "A review of the research literature on evidence based healthcare design", White Paper Series 5/5, Evidence-Based Design Resources for Healthcare Executives, Center for Health Design, September 2008.
- The Center for Health Design
- Role of the Physical Environment in the Hospital of the 21st Century: Report published by The Center for Health Design in 2004 summarizing evidence-based design research for healthcare
- InformeDesign: Research database of studies linking environment to outcomes
- Center for Health Systems and Design
- Picker Institute
- Tulane Center for Evidence-Based Global Health
- A Visual Reference to Evidence-Based Design by Jain Malkin .
- Study Guide 1: An Introduction to Evidence-Based Design: Exploring Healthcare and Design.
- Study Guide 2: Building the Evidence-Base: Understanding Research in Helathcare Design.
- Study Guide 3: Integrating Evidence-Based Design: Practicing the Healthcare Design Process .
- A Practitioner's Guide to Evidence-Based Design by Debra D. Harris, PhD, Anjali Joseph, PhD, Franklin Becker, PhD, Kirk Hamilton, FAIA, FACHA, Mardelle McCuskey Shepley, AIA, D.Arch .
- Evidence-Based Design for Multiple Building Types by D. Kirk Hamilton and David H. Watkins .
- Pawson R., Evidence-based Policy: a realistic perspective. Sage Publications, 2006.
- Stout, Chris E. and Hayes, Randy A. The evidence-based practice: methods, models, and tools for mental health professionals. John Wiley and Sons, January 2005.
- Ulrich, R., Quan, X., Zimring, C., Joseph, A. and, Choudhary, R., "The Role of the Physical Environment in the Hospital of the 21st Century". Report to the Center for Health Design, September 2004.