Life-Span Design of Residential Environments for an Aging Population

Enhancing the Home Safety of the Elderly: Technological and Design Interventions

Sara J. Czaja, Ph.D.
Director of Research Stein Gerontological Institute

When considering the issue of universal design, researchers, designers, and policymakers need to address the critical question of how to maintain the older adult living at home. Data regarding the living arrangements of older adults show that most older people live in a household either alone or with a spouse and that the majority of these people own their home. It is expected, in fact, that the number of households occupied by elderly people will increase, given the increased number of older people in the population, the rising costs of institutionalization, and the fact that older people are less likely to move than younger people, preferring to remain at home for as long as possible despite personal impairments or declines in environmental quality. Additionally, among projected demographic trends, one of the most dramatic is an increase in the number of older females age 65+ living alone at home. This growth in a number of households maintained by older persons underscores the need to attend to the problems encountered by this population.

It is rather well established that older people often have difficulty remaining at home because routine living tasks become problematic. Current estimates suggest that of the elderly people living at home, 2.3 million need some type of assistance in conducting daily living activities and 2.7 million need assistance with instrumental activities¹. In addition, other estimates suggest that approximately 13 percent of older People living at home exhibit one major deficit in physical mobility². All told, these data indicate that a large number of people are at risk for institutionalization and lowered quality of life.

Further evidence for the lessened ability of older persons to remain at home is reflected in the high rate of home accidents among persons aged 65 and over, which accounts for 43 percent of all home fatalities. General information is available regarding the types of accidents older people have and why they occur; such information is useful to any attempt to identify ameliorative strategies. We know, for example, that the most common sources of accidental injury are falls on stairways, floors, and bathtubs; burns or scalds from cooking or hot water, and poisoning from medications³.

Falls represent the most frequent non-transportation related accidents occurring among older adults and are the leading cause of home fatalities for this population. Stairways are particularly hazardous for the elderly. Other types of falls include slipping in bathtubs and showers, slipping on tile or icy terrain, and tripping over objects on the floor. Falls associated with getting in and out of bed, getting on or off a chair, or using the bathroom are also frequent.

Burns are also common among older people. In fact, burns and other consequences of fire rank second as a cause of death among persons aged 65+. Among activities that lead to burns are cooking, smoking, and accidentally turning on and failing to turn off appliances. Scalds from hot water are also a frequent source of injury, especially in bathtubs and showers.

Poisoning from improper doses of medication ranks third as the most prevalent type of home accidents. Older people are especially susceptible to this kind of occurrence as they are likely to be taking several highly potent drugs at one time, to have visual or cognitive disabilities, and to live in environments that are conducive to medication errors (e.g., environments that are poorly lit).

The high rate of home accidents among older persons points to the need to understand the etiology of these accidents so that we can develop design interventions. The reasons for the high frequency of such accidents are complex but are likely to include the fact that older people spend most of their time at home and that age-related changes in functional abilities make it more difficult for them to complete home tasks. Moreover, the demands of the home environment are often substantive in that the homes of elderly people tend to be older than those of younger people, more difficult to operate and maintain, and more often in need of repair. As a result, housing deficiencies, such as broken stairs or poor electrical wiring, are more common in elderly housing⁴.

In essence, there appears to be a mismatch between the capabilities of the older person and the demands of the home environment. We need to consider how assistive devices can be used and residential environments modified so that older people can successfully live at home and perform routine asks. Solutions must be cost-effective, feasible, and acceptable to older adults. Although complex technologies such as computers can be used to solve living problems, they are not always affordable or necessary. Design efforts need to be directed toward developing simple, low-budget assistive devices and identifying ways to retrofit existing homes. In other words, strategies must be developed that allow individuals to age in place.

One critical first step to identify these strategies is gathering additional data about the needs of older people and the types of problems they encounter at home. For example, although information is available regarding the causes of accidents among elderly people, it is general and does not tell us what we need to know to develop design solutions. Essentially, we need more detailed data on the causes of specific home problems and accidents, and/or their relative frequency.

To date, the study of home activities among older populations has been largely epidemiological. For example, although data exist regarding the frequency of types of home accidents and the products and environments involved in these accidents, these data are too limited and insufficient to enable researchers to identify research priorities, hypotheses, and design activities. In essence, there is a large gap between the empirical data available and the data needed for design applications that is, detailed information on person and task characteristics, environmental features and demands, and products. Specifically, we need detailed data on the functional requirements of home tasks, on the products used to perform these tasks, and on the environments in which these tasks are performed so we can determine why these tasks are problematic for older people.

To meet this need, human factors task analytic techniques should be applied to the study of household behaviors to gain information on the functional requirements of these activities. In 1984, Falletti successfully applied such techniques to the study of meal preparation and identified the most important physiological demands associated with this activity⁵. Current work at the Stein Gerontological Institute is applying this methodology to additional household tasks. This is a valuable area of research as it provides a means of understanding the person-environment transactions involved in home tasks, which could lead to the identification of palliative interventions for personal, product, and environmental factors.

A second prerequisite for design is information about the capabilities and limitations of older adult populations. Although the gerontological literature is replete with information on older adult populations per se, it is hard to relate the the literature on age changes to applied contexts such as environmental design and safety. The data that are available have questionable application to real world contexts and are not in a form useable to design practicioners. There needs to be a closer integration between research results and design problems.

There are also areas where more data are required. For example, very limited data exist on the anthropometric characteristics of older adult populations, especially within the realm of functional anthropometry. In deciding what measurements to take, we need to know the frequency with which acitivities occur and the human actions they involve. Such information is critical if we are to design products and environments that "fit" older user groups. Similarly, we need data on the biomechanical characteristics of older populations. To design controls such as those found on appliances or in bathtubs/showers or to specify heights for cabinets and counters, we need data on the incidence of specific disabilities and diseases of older people. We need to know what proportion of older adults are afflicted with arthritis and how this affects their functional ability. Such data can be collected from task analysis and time sample studies. It is also important to recognize that the elderly population as a group is quite heterogeneous and that reported data should represent the variabilities at each age as well as the averages.

So far, the thrust of this paper has been on the need to collect data that will allow us to develop interventions that can enhance the safety and independence of older adults. Although new and better products are clearly called for, there are already a number of available products intended for this purpose. These include specially designed furnishings such as chairs that are easier to get into and out of, appliances with automatic sensors, and computer and communication technologies that allow direct links to emergency services, as well as simple products such as grabbers, reacher sticks, and walking aids. Unfortunately, in many cases either these products are underutilized or appropriate devices are not matched with appropriate people. Thus, we need to develop an effective means of disseminating information regarding the availability of such assistive products, and we need to develop methods to ensure that older adults are conversant in the use of the technologies. To this end, health care professionals and family members must be educated with respect to what is available and appropriate.

Of course, the effective dissemination of assistive devices is influenced in part by the extent to which these devices are useable by and acceptable to older people. Although a myriad of products are available, few have been evaluated with respect to intended user groups. In many instances, designers make assumptions about user needs and preferences that go untested in the design process. We need to conduct product evaluations to validate manufacturers claims and to determine the appropriateness of a given product for an individual, given a set of circumstances. For example, is a particular medical dispenser as effective for persons afflicted with arthritis as it is for those older persons who are "disease free"? More generally, we need data that allows us to match products and technologies to specific persons. Finally, we need information on the extent to which the applications of technology to the physical environment or of technological aids within the home mitigate the need for support services.

To achieve these goals, human performance testing must be a part of the design process and should involve representatives of intended user groups. This involves having older people interact with design prototypes and using data from these evaluations to refine the prototypes being developed. It also involves interviewing older adults to ascertain their needs and preferences. All too often, the needs of users, especially older users, are neglected by young, able-bodied designers. Additionally, the design team should be multidisciplinary, involving designers, gerontologists, health care and service providers, and human factors engineers. Human factors engineering, with its focus on fitting the designed environment to human capabilities, needs, and limitations, has direct conceptual and methodological relevance to product design and evaluation.

In sum, we need the following types of knowledge to enhance the functional independence of older adults and allow them to remain in their own homes:

A better understanding of which tasks are problematic for older adults and of the types and frequencies of difficulties they entail. Detailed data on the functional demands associated with environments, products, and tasks of daily living. As mentioned, task analytic techniques would be useful in the collection of such data.

Normative data on the characteristics of older adult populations, especially information on anthropometric and biomechanical characteristics and on the distribution of diseases and disabilities within these populations.
Information regarding the appropriateness of existing products and technologies for older people. As noted, product evaluations must include human performance testing with representative user groups.
Strategies for disseminating available assistive products to older adults, family members, and health care professionals as well as for training these individuals on how and when to use them.
Better design guidelines for housing design, based on information regarding the capabilities and limitations of older adult populations. Guidelines that currently exist are limited in scope and often conflict with each other.
More communication among designers, gerontologists, engineers, and older adults.

Finally, much more attention needs to be directed toward older people living at home. This means not only developing new and better products and assistive devices but also identifying ways to retrofit existing environments effectively.

ENDNOTES

1. D. Dawson, G. Hendershot, and T. Fulton, "Aging in the Eighties: Functional Limitations of Older Adults," Vital and Health Statistics, No. 133 (Hyattsville, Md.: National Center for Health Statistics, 1987.)

2. Department of Housing and Urban Development, Office of Policy Development and Research, Annual Housing Survey 1981 (Washington, D.C.: U.S. GPO, 1983).

3. H. L. Sterns, G. V. Barret, and R. A. Alexander, "Accidents an the Aging Individual," in Handbook of the Psychology of Aging, 2d ed., ed. James E. Birren and K. Warner Schaie (New York: Van Nostrand Reinhold, 1985), 703-719.

4. M. Powell Lawton, "Household Behaviors" (Paper prepared for the National Research Council Workshop on Human Factors Research Issues for an Aging Population, Washington, D.C., 12-13 August 1987).

5. M. V. Falletti, "Human Factors Research and Functional Environments for the Aged," in Elderly People and the Environment, ed. I. Altman, M. Lawton, and J. Wohlwill (New York: Plenum Press, 1984), 191-237.

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