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Correspondence: Address correspondence to Dr. Carol Giuliani, CB # 7135, Bondurant Hall 3030, 301 S Columbia St, Chapel Hill, NC 27599-7135, Carol_Giuliani{at}med.unc.edu
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Abstract |
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Key Words: Mobility • Function • Long-term care • Adverse outcomes • Fracture
Increased dependency in activities of daily living (ADLs) is one of the most common reasons for discharge from RC/AL to a nursing home (Aud & Rantz, 2005; Golant, 2004; Pruchno & Rose, 2000; Zimmerman et al., 2003). Pruchno and Rose suggested that lack of appropriate assessment and treatment may cause increased impairments. Thus, identifying RC/AL residents at high risk for decline in ADLs, incident fracture, or nursing home placement could help target intervention programs that would prevent or delay these adverse outcomes (Zimmerman et al., 2003).
Although measures of ADLs are valuable for identifying disability and estimating a resident's required level of care, they are not useful for identifying modifiable impairment and functional limitations that contribute to disability. However, several studies have reported that physical performance measures of impairment and function are valuable predictors of disability, death, and nursing home placement, even among older adults who self-report no disability (Fried, Bandeen-Roche, Chaves, & Johnson, 2000; Guralnik, Ferrucci, Simonsick, Salive, & Wallace, 1995; Guralnik & Winograd, 1994). Unfortunately, other than one recent study of 17 RC/AL facilities in Australia, there are no benchmarks for functional data of residents in RC/AL facilities (Lord et al., 2003). To date, most studies on RC/AL residents in the United States have only reported general functional ability such as ADLs (Kerse, Butler, Robinson, & Todd, 2004; Zimmerman et al., 2005). The few studies that have reported physical function are limited to small sample intervention studies and have not often clearly defined the type of long-term-care residence (Hawes, Phillips, Rose, Holan, & Sherman, 2003; Nowalk, Prendergast, Bayles, D'Amico, & Colvin, 2001; Singh, Chin A Paw, Bosscher, & van Mechelen, 2006).
Because characteristics of RC/AL residents vary systematically by facility size, staffing ratios, admission and discharge policies, and supportive programs, it is important that studies examining RC/AL resident characteristics account for these and other differences in facility characteristics. For example, smaller RC/AL facilities seem to house more impaired residents than larger, traditional types of board-and-care facilities (Zimmerman et al., 2003). Furthermore, these differences relate to the facility's capacity and likelihood to maintain residents in the face of functional decline. One can best understand this concept in relation to the model of aging in place (Bernard, Zimmerman, & Eckert, 2001). This framework recognizes that the physical performance ability of RC/AL residents and related outcomes are influenced by several individual/resident (demographics, health, and function) and facility-level factors (facility characteristics and environment). Understanding the relationships among these factors and physical performance measures can guide interventions that maintain or improve function and allow residents to age in place in RC/AL facilities. Thus, the purposes of this article are to (a) describe the functional characteristics (using physical performance and report) of RC/AL residents, (b) examine the relationships between resident- and facility-level characteristics and physical performance, and (c) determine the value of physical performance as a predictor of adverse outcomes in this population.
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Methods |
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The four-state nature of this study was chosen to create variation in the sample, reflecting the diversity of the field. The states were selected based on review of state regulation and recommendation of experts, and also proximity to allow onsite data collection. New Jersey was included, as it had progressed the furthest in defining new-model RC/AL facilities; Florida was included, as it contained a high representation of RC/AL beds compared to other states; North Carolina was included, as it contained more RC/AL Medicaid beneficiaries compared to other states; and Maryland was included, as it had fewer regulations compared to other states. Details of the sample and facilities are described elsewhere (Zimmerman et al., 2001).
Facility Measures
Facility administrators provided data regarding proprietary status and the availability of nursing staff (registered nurse or licensed practical nurse). Trained interviewers conducted a structured walk-through evaluation of the environment using the Therapeutic Environment Screening Survey–Residential Care (Zimmerman et al., 2007). This survey yields the Assisted Living Environmental Quality Scale (AL-EQS), a 15-item scale including items such as facility cleanliness, homelikeness, and privacy (
=.75).
Resident Measures, Baseline
In addition to basic resident demographics (age, race, education, gender, marital status, and medical conditions), CS-LTC staff gathered data on cognition, depression, function, comorbidities, and observed physical performance. The care provider who best knew the resident reported cognitive status using the Minimum Data Set Cognition Scale (MDS-COGS; Hartmaier, Sloane, Guess, & Kock, 1994). The MDS-COGS combines eight items into a 10-point additive scale ranging from no impairment (0–1) to very severe cognitive impairment (9–10). The care provider also provided information about depression using the Cornell Scale for Depression in Dementia (CSD-D), an observer-rated scale of depressive symptoms designed to rate depression in persons with dementia. The CSD-D consists of 19 items, each scored 0 to 2, with scores of 8 or higher indicative of depression in people with dementia (Alexopoulos, Abrahms, Young, & Shamoian, 1988). The need for assistance in seven ADLs (bed mobility, eating, locomotion, transferring, toileting, dressing, and personal hygiene) was determined from items on the MDS-ADL; Morris, Fries, & Morris, 1999). The care provider reported scores ranging from 0 (independence/no assistance) to 4 (total dependence) for each activity. From these reported scores, we also calculated a value for mobility ADLs (bed mobility, locomotion, transfer) to describe resident ability. We recorded the presence of comorbid conditions from resident records and summed this variable.
Performance-Based Measures
Physical performance was assessed using grip strength (Simonsick et al., 1997) and the Short Physical Performance Battery from the Established Populations for Epidemiologic Studies of the Elderly (walking speed, chair rise, balance; Guralnik et al., 1994). Grip strength has been associated with overall strength and is a predictor of mortality (Al Snih, Markides, Ray, Ostir, & Goodwin, 2002), functional decline (Laukkanen, Heikkinen, & Kauppinen, 1995; Rantanen, Era, & Heikkinen, 1994; Rantanen, Guralnik, Foley, et al., 1999), and nursing home placement (Al Snih et al., 2002; Lord, Ward, Williams, & Strudwick, 1995). Previous work in a community population suggested that each 1-kg decrease in grip strength was associated with a 3% increased risk of mortality (Al Snih et al., 2002).
Grip Strength
With residents seated in a chair, grip strength in kilograms (kg) was measured in the stronger arm (identified by self-report) using a dynamometer. The greater value of two trials was used for data analysis.
Walking Speed
Residents were timed as they walked 8 feet at their usual pace. Assistive devices were allowed if needed, and type of device was recorded. The best performance of two trials was converted to speed in meters per second (m/s) for analysis.
Chair Rise
Residents were instructed to stand up from a standard-height chair with their arms folded across their chest after the tester demonstrated the task (Guralnik et al., 1994). Residents first attempted a single chair rise. Those who could not stand from the chair were classified as unable. Residents who could complete the single stand then attempted five repeated chair rises as quickly as possible. Time to complete the task and the numbers of stands completed were recorded.
Balance
For balance testing, residents were asked to stand in three progressively difficult positions. First, residents were tested standing with their feet side by side, then in a semitandem position (heel of one foot beside the big toe of the other foot), and last in a tandem position (heel of one foot directly in front of the toe of the other foot) for 10 s in each position (Guralnik et al., 1994). Prior to testing, residents received instructions on each position followed by a demonstration. The time residents maintained each position was recorded in seconds.
Resident Measures, Adverse Outcomes
On a quarterly basis for 1 year after participant enrollment, facility staff were contacted by telephone and asked to report each resident's current functional (MDS-ADL) status and whether the resident had died, experienced a fracture, or transferred to a nursing home. For residents who had died or were discharged, fractures were retrospectively reported up to time of discharge/death and the MDS-ADL level of the resident immediately prior to discharge/death was reported.
Analyses
Data were available for 1,791 residents from 189 facilities. We included an additional 287 residents who did not participate in performance testing (were ill, unavailable, or refused) only for analyses related to facility questions. We calculated univariate statistics for the four physical performance measures (grip strength, walking speed, chair rise, and balance) and bivariate associations between physical performance, resident and facility variables, and outcomes. The coding of individual performance variables was as follows.
Grip Strength
We used two cut points for grip strength. One cut point (14 kg) was close to the mean (13.97 kg) for our sample. This value also corresponded to the lowest quartile of grip strength for community-dwelling older adults reported in other studies (Al Snih et al., 2002; Guralnik & Winograd, 1994; Onder et al., 2002). A second cut point was 10 kg and represented the lowest quartile value for RC/AL residents in this study. We compared residents whose strength was above the cut points to those with lower grip strength and those unable to perform the test.
Walking Speed
We classified walking speed as 
0.6 m/s, <0.6 m/s, or unable. Walking speed <0.6 m/s is a strong predictor of decline in physical function and increased difficulty in ADLs (Guralnik & Ferrucci, 2002; Guralnik, Ferrucci, et al., 1995; Studenski et al., 2003; VanSwearingen, Paschal, Bonino, & Chen, 1998) in community-dwelling older adults.
Chair Rise
We classified residents who were unable to complete a single chair stand as unable. For the remainder of the sample, we classified residents as able to perform five consecutive stands, or able to perform one to four stands but unable to do five consecutive stands. We viewed a single chair rise as a measure of transfer ability and the repeated chair rise task as an indication of leg strength (Simonsick et al., 1997).
Balance
We classified residents who could not stand independently as unable. Based on our distribution and similar to Guralnik, Fried, and colleagues (1995), we constructed a categorical variable that recorded the ability to tandem stand for at least 1 s, or unable to tandem stand. We based the decision for a cut point at 1-s tandem stand on the ability of residents to semitandem stand for 10 s and assume the tandem stand position. The large majority of residents were unable to tandem stand (81%), 11% could stand 1 to 9 s, and only 8% could stand for 10 s.
We analyzed descriptive statistics and univariate distributions using SAS 8.2 (SAS Institute, Cary, NC) and conducted multivariate modeling using Stata 7.0 (StataCorp, College Station, TX). All regression models controlled for clustering within the facility and for length of follow-up (exposure) using STATA xtgee procedure, which uses robust variance estimation (Huber, 1967). We used logistic regression to examine differences in physical performance by resident and facility factors. We modeled the probability of good versus poor physical function as a dichotomous outcome. We modeled rates of mortality and probability of nursing home transfer using Cox proportional hazards methods (Cox, 1972). We modeled fracture as incidence per quarter using repeated measures analysis, in which generalized estimating equations were employed to fit a Poisson regression model (Liang & Zeger, 1986). We modeled functional change using generalized estimating equations to estimate differences in means at baseline and follow-up, assuming a Gaussian distribution and identity link function (Liang & Zeger, 1986).
We ran models for each performance predictor separately. We calculated relative risks of outcome events (mortality, nursing home transfer, fracture) using performance measures as the explanatory variables, controlling for baseline individual characteristics (age, gender, race, marital status, seven ADLs, MDS-COGS, CSD-D, and comorbidities). A relative risk greater than 1 indicates that the rate in the higher performance group (those with higher tested performance) is higher than in the reference group (unable to perform or lower level performance); values less than 1 indicate that the rate is lower in the higher performance group than in the reference group. For generalized estimating equations analyses of functional change, larger numbers indicate greater functional decline (increased impairment).
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Relative Risk of Adverse Outcomes Related to Physical Performance
Table 5 demonstrates the relationship of physical performance to adverse outcomes over 1 year. In general, adjusted analyses indicated that better physical performance was associated with the reduced risk of nursing home transfer, fracture, and functional change during a 1-year interval. Walking speed 0.6 m/s (relative risk range = 0.49–0.61) and ability to perform chair rise five times (relative risk range = 0.46–0.57) were most protective for these outcomes in analyses adjusting for resident age, gender, race, marital status, cognition, ADLs, affect, morbidities, and within-facility clustering. Greater grip strength (>14 kg) and ability to tandem stand for more than 1 s were also associated with the reduced risk of each outcome, but adjusted relative risks were not always statistically significant. None of the physical performance measures was associated with mortality in adjusted analyses.
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Discussion |
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Grip strength, which is a good indicator of overall function, disability, and mortality risk, averaged 14 kg in this RC/AL cohort, well below the 17 kg reported for the lowest quartile of community-dwelling women with disability in the Women's Health and Aging Study (Guralnik, Fried, et al., 1995; Onder et al., 2002) and similar to the lowest quartile for Mexican American women (Al Snih et al., 2002). Given that 42% of Mexican American women with grip strength less than 14 kg and 38% of men with grip strength less than 22 kg died within 5 years (Al Snih et al., 2002), this finding suggests that many of these RC/AL residents are at high risk for adverse outcomes.
Further evidence that RC/AL residents in this sample were not functioning as well as their reported ADL level might indicate is the very slow average walking speed of 0.41 m/s, which is well below the average speed for community-dwelling older adults and was associated with increased risk of adverse outcomes in numerous previous studies (Guralnik et al., 2000; Onder et al., 2002; Studenski et al., 2003). Having slower walking speed is also associated with using an assistive device. However, whereas residents who used an assistive device had an average walking speed of 0.33 m/s, the 57.4% who walked independently without an assistive device only walked at 0.48 m/s. Therefore, it is unlikely that use of a device accounted for the extremely slow walking in these residents. Average walking speed for healthy older adults is 1.0 to 1.2 m/s (Brach, VanSwearingen, Newman, & Kiska, 2002; Onder et al., 2002). Several authors have shown that in community-dwelling older adults, walking speed <0.6 m/s is an independent predictor of change in health status, decline in function, falls, nursing home placement, and disability (Guralnik, Ferrucci, et al., 1995; Lan, Melzer, Tom, & Guralnik, 2002; Onder et al., 2002; Studenski et al., 2003; VanSwearingen et al., 1998).
Chair rise ability is also an area of concern in this population because it is associated with walking, transfers, and other key mobility skills. Fifty percent of these residents were unable to stand once from a standard-height chair without using their hands, which is more than the 26% that Alexander and colleagues (2001) reported among residents in congregate housing. For the 26.2% of our residents who were able to perform five repeated chair rises, their average time was 18 s. In comparison, the lowest quartile in a community sample was 16.7 s (Guralnik et al., 2000). Values greater than 16.7 s are associated with risk of decreased mobility (Ostir et al., 1998). Several investigators have attributed decreased strength, flexibility, and balance to chair rise difficulty (Lord, Murray, Chapman, Munro, & Tiedemann, 2002; McCarthy, Horvat, Holtsberg, & Wisenbaker, 2004).
Standing balance was also severely impaired in these RC/AL residents: 39.6% were unable to stand with feet side by side for 10 s, and only 19.2% of residents could stand at least 1 s or more in the tandem stand position. Difficulties with tandem stance are associated with increased lateral balance instability, hip muscle weakness, and increased risk of falls (J. Gill et al., 2001; Stel, Smit, Pluijm, & Lips, 2003). These balance impairments are also indicators of walking disability (walking speed <0.4 m/s; Rantanen et al., 2001).
Although there is ample evidence that physical performance is a good predictor of adverse events in community-dwelling older adults, researchers have not studied such relationships in a large sample of RC/AL residents. This study examined the ability of these measures to predict adverse events, including death, nursing home placement, fracture, and functional decline among more than 1,700 residents of 189 facilities. At 1-year follow-up, better grip strength, walking speed, and chair rise at baseline were associated with decreased risk of nursing home placement, fracture, and functional decline; however, none of these performance variables predicted mortality. These findings suggest that residents who are at risk for adverse events may be identified using simple tests of physical performance, but that mortality is most likely associated with some other variable (e.g., comorbidity).
Although intervention studies are largely lacking in the RC/AL setting, these results suggest that interventions that improve physical performance may decrease the incidence of fracture and disability in this population, as has been demonstrated in community-dwelling older adults (T. M. Gill et al., 2002; King et al., 2002; Lord et al., 1995; Malbut, Dinan, & Young, 2002; Resnick, Magaziner, Orwig, & Zimmerman, 2002; Rubenstein et al., 2000). A recent study showed that providing a task-specific strength and flexibility program to a small sample of RC/AL residents who had mobility disability improved chair rise ability (Alexander et al., 2001). Similarly, an exercise program for 280 residents living in intermediate-care housing units improved function and reduced falls (Lord et al., 2003). This intervention used a group exercise program of strength, balance, endurance training, and functional tasks that emphasized enjoyment and social interaction. Additional research is needed to identify interventions that maintain or improve the function of RC/AL residents, especially those that target residents at risk and that are feasible within the constraints of the facility and the health care system.
This study's large sample of facilities also permitted examination of the relationship between facility characteristics and physical performance. The only association for facility type was that residence in traditional facilities was associated with better grip strength, but not other performance measures. Traditional facilities tend to have a less impaired resident case mix; however, it is difficult to explain why only grip strength was associated with traditional facility type, because grip strength is associated with overall functional ability and ADL. Poorer physical performance was more common in for-profit settings, but nurse availability and environmental quality were not related to performance. Residents in for-profit facilities tend to be more impaired, which may be related to the less restrictive admission and discharge policies of these facilities (Zimmerman et al., 2003) and which helps to explain some of these results. The few facility associations observed suggest that resident characteristics are far stronger predictors of physical function than are facility factors. However, the association between proprietary status and function merits further investigation, most likely requiring comparative study of admission cohorts in nonprofit and for-profit settings.
Noted limitations of this study include the reporting of adverse events and ADL status. The reporting of adverse events was based on recall from facility staff during phone interviews conducted each quarter. Functional status (ADLs) at time of discharge or death was also reported by a caretaker who was most familiar with the resident. We acknowledge that reported recall or the quality of records maintained by each caretaker or facility is prone to recall error and misinformation.
Most of the RC/AL residents in this study were reportedly independent in ADLs; however, based on actual physical performance, residents had substantial mobility-related problems. These analyses indicate that a few simple performance measures may identify functional deficits that are modifiable. This is an important finding, because RC/AL facilities provide supportive services to help residents maintain independence, competence, dignity, and quality of life. These services usually include up to three meals a day served in a common dining area; housekeeping services; assistance with eating, bathing, dressing, toileting and walking; and other medical and safety services. Results of this study suggest that in addition to these supportive services, programs are needed that promote optimal physical functioning.
The prevalence of physical impairment reported in this study and its relationship to adverse outcomes suggest that RC/AL residents might benefit from performance-based screening for mobility disability, exercise interventions, and physical activities designed to improve physical performance. Indeed, if RC/AL facilities intend to meet the needs of their residents and allow them to age in place, they will need to address the deficits that lead to increased disability and transfer to a nursing home. By implementing effective interventions, it may be possible to prolong independent mobility so that RC/AL residents can remain in the more homelike RC/AL facility environment rather than be transferred to a potentially objectionable and more costly nursing home.
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Footnotes |
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1 Center for Human Movement Science, University of North Carolina at Chapel Hill.
2 Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore.
3 School of Social Work, The University of Alabama, Tuscaloosa.
4 Department of Physical Therapy, Western Carolina University, Cullowhee, NC.
5 Program in Healthcare and Aging Research, University of North Carolina at Chapel Hill.
6 The Carolinas Center for Medical Excellence, Cary, North Carolina.
7 Cecil G. Sheps Center in Health Services Research, University of North Carolina at Chapel Hill.
8 Department of Family Medicine, University of North Carolina at Chapel Hill.
9 School of Social Work, University of North Carolina at Chapel Hill.
Decision Editor: William J. McAuley, PhD
Received for publication March 23, 2007. Accepted for publication August 5, 2007.
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