[Development of indicators to promote measures for the prevention and rehabilitation of functional decline in older people]. / Développement d'indicateurs pour valoriser des actions de prévention et de réadaptation de la perte d'autonomie des personnes âgées.

BACKGROUND: In Europe and Asia, long-term care funding is disability-based. This introduces a perverse effect by inappropriately adding value to functional decline among beneficiaries. To support the efforts in prevention and rehabilitation made by personnel in long-term care services, indicators have to be developed to promote functional improvement of beneficiaries. As people receiving those services are already experiencing a functional decline process, it is essential to know the natural magnitude of functional decline in order to assess deviation from this expected decline. The objective of the study was to estimate the natural decrease of autonomy in beneficiaries of home care services and nursing homes. METHODS: Two databases were used: for home-dwelling people, 1235 subjects over 75 years old who participated in the PRISMA study; for institutions, 1330 residents over 65 years old of a nursing home in Sherbrooke (QC, Canada). These subjects were assessed several times over many years with the Functional Autonomy Measurement System (SMAF). Growth analyses were used to estimate the annual decrease in the SMAF score according to age, gender and the initial autonomy status. RESULTS: At home, only age was significantly associated with the slope of functional decline. The average annual decrease of subjects 75-84 years old was 2.4 points on the SMAF score (out of 87); for those aged over 85, the annual loss was 3.8 points. In institutions, gender and the initial autonomy profile were associated with the annual decrease. For men, the annual decrease varied between 0.7 for the most disabled subjects to 5.2 for the most autonomous. For women, those values varied from 0.2 to 6.6, respectively. CONCLUSION: A decrease in the SMAF score less than these expected values should be associated with a bonus to support personnel training, prevention activities, rehabilitation and activities aimed at supporting the autonomy of the beneficiaries. Such a strategy requires the implementation of a precise and reliable assessment instrument like the SMAF and also the availability of a longitudinal database where data for each beneficiary could be linked over time.

Postural control in the elderly: an analysis of test-retest and interrater reliability of the COP-COM variable.

OBJECTIVES: To estimate the test-retest and interrater reliability of the center of pressure-center of mass (COP-COM) variable of postural control in the elderly. DESIGN: The biomechanic variable COP-COM, which represents the distance between the COP and the COM, was determined from 2 AMTI force platforms and 3 OPTOTRAK position sensors. Measurements were taken in quiet position, double leg stance, and eyes open and eyes closed conditions. SETTING: Laboratory environment. PARTICIPANTS: Forty-five healthy subjects, 8 patients with diabetes neuropathy, and 7 stroke survivors, all of whom were at least 60 years old. INTERVENTIONS: Subjects were evaluated on 2 separate occasions within 7 days by the same evaluator to determine test-retest reliability. Interrater reliability was determined the same day. MAIN OUTCOME MEASURES: The biomechanic variable COP-COM, which represents the distance between the COP and the COM in terms of root mean square. The mean of 4 trials of the COP-COM variable for each condition was used for statistical analysis. Intraclass correlation coefficients (ICCs) were used. RESULTS: The COP-COM variable has good reliability for both the test-retest and interrater studies, but its reliability varies according to the direction of the COP-COM. For the test-retest and interrater studies, the ICC ranged from.89 to.93 in the anteroposterior direction and from.74 to.79 in the mediolateral direction. CONCLUSION: The equivalence of the test-retest and interrater coefficients obtained suggests that the measurement error of the COP-COM variable is mainly linked to the biologic variability of this measure over a short period of time. Using the mean of 4 trials stabilizes the COP-COM variable enough to be potentially used to evaluate clinical change.

Screening older adults at risk of falling with the Tinetti balance scale.

In a prospective study of 225 community dwelling people 75 years and older, we tested the validity of the Tinetti balance scale to predict individuals who will fall at least once during the following year. A score of 36 or less identified 7 of 10 fallers with 70% sensitivity and 52% specificity. With this cut-off score, 53% of the individuals were screened positive and presented a two-fold risk of falling. These characteristics support the use of this test to screen older people at risk of falling in order to include them in a preventive intervention.

Evaluation of postural stability in elderly with diabetic neuropathy.

OBJECTIVE: The objective of this study was to compare clinical and biomechanical characteristics of balance in diabetic polyneuropathic elderly patients and normal age-matched subjects. RESEARCH DESIGN AND METHODS: Fifteen elderly with distal neuropathy (DNP) and 15 healthy age-matched subjects were evaluated with the biomechanical variable COP-COM, which represents the distance between the center of pressure (COP) and the center of mass (COM). Measurements were taken in the quiet position with a double-leg stance, in eyes-open (EO) and eyes-closed (EC) conditions. Subjects were also assessed with clinical balance evaluations. RESULTS: The COP-COM variable was statistically significantly larger in the DNP group than in the healthy group in anterior-posterior (A/P) and medial-lateral (M/L) directions. Furthermore, the DNP group showed statistically significantly larger amplitudes of the COP-COM variable without vision. The severity of the neuropathy, as quantified using the Valk scoring system, was correlated with COP-COM amplitude in both directions. CONCLUSIONS: Evaluation of the postural stability of an elderly diabetic population using the COP-COM variable can detect a very small change in postural stability and could be helpful in identifying elderly with DNP at risk of falling.

Effect of ageing and vision on limb load asymmetry during quiet stance.

Although the identification and characterization of limb load asymmetries during quiet standing has not received much research attention, they may greatly extend our understanding of the upright stance stability control. It seems that the limb load asymmetry factor may serve as a veridical measure of postural stability and thus it can be used for early diagnostic of the age-related decline in balance control. The effects of ageing and of vision on limb load asymmetry (LLA) during quiet stance were studied in 43 healthy subjects (22 elderly, mean age 72.3+/-4.0 yr, and 21 young, mean age 23.9+/-4.8 yr). Postural sway and body weight distribution were recorded while the subject was standing on two adjacent force platforms during two 120 s trials: one trial was performed with the eyes open (EO), while the other trial was with the eyes closed (EC). The results indicate that LLA was greater in the old adults when compared with the young control subjects. The LLA values were correlated with the postural sway magnitudes especially in the anteroposterior direction. Eyes closure which destabilized posture resulted in a significant increase of body weight distribution asymmetry in the elderly but not in the young persons. The limb load difference between EO and EC conditions showed a significantly greater effect of vision on LLA in the elderly compared to the young subjects. The observed differences in the LLA may be attributed to the decline of postural stability control in the elderly. Ageing results in the progressive decline of postural control and usually the nervous system requires more time to complete a balance recovery action. To compensate for such a deficiency, different compensatory strategies are developed. One of them, as evidenced in our study, is preparatory limb unload strategy (a stance asymmetry strategy) which could significantly shorten reaction time in balance recovery.

Intrasession reliability of the "center of pressure minus center of mass" variable of postural control in the healthy elderly.

OBJECTIVES: To estimate the intrasession reliability of a single measure of the biomechanical variable "center of pressure minus center of mass" (COP-COM) to determine, first, how many trials must be averaged to obtain a reliable measure of postural stability, and second, the minimal metrically detectable change of the COP-COM. PARTICIPANTS: Community-living, healthy, elderly people over 60 years of age (n = 7). DESIGN: Measurements were made in double leg stance, eyes-open condition. Nine successive trials, with rests between, were carried out for each subject. DATA ANALYSIS: Intraclass correlation coefficients (ICCs). MAIN OUTCOME MEASURE: The biomechanical variable COP-COM, which represents the distance between the center of pressure and the center of mass, was measured from two force platforms and three position sensors. RESULTS: The ICCs obtained for one measure of the COP-COM were .79 in the anterior-posterior (AP) direction and .69 in mediolateral (ML) direction. With four trials, the COP-COM variable is reliable at .94 in the AP direction and .90 in the ML direction. Minimal metrically detectable changes were .10 mm (AP) and .16 mm (ML). CONCLUSION: Using four repetitions of the COP-COM variable provides a reliable measurement of postural stability.