Prior national surveys suggested that treatment and control of hypertension were poor in individu... more Prior national surveys suggested that treatment and control of hypertension were poor in individuals with diabetes. Using measured blood pressures, we estimated prevalence, awareness, treatment, and control of hypertension between 2007 and 2009 among Canadians with diabetes and sought to determine whether a treatment gap still exists for individuals with diabetes. Using data from cycle 1 of the Canadian Health Measures Survey, estimates of hypertension prevalence, awareness, treatment, and control were described and compared between individuals with and without self-reported diabetes. Three-quarters of individuals reporting diabetes also had hypertension; of these, 89% (95% confidence interval [CI], 80%-98%) were aware, 88% (95% CI, 81%-94%) were treated, and 56% (95% CI, 45%-66%) were controlled to < 130/80 mm Hg. Among those treated with pharmacotherapy, 39% (95% CI, 31%-48%) were using monotherapy, 29% (95% CI, 18%-40%) were taking 2 medications, and 31% (95% CI, 22%-39%) were taking 3 or more medications; control to < 130/80 mm Hg was achieved by 63% (95% CI, 53%-74%). Among those treated, individuals with diabetes were significantly less likely to be treated to their recommended target (< 130/80 mm Hg) compared with individuals without diabetes (< 140/90 mm Hg; odds ratio(adjusted) 0.3; 95% CI, 0.2-0.6). Hypertension treatment and control among people with diabetes have improved in Canada during the past 2 decades. Nonetheless, nearly half of people with diabetes are above the treatment target. Health care professionals should continue to increase their efforts in supporting patients with diabetes in achieving blood pressure control, with emphasis on lifestyle management and pharmacotherapy.
Background: It is unclear whether blood pressure control varies across the spectrum of atheroscle... more Background: It is unclear whether blood pressure control varies across the spectrum of atherosclerotic risk. Methods: We used data from nonpregnant adults who had fasted laboratory samples drawn for the 2007-2009 cycle of the Canadian Health Measures Survey (CHMS) or the 2005-2008 US National Health and Nutrition Examination Survey (NHANES). Results: The 1692 CHMS subjects and 3541 NHANES participants were demographically similar (aged a mean of 45 years), although NHANES participants exhibited higher obesity rates (33.8% vs 22.2%, P < 0.001). Over 80% of CHMS and NHANES subjects with hypertension had at least 1 other cardiovascular risk factor. As the number of atherosclerotic risk factors increased, hypertension prevalence increased, but blood pressure control rates improved (from 48% among hypertensives with no other risk factors in CHMS to 77% RESUME
Objectives: This article compares influenza vaccination rates in 1996/97 and 2000/01 and describe... more Objectives: This article compares influenza vaccination rates in 1996/97 and 2000/01 and describes the characteristics of adults who were vaccinated. Data sources: The data on influenza vaccination are from the 1996/97 National Population Health Survey and the 2000/01 Canadian Community Health Survey, both conducted by Statistics Canada. Data on hospitalizations and deaths are from the Hospital Mortality Data Base and the Canadian Mortality Data Base, respectively. Analytical techniques: Cross-tabulations were used to estimate rates of vaccination among seniors, people with chronic conditions, and the total population aged 20 or older. Multiple logistic regression was used to assess relationships between being vaccinated and selected characteristics. Main results: Between 1996/97 and 2000/01, the percentage of Canadians aged 20 or older who reported having had a flu shot the previous year rose from 16% to 28%. Rates were higher for seniors and people with chronic conditions. The odds of vaccination were high for residents of middle-to-high income households, people with at least some postsecondary education, former smokers, and people with a regular doctor. Smokers and people who reported their health as good to excellent had lower odds of being vaccinated.
Comparing influenza-related mortality and health care use between Ontario and other Canadian prov... more Comparing influenza-related mortality and health care use between Ontario and other Canadian provinces, Jeffrey Kwong and colleagues find evidence that Ontario's universal vaccination program has reduced the burden of influenza
Current clinical approaches may not always be helpful in the early differentiation of necrotic ti... more Current clinical approaches may not always be helpful in the early differentiation of necrotic tissue from ischemic viable myocardium in patients with acute myocardial infarction. Tc-99m-glucaric acid is a carbohydrate ligand that may permit differentiation of necrosis from ischemia. However, the myocardial kinetics of Tc-99m-glucaric acid have not been well defined early after myocardial injury. The aim of this study was to evaluate the effect of necrosis in comparison to postischemic injury alone on the kinetics of Tc-99m-glucaric acid with the use of an isolated perfused rat heart model. Three groups of hearts were studied: group I: control (n = 6); group II: postischemia (15 minutes of no flow with complete reperfusion, n = 6); and group III: necrosis (90 minutes of no flow to induce necrosis with complete reperfusion, n = 6). Tc-99m-glucaric acid (1.3 +/- 0.6 mCi/L of buffer) was perfused for 30 minutes to evaluate tracer accumulation. Then tracer-free buffer was perfused for 45 minutes to evaluate clearance. The peak accumulation relative to the control group mean was significantly increased (p &lt; 0.01) in group III (necrosis) (254% +/- 75%) compared with control (100% +/- 10%) and compared with postischemia (108% +/- 26%). On kinetic data analysis, the monoexponential clearance rate constant: (kc) was significantly reduced with necrosis (control: kc = 20.2 +/- 14.0 x 10(-4) sec-1; postischemia: kc = 22.3 +/- 15.2 x 10(-4) sec-1; and necrosis: kc = 1.2 +/- 0.3 x 10(-4) sec-1; p &lt; 0.05). A retention fraction was calculated from the activity after 45 minutes of clearance corrected for the peak activity for each group. The necrotic group had significant myocardial retention in comparison to control and postischemia (control: 12% +/- 8%; postischemia: 14% +/- 16%; necrosis: 64% +/- 10%; p &lt; 0.01). The accumulation and retention of Tc-99m-glucaric acid is markedly increased in the presence of myocardial necrosis in comparison to control and postischemic myocardial injury. In this model, Tc-99m-glucaric acid is capable of defining the presence of necrotic myocardial injury in comparison to postischemic injury alone. This agent may have potential application for the early differentiation of ischemic from necrotic myocardium in acute myocardial infarction.
Objectives This article examines the association between introduction of Ontario's Universal Infl... more Objectives This article examines the association between introduction of Ontario's Universal Influenza Immunization Program and changes in vaccination rates over time in Ontario, compared with the other provinces combined.
The possible role of magnesium (Mg) deficiency in cardiovascular disease (CVD) has been stressed ... more The possible role of magnesium (Mg) deficiency in cardiovascular disease (CVD) has been stressed and reviewed in the literature (Szelenzi, 1973; Seelig and Heggtveit, 1974; Birch and Giles, 1977; Neri and Johansen, 1978). These and other articles have stimulated a new interest in the relationship between Mg and CVD, and it was in this context that the World Health Organization (WHO) Collaborating Center for Reference on Studies of Cardiovascular Disease in Relation to Water Quality of the Department of Epidemiology, at the University of Ottawa, Ottawa, Canada and the Bureau of Epidemiology, National Health, and Welfare of Canada, cosponsored a workshop March 9th and 10th; 1978 to study the feasibility, practicality, and modality of magnesium intervention trials. The participants were Profs. T. Anderson and D. Hewitt from Toronto, Dr. H.L. Johansen, Mr. J.R. Marier, and Prof. L.C. Neri from Ottawa, Prof. G. Fodor from Newfoundland, Dr. M. Seelig from New Jersey, and Dr. R. Sharrett from Bethesda, Maryland. In the initial review of the available evidence, the following points were stressed.
Data from the Discharge Abstract Database of the Canadian Institute for Health Information were u... more Data from the Discharge Abstract Database of the Canadian Institute for Health Information were used to examine acute care hospital days for patients with a mental condition coded as the most responsible diagnosis or a comorbid diagnosis. In 2009/2010, patients with a mental diagnosis represented 11.8% of people who had been hospitalized and 25.5% of acute care hospital days. Those for whom the mental condition was the most responsible diagnosis accounted for 9.0% of hospital days (1.2 million), and those with a comorbid mental diagnosis accounted for 16.5% of hospital days (2.3 million). Mental diagnoses were often associated with physical conditions. The average hospitalization with a mental diagnosis was two and a half times as long as the average for hospitalizations without a mental diagnosis. About one-quarter of hospital days with a mental diagnosis were designated as alternate level of care days.
Objectives: This article examines the association between introduction of Ontario's Universal Inf... more Objectives: This article examines the association between introduction of Ontario's Universal Influenza Immunization Program and changes in vaccination rates over time in Ontario, compared with the other provinces combined. Data sources: The data are from the 1996/97 National Population Health Survey and the 2000/01 and 2003 Canadian Community Health Survey, both conducted by Statistics Canada. Analytical techniques: Cross-tabulations were used to estimate vaccination rates for the total population aged 12 or older, for groups especially vulnerable to the effects of influenza, and by selected socio-demographic variables. Z tests and multiple logistic regression were used to examine differences between estimates. Main results: Between 1996/97 and 2000/01, the increase in the overall vaccination rate in Ontario was 10 percentage points greater than the increase in the other provinces combined. Increases in Ontario were particularly pronounced among people who were: younger than 65, more educated, and had a higher household income. Between 2000/01 and 2003, vaccination rates were stable in Ontario, while rates continued to rise in the other provinces. Even so, Ontario's 2003 rates exceeded those in the other provinces.
In 1983, Bendectin was voluntarily removed from the market by Merrell Dow Pharmaceuticals Inc. be... more In 1983, Bendectin was voluntarily removed from the market by Merrell Dow Pharmaceuticals Inc. because of the many product liability suits pending. Earlier, 10 to 25% of pregnancies were exposed to Bendectin and over the years the drug was used in as many as 33 million pregnancies. The scientific evidence available pointed to the safety of Bendectin. This article considers some of the effects of the withdrawal of the drug. In 1983, hospital admissions for excessive vomiting in pregnancy per thousand live births rose by 37% over 1980-82 ratios and by 50% in 1984. In the United States, hospitalization rose by similar amounts. A rough estimate of excess hospital costs over the years 1983-87 is $16 million for Canada and $73 million for the U.S. Such estimates do not take into consideration other costs, such as extra physician visits, increased absenteeism from work, and the effect on quality of life of the pregnant woman and her family. No decrease in rates of congenital malformations could be shown to offset this increased cost to society.
S udden cardiac death is the second-leading cause of death in the United States, with over 400 00... more S udden cardiac death is the second-leading cause of death in the United States, with over 400 000 deaths annually 1,2 (comparable data for Canada are unavailable). Most such sudden deaths are from ventricular fibrillation secondary to coronary artery disease; 3 primary ventricular arrhythmias, bradycardia, asystole and pulseless electrical activity are the other broad mechanisms. Studies 4-6 published prior to the major trials 7-9 of implantable cardioverter defibrillators showed that survivors of sudden cardiac arrest are at high risk of another episode within a few years; over half of the deaths that result are due to recurrences. There have been 3 large randomized studies that compared cardioverter defibrillator implantation with the best known medical therapy, in patients surviving sudden cardiac death. 7-9 The largest of these was the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial, reported in 1997, 7 which at 1 year found a relative reduction in deaths of 39%; the other studies 8,9 showed similar results. A metaanalysis 10 of all 3 studies indicated that implantable cardioverter defibrillators reduced the relative risk of recurrent sudden cardiac death by 50% (95% confidence interval [CI] 0.37%-0.67%) and death from any cause by 28% (95% CI 0.60%-0.87%). Since 1998, the guidelines of the American College of Cardiology and the American Heart Association have recommended that a "cardiac arrest due to ventricular fibrillation or ventricular tachycardia not due to a transient or reversible cause is a class 1 indication for an implantable cardioverter defibrillator." 11 The Canadian guidelines, first published in 2000, are similar. 12 Previous data from Ontario have revealed a low rate of cardioverter defibrillator implantation (12.8%) after an out-of-hospital cardiac arrest. 13 The aims of our study were 3-fold: to examine temporal trends of cardioverter defibrillator implantation in Canada during periods before and after publication of the related trials and guidelines; to compare implant rates in Canada with those in the United States; and to examine in detail the factors influencing implantation in Canada. Methods Study population We obtained data on all Canadian and US patients with a primary diagnosis of cardiac arrest, ventricular fibrillation or ventricular flutter and not also having a diagnosis of myocardial infarction who survived to be discharged from hospital for the period
Abstract Among elderly people seeking treatment for nonheroin opioid addiction, by far the larges... more Abstract Among elderly people seeking treatment for nonheroin opioid addiction, by far the largest source of the opioids for feeding their addiction was physician prescriptions. Knowing the patterns of prescribing potentially addictive medication such as opioids and benzodiazepines and derivatives will be informative. Prescribing strong opioids is a balancing act among a variety of pressures, such as providing optimal pain control, minimizing potential for abuse, and dealing with side effects. In spite of the restrictions on the use of addictive drugs, use of strong opioids such as oxycodone continues to increase. Use of large prescription databases shows that polypharmacy of addictive medications is common, and that multiple prescribers are involved. Reducing the number of prescribers will likely improve the quality of prescribing.
Objectives This article examines the association between introduction of Ontario's Universal Infl... more Objectives This article examines the association between introduction of Ontario's Universal Influenza Immunization Program and changes in vaccination rates over time in Ontario, compared with the other provinces combined.
Objective: to examine the changing pattern of age distributions of hospitalisation for chronic ob... more Objective: to examine the changing pattern of age distributions of hospitalisation for chronic obstructive pulmonary disease (COPD) among Canadian men and women. Design: retrospective cohort study. Participants: 257,604 COPD inpatients aged 55-90 years with 463,089 hospital admissions during a 3-year study period (1994/95, 1995/96 and 1996/97) in Canada. Main outcome measures: COPD listed as one of the first five underlying diagnoses (broad definition, 463,089 hospitalisations) or as first diagnosis (narrow definition, 142,770 hospitalisations). Results: overall, men were more likely to have hospitalisations for COPD and had a higher proportion of death at hospital than did women. The 3-year cumulative incidence was 42.2/1,000 for the broadly defined COPD hospitalisation and 14.0/ 1,000 for the narrowly defined COPD hospitalisation, and steadily increased with increasing age. The relative risk for women versus men gradually increased with decreasing age, and was significantly greater than unity in the 55-59 year group for narrowly defined COPD hospitalisation. Conclusions: in terms of impact on secondary care COPD is a disease of the elderly and is becoming more common in women, particularly in younger age groups.
Record linkage in the context of epidemiology refers to the putting together of information (reco... more Record linkage in the context of epidemiology refers to the putting together of information (records) on the same person which may have been recorded on different occasions and became part of different data collections. The objective of this article is to provide an overview of the use of record linkage in epidemiology, particularly as it pertains to nutrition and food studies. A short description of epidemiological methodology is provided in order to clarify what epidemiologists expect to achieve by record linkage. A general description of the mechanics of record linkage explains how the methodology relates to the quality of the resulting data sets. The potential impact of the approach of record linkage on epidemiological research is discussed, particularly as it relates to nutritional and other food related studies. Ethical considerations related to record linkage are discussed, and in conclusion the future of record linkage is considered.
Objectives: The self-reported prevalence of risk factors for heart disease among Canadians with a... more Objectives: The self-reported prevalence of risk factors for heart disease among Canadians with and without heart disease is estimated. The characteristics associated with these risk factors are examined in order to identify groups to be targeted for primary and secondary prevention. Data source: The data are from the household component of the 1994/95 National Population Health Survey (NPHS). Analytical techniques: For the population aged 20 and older with and without heart disease, bivariate and multiple regression analyses were used to determine associations between four risk factors (smoking, high blood pressure, diabetes, and inactivity) and demographic characteristics and socioeconomic status. Main results: According to the NPHS, 4.4% of people aged 20 and older reported that they heart disease. However, many more adults had risk factors for this disease. As well, about one-quarter of those without heart disease and half of those with heart disease had two or more risk factors. To some extent, many of these risks are modifiable. The groups particularly at risk were people older than 35, those with less than high school graduation, those in households with inadequate income, people who consumed three or more drinks a day, and residents of the Atlantic provinces, Quebec and Ontario.
Prior national surveys suggested that treatment and control of hypertension were poor in individu... more Prior national surveys suggested that treatment and control of hypertension were poor in individuals with diabetes. Using measured blood pressures, we estimated prevalence, awareness, treatment, and control of hypertension between 2007 and 2009 among Canadians with diabetes and sought to determine whether a treatment gap still exists for individuals with diabetes. Using data from cycle 1 of the Canadian Health Measures Survey, estimates of hypertension prevalence, awareness, treatment, and control were described and compared between individuals with and without self-reported diabetes. Three-quarters of individuals reporting diabetes also had hypertension; of these, 89% (95% confidence interval [CI], 80%-98%) were aware, 88% (95% CI, 81%-94%) were treated, and 56% (95% CI, 45%-66%) were controlled to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 130/80 mm Hg. Among those treated with pharmacotherapy, 39% (95% CI, 31%-48%) were using monotherapy, 29% (95% CI, 18%-40%) were taking 2 medications, and 31% (95% CI, 22%-39%) were taking 3 or more medications; control to &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 130/80 mm Hg was achieved by 63% (95% CI, 53%-74%). Among those treated, individuals with diabetes were significantly less likely to be treated to their recommended target (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 130/80 mm Hg) compared with individuals without diabetes (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 140/90 mm Hg; odds ratio(adjusted) 0.3; 95% CI, 0.2-0.6). Hypertension treatment and control among people with diabetes have improved in Canada during the past 2 decades. Nonetheless, nearly half of people with diabetes are above the treatment target. Health care professionals should continue to increase their efforts in supporting patients with diabetes in achieving blood pressure control, with emphasis on lifestyle management and pharmacotherapy.
Background: It is unclear whether blood pressure control varies across the spectrum of atheroscle... more Background: It is unclear whether blood pressure control varies across the spectrum of atherosclerotic risk. Methods: We used data from nonpregnant adults who had fasted laboratory samples drawn for the 2007-2009 cycle of the Canadian Health Measures Survey (CHMS) or the 2005-2008 US National Health and Nutrition Examination Survey (NHANES). Results: The 1692 CHMS subjects and 3541 NHANES participants were demographically similar (aged a mean of 45 years), although NHANES participants exhibited higher obesity rates (33.8% vs 22.2%, P < 0.001). Over 80% of CHMS and NHANES subjects with hypertension had at least 1 other cardiovascular risk factor. As the number of atherosclerotic risk factors increased, hypertension prevalence increased, but blood pressure control rates improved (from 48% among hypertensives with no other risk factors in CHMS to 77% RESUME
Objectives: This article compares influenza vaccination rates in 1996/97 and 2000/01 and describe... more Objectives: This article compares influenza vaccination rates in 1996/97 and 2000/01 and describes the characteristics of adults who were vaccinated. Data sources: The data on influenza vaccination are from the 1996/97 National Population Health Survey and the 2000/01 Canadian Community Health Survey, both conducted by Statistics Canada. Data on hospitalizations and deaths are from the Hospital Mortality Data Base and the Canadian Mortality Data Base, respectively. Analytical techniques: Cross-tabulations were used to estimate rates of vaccination among seniors, people with chronic conditions, and the total population aged 20 or older. Multiple logistic regression was used to assess relationships between being vaccinated and selected characteristics. Main results: Between 1996/97 and 2000/01, the percentage of Canadians aged 20 or older who reported having had a flu shot the previous year rose from 16% to 28%. Rates were higher for seniors and people with chronic conditions. The odds of vaccination were high for residents of middle-to-high income households, people with at least some postsecondary education, former smokers, and people with a regular doctor. Smokers and people who reported their health as good to excellent had lower odds of being vaccinated.
Comparing influenza-related mortality and health care use between Ontario and other Canadian prov... more Comparing influenza-related mortality and health care use between Ontario and other Canadian provinces, Jeffrey Kwong and colleagues find evidence that Ontario's universal vaccination program has reduced the burden of influenza
Current clinical approaches may not always be helpful in the early differentiation of necrotic ti... more Current clinical approaches may not always be helpful in the early differentiation of necrotic tissue from ischemic viable myocardium in patients with acute myocardial infarction. Tc-99m-glucaric acid is a carbohydrate ligand that may permit differentiation of necrosis from ischemia. However, the myocardial kinetics of Tc-99m-glucaric acid have not been well defined early after myocardial injury. The aim of this study was to evaluate the effect of necrosis in comparison to postischemic injury alone on the kinetics of Tc-99m-glucaric acid with the use of an isolated perfused rat heart model. Three groups of hearts were studied: group I: control (n = 6); group II: postischemia (15 minutes of no flow with complete reperfusion, n = 6); and group III: necrosis (90 minutes of no flow to induce necrosis with complete reperfusion, n = 6). Tc-99m-glucaric acid (1.3 +/- 0.6 mCi/L of buffer) was perfused for 30 minutes to evaluate tracer accumulation. Then tracer-free buffer was perfused for 45 minutes to evaluate clearance. The peak accumulation relative to the control group mean was significantly increased (p &lt; 0.01) in group III (necrosis) (254% +/- 75%) compared with control (100% +/- 10%) and compared with postischemia (108% +/- 26%). On kinetic data analysis, the monoexponential clearance rate constant: (kc) was significantly reduced with necrosis (control: kc = 20.2 +/- 14.0 x 10(-4) sec-1; postischemia: kc = 22.3 +/- 15.2 x 10(-4) sec-1; and necrosis: kc = 1.2 +/- 0.3 x 10(-4) sec-1; p &lt; 0.05). A retention fraction was calculated from the activity after 45 minutes of clearance corrected for the peak activity for each group. The necrotic group had significant myocardial retention in comparison to control and postischemia (control: 12% +/- 8%; postischemia: 14% +/- 16%; necrosis: 64% +/- 10%; p &lt; 0.01). The accumulation and retention of Tc-99m-glucaric acid is markedly increased in the presence of myocardial necrosis in comparison to control and postischemic myocardial injury. In this model, Tc-99m-glucaric acid is capable of defining the presence of necrotic myocardial injury in comparison to postischemic injury alone. This agent may have potential application for the early differentiation of ischemic from necrotic myocardium in acute myocardial infarction.
Objectives This article examines the association between introduction of Ontario's Universal Infl... more Objectives This article examines the association between introduction of Ontario's Universal Influenza Immunization Program and changes in vaccination rates over time in Ontario, compared with the other provinces combined.
The possible role of magnesium (Mg) deficiency in cardiovascular disease (CVD) has been stressed ... more The possible role of magnesium (Mg) deficiency in cardiovascular disease (CVD) has been stressed and reviewed in the literature (Szelenzi, 1973; Seelig and Heggtveit, 1974; Birch and Giles, 1977; Neri and Johansen, 1978). These and other articles have stimulated a new interest in the relationship between Mg and CVD, and it was in this context that the World Health Organization (WHO) Collaborating Center for Reference on Studies of Cardiovascular Disease in Relation to Water Quality of the Department of Epidemiology, at the University of Ottawa, Ottawa, Canada and the Bureau of Epidemiology, National Health, and Welfare of Canada, cosponsored a workshop March 9th and 10th; 1978 to study the feasibility, practicality, and modality of magnesium intervention trials. The participants were Profs. T. Anderson and D. Hewitt from Toronto, Dr. H.L. Johansen, Mr. J.R. Marier, and Prof. L.C. Neri from Ottawa, Prof. G. Fodor from Newfoundland, Dr. M. Seelig from New Jersey, and Dr. R. Sharrett from Bethesda, Maryland. In the initial review of the available evidence, the following points were stressed.
Data from the Discharge Abstract Database of the Canadian Institute for Health Information were u... more Data from the Discharge Abstract Database of the Canadian Institute for Health Information were used to examine acute care hospital days for patients with a mental condition coded as the most responsible diagnosis or a comorbid diagnosis. In 2009/2010, patients with a mental diagnosis represented 11.8% of people who had been hospitalized and 25.5% of acute care hospital days. Those for whom the mental condition was the most responsible diagnosis accounted for 9.0% of hospital days (1.2 million), and those with a comorbid mental diagnosis accounted for 16.5% of hospital days (2.3 million). Mental diagnoses were often associated with physical conditions. The average hospitalization with a mental diagnosis was two and a half times as long as the average for hospitalizations without a mental diagnosis. About one-quarter of hospital days with a mental diagnosis were designated as alternate level of care days.
Objectives: This article examines the association between introduction of Ontario's Universal Inf... more Objectives: This article examines the association between introduction of Ontario's Universal Influenza Immunization Program and changes in vaccination rates over time in Ontario, compared with the other provinces combined. Data sources: The data are from the 1996/97 National Population Health Survey and the 2000/01 and 2003 Canadian Community Health Survey, both conducted by Statistics Canada. Analytical techniques: Cross-tabulations were used to estimate vaccination rates for the total population aged 12 or older, for groups especially vulnerable to the effects of influenza, and by selected socio-demographic variables. Z tests and multiple logistic regression were used to examine differences between estimates. Main results: Between 1996/97 and 2000/01, the increase in the overall vaccination rate in Ontario was 10 percentage points greater than the increase in the other provinces combined. Increases in Ontario were particularly pronounced among people who were: younger than 65, more educated, and had a higher household income. Between 2000/01 and 2003, vaccination rates were stable in Ontario, while rates continued to rise in the other provinces. Even so, Ontario's 2003 rates exceeded those in the other provinces.
In 1983, Bendectin was voluntarily removed from the market by Merrell Dow Pharmaceuticals Inc. be... more In 1983, Bendectin was voluntarily removed from the market by Merrell Dow Pharmaceuticals Inc. because of the many product liability suits pending. Earlier, 10 to 25% of pregnancies were exposed to Bendectin and over the years the drug was used in as many as 33 million pregnancies. The scientific evidence available pointed to the safety of Bendectin. This article considers some of the effects of the withdrawal of the drug. In 1983, hospital admissions for excessive vomiting in pregnancy per thousand live births rose by 37% over 1980-82 ratios and by 50% in 1984. In the United States, hospitalization rose by similar amounts. A rough estimate of excess hospital costs over the years 1983-87 is $16 million for Canada and $73 million for the U.S. Such estimates do not take into consideration other costs, such as extra physician visits, increased absenteeism from work, and the effect on quality of life of the pregnant woman and her family. No decrease in rates of congenital malformations could be shown to offset this increased cost to society.
S udden cardiac death is the second-leading cause of death in the United States, with over 400 00... more S udden cardiac death is the second-leading cause of death in the United States, with over 400 000 deaths annually 1,2 (comparable data for Canada are unavailable). Most such sudden deaths are from ventricular fibrillation secondary to coronary artery disease; 3 primary ventricular arrhythmias, bradycardia, asystole and pulseless electrical activity are the other broad mechanisms. Studies 4-6 published prior to the major trials 7-9 of implantable cardioverter defibrillators showed that survivors of sudden cardiac arrest are at high risk of another episode within a few years; over half of the deaths that result are due to recurrences. There have been 3 large randomized studies that compared cardioverter defibrillator implantation with the best known medical therapy, in patients surviving sudden cardiac death. 7-9 The largest of these was the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial, reported in 1997, 7 which at 1 year found a relative reduction in deaths of 39%; the other studies 8,9 showed similar results. A metaanalysis 10 of all 3 studies indicated that implantable cardioverter defibrillators reduced the relative risk of recurrent sudden cardiac death by 50% (95% confidence interval [CI] 0.37%-0.67%) and death from any cause by 28% (95% CI 0.60%-0.87%). Since 1998, the guidelines of the American College of Cardiology and the American Heart Association have recommended that a "cardiac arrest due to ventricular fibrillation or ventricular tachycardia not due to a transient or reversible cause is a class 1 indication for an implantable cardioverter defibrillator." 11 The Canadian guidelines, first published in 2000, are similar. 12 Previous data from Ontario have revealed a low rate of cardioverter defibrillator implantation (12.8%) after an out-of-hospital cardiac arrest. 13 The aims of our study were 3-fold: to examine temporal trends of cardioverter defibrillator implantation in Canada during periods before and after publication of the related trials and guidelines; to compare implant rates in Canada with those in the United States; and to examine in detail the factors influencing implantation in Canada. Methods Study population We obtained data on all Canadian and US patients with a primary diagnosis of cardiac arrest, ventricular fibrillation or ventricular flutter and not also having a diagnosis of myocardial infarction who survived to be discharged from hospital for the period
Abstract Among elderly people seeking treatment for nonheroin opioid addiction, by far the larges... more Abstract Among elderly people seeking treatment for nonheroin opioid addiction, by far the largest source of the opioids for feeding their addiction was physician prescriptions. Knowing the patterns of prescribing potentially addictive medication such as opioids and benzodiazepines and derivatives will be informative. Prescribing strong opioids is a balancing act among a variety of pressures, such as providing optimal pain control, minimizing potential for abuse, and dealing with side effects. In spite of the restrictions on the use of addictive drugs, use of strong opioids such as oxycodone continues to increase. Use of large prescription databases shows that polypharmacy of addictive medications is common, and that multiple prescribers are involved. Reducing the number of prescribers will likely improve the quality of prescribing.
Objectives This article examines the association between introduction of Ontario's Universal Infl... more Objectives This article examines the association between introduction of Ontario's Universal Influenza Immunization Program and changes in vaccination rates over time in Ontario, compared with the other provinces combined.
Objective: to examine the changing pattern of age distributions of hospitalisation for chronic ob... more Objective: to examine the changing pattern of age distributions of hospitalisation for chronic obstructive pulmonary disease (COPD) among Canadian men and women. Design: retrospective cohort study. Participants: 257,604 COPD inpatients aged 55-90 years with 463,089 hospital admissions during a 3-year study period (1994/95, 1995/96 and 1996/97) in Canada. Main outcome measures: COPD listed as one of the first five underlying diagnoses (broad definition, 463,089 hospitalisations) or as first diagnosis (narrow definition, 142,770 hospitalisations). Results: overall, men were more likely to have hospitalisations for COPD and had a higher proportion of death at hospital than did women. The 3-year cumulative incidence was 42.2/1,000 for the broadly defined COPD hospitalisation and 14.0/ 1,000 for the narrowly defined COPD hospitalisation, and steadily increased with increasing age. The relative risk for women versus men gradually increased with decreasing age, and was significantly greater than unity in the 55-59 year group for narrowly defined COPD hospitalisation. Conclusions: in terms of impact on secondary care COPD is a disease of the elderly and is becoming more common in women, particularly in younger age groups.
Record linkage in the context of epidemiology refers to the putting together of information (reco... more Record linkage in the context of epidemiology refers to the putting together of information (records) on the same person which may have been recorded on different occasions and became part of different data collections. The objective of this article is to provide an overview of the use of record linkage in epidemiology, particularly as it pertains to nutrition and food studies. A short description of epidemiological methodology is provided in order to clarify what epidemiologists expect to achieve by record linkage. A general description of the mechanics of record linkage explains how the methodology relates to the quality of the resulting data sets. The potential impact of the approach of record linkage on epidemiological research is discussed, particularly as it relates to nutritional and other food related studies. Ethical considerations related to record linkage are discussed, and in conclusion the future of record linkage is considered.
Objectives: The self-reported prevalence of risk factors for heart disease among Canadians with a... more Objectives: The self-reported prevalence of risk factors for heart disease among Canadians with and without heart disease is estimated. The characteristics associated with these risk factors are examined in order to identify groups to be targeted for primary and secondary prevention. Data source: The data are from the household component of the 1994/95 National Population Health Survey (NPHS). Analytical techniques: For the population aged 20 and older with and without heart disease, bivariate and multiple regression analyses were used to determine associations between four risk factors (smoking, high blood pressure, diabetes, and inactivity) and demographic characteristics and socioeconomic status. Main results: According to the NPHS, 4.4% of people aged 20 and older reported that they heart disease. However, many more adults had risk factors for this disease. As well, about one-quarter of those without heart disease and half of those with heart disease had two or more risk factors. To some extent, many of these risks are modifiable. The groups particularly at risk were people older than 35, those with less than high school graduation, those in households with inadequate income, people who consumed three or more drinks a day, and residents of the Atlantic provinces, Quebec and Ontario.
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Papers by Helen Johansen