Canadian medical education: 50 years of innovation and leadership.

Over the past 50 years, many Canadian medical educators have pursued ideas and visions, as individuals in the 1950s and 1960s and later in partnership with various national bodies. Relations between universities and national medical organizations have been productive in dealing with issues of postgraduate education and clinical assessment, in particular. From 1970 to 1990, strong education offices and formally trained educators led to many successes in the areas of research in cognition, continuing medical education and clinical assessment. Canadian medical education has now achieved international recognition for its work in all aspects of the continuum of the physician''s education through vision, initiative and cooperation.     

Drugs,Money, and Power: The Canadian Drug Shortage

This article describes the shortage of generic injectable medications in Canada that affected hospitals in 2012. It traces the events leading up to the drug shortage, the causes of the shortage, and the responses by health administrators, pharmacists, and ethicists. The article argues that generic drug shortages are an ethical problem because health care organizations and governments have an obligation to avoid exposing patients to resource scarcity. The article also discusses some options governments could pursue in order to secure the drug supply and thereby fulfill their ethical obligations.     

Canadian outpatients and advance directives: poor knowledge and little experience but positive attitudes.

OBJECTIVE: To examine the knowledge of, previous experience with, attitudes toward and perceived barriers to completing advance directives among outpatients at two general medicine clinics. DESIGN: Cross-sectional questionnaire administered in face-to-face structured interviews. SETTING: General internal-medicine outpatient clinics at a university teaching hospital. PATIENTS: One hundred and five adult outpatients who could communicate in spoken English and who consented to be interviewed. RESULTS: Of 167 patients approached, 58 were excluded because they could not communicate in spoken English, and 4 refused to participate. Of the remaining 105 patients, 17 (16%) knew about living wills, 12 (11%) about durable powers of attorney for health care and 4 (4%) about advance directives. Twenty-three (22%) had thought about their preferences for life-sustaining treatment, 20 (19%) had discussed them, none had written them down, and 45 (43%) had thought about choosing a proxy. Sixty-one (58%) wanted to think about their preferences for treatment, 65 (62%) wanted to discuss them, 32 (30%) wanted to write them down, and 80 (76%) wanted to choose a proxy. The perceived barriers to completing an advance directive were inability to write, the belief that an advance directive was unnecessary, a fatalistic attitude, previous discussion of preferences, a desire to leave the decision to doctors, uncertainty about preferences, a desire to discuss preferences rather than document them, a desire to wait until the situation arose, a desire to write down preferences in the future and a desire to avoid thinking about preferences or advance directives. Respondents with more knowledge of life-sustaining treatments were more likely to want to complete an advance directive. CONCLUSIONS: Outpatients have positive attitudes toward advance directives, but their knowledge and experience are limited. These data underscore the need for patient education and for policies to eliminate the barriers to completing advance directives that patients face.     

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.     

Focus: The Aging Brain: Social capital,health, and elderly driver status

Driving a car enables many people to engage in meaningful activities that, in turn, help develop and maintain personal social capital. Social capital, a combination of community participation and social cohesion, is important in maintaining well-being. This paper argues that social capital can provide a framework for investigating the general role of transportation and driving a car specifically to access activities that contribute to connectedness and well-being among older people. This paper proposes theoretically plausible and empirically testable hypotheses about the relationship between driver status, social capital, and well-being. A longitudinal study may provide a new way of understanding, and thus of addressing, the well-being challenges that occur when older people experience restrictions to, or loss of, their driver’s license.     

Semantics in action: an electrophysiological study on the use of semantic knowledge for action.

Recent studies have supported close interactions between language and action-related processes, suggesting comparable neural mechanisms. However, relatively little is known about the semantics involved in action planning. The present study investigated the activation of semantic knowledge in meaningful actions by recording event-related potentials (ERPs). Subjects prepared meaningful or meaningless actions with objects and made a semantic categorization response before executing the action. Words presented could be either congruent or incongruent with respect to the goal of the action. Preparation of meaningful actions elicited a larger anterior N400 for words incongruent to the present action goal as compared to congruent words, while no N400 effect was found when subjects prepared meaningless actions. These findings indicate that the preparation of meaningful actions with objects is accompanied by the activation of semantic information representing the usual action goals associated with those objects.     

Incidence and outcomes of diabetes mellitus in elderly people: report from the Canadian Study of Health and Aging

BACKGROUND: The epidemiology of diabetes in elderly people is not well understood. The purpose of this study was to estimate the incidence of diabetes mellitus among elderly people in Canada and the relative risks of death and admission to an institution among elderly diabetic patients. METHODS: The study was a secondary analysis of data for a community-dwelling sample from the Canadian Study of Health and Aging, a nationwide representative cohort study of 9008 elderly people (65 years of age or older at baseline) in Canada. Diabetes was identified primarily by self-reporting, and a clinician''s diagnosis and the presence of treatments for diabetes were used to identify diabetic patients who did not report that they had the condition. RESULTS: The reliability of self-reported diabetes (the kappa statistic) was 0.85. The estimated annual incidence of diabetes was 8.6 cases per thousand for elderly Canadians. Incidence decreased with age, from 9.5 for subjects 65-74 years of age, to 7.9 for those 75-84 years of age and then to 3.1 for those 85 years of age and older. Diabetes was associated with death (relative risk 1.87, 95% confidence interval 1.59-2.19) and admission to an institution (relative risk 1.58, 95% confidence interval 1.28-1.94). INTERPRETATION: Diabetes mellitus is common among elderly people, but the incidence declines among the very old.     

Causes of Blindness in Canada: An Analysis of 24,605 Cases Registered with The Canadian National Institute for the Blind

A survey of blind persons in Canada, based on registrations with The Canadian National Institute for the Blind (C.N.I.B.), is reported. This is the first study of its type having national scope and based on data registered in a central file. It covered 24,605 living registered blind persons ranging from premature infants to very elderly persons. Causes of blindness are broken down with respect to topography (site and type of lesion) and etiology. In terms of frequency, the principal causes were lesions affecting the globe (e.g. glaucoma, myopia), 36%; the retina, 23%; the lens, 16%; and the optic nerve, 11%. In this study, 32% of the blindness was due to prenatal causes. The prevalence of blindness per 100,000 persons in Canada, based on C.N.I.B. data, was 131, varying among the provinces from 108 to 376. Serious ocular disease was four times more prevalent than blindness; 101,436 such cases (the prevention group) were listed by the C.N.I.B.     

Food-web studies in shallow eutrophic lakes by the Netherlands Institute of Ecology: Main results,knowledge gaps and new perspectives

For more than 20 years scientists of the ‘Food-chain studies’ Group of the former Limnological Institute have been studying interactions within the pelagic food web. Purpose of research was to explain the structure and dynamics of the zooplankton and fish communities in lakes and reservoirs in relation to biotic and abiotic environmental factors. A so-called multi-species approach was used, in which all common and abundant species within a specific ecosystem were studied on the individual and population level with the same degree of detail. The recent results and the scientific approach used are evaluated and the main gaps in knowledge about food-web dynamics in shallow eutrophic lakes are identified and discussed. It is concluded that instead of the purely functional approach used so far, future studies should also include evolutionary aspects which determine the success of an organism in a given environment and that more attention should be paid to central questions in ‘community ecology’. This paper is based on a lecture given by the first author for the Netherlands Society of Aquatic Ecology on May 12th, 1992, in Amsterdam, The Netherlands.