Surveillance of ischemic heart disease should include physician billing claims: population-based evidence from administrative health data across seven Canadian provinces.

BACKGROUND: Canadian provinces and territories routinely collect health information for administrative purposes. This study used Canadian medical and hospital administrative data for population-based surveillance of diagnosed ischemic heart disease (IHD). METHODS: Hospital discharge abstracts and physician billing claims data from seven provinces were analyzed to estimate prevalence and incidence of IHD using three validated algorithms: a) one hospital discharge abstract with an IHD diagnosis or procedure code (1H); b) 1H or at least three physician claims within a one-year period (1H3P) and c) 1H or at least two physician claims within a one-year period (1H2P). Crude and age-standardized prevalence and incidence rates were calculated for Canadian adults aged 20 +. RESULTS: IHD prevalence and incidence varied by province, were consistently higher among males than females, and increased with age. Prevalence and incidence were lower using the 1H method compared to using the 1H2P or 1H3P methods in all provinces studied for all age groups. For instance, in 2006/07, crude prevalence by province ranged from 3.4%-5.5% (1H), from 4.9%-7.7% (1H3P) and from 6.0%-9.2% (1H2P). Similarly, crude incidence by province ranged from 3.7-5.9 per 1,000 (1H), from 5.0-6.9 per 1,000 (1H3P) and from 6.1-7.9 per 1,000 (1H2P). CONCLUSIONS: Study findings show that incidence and prevalence of diagnosed IHD will be underestimated by as much as 50% using inpatient data alone. The addition of physician claims data are needed to better assess the burden of IHD in Canada.

Self-monitoring of blood glucose in type 2 diabetes: Results of the 2011 Survey on Living with Chronic Diseases in Canada.

BACKGROUND: For insulin-treated patients with type 2 diabetes mellitus (T2DM), self-monitoring of blood glucose (SMBG) may be vital in adjusting insulin dosages. For patients who do not use insulin, evidence supporting the use of SMBG is inconclusive. METHODS: The prevalence, frequency and correlates of SMBG are examined. Data pertain to 2,682 individuals aged 20 or older with T2DM who responded to the 2011 Survey on Living with Chronic Diseases in Canada. Multivariate prevalence rate ratios for associations between respondents' characteristics and their use of SMBG were derived using binomial regression models. RESULTS: A large majority of the study population (87.8%) reported SMBG. No difference in the prevalence of SMBG was observed between oral medication users compared with insulin users; however, the frequency of SMBG was lower for those taking oral medication only. Significant determinants of SMBG were a health professional's recommendation, having insurance coverage, and receiving an A1C test from a health professional. INTERPRETATION: The use of SMBG by adults with T2DM is common, and does not differ between those taking oral medication only and those treated with insulin.

Long-term association between leisure-time physical activity and changes in happiness: analysis of the Prospective National Population Health Survey.

Happiness is among the most fundamental of all human goals. Although the short-term association between physical activity and happiness is well known, the long-term associations are not. Data from the National Population Health Survey cycles conducted between 1994/1995 and 2008/2009 (cycles 1 through 8) were analyzed. Happy respondents were classified as physically active or inactive at baseline and then were followed up in subsequent cycles to examine their likelihood of becoming unhappy. Individuals who changed their activity level also were examined. After controlling for potential confounding factors, the authors found that leisure-time physical activity (LTPA) was associated with reduced odds of unhappiness after 2 years and 4 years. People who were inactive in 2 consecutive cycles were more than twice as likely to be unhappy as those who remained active in both cycles after 2 years. Compared with those who became active, inactive participants who remained inactive were also more likely to become unhappy. A change in LTPA from active to inactive was associated with increased odds of becoming unhappy 2 years later. This study suggests that LTPA has a long-term association with happiness. Changes in LTPA are associated with subsequent mood status.

Diagnosed hypertension in Canada: incidence, prevalence and associated mortality.

BACKGROUND: Hypertension is a leading risk factor for cardiovascular diseases. Our objectives were to examine the prevalence and incidence of diagnosed hypertension in Canada and compare mortality among people with and without diagnosed hypertension. METHODS: We obtained data from linked health administrative databases from each province and territory for adults aged 20 years and older. We used a validated case definition to identify people with hypertension diagnosed between 1998/99 and 2007/08. We excluded pregnant women from the analysis. RESULTS: This retrospective population-based study included more than 26 million people. In 2007/08, about 6 million adults (23.0%) were living with diagnosed hypertension and about 418,000 had a new diagnosis. The age-standardized prevalence increased significantly from 12.5% in 1998/99 to 19.6% in 2007/08, and the incidence decreased from 2.7 to 2.4 per 100. Among people aged 60 years and older, the prevalence was higher among women than among men, as was the incidence among people aged 75 years and older. The prevalence and incidence were highest in the Atlantic region. For all age groups, all-cause mortality was higher among adults with diagnosed hypertension than among those without diagnosed hypertension. INTERPRETATION: The overall prevalence of diagnosed hypertension in Canada from 1998 to 2008 was high and increasing, whereas the incidence declined during the same period. These findings highlight the need to continue monitoring the effectiveness of efforts for managing hypertension and to enhance public health programs aimed at preventing hypertension.

Influence of Combustion Modifiers on the Cure Kinetics of Glycidyl Azide Polymer Based Propellant-Evaluated through Rheo-Kinetic Approach.

To investigate the influence of combustion modifiers on the curing of glycidyl azide polymer spherical propellants (GAPSPs), the curing process of the GAPSPs was explored using an isothermal rheological measurement method. The parameters of cure kinetics were solved to further establish a kinetic model for the curing reaction of GAPSPs. The results showed that the curing process of GAPSPs under isothermal conditions conformed to the Kamal and LSK (Lu⁻Shim⁻Kim) models. The model data indicated significant agreement with the experimental data. The influence of four kinds of combustion performance modifiers on the curing process was explored and the results demonstrated that lead phthalate had a catalytic effect on the curing reaction of GAPSPs, whilst oxides of lead and copper, and copper adipate had no influence on the curing reaction.

Comorbid Conditions in Canadians Hospitalized Because of Diabetes.

OBJECTIVES: The number of hospital discharges involving type 1 or type 2 diabetes as the first-listed diagnosis has increased over the past few decades. Such cases are commonly associated with various comorbidities. We analyzed data collected from hospital separations in Canada to determine the number and proportion of comorbid conditions in Canadians hospitalized because of diabetes. METHODS: The most responsible diagnosis (MRDx) of diabetes (ICD-10-CA: E10 [type 1 diabetes] or E11 [type 2 diabetes]) was identified from acute care hospital separations (Discharge Abstract Database) from 2013 to 2014 in all Canadian jurisdictions except Quebec. Hospital separations were calculated by 5-year age groups and sex. The most common comorbid (secondary) diagnoses were identified for hospital separations with diabetes as the MRDx, and the average lengths of stay associated with diabetes were determined. RESULTS: The total number of hospital separations in 2013-2014 in Canada (excluding Quebec) with diabetes as the MRDx in all ages was 30,422, and males represented more than half (58.7%) of the separations. The median age group when diabetes is the MRDx is 60 to 64. For all patients hospitalized with an MRDx of diabetes, there were 2.2% deaths. Hypertension was the most common comorbid diagnosis in patients with diabetes as the MRDx, followed by glomerular disorders, peripheral angiopathy and acute renal failure. CONCLUSIONS: Hospitalizations resulting from diabetes are associated with vascular comorbidities, and hypertension is the most common. Prevention of shared predisposing factors should reduce the burden of hospitalizations associated with diabetes.

The Development and Feasibility Assessment of Canadian Quality Indicators for Atrial Fibrillation.

In 2010, the Canadian Cardiovascular Society embarked on an initiative to develop pan-Canadian quality indicators (QIs) and standardized data definitions with the ultimate goal of monitoring, comparing, and contrasting national cardiovascular care and its outcomes. One of the first working groups to be established was tasked with identifying and then defining a set of QIs for atrial fibrillation/flutter (AF/AFL). The Canadian Cardiovascular Society "Best Practices for Developing Cardiovascular Quality Indicators" methodology was used to develop an initial catalogue of 25 QIs intended to measure critical issues around access, process, and outcomes relating to AF/AFL management. This list was subsequently pared down to 5 QIs felt to have the greatest relative importance for quality assurance and measurability so as to facilitate early adoption. Three of these QIs were finally selected to assess the feasibility of their measurement using existing administrative datasets. These were the number of patients with a diagnosis of nonvalvular AF/AFL at high risk of stroke (75 years or older, or CHADS2 ≥ 2) receiving an oral anticoagulant, and the rates of stroke and major haemorrhage in patients with nonvalvular AF/AFL according to CHA2DS2-VASc score and anticoagulant use. Despite their clear importance in assessing AF/AFL care, none of these 3 QIs were found to be readily measurable across Canada using existing national datasets. Investment in new medical data infrastructure is required to facilitate regular monitoring of QIs to improve cardiovascular care.

Canadian Cardiovascular Society Quality Indicators for Heart Failure.

A working group was convened by the Canadian Cardiovascular Society (CCS) in 2010 to identify quality indicators (QIs) for heart failure (HF). Using the CCS "Best Practices for Developing Cardiovascular Quality Indicators" methodology, a total of 49 "long-list" QIs was identified and rated. Subsequent ranking and discussion led to the selection of an initial "short-list" of 6 QIs to evaluate quality care, including daily assessment of blood chemistry indicators, chest radiography, patient education, in-hospital use of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, assessment of left ventricular function, and 30-day hospital readmission. The short-list QIs were selected as being important for quality assurance and because the patient information, for the most part, can be captured during the inpatient setting, which would allow these QIs to be adopted more easily. These 6 QIs were subjected to a feasibility test that found that even within the inpatient setting, there is a significant gap between the existing knowledge infrastructure and the necessary information-tracking processes to measure QIs. Only 1 QI (30-day hospital readmission) can currently be measured comparatively across Canada, although the other 5 of 6 short-list QIs can be measured using other data collected by jurisdictions. Standardization and enhancements to knowledge infrastructure are essential to provide the comprehensive patient data necessary to evaluate the quality of HF care across Canada.

Predictors of decreased physical activity level over time among adults: a longitudinal study.

BACKGROUND: Leisure-time physical activity (LTPA) plays a key role in chronic disease prevention and health promotion. The impact of life-changing events on LTPA among adults is unknown. PURPOSE: To examine the association between life-changing events and decreased LTPA levels. METHODS: Eight cycles of Canadian National Population Health Survey data were used for this study. A total of 12,901 respondents aged ≥18 years in 1994-1995 completed biannual follow-ups until 2008-2009. The association between life-changing events and decreased LTPA in any 2-year period was assessed with adjustment of potential confounding factors. Data were analyzed in 2012. RESULTS: From 1994-1995 to 2008-2009, nine of ten people changed their LTPA levels. Within each 2-year period, individuals were more likely to decrease their LTPA levels if they married within the 2-year period (men); became or remained overweight/obese (women); remained a regular smoker (men); became or remained unhealthy (men and women); developed or continued to have body pain (women); and acquired social support or remained without support (men). CONCLUSIONS: Most people change their LTPA levels or patterns, which are significantly influenced by life-changing events. An improved understanding of factors that influence LTPA may help better target those at high risk.

Assessing the burden of hospitalized and community-care heart failure in Canada.

BACKGROUND: The surveillance of heart failure (HF) is currently conducted using either survey or hospital data, which have many limitations. Because Canada is collecting medical information in administrative health data, the present study seeks to propose methods for the national surveillance of HF using linked population-based data. METHODS: Linked administrative data from 5 Canadian provinces were analyzed to estimate prevalence, incidence, and mortality rates for persons with HF between 1996/1997 and 2008/2009 using 2 case definitions: (1) 1 hospitalization with an HF diagnosis in any field (H_Any) and (2) 1 hospitalization in any field or at least 2 physician claims within a 1-year period (H_Any_2P). One hospitalization with an HF diagnosis code in the most responsible diagnosis field (H_MR) was also compared. Rates were calculated for individuals aged ≥ 40 years. RESULTS: In 2008/2009, combining the 5 provinces (approximately 82% of Canada's total population), both age-standardized HF prevalence and incidence were underestimated by 39% and 33%, respectively, with H_Any when compared with H_Any_2P. Mortality was higher in patients with H_MR compared with H_Any. The degree of underestimation varied by province and by age, with older age groups presenting the largest differences. Prevalence estimates were stable over the years, especially for the H_Any_2P case definition. CONCLUSIONS: The prevalence and incidence of HF using inpatient data alone likely underestimates the population rates by at least 33%. The addition of physician claims data is likely to provide a more inclusive estimate of the burden of HF in Canada.

Erectile dysfunction and fruit/vegetable consumption among diabetic Canadian men.

OBJECTIVE: To evaluate the association between fruit/vegetable consumption and erectile dysfunction (ED) among Canadian men with diabetes. METHODS: Data from the 2011 Survey on Living with Chronic Diseases in Canada - Diabetes Component were analyzed using Statistical Analysis System Enterprise Guide (SAS EG). Respondents were asked a series questions related to their sociodemographics, lifestyle, and chronic health conditions. The association between fruit/vegetable consumption and ED was examined using logistic regression after controlling for potential confounding factors. Bootstrap procedure was used to estimate sample distribution and calculate confidence intervals. RESULTS: Overall, 26.2% of respondents reported having ED. The prevalence increased with age and duration of diabetes. Compared with respondents without ED, those with ED were more likely to be obese, smokers, physically inactive, and either divorced, widowed, or separated. Diabetes complications such as nerve damage, circulation problems, and kidney failure or kidney disease were also significantly associated with ED. After controlling for potential confounding factors, a 10% risk reduction of ED was found with each additional daily serving of fruit/vegetable consumed. CONCLUSION: ED is common among Canadian men with diabetes. ED was highly associated with age, duration of diabetes, obesity, smoking, and the presence of other diabetes-related complications. Fruit and vegetable consumption might have a protective effect against ED.

Comparison of diagnosed, self-reported, and physically-measured hypertension in Canada.

BACKGROUND: Hypertension is a substantial health concern because it poses significant risks for cardiovascular morbidity and mortality and is highly prevalent in the population. Tracking hypertension is important because it is a risk factor for other conditions, but prevalence estimates might vary depending on the data source used. METHODS: This report describes 3 national population-based data sources for estimating hypertension prevalence in Canada and discusses their strengths and weaknesses to aid in their use for policy and program planning. They are compared based on: sample coverage, case identification, and prevalence estimates. RESULTS: Each source produces a different measure of hypertension prevalence, as follows: (1) diagnosed hypertension from the Canadian Chronic Disease Surveillance System (CCDSS) (2007/2008); (2) self-reported diagnosed hypertension from the Canadian Community Health Survey (CCHS) (2007-2008); and, (3) physically-measured hypertension from the Canadian Health Measures Survey (CHMS) (2007-2009). Crude rates and counts of hypertension prevalence among individuals aged 20 to 79 years of age, excluding pregnant women, are compared, resulting in prevalence ranging from 18.2% in self-report data to 20.3% in diagnosed data. The data sources differ in terms of target population, case identification, and limitations, which affects the estimates. CONCLUSIONS: Each source has unique strengths and is best suited for addressing particular research questions. For example, diagnosed hypertension can be used to determine health care utilization patterns, self-reported to examine health determinants, and measured high blood pressure to improve awareness, treatment, and control. Combined, they can address multiple issues and increase our knowledge of hypertension in Canada.

Incidence, cardiovascular complications and mortality of hypertension by sex and ethnicity.

OBJECTIVE: To compare ethnic and sex difference in the incidence of newly diagnosed hypertension, and subsequent risk of cardiovascular disease outcomes among South Asian, Chinese and white patients. METHODS: We identified patients with newly diagnosed hypertension aged ≥20 years. Patients were followed for 1-9 years for all-cause mortality and cardiovascular disease with myocardial infarction, heart failure and stroke. Cox proportional hazard models stratified by sex and adjusted for age, median income and co-morbid conditions, were constructed to determine the independent association between ethnicity and the development of the combined cardiovascular endpoint as well as death. RESULTS: There were 39 175 South Asian (49.4% men, 34.4% age ≥65), 49 892 Chinese (48.1% men, 36.7% age ≥65) and 841 277 white (47.9% men, 38.8% age ≥65) patients with newly diagnosed hypertension. Age and sex adjusted incidence of hypertension was highest in South Asian patients and lowest in Chinese patients. Compared with white patients, South Asian and Chinese patients had a lower mortality (adjusted HR (aHR) 0.91 and 0.66) and risk of cardiovascular disease outcomes (aHR 0.94 and 0.49). Compared to men, women had significantly lower mortality (aHR: 0.83 for Chinese, 0.78 for South Asian and 0.77 for white) and cardiovascular disease outcomes (0.72 for Chinese, 0.63 for South Asian and 0.65 for white). CONCLUSIONS: South Asian patients had higher rates of hypertension compared to the other ethnic groups. South Asian and Chinese patients had a lower risk of death and developing cardiovascular outcomes compared to whites. Women with hypertension have a better prognosis than men regardless of ethnicity.

The impact of cardiovascular risk-factor profiles on blood pressure control rates in adults from Canada and the United States.

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% among those with 3 or more risk factors, and from 35% to 53% in NHANES). However, the converse was not true: The distribution of Framingham risk scores for those subjects with "controlled hypertension" was nearly identical to the distribution among those adults with uncontrolled hypertension in both CHMS and NHANES and substantially higher than scores in normotensive subjects. CONCLUSIONS: Although control of blood pressure was better in patients with multiple atherosclerotic risk factors, hypertensives with controlled blood pressures exhibited risk-factor profiles similar to those of participants with uncontrolled blood pressures. This suggests the need, in educational messaging and therapy decision making, for an increased focus on total atherosclerotic risk rather than just blood pressure control.

Comorbidities and mortality associated with hospitalized heart failure in Canada.

BACKGROUND: Heart failure (HF) is a leading morbid cause of hospitalization and death. HF is often accompanied by comorbid conditions, increasing the health care burden. This study describes hospital mortality and identifies comorbid conditions associated with HF. METHODS: Acute care hospital separations in 2005-2006, with a diagnosis of HF I50, I500, I501, I509 (The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Canada [ICD-10-CA]) were identified from all Canadian jurisdictions except Québec. RESULTS: A total of 2,457,527 hospital separations among 1,812,923 individuals, identifying 8,212,869 diagnoses were reported. Among those, a total of 33,693 (1.9%) of all hospitalized individuals had a most responsible diagnosis of HF, accounting for 42,399 hospital separations. Further, HF was coded 77,049 times as a comorbid diagnosis, altogether occurring in 4.9% of all hospitalizations. The most common primary diagnoses associated with comorbid HF were acute myocardial infarction (AMI), chronic obstructive pulmonary disease (COPD), and pneumonia. Seniors had a much higher hospitalization rate due to HF. Hospitalized individuals with a primary diagnosis of HF had an almost 3-fold higher 30-day in-hospital mortality rate and nearly double the mean hospital stay than that for all causes. On average, hospitalizations with a primary diagnosis of HF had 3.9 comorbidities, most commonly chronic ischemic heart disease (IHD), atrial fibrillation and flutter, diabetes, renal failure, etc.; 1.7 times greater for HF than for all causes. CONCLUSIONS: HF has a high in-hospital mortality rate particularly among the elderly and is associated with many cardiac and noncardiac conditions. HF necessitates long hospital stays, which increases the burden on the health care system in Canada.

Prevalence of, and barriers to, preventive lifestyle behaviors in hypertension (from a national survey of Canadians with hypertension).

Patients with hypertension are advised to lower their blood pressure to <140/90 mm Hg through sustained lifestyle modification and/or pharmacotherapy. To describe the use of lifestyle changes for blood pressure control and to identify the barriers to these behaviors, the data from 6,142 Canadians with hypertension who responded to the 2009 Survey on Living With Chronic Diseases in Canada were analyzed. Most Canadians with diagnosed hypertension reported limiting salt consumption (89%), having changed the types of food they eat (89%), engaging in physical activity (80%), trying to control or lose weight if overweight (77%), quitting smoking if currently smoking (78%), and reducing alcohol intake if currently drinking more than the recommended levels (57%) at least some of the time to control their blood pressure. Men, those aged 20 to 44 years, and those with lower educational attainment and lower income were, in general, less likely to report engaging in lifestyle behaviors for blood pressure control. A low desire, interest, or awareness were commonly reported barriers to salt restriction, changes in diet, weight loss, smoking cessation, and alcohol reduction. In contrast, the most common barrier to engaging in physical activity to regulate blood pressure was the self-reported challenge of managing a coexisting physical condition or time constraints. In conclusion, programs and interventions to improve the adherence to lifestyle changes to treat hypertension may need to consider the identified barriers to lifestyle behaviors in their design.

Antihypertensive medication use, adherence, stops, and starts in Canadians with hypertension.

BACKGROUND: Some of the greatest barriers to achieving blood pressure control are perceived to be failure to prescribe antihypertensive medication and lack of adherence to medication prescriptions. METHODS: Self-reported data from 6017 Canadians with diagnosed hypertension who responded to the 2008 Canadian Community Health Survey and the 2009 Survey on Living with Chronic Diseases in Canada were examined. RESULTS: The majority (82%) of individuals with diagnosed hypertension reported using antihypertensive medications. The main reasons for not taking medications were either that they were not prescribed (42%) or that blood pressure had been controlled without medications (45%). Of those not taking antihypertensive medications in 2008 (n = 963), 18% had started antihypertensive medications by 2009, and of those initially taking medications (n = 5058), 5% had stopped. Of those taking medications in 2009, 89% indicated they took the medication as prescribed, and 10% indicated they occasionally missed a dose. Participants who were recently diagnosed, not measuring blood pressure at home, not having a plan to control blood pressure, or not receiving instructions on how to take medications were less likely to be taking antihypertensive medications; similar factors tended to be associated with stopping antihypertensive medication use. CONCLUSIONS: Compatible with high rates of hypertension control, most Canadians diagnosed with hypertension take antihypertensive medications and report adherence. Widespread implementation of self-management strategies for blood pressure control and standardized instructions on antihypertensive medication may further optimize drug treatment.

Leisure-time physical activity and marital status in relation to depression between men and women: A prospective study.

BACKGROUND: Previous studies have identified the preventive effect of leisure-time physical activity (LTPA) on depression. Women and men have different emotional vulnerabilities. The impact of LTPA on depression varies by gender. Little is known about the impact of LTPA on depression for people with different marital status. OBJECTIVES: The objective of this study was to assess the long-term effects of LTPA, changes in LTPA, and marital status on the risk of developing depression for general Canadians. METHODS: Data from the biennial National Population Health Survey (NPHS) cycles conducted between 1994/95 and 2004/05 were analyzed in 2008. After excluding individuals with preexisting depression at baseline, respondents were classified as physically active or inactive and then followed up in subsequent cycles of the NPHS to look at risk of developing depression. Individuals who changed their activity level were also examined. Subgroup analyses by different marital status were performed to identify high-risk populations. RESULTS: In 1994/1995, 17,276 participants were included in the NPHS longitudinal panel. Respondents who were inactive were more likely to be older, female, obese, widowed/separated/divorced, not working, low income, and lacking social support. After controlling for potential confounding factors, it was found that LTPA reduced the risk of developing depression for women. The modest risk reduction observed for men was not statistically significant. Women who were active at baseline and two years of follow-up were significantly less likely to report depression at four years of follow-up compared to women who were inactive at baseline and at two years of follow-up. A 51% greater probability of developing depression was observed after two years for women who changed their LTPA from active to inactive compared to women who remained active. No significant results were found for men. Divorced/separated/widowed women who stopped LTPA had 4.2 times the risk of developing depression after two years compared to those who remained active. The risk of developing depression after stopping activity did not vary according to marital status among men. CONCLUSIONS: LTPA has preventive effects on depression for women. Reduction in LTPA level is associated with subsequent depression for women. Divorced/separated/widowed women are at particularly high risk of developing depression if LTPA is stopped.