Where Is the Vision for Fall Prevention?

In this month's Journal of the American Geriatrics Society, Lord reports on one of his series of investigations addressing the sensory and physiologic risk factors for falling among older persons.1 In the present study, he examines the relative predictive power of several assessments of vision (high- and low-contrast visual acuity, contrast sensitivity, depth perception, stereoacuity, and lower visual field size) for predicting subsequent falls in a population of community-dwelling older persons with a mean age of 76.5 years. Previous studies of the relationship between visual function and falling or fall injuries have been inconsistent.2–8 Although the ability to judge distance and to recognize obstacles and hazards would seem essential to safe ambulation, several prior studies have failed to detect a significant relationship between visual acuity and falling.4,5,8 As noted by Lord, the inability to detect an association in these investigations might have occurred because the most relevant measures of visual functioning were not assessed. Lord studied a relatively large number of individuals who, by their self-reported chronic conditions and subsequent fall rate, appear to represent a fairly typical spectrum of community-dwelling older persons. While the participation rate (slightly less than 50%) is disappointing, it is unlikely that this participation rate significantly influenced results or, by extension, interpretation of the findings. Depth perception, low-contrast visual acuity, and contrast sensitivity were the visual functions most closely linked to falling. The dose-response relationships between the severity of these impairments and risk of falling—which might have been even stronger had there been larger numbers of persons in the various categories—further support a causal relationship between these visual functions and fall risk. While not completely resolving the inconsistencies among studies—no single study can be expected to—the present study supports the particular importance of binocular vision, depth perception, and contrast sensitivity to postural stability and object recognition and, consequently, to fall prevention. The clinical and public health relevance of these findings is direct and obvious. Findings should help inform such questions as: Who should be offered second cataract surgery (a topic of current coverage debate)?9–11 What should older persons be advised concerning the use of multifocal corrective lenses during ambulation? What constitutes safe and appropriate floor patterns for areas used by older persons? and Should cities provide high-contrast markings on curbs and stairs? Where does the present study fit within the burgeoning number of epidemiological and intervention studies addressing falls in older persons? Less than 2 decades ago, falls were largely considered inevitable and, by extension, not preventable occurrences and thus, presumably, not under the purview of clinical care or public health. However, over the past 15 years investigators around the world have contributed a wealth of evidence describing the physical and psychological morbidities associated with falling, affirming the predictability of fall risk, and, most importantly, determining the preventability of falls. The surge in scrutiny afforded the topic is well attested to by the marked increase in MEDLINE citations. Between 1970 and 1986, only two publications were listed under the combined search terms of “accidental falls” and “aged.” The comparable number for the years 1986 to 2000 was 1,767. From this concentrated research effort has emerged a consistent picture of the multifactorial nature of fall etiology and, conversely, the effectiveness of multifactorial interventions at reducing the rate of falls among at-risk older persons. Many of the epidemiological studies performed from the mid 1980s through the 1990s were designed to identify the multiple domains that serve as fall risk factors. By necessity, therefore, each domain was usually assessed by a single, often crude, measure. Lord's study, which focuses intently on a single domain, is the next logical step in our further exploration of fall etiology. His work complements the breadth of previous investigations with greater depth within a single domain. The breadth, and now depth, of research addressing fall etiology is a testament to what can be accomplished when efforts are concentrated on an important topic. The gratifyingly rapid increase in our understanding of fall etiology and prevention should encourage funders and investigators to focus similar resources and efforts toward other important health problems of older persons. While our progress in understanding fall etiology is commendable, it is equally, and perhaps more so, a source of chagrin. There remains a great disconnect between the wealth of evidence supporting fall prevention efforts and real-world practice. The clinical and public health integration of fall prevention programs has lagged, and continues to lag, far behind the research findings. While there is increasing interest among geriatrically oriented health-care providers in screening for, and intervening upon, fall risk factors, there is no simple mechanism in our fragmented, disease-oriented healthcare system for referring individuals to the relevant professionals to implement the various components of the multifactorial prevention program. If referrals are made, there is no assurance that assessment and intervention efforts will be reimbursed by the diagnosis-driven reimbursement system administrated by the Health Care Financing Administration (HCFA). There are few examples of such a common and morbid health condition with such compelling evidence of effectiveness that has remained largely ignored outside the practice of geriatrics and for which there remain so many barriers for those who wish to institute evidence-based fall-prevention strategies. Who is responsible for translating the increasing body of research on fall etiology and prevention into clinical and public health practice? The simple—but in this case correct—answer is everyone. Funding agencies that support the initial research have some obligation to ensure that these research findings are disseminated. It is not appropriate to leave this dissemination and translational work to a few foundations or to the underfunded Agency for Health Care Research and Quality. Health care payors, such as HCFA, managed care companies, and the National Health Service, have a responsibility to be aware of, and responsive to, research supporting the effectiveness and cost-effectiveness of interventions whether they be treatment strategies for specific diseases or preventive strategies for multifactorial health conditions such as falls. Practicing clinicians appropriately complain of the burden imposed by the increasing number of prevention and disease-management guidelines they are expected to follow. However, clinicians do have some obligation to implement screening, assessment, and treatment strategies for health conditions for which there exist strong evidence of effectiveness, particularly given the amount of time spent performing diagnostic and treatment activities for which there is little or no evidence. Finally, investigators have a particular obligation to clearly articulate the clinical and public health relevance of their findings, to command the attention of payors and providers, and to work toward translating their research findings into better clinical and public health practice. Given the mounting evidence supporting the relationship between visual functions, such as stereoacuity and contrast sensitivity, and fall risk, how long will it be before second cataract surgery is recommended, and paid for, because binocular visual acuity is important for safe mobility? Before counseling older persons to avoid the use of multifocal lens while walking becomes part of standard practice? Before there are public health–mandated changes in the environment, such as high-contrast markings on curbs and stairs in public spaces?