Noriko Yabushita

Alternative items for identifying hierarchical levels of physical disability by using physical performance tests in women aged 75 years and older.

Aim:  To identify individuals at hierarchical levels of physical disability by using physical performance tests and to determine threshold values for the discriminating of levels of physical disability in women aged 75 years or older.

Mobility performance tests for discriminating high risk of frailty in community-dwelling older women

We aimed to compare and identify high and low risk of frailty in community-dwelling older women by using five mobility performance tests. The participants were 166 older women at high risk and 171 age-matched controls at low risk of frailty according to the long-term care insurance (LTCI) system (age: 65-90 years). The mobility performance tests included 5-chair sit-to-stand (STS), alternate step, timed up-and-go (TUG), timed rapid gait (TRG), and usual gait speed (UGS). Data analysis showed that high-risk individuals (81.9%) were more likely to be pre-frail than low-risk individuals (55.0%) by Frieds frailty phenotype. The four mobility performance tests, except the 5-chair STS, had the largest areas under the curve (AUC) for discriminating older women at high and low risk (AUC>0.80, p<0.001). The optimal cutpoint (6 s) for the TRG test had the highest sensitivity (78%) and specificity (83%) in identifying high risk of frailty. Our results suggest that walking ability tests are clinically useful in screening older individuals at high risk of frailty. In particular, the TRG test is more likely than other tests to discriminate older women at high risk of frailty based on the LTCI system.

Validation of lower extremity performance tests for determining the mobility limitation levels in community-dwelling older women

Background and aims: Assessment of mobility status among community-dwelling older people is important for preventing further deterioration of mobility and identifying changes in mobility as early as possible. We attempted to identify the optimal cut-off values for eight lower extremity performance (LEP) tests in community-dwelling older women with mobility limitation (ML) levels. Methods: The ML levels of 433 community-dwelling older women, mean age 73.2 years (SD 5.7, range 65–93) were classified according to self-reports. ML levels were identified by face-to-face interviews and according to self-reported difficulty in walking one-quarter of a mile or climbing 10 steps without resting. The LEP tests comprised one-legged stance, tandem stance, functional reach, tandem walk, alternate step, five chair sit-to-stands, timed up-and-go (TUG) and usual gait speed. Receiver-operating characteristic curves were obtained for all scales to assess optimal cut-off values. Results: The optimal cut-off value of 6.52 (s) for the TUG test was shown by the highest sensitivity (74%) and specificity (71%) in the discrimination of no ML from moderate ML, whereas the optimal cut-off value of 1.05 (m/s) in the usual gait speed test showed the highest sensitivity (73%) and specificity (67%) in the discrimination of moderate ML from severe ML. Conclusions: Among community-dwelling older women, TUG and usual gait speed had the highest sensitivity and specificity in discriminating ML levels.

Longitudinal association between habitual walking and fall occurrences among community-dwelling older adults: Analyzing the different risks of falling

The purpose of this longitudinal study was to examine the association between habitual walking and multiple or injurious falls (falls) among community-dwelling older adults, by considering the relative risk of falling. A cohort of Japanese community-dwelling older adults (n=535) aged 60-91 years (73.1±6.6 year, 157 men and 378 women) who underwent community-based health check-ups from 2008 to 2012 were followed until 2013. Incidence rate of falls between walkers and non-walkers was compared separately by the number of risk factors (Groups R0, R1, R2, R3 and R4+). The Cox proportional hazard model was used to assess the association between habitual walking and falls separately by lower- (R<2) and higher- (R≥2) risk groups. In Groups R0 and R1, the incidence of falls was lower in walkers than non-walkers; however, in Groups R2, R3, and R4+, the incidence of falls was higher in walkers. The Cox proportional hazard model showed that habitual walking was not significantly associated with falls (hazard ratio (HR): 0.88, 95% confidence interval (CI): 0.48-1.62) among the lower risk group but that it was significantly associated with increased falls (HR: 1.89, 95% CI: 1.04-3.43) among the higher risk group. The significant interaction between habitual walking and higher risk of falling was found (P<0.05). When individuals have two or more risk factors for falling, caution is needed when recommending walking because walking can actually increase their risk of experiencing multiple or injurious falls.

Assessment of vulnerable older adults' physical function according to the Japanese Long-Term Care Insurance (LTCI) system and Fried's criteria for frailty syndrome

This study aimed to evaluate the physical frailty status of vulnerable older adults as classified in the Japanese LTCI system and to compare this with Frieds definition. A total of 444 older adults were classified based on the LTCI system as independent, vulnerable, or dependent, and 400 of these participants also fit Frieds criteria for not frail, pre-frail or frail. We evaluated their physical function with a 12 item physical function test. We derived a physical function score (PFS) from these 12 items and a principal component analysis was used to make comparisons. The receiver operating characteristic (ROC) curve analysis was performed to identify the sensitivity and specificity of the PFS cut-off points to distinguish the dependent category from the other categories. We found significant differences and a hierarchical order for the PFSs among the three groups of the LTCI system (the independent, 0.41 ± 0.54; the vulnerable, -0.40 ± 0.76; and the dependent, -1.49 ± 0.73) and of Frieds definition (not frail, 0.50 ± 0.51; pre frail, -0.11 ± 0.63; and frail, -1.25 ± 0.98). The optimal cut-off value (OCV) was -0.593. This study showed that the range of physical function of people considered frail category (pre-frail, vulnerable, and frail) is wide and overlapping. That is, the physical function of vulnerable older adults is worse than the pre-frail, but better than the frail. To better recognize older adults in need of greater support, the vulnerable should also receive assessment of their frailty status according to Frieds definition.

Is a composite score of physical performance measures more useful than usual gait speed alone in assessing functional status

Overall physical performance can be represented by a composite score that is derived from upper and lower extremity performance measures. We aimed to identify whether composite scores of performance measures, particularly the lower extremity performance (LEP) score, upper extremity performance (UEP) score, and an overall score, are more accurate than usual gait speed (UGS) for assessing a wide range of functional status. We conducted a cross-sectional analysis on data from 701 community-dwelling older women (mean age 74.3 years). Trained testers measured UGS and the seven tests included in the composite scores. Using self-reported questionnaires, we assessed multiphasic functional status: physical function, higher-level functional capacity, mobility limitation, activities of daily living (ADLs), and falls. We compared the areas under the receiver operating characteristic curves (AUCs) of UGS with LEP, UEP, and overall scores for each status. We found no significant differences between the AUCs of UGS and LEP score for each status. The UEP score had significantly smaller AUCs for low physical function (0.73) and mobility limitation (0.78) than UGS alone (0.81 and 0.85, respectively), and the differences were substantial. Although the overall score had significantly greater AUCs for low higher-level functional capacity (0.83) and ADLs disability (0.83) than UGS alone (0.78 and 0.80, respectively), the differences were only 3-5%. The UGS should not be regarded solely as a measure of lower extremity function; this single test may represent overall physical performance. The UGS alone, which can be measured quickly and easily, suffice for assessing a wide range of functional status in older women.

Exploring effective items of physical function in slow walking speed and self-reported mobility limitation in community-dwelling older adults

Aim:  To examine gender differences in regards to the disagreement between walking speed and self‐reported mobility limitations, and, furthermore, to explore the items that affect each physical function task by comparing slow walking speed and self‐reported mobility limitation in community‐dwelling older adults.

Obesity and muscle weakness as risk factors for mobility limitation in community-dwelling older Japanese women: A two-year follow-up investigation

OBJECTIVES To examine the combined association of obesity and low muscle strength with mobility limitation in older adults. DESIGN, SETTING AND PARTICIPANTS This two-year follow-up longitudinal study included pooled data from 283 older community-dwelling Japanese women without mobility limitations who were 65 to 87 years of age (mean age 72.2 ± 5.0 years). MEASUREMENTS Muscle strength was measured by hand-grip strength (HGS). The participants were categorized by HGS (high muscle strength: HGS ≥19.6 kg, low muscle strength: HGS <19.6 kg) and body mass index (BMI) (obese: BMI ≥25 kg/m2, normal weight: BMI <25 kg/m2). The main outcome was mobility limitation, assessed by a self-reported questionnaire (difficulty walking one-half mile or climbing 10 steps without resting). Multivariate logistic regression analysis was performed to determine the combined effect of HGS and BMI on mobility limitation, adjusting for age, exercise habits, medications, and knee pain. RESULTS During the follow-up period, 82 of 283 participants (29.0%) developed mobility limitation. The adjusted odds ratios (95% confidence interval) for the incidence of mobility limitation were 1.53 (0.86-2.73) and 2.05 (1.08-3.91) in the obese and low muscle strength groups, respectively. Obesity combined with low muscle strength exhibited a significant and strong association with mobility limitation (odds ratio: 3.88, 1.08-13.91) compared with participants with normal weight and high muscle strength. CONCLUSION Among community-dwelling older Japanese women, obesity alone was not associated with the incidence of mobility limitation, but when combined with low muscle weakness, the risk of developing mobility limitation was 3.9-fold greater than for the reference group.

Comparison of a combination of upper extremity performance measures and usual gait speed alone for discriminating upper extremity functional limitation and disability in older women

Although usual gait speed (UGS) is considered an indicator of overall well-being, it is unclear whether upper extremity performance (UEP) measures provide a similar, additive contribution to functional status. We aimed to identify whether combining UEP measures can more accurately discriminate upper extremity functional limitation (UE limitation) and disability compared to UGS. We conducted a cross-sectional analysis on data from 322 community-dwelling older women, aged 65-96 years. Trained testers assessed UGS, and hand-grip strength (GRIP), functional reach (FR), back scratch, manipulating pegs (PEG), and moving beans with chopsticks as UEP measures. We assessed three functional statuses: UE limitation, activities of daily living (ADLs) and instrumental ADLs (IADLs) disabilities using self-reported questionnaires. Areas under the receiver operating characteristic curves (AUCs) were used to compare the discriminating power of UGS, with the individual and combined UEP measures for each status. Among UEP measures, only GRIP (AUC=0.68 for UE limitation, 0.81 for IADLs disability, and 0.84 for ADLs disability) could accurately discriminate each status as well as UGS (AUC=0.65, 0.83, and 0.91, respectively). Furthermore, UGS alone could discriminate UE limitation almost as well as the combination of GRIP, PEG, and FR (AUC=0.70). Combining other UEP measures did not help discriminate further. There were few advantages to combining UEP measures, and UGS or GRIP alone may suffice for assessing UE limitation and disability. However, the UGS should be the test of first choice, certainly more than GRIP, in routine assessment of functional limitation and disability, including UE limitation.

Physical performance measures as a useful indicator of multiple geriatric syndromes in women aged 75 years and older

To identify whether individual physical performance measures or a combination of measures is a better indicator of multiple geriatric syndromes (MGS) defined as the concomitant presence of more than one geriatric syndrome in an individual.