Réjean Hébert

Gait in the elderly

Abstract Walking is one of the most common of all human movements. It exists to transport the body safely and efficiently across ground level, uphill or downhill. Walking is learned during the first year of life and reaches maturity around 7 until 60 years. Elderly walking performance then starts to decline and the elderly slow down gradually. Falls are a major cause of morbidity in the elderly and in almost all incidences of falls, some aspects of locomotion have been implicated. With the increased life expectancy of the elderly and their more active lifestyle there is now an emphasis on determining any changes that occur in their gait patterns in order to reduce the frequency of falls, to identify diagnostic measures that are reliable predictors of fall-prone elderly and finally to develop programs for preventing such falls. This review addresses the gait related changes in the elderly in order to pinpoint the effect of normal aging for comparison with different gait deviations related to some pathologies. Spatio-temporal, kinematics, kinetics and EMG data will be reviewed as well as the physiological changes associated with gait and aging. Finally, the selection criteria will be reviewed and recommendation on the urgent need of a valid healthy elderly database will be addressed.

Reliability, Validity and Reference Values of the Zarit Burden Interview for Assessing Informal Caregivers of Community-Dwelling Older Persons with Dementia

Zarit Burden Interview (ZBI) is the most widely used instrument for assessing the burden experienced by the caregivers of persons with dementia. As part of the Canadian Study of Health and Aging, the 22-item ZBI was administered to a representative sample of 312 informal caregivers of community-dwelling subjects with dementia. The mean score was 22.4 out of 88 (sd: 16.2) and the median score was 18.5, which is far lower than those reported in previous studies using this instrument with convenience samples. There was no significant difference in the burden score according to the age, gender, living arrangement, marital status or employment status of the caregiver. The ZBI score was more strongly correlated to the depressive mood of the caregivers (r = 0.59) and the behaviour problems of the care recipients (r = 0.64) than their cognitive (r = 0.32) and functional (r = 0.31) status. Following a factor analysis, a 12-item short version of the instrument is proposed with two factors: personal strain (3 items) and role strain (9 items).

Age- and education-specific reference values for the mini-mental and modified mini-mental state examinations derived from a non-demented elderly population

Main objective. To report age‐ and education‐specific reference values for the Mini‐Mental State Examination (MMSE) and Modified Mini‐Mental State (3MS) Examination.

Community screening for dementia: The Mini Mental State Exam (MMSE) and modified Mini-Mental State Exam (3MS) compared☆

The objectives of this study were to assess whether Tengs modification of the Mini-Mental State Examination (MMSE) improves its performance as a screening test for cognitive impairment and dementia, and to replicate this comparison in French and English language groups, and for differing assumptions concerning the relative importance of false negative and false positive errors. Screening interviews were conducted with representative samples of people aged 65 or over, set in 36 communities in 10 Canadian provinces. There were 8900 community participants in the Canadian Study of Health and Aging, of whom 1600 also underwent an extensive clinical and neuropsychological examination. Sensitivity, specificity and areas under the receiver operating characteristic (ROC) curve for the original MMSE and modified version (the 3MS) were the main outcome measures. Results are reported for French and English versions of the tests. The results indicate the alpha internal consistency for the 3MS was 0.87, compared to 0.78 for the MMSE. The area under the ROC curve in identifying dementia was 0.93 for the 3MS and 0.89 for the MMSE (p < 0.001). There was less difference between the two tests in identifying all levels of cognitive impairment (AUC 0.80 versus 0.77, p < 0.01). The superiority of the 3MS appears more due to its extended scoring system than to its additional questions. The validity of the MMSE was comparable in English and French samples; results for the 3MS were inconsistent between the two samples, suggesting possible translation problems. In conclusion, the 3MS was superior to the MMSE, justifying the slightly greater burden for its administration and scoring. Neither test worked well in identifying lower levels of cognitive impairment.

The Purdue Pegboard Test: Normative data for people aged 60 and over

Manual dexterity is frequently evaluated in rehabilitation services to estimate hand function. Several tests have been developed for this purpose, including the Purdue Pegboard, which measures fine manual dexterity. The goals of the study were to verify the test-retest reliability with subjects aged 60 and over without upper limb impairment, and to develop normative data based on a random sample of healthy older community-living individuals. The results show that the test-retest reliability is good (intra-class correlation coefficients from 0.66 to 0.90, depending on the subtest). Norms are presented to help clinicians involved in rehabilitation services to better differentiate real dexterity deficits from those that may be attributed to normal ageing.

Vascular Dementia Incidence and Risk Factors in the Canadian Study of Health and Aging

BACKGROUND AND PURPOSE Very few population-based studies have systematically examined incident vascular dementia (VaD). From the Canadian Study of Health and Aging cohort, incidence rates of VaD were determined and risk factors analyzed. METHODS This was a cohort incidence study that followed 8623 subjects presumed to be free of dementia over a 5-year period. The risk factors were examined with a nested prospective case-control study. Exposure was determined by means of a risk factor questionnaire administered to the subject or a proxy at the beginning of the study. RESULTS On the basis of 38 476 person-years at risk, the annual incidence rate was estimated to be 2.52 per thousand undemented Canadians (95% CI 2. 02 to 3.02). Including an estimation of the probability of VaD among the decedents, this figure rose to 3.79. For the risk factors study, 105 incident cases of VaD according to the NINCDS-AIREN criteria were compared with 802 control subjects. Significant risk factors were: age (OR=1.05), residing in a rural area (2.03), living in an institution (2.33), diabetes (2.15), depression (2.41), apolipoprotein E epsilon4 (2.34), hypertension for women (2.05), heart problems for men (2.52), taking aspirin (2.33), and occupational exposure to pesticides or fertilizers (2.05). Protective factors were eating shellfish (0.46) and regular exercise for women (0.46). There was no relation with sex, education, or alcohol. CONCLUSIONS The study confirmed some previously reported risk factors but also suggested new ones. It raised concerns about the prescription of aspirin and perhaps other factors related to rural life.

Epidemiology of vascular dementia.

Vascular dementia (VaD) is the second commonest dementia after Alzheimers disease (AD). Epidemiological studies of this condition suffer from many shortcomings related to definition of the disease, diagnostic criteria and assessment of subjects. The prevalence of VaD increases linearly with age and varies greatly from country to country, ranging from 1.2 to 4.2% of people over 65 years old, even after adjustment for age and sex. The incidence of VaD is more homogeneous than prevalence and is estimated at 6-12 cases per 1,000 persons over 70 years per year. The mean duration of the disease is around 5 years and survival is less than for the general population and for AD. The major risk factors for VaD appear to be hypertension, diabetes, heart disease and stroke. Although some of these risk factors are modifiable, there is no study on efficacy of prevention of VaD.

The Canadian Study of Health and Aging Risk Factors for Vascular Dementia

BACKGROUND AND PURPOSE The Canadian Study of Health and Aging (CSHA) was conducted in communities and institutions in 10 Canadian provinces. One objective of the study was to study risk factors for vascular dementia (VaD). METHODS This was a population-based case-control study. It included 129 patients clinically diagnosed with VaD with duration of symptoms no more than 3 years and 535 control subjects, frequency matched by age group, study center, and residence in community or institution, who were clinically confirmed to be cognitively normal. Odds ratios (ORs) were calculated using unconditional logistic regression for potential risk factors for VaD. RESULTS Risk of VaD was associated with history of arterial hypertension (OR, 2.08; 95% confidence interval, 1.29 to 3.35). Other significantly elevated ORs were seen for history of alcohol abuse (2.45), history of heart condition (1.71), use of aspirin (3.10), and occupational exposure to pesticides and herbicides (2.60), as well as liquid plastic or rubber (2.59). The OR for less than 6 years of education compared with 10 or more years was 4.02. CONCLUSIONS The study confirmed some previously reported risk factors for VaD, such as history of heart disease. Higher levels of education seemed to lower the risk or delay onset of symptoms of VaD. Use of aspirin may be a predictor of survival rather than a risk factor. The occupational associations, particularly with pesticides and fertilizers, need further study.

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.

Impact of PRISMA, a Coordination-Type Integrated Service Delivery System for Frail Older People in Quebec (Canada): A Quasi-experimental Study

OBJECTIVES To evaluate the impact of a coordination-type integrated service delivery (ISD) model on health, satisfaction, empowerment, and services utilization of frail older people. METHODS Program of Research to Integrate Services for the Maintenance of Autonomy (PRISMA) is a population-based, quasi-experimental study with three experimental and three comparison areas. From a random selection of people 75 years or older, 1,501 persons identified at risk of functional decline were recruited (728 experimental and 773 comparison). Participants were measured over 4 years for disabilities (Functional Autonomy Measurement System), unmet needs, satisfaction with services, and empowerment. Information on utilization of health and social services was collected by bimonthly telephone questionnaires. RESULTS Over the last 2 years (when the implementation rate was over 70%), there were 62 fewer cases of functional decline per 1,000 individuals in the experimental group. In the fourth year of the study, the annual incidence of functional decline was lower by 137 cases per 1,000 in the experimental group, whereas the prevalence of unmet needs in the comparison region was nearly double the prevalence observed in the experimental region. Satisfaction and empowerment were significantly higher in the experimental group. For health services utilization, a lower number of visits to emergency rooms and hospitalizations than expected was observed in the experimental cohort. CONCLUSION The PRISMA model improves the efficacy of the health care system for frail older people.