The Key to Fighting Physical Decline: The Short Physical Performance Battery (SPPB)

The following post focuses on the Short Physical Performance Battery (SPPB), one of several tests designed to measure functional status and physical performance. Other tests, such as the Short Form 36 Health Survey, the Late Life Disability Instrument and the Physical Performance Test, can also measure physical function and predict the onset of disability. However, unlike other tests, the SPPB focuses exclusively on lower extremity function. Due to its close link to mobility disability and patient outcomes including hospitalization, institutionalization, and mortality, lower extremity function is receiving increasing attention from the research and medical communities as an important factor of overall health and healthy aging. The SPPB has been the focus of numerous studies throughout the international research community, providing a growing body of data that demonstrates the efficacy of the test as an assessment tool of functional status and risk of disability onset.

This post provides an overview of demographic trends which call for greater investment and attention to this area of research, the features of the test and a survey of some of the clinical success that the assessment has already demonstrated. This overview also calls attention to the potential role that the SPPB can hold in the care for older patients, as well as the development of therapies to manage and prevent disability and functional decline.

Functional Decline: A Rapidly Growing and Complex Problem

Assessing disability and physical decline in the elderly is an often difficult process, though widely recognized as an important indicator of overall health in older patients. Disability onset generally develops very gradually as people age, which makes changes in an older patient’s functional status difficult to perceive without a standardized means of measuring physical performance, especially over time. Additionally, more than half of all Americans live with at least one chronic disease that presents further complications to a person’s mobility and functional status. These factors, along with other health behaviors and risk factors like obesity and social isolation, make assessing physical decline and risk of developing a disability a crucial, but very complex, piece in preserving the overall health and independence of the nation’s aging population.

In 2007, 25% of community-dwelling Medicare beneficiaries over age 65 had difficulties with activities of daily living (ADLs), or basic self-care tasks such as eating, dressing, bathing, using the toilet and transferring from bed to chair, while 83% of institutionalized Medicare beneficiaries age 80 or older had difficulties with at least one ADL (67% of this group had difficulties with three or more ADLs) (1). As the aging population continues to rapidly grow and live longer, establishing an effective and reliable means of quantifying patients’ functional status and vulnerability to disability development is critical to ensuring healthy aging and independence for older Americans, while simultaneously easing the burden on the nation’s health care system.

The SPPB Establishes Universal Standards

The Short Physical Performance Battery (SPPB) is a tool designed to quantify physical performance and decline over time. The test focuses primarily on lower extremity function and includes a 4 meter walk to measure gait speed, one chair stand (followed by 5 timed chair stands, if the first is successfully completed), and balance stands with the feel held in different positions for 10 seconds each. The test is designed to be easily administered in a variety of contexts or settings, can be administered by medical assistants and interviewers after a short course of training, and takes about 10 minutes to complete.

Unlike other studies that established standards to measure functional status and performance particular to that study, the SPPB establishes parameters of measuring physical function that can be used uniformly across almost all clinical and research settings. This aspect of the SPPB makes the test a potential resource to physicians who care for older patients, particularly as research continues to move forward in the development of treatments and therapeutic interventions for disability and physical decline. Even more, having a universally accepted standard for measuring functional status will allow for greater comparison and collaboration across past, present and future research, as the SPPB, being a standardized test, makes it possible to compare functioning across cultures, demographics, or across a patients’ changing environment or health status change.

Other means of assessing functional decline rely on self-reporting t by patients or their proxies, which may not be entirely accurate, due to a desire to do well on the part of the patient, or to cognitive impairment or illness that might affect the patient’s ability to communicate or accurately describe problems. Additionally, the standardized measures of functional decline that the SPPB provides eliminate differences in reporting across patients with different demographic characteristics or environments. For example, one patient might report not having difficulty performing certain ADLs due to access to assistive devices or features in her home that make the task easier, thereby missing the opportunity to truly gauge her level of physical function. Because the SPPB does not require specialized equipment that might be difficult to obtain in some areas, the SPPB removes obstacles to obtaining a true measure of physical capacity.

The most important aspect of any measure of physical function is to reflect changes, both positive and negative, of a patient’s physical function in response to any number of factors, including aging, chronic conditions or medical events, psychosocial and behavioral factors, as well as a response to any management or treatment strategies, or therapeutic interventions. The SPPB uniformly assesses a patient’s progress or decline, with the hope of predicting the onset of any disability or functional limitation that may emerge from any factor, in hopes of mitigating or eliminating that risk through interventions and therapies.

The SPPB establishes standards that are both calculable and accurate across different clinical and research settings to gauge clinically meaningful change in patients, a feature of the test that is crucial to the growing body of emerging clinical trials and other trials which focus on predicting disability and assessing physical function and rely on the outcome data of such performance tests – particularly those tests, like the SPPB, that can be used over a ‘trajectory of functioning’ that will reflect changes of a multitude of factors over time in the long term, which will be key in preventing the loss of independence and decline of older patients.

The SPPB: An Effective Means of Measuring and Predicting Disability

The SPPB test has already been successfully integrated in two different clinical contexts, including two geriatric outpatient settings and in a hospital setting in which geriatric patients were admitted for various medical diagnoses. The test was very predictive of risk of disability among the community-dwelling patients (2). In addition, use of the test has predicted patient mortality, the need for admission to a nursing home and reliance on health care among the general older population, as well as continued decline in ADLs. Most importantly, the SPPB has been successful in predicting the development of disability (inability to perform ADLs or decreased mobility) among those individuals who had no disability at the time of administering the test (3).

When administered within the first 24 hours of admission to a hospital, the SPPB was also found to accurately predict the patient’s length of stay in the hospital, as well as re-hospitalization and mortality over the year after hospital discharge. (4)

Such sensitivities to change in functional status, or the potential for change, makes the SPPB an important tool to identify those older patients who are at an especially high risk of developing debilitating physical decline, in hopes of utilizing therapeutic, preventive interventions.

Future Possibilities for the SPPB:

Given the global picture that disability measurement and functional status can give in regards to a patient’s overall health, the SPPB test has the potential to be highly influential in clinical decision making and patient outcomes. The results of the SPPB are able to transcend the many complex and interacting effects of chronic disease and other health risks and factors, and can provide valuable insight on patient physical function trends over time, all of which can have direct implications on decision-making in determining the long-term care needs of older patients. Because of the effectiveness of the SPPB in predicting health outcomes in both outpatient and hospital setting, the use of the test will open many opportunities to physicians and researchers to further understand the interactions of multiple factors on disability and an older person’s overall health.

Because of improvements in health care treatments and technology, older Americans are able to enjoy a greater number of healthy years than ever before. However, this new reality presents new and complex challenges to stakeholders. Finding an effective means of identifying risks of disability and physical decline will continue to be an important first step to ensure healthy aging; the SPPB test is a reliable, cost-effective tool that will help us reach that goal.

CITATIONS:
(1) Administration on Aging. A Profile of Older Americans 2010. http://www.aoa.gov/aoaroot/aging_statistics/Profile/2010/16.aspx 17 January 2012.
(2) Studenski S, Perera S, Wallace D, et al. Physical performance measures in the clinical setting. J Am Geriatr Soc 2003;51:314-22.
(3) Guralnik JM, Ferrucci L, Simonsick EM, Salive ME, Wallace RB. Lower extremity function in persons over the age of 70 years as a predictor of subsequent disability. N Engl J Med 1995;332:556-561.
(4) Volpato S, Cavalieri M, Sioulis F, et al. Predictive value of the Short Physical Performance Battery following hospitalization in older patients. J Gerontol Med Sci 2011;66:89-96.