Investigation to Determine Whether the Built Environment Affects Patients' Medical Outcomes

by Haya R. Rubin, M.D., Ph.D.; ;Amanda J. Owens, J.D.; and Greta Golden; with an introduction by David O. Webber

Quality of Care Research, The Johns Hopkins University

Published by The Center for Health Design, 1998

INTRODUCTION

In a dark place the sick indulge themselves too much in various fancies, and are harassed by imaginings devised in an alienated mind, since no external phenomena can fall on the senses; but in a bright place they are prevented from being wholly in their own fancies, which are rather weakened by external phenomena. — Asclepiades of Bithynia, ca. 50 B.C.¹

Second only to fresh air … I should be inclined to rank light in importance for the sick. Direct sunlight, not only daylight, is necessary for speedy recovery … I mention from experience, as quite perceptible in promoting recovery, the being able to see out of a window, instead of looking against a dead wall; the bright colours of flowers; the being able to read in bed by the light of the window close to the bed-head. It is generally said the effect is upon the mind. Perhaps so, but it is not less so upon the body on that account ....— Florence Nightingale, 1860²

Througout the long history of Western medicine, sensitive caregivers have believed that the physical environment in which therapy is provided may modify that therapy’s effect on patients.

In pre-Christian Rome, the influential physician Asclepiades of Bithynia argued against the prevailing practice of sequestering the sick in shadowy rooms — itself based on the notion that darkness is soothing and contributes to patients’ peace of mind.

From her experiences ministering to the wounded in the Crimean War, Florence Nightingale strongly advised the British government that the convalescence of patients would be hastened if hospitals were built to afford them fresh air, sunlight, calm and quiet, views of nature, and a setting filled with “beautiful objects … especially of brilliancy of colour.”³

Surprisingly, given the ancient and honorable lineage of this hypothesis, little modern scientific research has been conducted to test the premise that aspects of the healthcare environment (other than cleanliness) have effects on therapeutic outcomes. We know as much from a major review of the medical literature performed in 1995 and updated in 1997 and 1998 by Haya R. Rubin, M.D., Ph.D., and colleagues from Quality of Care Research at The Johns Hopkins University, in Baltimore, conducted under the auspices of The Center for Health Design.

After culling more than 78,761 potentially relevant titles from medical databases, the research team identified only 1,219 articles that appeared to describe investigations into the impact of environmental elements on health outcomes.

They had cast their net broadly, too. They looked for any study in which scientists had attempted to gauge the relationship between health outcomes and the physical environment. A wide range of diverse aspects of the physical environment were addressed, including such topics as room size, room privacy, controllability of the environment by the patient, music, lighting, type of window view, humidity, and temperature.

Nevertheless, only a few dozen reports in the medical literature since 1966 actually turned out to contain data that relate a particular design feature to a specific clinical outcome for a particular study population. The 84 studies judged relevant are outlined in greater detail in Appendix B of this report.

Unfortunately, moreover, the methodological rigor of this small volume of research varied enormously. Fewer than a third of the studies, for example, were randomized, controlled trials — the most reliable scientific technique for assessing the effects of a medical intervention or a treatment variable.

One such, as an illustration, tested the impact of artificial light on babies in hospital nurseries by randomly assigning a sample of 50 newborns to cribs under blue light (the highest-intensity visible wavelength), while another matched sample of 50 babies were placed in cribs under red light (the lowest-intensity visible wavelength). The researchers observed and reported in 1992 that the babies subjected to blue light were more wakeful, slept more often but more briefly, and had more irregular patterns of sleep. Yet for all its strength of research design, a single study of 100 babies — all healthy and sharing a single ethnic background — leaves open the question of whether the same results would pertain among babies of other ethnicities, or among sick or premature babies, for whom regular, sound sleep may be an important factor if they are to thrive.

Another small subset of the studies were experimental trials with paired data, or observational studies with paired data, both of which are also considered by scientists to be reasonable constructs for drawing relatively reliable research conclusions when well crafted.

An instance of the former involved a 1975 study of 19 premature infants whose incubators were first set at high humidity and then at low humidity. Eight of the infants experienced severe breathing problems, and the episodes of apnea occurred in significantly greater proportion when the humidity was kept low. Here again, however, a single study of a very small group of subjects is not sufficient to support broad generalizations even when the method is sound. Similarly, a 1992 observational study of nearly 14,000 patients in a state mental hospital indicated that when rock or rap music was played in a common area, the patients exhibited more incidents of “inappropriate behavior” than when country or “easy listening” music was played. The unusually large cohort of subjects involved lends weight to the finding, but the study did not control for the various rhythms or lyrics of the music that could possibly be provocative factors.

Indeed, none of the investigations into the effects of environmental features on patient outcomes undertaken in the last 30 years is immune to criticism. The majority are significantly flawed. To be sure, few if any scientific studies produce incontrovertible evidence. Unshakable judgments based on one or two trials, no matter how large or tightly controlled to eliminate chance, confounding factors, and experimenter bias, are rarely if ever drawn by circumspect scientists. And analysis of this body of research is at least suggestive that a cause-effect relationship exists between some health-care environmental factors and therapeutic outcomes for some types of patients.

Thus, one conclusion from the research team’s initial assessment is that research in this field holds promise, but that more and better studies are vitally needed. The effort would appear to be justified if nothing else on the evidence of the best of the studies surveyed, a high proportion of which did find significant associations between the environmental variable investigated and a health outcome.

In an era of intense concern over the rising costs of medical care, improving therapeutic results through the most efficient allocation of finite resources has become the touchstone of healthcare practice and processes. If, in fact, the very environment in which patients receive treatment has a significant influence on their physical responsiveness and prognosis, it is important to determine which elements can promote more satisfactory outcomes under what circumstances. Healthcare facilities can then be designed to take advantage of such knowledge.

Continued expenditure for structures whose layout, ambience, and appurtenances are informed by guess, fad, or the personal preferences of designers, administrators, healthcare professionals, or even patients themselves — absent solid efforts to square aesthetic leanings and unsupported theories with outcomes data to the extent scientifically possible — is a frivolity we can no longer afford.

This report builds on an analysis of past research to suggest an agenda for further inquiry into the effects of healthcare settings on patient outcomes. It offers a general conceptual model of the ways in which environmental features may influence patients’ health, as a guide to the formulation of future research protocols. And it provides four illustrative design applications of how credible scientific evidence might be incorporated into the design of specific aspects of the physical environment to improve therapeutic results.

The research team also outlines a complete research program aimed at validating or discrediting hypotheses about the degree to which the efficacy of healthcare can be enhanced or diminished by key aspects of the designed environment.

Finally, as recommended in the first element of this agenda, the research team conducted focus groups to assist in the identification of patient populations in whom hypotheses about the influences of the healthcare environment might be proven or disproven.

Sponsored and coordinated by The Center for Health Design, with funding from outside sources and augmented by the ongoing investigations of independent scientists, the completion of the major research agenda outlined in this report might at last bring to reality a future foreseen a quarter of a century ago by another visionary healthcare observer, noted hospital architect E. Todd Wheeler:

Eventually scientific findings will go beyond subjective responses .... The doctor will then know how to write a prescription for environment even as he now does for drugs, and technology will modify and maintain it to his prescription, applying all beneficial variables, including … temperature; air content of solids, liquids and gases; air pressure and movement; light in all its aspects, including movement and color; other forms of radiation; ionization; size and shape of enclosure; physical movement of the enclosure; pattern and texture of materials; sound, both generated and absorbed; and the physical form.⁴

— David O. Weber Berkeley, California, September 1996

¹ From Gumpert, Christian Gottlieb, Fragments from Asclepiades of Bithynia, Weimar, 1794, in Green, Robert M., Asclepiades: His Life and Writings (New Haven: Elizabeth Licht, 1955).

² Nightingale, Florence, Notes on Nursing: What It Is and What It Is Not (London: Harrison, 1960).

³ibid.

⁴ Wheeler, E. Todd, Hospital Modernization and Expansion (New York: McGraw-Hill, 1971).