Let’s Talk EBD

Evidence-based design (EBD) is the process of basing decisions about the built environment on credible research to achieve the best possible outcomes. Originally derived from evidence-based medicine, the term is applied to healthcare facility design to describe the foundations by which decisions are guided.

Sounds great, right?

Most if not all of us would agree that healthcare facilities should be designed in such a way as to enhance healing, promote patient safety, reduce infection and readmission rates, improve patient and staff satisfaction, and so on. Many design decisions have a very measurable impact. For example, by making all patient bedrooms in a hospital setting same-handed, do we reduce sound transmission between rooms and provide a more restful healing environment? It seems logical. It is possible to calculate and/or measure the resulting sound transmission, and if a study is structured that includes other room layouts that are in most other ways similar, we can measure whether patient outcomes are in fact improved (shorter length of stay, etc.) over rooms that place the headwalls back-to-back.

The data would be very helpful.

EBD has become a buzzword that is thrown around a lot. Some healthcare architects may promote certain features as “evidence-based” when they have not in fact been studied in a rigorous way. This dilutes the potential impact of EBD and overstatement is something that we should avoid.

A role for creativity and innovation

Healthcare environments are very complex, and when you layer on the variations of patient types and provider work patterns, our understanding of what works and what doesn’t work is changing all the time. While the existing body of EBD research can and should inform our decisions, there is also a place for innovation and creativity to uncover new and better design strategies. The challenge is to try and measure whether these new strategies produce the improved outcomes we desire, and this involves a commitment on the part of the healthcare organization, the design team, and professional healthcare researchers to design and incorporate an EBD study that will measure and compare results against alternative strategies.


  1. Sinclair Webster /

    You have it in one. The problems with EBD are two fold:
    1) As designers talking to health care professionals we want to talk as peers so try to use the same terms of reference: evidence, as medicine is based on evidence. So design based on evidence would appear to be following the same logical process. The weakness is that often the evidence base is very slight and the causal link unprovable. If you are going to talk evidence, it has to be statistically sound. No one would accept a clinical trial based on ten patients.

    2) The problem withthe evidence is that itis retrospective. This worked then, so we will do it now. EBD ignores the dynamics of healthcare where processes and technology are constantly changing.

    The hope is as we become more accustomed to an information based society the feedback loop will become shorter, and by accessing a wider field of endeavour, evidence from all over the world can be examined and applied as seems best in the particular circumstances of the brief.

  2. Robert Menzies /

    I agree healthcare is dynamic. But it has always been that way. What’s different today is that it is changing at an ever increasing rate and at times we are struggling to catch up. By the time we get some projects to site the clinical solution thast was careflly evolved via a number of iterations and user meetings is already unravelling due to new approaches, staff changes, new equipment on the market, or simply new infection standards being issued.

    In tandem with this, when we have successfully derived an economic yet flexible solution for one hospital we often find it getting rejected for an identical department in another hospital. One of the main reasons for this is that each lead clinician has his/her way of running “their”department. It is often very hard to shift them from their ‘vision’ or to get them looking at the longer term operation of the whole facility.

    We have looked at EBD but there are often contradictions in interpretation. In the UK we are expected to use AEDET, a design tool based on observations to create more meaningful environments. However a UK Department of Health research project into maternity hospital design found that areas that scored highly under AEDET were scored badly by staff when interviewed directly. This anomaly can be partially explained because AEDET is based on assumptions made by architects and others as to what constitutes a good environment. It then scores each category on a scale to reflect this. However staff often have entirely different views on functionality and acceptability because they are at the ‘coalface’ every day. Another programme called ASPECT tried to remedy this but falls at the same hurdle.

    It is perhaps stating the obvious but the one thing I have learnt over the last forty years spent on healthcare design is to LISTEN to what healthcare staff tell you. Then INTERROGATE and EXPLORE options with them. Ask them to describe the patient pathway. Ask them how they deal with different categories of patient e.g. children or severely disabled. Ask them to describe their day and their work processes and crucially, ask them what really irritates them.

    Project managers generally hate this because they are no longer in control of the process. But the key for me is building a relationship of TRUST with the staff and finding out from them what the EVIDENCE is for something working or not rather than relying solely on research.

  3. Randy Cole /

    I couldn’t agree more, Robert. Your comment also underscores the importance of people skills for healthcare architects, since they are necessary if high quality communication and levels of trust are going to be established with the staff.

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