Regional variation in the use of medications by older Canadians--a persistent and incompletely understood phenomena.

BACKGROUND: We have previously reported on regional variability in medication consumption by older Canadians. In this study, we used longitudinal data to determine whether regional differences in commonly consumed medications persisted and to explore potential explanatory factors for observed differences. METHODS: We utilized data from the second phase of the Canadian Study of Health and Aging to assess the number, types, and variability of medications used between regions. Linear and logistic regressions (LRs) were used to predict the number of medications and the use of specific agents where significant regional variability was found to exist. RESULTS: There were significant regional differences in the number of medications consumed and in the prevalence of use of acetaminophen (p < 0.002), benzodiazepines (p < 0.020), nitrates (p = 0.040), and complementary and alternative medicines (CAMs; p < 0.020). The proportion of subjects using acetaminophen was highest in British Columbia (44.6%) and lowest in Quebec (27.3%). Benzodiazepine and nitrate consumption was highest in Quebec (35.9 and 19%, respectively) and lowest in the Praires (18.2%) and Atlantic Canada (6.6%). CAM use was highest in British Columbia (47.1%) and lowest in the Atlantic region (26.8%). Similar inter-regional differences had been found 5 years previously. There were no significant regional differences in the prevalence of hypertension, myocardial infarction, diabetes, arthritis/rheumatism, or depression. Region remained a significant explanatory variable for the number of medications and nitrate, benzodiazepine, and CAM use in our multivariate models. CONCLUSIONS: Regional differences in medication use persisted over the course of this longitudinal study. Much of the variability remains unexplained. The reasons for regional differences in consumption of drugs and their clinical significance should be addressed.

A randomized controlled trial of a community-based consultation service to prevent falls.

BACKGROUND: Multifaceted programs that combine assessment with interventions have been shown to reduce subsequent falls in some clinical trials. We tested this approach to see whether it would be effective if offered as a consultation service using existing health care resources. METHODS: The subjects of this randomized controlled trial had to be aged 65 years or more and had to have fallen within the previous 3 months. They were randomly assigned to receive either usual care or the intervention, which consisted of in-home assessment in conjunction with the development of an individualized treatment plan, including an exercise program for those deemed likely to benefit. The primary outcomes were the proportion of participants who fell and the rate of falling during the following year. Visits to the emergency department and admissions to hospital were secondary outcomes. RESULTS: One hundred and sixty-three subjects were randomly assigned to either the control or the intervention group, and 152 provided data about their falls. There were no significant differences between the control and intervention groups in the cumulative number of falls (311 v. 241, p = 0.34), having one or more falls (79.2% v. 72.0%, p = 0.30) or in the mean number of falls (4.0 v. 3.2, p = 0.43). Analysis of secondary outcomes (health care use) also showed no significant differences between the intervention group and the control group. In the Cox regression analysis, there was no significant difference between the groups in the proportion of subjects having one or more falls (p = 0.55), but there was a significantly (p < 0.001) longer time between falls in the intervention group. In a post hoc subgroup analysis, subjects with more than 2 falls in the 3 months preceding study entry who had been assigned to the intervention group were less likely to fall (p = 0.046) and had a significantly longer time between falls (p < 0.001), when compared with the group who received usual care. INTERPRETATION: The intervention did not decrease significantly the cumulative number of falls, the likelihood of participants having at least one fall over the next year or the mean number of falls. It did increase significantly the time between falls in a survival analysis when age, sex and history of falling were used as covariates.

Predicting who will develop dementia in a cohort of Canadian seniors.

OBJECTIVES: We examined whether easily attainable variables were useful in predicting who became demented over a five year period and determined the rates of incident dementia for different categories of mild cognitive impairment. METHODS: This was a cohort study of subjects recruited nationally in a population-based survey of Canadians 65 years and older (the Canadian Study of Health and Aging). After standardized clinical assessments, a subset of subjects (n = 1782) was categorized as not demented at time one. Identical study methods allowed a reassessment of the cognitive status of surviving subjects (n = 892) five years later. RESULTS: Three baseline variables (Modified Mini Mental State (3MS) score, subject's age, and an informant's report of the presence of memory problems) were statistically significant predictors of the development of a dementia. An equation incorporating these three variables had a sensitivity of 79% and a specificity of 56% for predicting dementia among survivors at time two. An equation substituting the MMSE for the 3MS showed similar results. The various categories of mild cognitive impairment examined showed significantly different likelihoods for the subsequent development of a dementia. Some categories with a higher dementia risk were characterized by inclusion criteria requiring neuropsychological test scores that were greater than one standard deviation (SD) below the mean of age based normative data. CONCLUSION: In the absence of extensive laboratory, radiologic or neuropsychological tests, simple variables that can be easily determined in the course of a single clinical encounter were useful in predicting subjects with a higher risk of developing dementia. Attempts to use neuropsychological results to predict the development of dementia should look for significant impairments on age-standardized tests.

Nifedipine and mortality risk in the elderly: relevance of drug formulation, dose and duration.

PURPOSE: This study examines the risk of all-cause and cardiac-related mortality associated with calcium channel blockers (CCBs) and other antihypertensives/diuretics compared with beta-blockers among an elderly cohort. We explored variations in mortality risk according to CCB formulation, dose and duration of use. METHODS: Data are from the clinical sample of the Canadian Study of Health and Aging, a population-based prospective study of community and institutional residing persons aged 65+ years. The sample comprised 837 subjects without dementia and reporting use of 1+ antihypertensive/diuretic agents at baseline (1991) and with survival data during follow-up (1996). RESULTS: Risk of all-cause and cardiac-related mortality was significantly higher among nifedipine users (HR=1.85, 95%CI 1.12, 3.05 and HR=2.22, 95%CI 1.02, 4.84, respectively) compared with beta-blocker users. After adjusting for covariates, the hazard ratios (95% confidence interval) for selected drug classes compared with beta-blockers were: nifedipine HR=1.82 (1.09-3.04), diltiazem/verapamil HR=0.96 (0.58-1.60), loop diuretics HR=1.84 (1.21-2.82), ACE inhibitors HR=0.98 (0.54-1.78) and other diuretics/antihypertensives HR=1.10 (0.70-1.72). Among nifedipine users, mortality risk increased with average daily dose and with recent (

Health, function and survival of a cohort of very old Canadians: results from the second wave of the Canadian Study of Health and Aging.

Seniors 85 years of age and older (85+) make up the fastest-growing segment of the Canadian population. There is a need for longitudinal data on the health status of this group. We used data collected as part of the Canadian Study of Health and Aging to examine how health status changed over five years in a large (n = 1799) cohort of Canadians 85+. By the time of the follow-up assessment, 60.1% had died and 33.9% of those who had been residing in the community when the cohort was initially formed had been institutionalized. Most (79.2%) of the community survivors felt that their health had stayed the same or improved, even though over two thirds (67.9%) reported a decline in their functional abilities. Potential predictors of both good and adverse outcomes were explored. While disease prevention, health promotion and environmental modifications may decrease the personal and societal impacts of these age-associated findings, health care planning for the very old should take these data into account.

Living alone with dementia.

This report describes a population of individuals with dementia living alone in the community. Data were collected as part of the Canadian Study of Health and Aging (CSHA). We found that one third of the subjects in the CSHA sample with a dementia residing in the community lived alone. Whether their identified informal caregiver had thought about institutionalization was an important factor in actual short-term (2-year) institutionalization and appeared to be influenced by living arrangements. Caregivers of those living alone provided less hands-on assistance, experienced less burden, and were less likely to be depressed than those living with the demented person, but were more likely to have considered institutionalization. Presumably, this was driven by concerns about safety and support. How to support the growing numbers of individuals with dementia living alone in the community will be a significant challenge. Copyrightz1999S.KargerAG,Basel

Calcium-channel blockers and cognitive function in elderly people: results from the Canadian Study of Health and Aging.

BACKGROUND: Concern has been raised about the potential for adverse cognitive effects associated with the use of calcium-channel blockers (CCBs) in older people. This study was undertaken to examine prospectively the association between the use of these and other antihypertensive drugs and cognitive function. METHODS: The authors examined data from the Canadian Study of Health and Aging (CSHA), a population-based, prospective 5-year investigation of the epidemiology of dementia and other health problems in Canadians 65 years of age and older. The risk of cognitive decline, as indicated by a decline in performance on the Modified Mini-Mental State (3MS) examination over the 5-year period, was assessed in relation to the use of antihypertensive and diuretic drugs by 205 subjects with a history of hypertension and no evidence of dementia at baseline. RESULTS: The proportion of subjects whose cognitive performance declined over the study period was significantly higher in the group using CCBs than in the group using other antihypertensive agents (75% v. 59%). The adjusted odds ratio (OR) for a significant decline in cognitive performance (defined as a decrease in 3MS score of 10 points or more) was 2.28 (95% confidence interval [CI] 1.12-4.66) for subjects using CCBs. The adjusted ORs (and 95% CIs) for cognitive decline in subjects using selected antihypertensive agents or diuretics relative to those exposed to beta-blockers were as follows: angiotensin-converting-enzyme inhibitor, OR 1.36 (95% CI 0.41-4.55); diuretic or other antihypertensive drug, OR 1.45 (95% CI 0.51-4.14); dihydropyridine CCB (nifedipine), OR 1.94 (95% CI 0.52-7.27) and non-dihydropyridine CCB (diltiazem or verapamil), OR 3.72 (95% CI 1.22-11.36). INTERPRETATION: Older people taking CCBs were significantly more likely than those using other agents to experience cognitive decline. These findings are consistent with the results of previous cross-sectional research and emphasize the need for further trials to examine the associations between CCB use, blood pressure and cognitive impairment in elderly patients.

Disease, disability, and age in cognitively intact seniors: results from the Canadian Study of Health and Aging.

BACKGROUND: Many diseases have been identified as risk factors for disability in the elderly. This report contrasts disability in the old-old (85 years of age or older, 85+) with younger seniors (65-84 years of age) and examines whether diseases have an equivalent impact on the two groups. METHODS: Subjects were 603 cognitively intact community residents 65 years of age and older from 10 Canadian provinces. The purpose of the analysis was to try to isolate the effects of age and nondementing disease on function. Frequency of disease and functional disabilities was calculated. Logistic regression was used to determine significant explanatory variables for moderate, severe, or total disability and for specific disabilities. RESULTS: Nearly twice as many of the cognitively intact 85+ had functional disabilities compared to those 65-84 years of age. In the 85+, increasing age was the only significant explanatory variable for moderate, severe, or total disability and for problems with walking, showering, shopping, getting to places out of walking distance, and preparing meals. Diseases were also significant explanatory variables for functional disabilities, particularly in the 65-84 age range. An increase in the proportion with functional disability was found with increasing age even in those without the relevant disease risk factors. CONCLUSIONS: Disease prevention would only be partially effective in avoiding disability in the very old because disability occurred even in those without explanatory disease.

Folate status, vascular disease and cognition in elderly Canadians.

OBJECTIVE: To report on the relationship between serum folate levels and the prevalence of stroke, peripheral vascular disease, cognitive problems and short-term mortality in elderly people. SETTING AND PARTICIPANTS: 1171 subjects whose serum folate was determined as part of their clinical examination in the Canadian Study of Health and Aging, a population study of individuals 65 years and older. METHODS: Cross-sectional analysis compared relationships between serum folate levels and clinical features; longitudinal analysis examined mortality at follow-up by folate status at the time of the clinical examination. RESULTS: Membership in the lowest quartile for serum folate was associated with an increased likelihood of stroke. Those with low folate levels were more likely to be demented, institutionalized and depressed. In the cognitively impaired but not demented group, those with low folate levels scored lower on the Modified Mini Mental State and had more short-term memory problems. CONCLUSIONS: Low folate level was a significant explanatory variable for stroke. Low folate levels were common in all types of dementia and were associated with a history of weight loss, lower body mass index and lower serum albumin concentrations. This may reflect the reduced ability of cognitively impaired individuals to eat adequately.

Potential adverse outcomes of psychotropic and narcotic drug use in Canadian seniors.

Potential adverse outcomes (falls, impaired cognition, impaired self-care) of psychotropic (benzodiazepines, antidepressants, antipsychotics) and narcotic medication use were examined in a large sample of Canadians 65 years of age and older. We examined rates of reported falls, Digit Symbol Substitution Test (DSST) scores, and mean number of self-care impairments for those consuming psychotropic and/or narcotic drugs as compared to non-users. Use of psychotropic drugs and/or narcotics was associated with an increased prevalence of falls, lower DSST scores, and/or number of self-care difficulties. For example, in subjects who were cognitively normal, the frequency of falls was 60% greater in benzodiazepine users and 120% greater in users of antidepressants as compared to non-users. Adverse outcomes increased with the number of classes of psychotropic or narcotic medications used. These effects were most pronounced in cognitively normal subjects where the prevalence of falls increased from 13.9% in those consuming none of the medication classes to 42.6% for users of two or more classes. In subjects with mild dementia the use of these medications was not associated with any significant differences in the outcomes measured. Regression models showed that benzodiazepine, antidepressant, and narcotic use remained significant explanatory variables for potential adverse outcomes even after simultaneously considering the effects of several other variables. Although further work is necessary, our results suggest that individuals with better cognitive function may be at particular risk for adverse effects with use of these medications.

Weight, blood pressure, osmolarity, and glucose levels across various stages of Alzheimer's disease and vascular dementia.

Data collected as part of the Canadian Study of Health and Aging were analyzed to determine whether physiological changes associated with Alzheimer's disease are common to other types of dementia and are related more to the severity of cognitive impairment. We found that blood pressure and body mass index decreased with increasing dementia severity in both probable Alzheimer's disease and vascular dementia. There were no differences in mean random blood glucose levels or serum osmolarities between types or stages of dementia. We conclude that certain 'hypometabolic' features are associated with dementia severity and are not unique to Alzheimer's disease.

Correlates of self-rated health in persons aged 85 and over: results from the Canadian Study of Health and Aging.

This report describes self-rated health in 1,239 non-institutionalized Canadians aged 85 years and over who participated in the Canadian Study of Health and Aging. Most (76.8%) rated their health positively (i.e., very or pretty good). Stepwise multiple regression was used to determine the variables that were significantly correlated with self-rated health. A modestly successful model for predicting self-rated health (R2 = 0.27) was developed. Better understanding of the determinants of healthy aging hopefully will lead to effective interventions to improve the quality of life of the very old.

Complementary medicine use in a dementia clinic population.

Complementary medicine is frequently utilized for a variety of chronic health problems. We evaluated its use among patients attending a Canadian dementia clinic. Using a telephone survey, we inquired about the use of alternative therapy, including nutritional supplements, herbal remedies, and chelation therapy, for problems with cognition. Only 9.6% of our patient population used complementary medicine as a treatment for cognitive problems. A further 29% used complementary medicines for general health promotion. While higher use might have been anticipated because of the limited conventional therapies available, we did not find a high prevalence of consumption of alternative medicine for cognitive problems. Knowledge of the use of these therapies is still important and should not be neglected. A nonjudgmental inquiry into all therapies being used (for whatever reason) should be part of the assessment of any patient with suspected dementia.

Primitive reflexes and dementia: results from the Canadian Study of Health and Aging.

We report on the prevalence of primitive reflexes (PR) and their association with cognitive, behavioural, functional and clinical characteristics in 2914 Canadians 65 years and older. Data were collected as part of the Canadian Study of Health and Aging (1990-92) and included individuals living in the community and in institutions. PR were more commonly found in demented subjects. Demented subjects with prehensile PR (i.e. grasp, traction, suck) had significantly more functional and behavioural problems and were more severely demented. The presence of any PR increased the likelihood of other neurological findings (e.g. bradykinesia). Vascular dementia (VD) cases were more likely to have unilateral primitive PR than probable Alzheimer's disease (Pro AD) and Parkinson's dementia (PD) cases. PD cases were more likely to have glabellar and traction responses. While more common among the demented, PR lacked sufficient sensitivity to be an early diagnostic tool for dementia. Prehensile PR may help to define particular types or severity of dementia.

Cognitive impairment in the nondemented elderly. Results from the Canadian Study of Health and Aging.

STUDY OBJECTIVE: To describe a population that was categorized as "cognitively impaired not demented" (CIND) and to examine the utility of some of the proposed criteria for describing this degree of cognitive impairment. DESIGN: Population-based prevalence study of dementia in those subjects who were 65 years and older. SETTING: Community and institutional settings in Canada. SUBJECTS: Individuals who underwent a clinical evaluation (N = 2914). INTERVENTION: Initial screening with the Modified Mini-Mental State Examination (3MS) to identify potential cognitive impairment; the 3MS was followed by a detailed clinical examination to confirm the presence of dementia and to determine the probable cause. Clinical examinations were performed on all those subjects who were residing in institutions, those in the community with a 3MS score less than 78, and a sample of those in the community with a 3MS score of 78 or more. Neuropsychological testing was performed as part of the clinical examination when the 3MS score was 50 or more. At the conclusion of the assessment, subjects were categorized as being cognitively normal, CIND, and demented. MEASUREMENTS: Frequency of a diagnosis of CIND; demographical, cognitive, and functional characteristics of cognitively normal and CIND subjects and those with early and late dementia; and proportion of subjects who were CIND and met the proposed criteria. RESULTS: Subjects who were categorized as CIND were common and fell between cognitively normal subjects and those with dementia in terms of age, 3MS score, general intellectual function, and performance of daily activities. Because of the restrictive inclusion and exclusion criteria, the proposed criteria for cognitive impairment described only 30% of our subjects who were CIND. CONCLUSIONS: Subjects who were categorized as CIND appeared to be distinct from and intermediate between subjects with dementia and cognitively normal subjects. Most individuals did not meet the criteria that were evaluated for describing this group. While the various criteria that were evaluated may accurately define a select subset of cognitively impaired individuals, the natural history and prognosis of such groups, currently unknown, may not be generalizable to the larger population of subjects who are CIND. Further work is needed to clearly define this group, and longitudinal studies are required to determine an outcome.

Progression and outcome of patients in a Canadian dementia clinic.

Five hundred and fifty-three patients were referred to a Canadian dementia clinic for standardized evaluation. The majority (83.5%) had a dementia with Alzheimer's disease (AD) accounting for 89% of dementias. Patients with probable AD who were followed for five years had variable rates of progression, increased mortality (37.1%, 2.5 times the expected rate) and a high rate of institutionalization (79%). Simple demographic (age) and social factors (marital status) were strong predictors for institutionalization. It was extremely difficult at presentation to predict the rate of progression. The prevalence of AD in autopsied cases was 62.5%. Clinic patients were younger, had milder dementias, and were more likely to have AD than patients identified in the course of a contemporaneous population-based dementia prevalence study.

Prevalence and types of dementia in the very old: results from the Canadian Study of Health and Aging.

We report on the prevalence of dementia in Canadians age 85 years and older. The purpose of this study was to determine whether the prevalence of dementia continued to increase in the very old, and to define the types of dementia and their relative proportions in this age group. We collected data as part of the Canadian Study of Health and Aging (1990 to 1992), which consisted of a sample of 1,835 subjects from a population of 283,510 Canadians who were 85 years of age and older residing in the community or in institutions. The prevalence of dementia in the 85 years and older group was 28.5%, more than twice that of the 75- to 84-years cohort. The prevalence of dementia of 23% in the 85- to 89-years sample (n = 1,332) increased to 40% in the 90 to 94 years group (n = 371) and, in the 95 years and older sample (n = 104), reached 58%. Overall, Alzheimer's disease (AD; probable or possible) accounted for 75% of all dementias; a vascular etiology alone accounted for 13% of dementias. The proportion of clinically diagnosed AD cases to vascular dementia cases increased significantly after age 65 and was higher in the 85+ group than in a younger cohort (65 to 84 years).

Nonidet P40 and the retrograde transport of horseradish peroxidase in undamaged visceral nerves.

The cell bodies of origin of peripheral nerves, in particular visceral nerves, are often difficult to identify using standard horseradish peroxidase (HRP) methods. The non-ionic surfactant Nonidet-P40, when applied to intact peripheral nerve along with HRP, allows the investigator to examine the neurons of origin of the nerve without cutting the fibers or injecting label into its peripheral terminal field.