Increased winter mortality from acute myocardial infarction and stroke: the effect of age.
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OBJECTIVES: We examined seasonal variations in mortality from acute myocardial infarction (AMI) and stroke by age using 300,000 deaths in the Canadian Mortality Database for the years 1980 to 1982 and 1990 to 1992. BACKGROUND: The effect of age on environmental determinants of AMI and stroke is not well understood. METHODS: Seasonal variations were analyzed by month and for the four seasons (winter beginning in December). A chi-square test was used to test for homogeneity at p < 0.01, and relative risk ratios (RRs) for high and low periods were determined in relation to the overall mean. For each of four age subgroups, the magnitude of the seasonal variation was reported as the difference in mortality between the highest and lowest frequency seasons. RESULTS: By month, AMI deaths were highest in January (RR = 1.090) and lowest in September (RR = 0.904), a relative risk difference of 18.6%. The seasonal mortality variation in AMI deaths (winter vs. summer) increased with increasing age: 5.8% for <65, 8.3% for 65 to 74, 13.4% for 75 to 84 and 15.8% for >85 years (p < 0.005 for trend). Stroke mortality peaked in January (RR = 1.113) and had a trough in September (RR = 0.914), a relative risk difference of 19.9%. The seasonal variation in stroke mortality also increased with age. Seasonal variations were not seen in those aged <65 years, compared with 11.6% for 65 to 74, 15.2% for 75 to 84 and 19.3% for >85 years (p < 0.005 for trend). CONCLUSIONS: The elderly demonstrate a greater winter increase in AMI and stroke mortality than younger individuals. An understanding of these seasonal patterns may provide novel avenues for research in cardiovascular disease prevention. (+info)
Look before you leap: stratify before you standardize.
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This paper presents a mathematical model to show the conditions in which age standardization can be used to summarize age-specific rates for comparison purposes over calendar time. It shows that the conditions for valid comparison depend on the type of measure used for comparison, that is, difference, ratio, or percent change. If the measure for comparison is a difference of the standardized rates at two time points, then the age-specific rates need to maintain a constant rate difference over time for the comparison to be valid. If the measure for comparison is a ratio or percent change of the standardized rates at two time points, then the age-specific rates need to maintain a constant rate ratio over time for the comparison to be valid. Since in reality, as shown by our Canadian empirical data, age-specific rates do not always maintain a consistent pattern over time, it is recommended that one should always stratify the data to look at patterns of age-specific rates before applying age standardization. (+info)
Advocacy--answering old mail. Canadian Association of General Surgeons.
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Since its inception in 1977, the Canadian Association of General Surgeons (CAGS) has struggled with its responsibility to represent general surgeons in practices across this country. The CAGS has tended to be mute in the presentation of many of its accomplishments, which have improved the role of specialists in community practice, training programs and the subspecialties of general surgery. With the forthcoming changes in direction for the Royal College of Physicians and Surgeons of Canada, based on a recent external survey, the CAGS has a golden opportunity to advocate for a clear identity, autonomous from the Royal College for the purposes of scientific meetings, continuing professional development, scientific and practice affiliation with other surgical specialty societies, and new developments with corporate sector support for advancements in science technology and education. Advocacy for general surgery must be stressed as the priority for the CAGS into the future. (+info)
Early experience with simulated trauma resuscitation.
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Although trauma resuscitation is best taught through direct exposure with hands-on experience, the opportunities for this type of teaching in Canada are limited by the relatively low incidence of serious injury and the consolidation of trauma care to a small number of centres. Simulators have been used extensively outside the health care environment and more recently have been used by anesthetists to simulate intraoperative crises. In this paper early experience using a realistic mannequin, controlled by a remote computer, that simulates a variety of physiologic and injury specific variables is presented. The resource implications of simulated resuscitation are reviewed, including one-time and operating costs. Simulated trauma resuscitation may be an educational alternative to "real-life" trauma resuscitation, but careful evaluation of the benefits and resource implications of this type of teaching through well-designed research studies will be important. (+info)
End-stage renal disease in Canada: prevalence projections to 2005.
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BACKGROUND: The incidence and prevalence of end-stage renal disease (ESRD) have increased greatly in Canada over the last 2 decades. Because of the high cost of therapy, predicting numbers of patients who will require dialysis and transplantation is necessary for nephrologists and health care planners. METHODS: The authors projected ESRD incidence rates and therapy-specific prevalence by province to the year 2005 using 1981-1996 data obtained from the Canadian Organ Replacement Register. The model incorporated Poisson regression to project incidence rates, and a Markov model for patient follow-up. RESULTS: Continued large increases in ESRD incidence and prevalence were projected, particularly among people with diabetes mellitus. As of Dec. 31, 1996, there were 17,807 patients receiving renal replacement therapy in Canada. This number was projected to climb to 32,952 by the end of 2005, for a relative increase of 85% and a mean annual increase of 5.8%. The increased prevalence was projected to be greatest for peritoneal dialysis (6.0% annually), followed by hemodialysis (5.9%) and functioning kidney transplant (5.7%). The projected annual increases in prevalence by province ranged from 4.4%, in Saskatchewan, to 7.5%, in Alberta. INTERPRETATION: The projected increases are plausible when one considers that the incidence of ESRD per million population in the United States and other countries far exceeds that in Canada. The authors predict a continued and increasing short-fall in resources to accommodate the expected increased in ESRD prevalence. (+info)
Non-heart-beating organ donors as a source of kidneys for transplantation: a chart review.
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BACKGROUND: Organ transplantation is the treatment of choice for patients with end-stage organ failure, but the supply of organs has not increased to meet demand. This study was undertaken to determine the potential for kidney donation from patients with irremediable brain injuries who do not meet the criteria for brain death and who experience cardiopulmonary arrest after withdrawal of ventilatory support (controlled non-heart-beating organ donors). METHODS: The charts of 209 patients who died during 1995 in the Emergency Department and the intensive care unit at the Foothills Hospital in Calgary were reviewed. The records of patients who met the criteria for controlled non-heart-beating organ donation were studied in detail. The main outcome measure was the time from discontinuation of ventilation until cardiopulmonary arrest. RESULTS: Seventeen potential controlled non-heart-beating organ donors were identified. Their mean age was 62 (standard deviation 19) years. Twelve of the patients (71%) had had a cerebrovascular accident, and more than half (10 [59%]) did not meet the criteria for brain death because one or more brain stem reflexes were present. At the time of withdrawal of ventilatory support, the mean serum creatinine level was 71 (29) mumol/L, mean urine output was 214 (178) mL/h, and 9 (53%) patients were receiving inotropic agents. The mean time from withdrawal of ventilatory support to cardiac arrest was 2.3 (5.0) hours; 13 of the 17 patients died within 1 hour, and all but one died within 6 hours. For the year for which charts were reviewed, 33 potential conventional donors (people whose hearts were beating) were identified, of whom 21 (64%) became donors. On the assumption that 40% of the potential controlled non-heart-beating donors would not in fact have been donors (25% because of family refusal and 15% because of nonviability of the organs), there might have been 10 additional donors, which would have increased the supply of cadaveric kidneys for transplantation by 48%. INTERPRETATION: A significant number of viable kidneys could be retrieved and transplanted if eligibility for kidney donation was extended to include controlled non-heart-beating organ donors. (+info)
House fire injury prevention update. Part I. A review of risk factors for fatal and non-fatal house fire injury.
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OBJECTIVE: To summarize house fire injury risk factor data, using relative risk estimation as a uniform method of comparison. METHODS: Residential fire risk factor studies were identified as follows: MEDLINE (1983 to March 1997) was searched using the keywords fire*/burn*, with etiology/cause*, prevention, epidemiology, and smoke detector* or alarm*. ERIC (1966 to March 1997) and PSYCLIT (1974 to June 1997) were searched by the above keywords, as well as safety, skills, education, and training. Other sources included: references of retrieved publications, review articles, and injury prevention books; Injury Prevention journal hand search; government documents; and internet sources. When not provided by the authors, relative risk (RR), odds ratio, and standardized mortality ratios were calculated, to enhance comparison between studies. RESULTS: Fifteen relevant articles were retrieved, including two case-control studies. Non-modifiable risk factors included young age (RR 1.8-7.5), old age (RR 2.6-3.6), male gender (RR 1.4-2.9), non-white race (RR 1.3-15.0), low income (RR 3.4), disability (RR 2.5-6.5), and late night/early morning occurrence (RR 4.1). Modifiable risk factors included place of residence (RR 2.1-4.2), type of residence (RR 1.7-10.5), smoking (RR 1.5 to 7.7), and alcohol use (RR 0.7-7.5). Mobile homes and homes with fewer safety features, such as a smoke detector or a telephone, presented a higher risk of fatal injury. CONCLUSIONS: Risk factor data should be used to assist in the development, targeting, and evaluation of preventive strategies. Development of a series of quantitative systematic reviews could synthesize existing data in areas such as house fire injury prevention. (+info)
Health care in Canada: incrementalism under fiscal duress.
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Driven by fiscal pressures in the 1990s, Canada's provincial Medicare systems cut inpatient care, expanded community services, and consolidated hospitals under regional authorities in nine of ten provinces. Public confidence has been badly shaken by the transition. No province has successfully integrated services across the continuum of care. Home care and prescription drug coverage vary from province to province. Efforts to reform physician payment have stalled, and capacity to measure and manage the quality of care is generally underdeveloped. Thus, for the next few years, policymakers must stabilize the acute care sector, while cautiously pursuing an agenda of piece-meal reforms. (+info)