Association between hypnotics use and increased mortality: causation or confounding?

PURPOSE: Many research studies have found associations between benzodiazepines and/or z-hypnotics (BZZ) and increasing mortality, leading to a discussion about causation or confounding. This study suggests a factor that could produce this association through confounding. METHODS: The Norwegian population in 2010 supplied 8862 deaths ages 41-80 and 898,289 controls. Index dates were added to control records which corresponded to death dates. BZZ use was recorded for 2 years before death/index date. RESULTS: Persons exposed to BZZ were more likely (OR = 2.3) to die than those who were not. With proximity of death, increasingly larger proportions of the prospective deaths received prescriptions for BZZ, until in the last 2 months 40-45% received BZZ. The frequency of BZZ use in controls increased with age as opposed to the death cohort where all ages showed similar rates of BZZ use. In the last few months before death, the youngest age group had an OR = 5.8 for BZZ use while the oldest age group an OR = 1.8, adjusted for age and sex. Opioid use showed a similar pattern of increasing use near death. CONCLUSIONS: The increased use of BZZ with approaching death is consistent with increasing symptomatic treatment in terminal illness. Thus, the association of BZZ and mortality is more likely to be due to confounding than to causality. Further evidence from this and other research includes similar use patterns for other drugs such as opioids, the lack of specificity in cause of death and the size of the association regarding age and time to death.

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.

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.

Hypertension prevalence, awareness, treatment and control in national surveys from England, the USA and Canada, and correlation with stroke and ischaemic heart disease mortality: a cross-sectional study.

OBJECTIVE: Comparison of recent national survey data on prevalence, awareness, treatment and control of hypertension in England, the USA and Canada, and correlation of these parameters with each country stroke and ischaemic heart disease (IHD) mortality. DESIGN: Non-institutionalised population surveys. SETTING AND PARTICIPANTS: England (2006 n=6873), the USA (2007-2010 n=10 003) and Canada (2007-2009 n=3485) aged 20-79 years. OUTCOMES: Stroke and IHD mortality rates were plotted against countries' specific prevalence data. RESULTS: Mean systolic blood pressure (SBP) was higher in England than in the USA and Canada in all age-gender groups. Mean diastolic blood pressure (DBP) was similar in the three countries before age 50 and then fell more rapidly in the USA, being the lowest in the USA. Only 34% had a BP under 140/90 mm Hg in England, compared with 50% in the USA and 66% in Canada. Prehypertension and stages 1 and 2 hypertension prevalence figures were the highest in England. Hypertension prevalence (≥140 mm Hg SBP and/or ≥90 mm Hg DBP) was lower in Canada (19·5%) than in the USA (29%) and England (30%). Hypertension awareness was higher in the USA (81%) and Canada (83%) than in England (65%). England also had lower levels of hypertension treatment (51%; USA 74%; Canada 80%) and control (<140/90 mm Hg; 27%; the USA 53%; Canada 66%). Canada had the lowest stroke and IHD mortality rates, England the highest and the rates were inversely related to the mean SBP in each country and strongly related to the blood pressure indicators, the strongest relationship being between low hypertension awareness and stroke mortality. CONCLUSIONS: While the current prevention efforts in England should result in future-improved figures, especially at younger ages, these data still show important gaps in the management of hypertension in these countries, with consequences on stroke and IHD mortality.

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.

Outcomes among 3.5 million newly diagnosed hypertensive Canadians.

BACKGROUND: This population-based study assessed rates of all-cause mortality, myocardial infarction, heart failure, and stroke for up to 12 years of follow-up in 3.5 million Canadian adults newly diagnosed with hypertension. METHODS: Hypertension cohort, outcomes, and covariates were defined using validated case definitions applied to inpatient and outpatient administrative health databases. Factors associated with each outcome were identified using Cox proportional hazards models. RESULTS: Of 3,531,089 adults newly diagnosed with hypertension and without a previous history of cardiovascular disease, 29.4% were younger than 50 years of age; 48.2% were male, and 17.2% resided in a rural area. Over a median follow-up length of 6.1 years, the crude all-cause mortality rate was 22.4 per 1000 person-years. The incidence of hospitalized myocardial infarction (8.4 per 1000 person-years) and hospitalized heart failure (8.5 per 1000 person-years) was higher than stroke (6.9 per 1000 person-years). The incidence rate for any cardiovascular hospitalization was 19.3 per 1000 person-years. Older age, male sex, lower income, rural residence, and a higher number of Charlson comorbidities were each independently associated with a higher risk of mortality and incident cardiovascular disease hospitalizations. CONCLUSIONS: In a nationally-representative incident cohort of hypertensive adults we have demonstrated higher mortality rates and poorer outcomes for the elderly, males, and those living in rural or low income locations. Innovative approaches to the provision of care for these high-risk individuals will lead to improved patient outcomes.

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.

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.

Implementation of ICD-10 in Canada: how has it impacted coded hospital discharge data?

BACKGROUND: The purpose of this study was to assess whether or not the change in coding classification had an impact on diagnosis and comorbidity coding in hospital discharge data across Canadian provinces. METHODS: This study examined eight years (fiscal years 1998 to 2005) of hospital records from the Hospital Person-Oriented Information database (HPOI) derived from the Canadian national Discharge Abstract Database. The average number of coded diagnoses per hospital visit was examined from 1998 to 2005 for provinces that switched from International Classifications of Disease 9(th) version (ICD-9-CM) to ICD-10-CA during this period. The average numbers of type 2 and 3 diagnoses were also described. The prevalence of the Charlson comorbidities and distribution of the Charlson score one year before and one year after ICD-10 implementation for each of the 9 provinces was examined. The prevalence of at least one of the seventeen Charlson comorbidities one year before and one year after ICD-10 implementation were described by hospital characteristics (teaching/non-teaching, urban/rural, volume of patients). RESULTS: Nine Canadian provinces switched from ICD-9-CM to ICD-I0-CA over a 6 year period starting in 2001. The average number of diagnoses coded per hospital visit for all code types over the study period was 2.58. After implementation of ICD-10-CA a decrease in the number of diagnoses coded was found in four provinces whereas the number of diagnoses coded in the other five provinces remained similar. The prevalence of at least one of the seventeen Charlson conditions remained relatively stable after ICD-10 was implemented, as did the distribution of the Charlson score. When stratified by hospital characteristics, the prevalence of at least one Charlson condition decreased after ICD-10-CA implementation, particularly for low volume hospitals. CONCLUSION: In conclusion, implementation of ICD-10-CA in Canadian provinces did not substantially change coding practices, but there was some coding variation in the average number of diagnoses per hospital visit across provinces.

Factors associated with lack of awareness and uncontrolled high blood pressure among Canadian adults with hypertension.

BACKGROUND: Approximately 17% of Canadians with high blood pressure were unaware of their condition, and of Canadians aware of having the condition, approximately 1 in 5 have uncontrolled high blood pressure despite high rates of pharmacotherapy. The objectives of the current study are to estimate the prevalence of resistant hypertension and examine factors associated with (1) lack of awareness and (2) uncontrolled hypertension despite pharmacotherapy. METHODS: Using the 2007-2009 Canadian Health Measures Survey (N = 3473, aged 20-79 years) and logistic regression, we quantified relationships between characteristics and (1) presence of hypertension, (2) lack of awareness (among those with hypertension), and (3) uncontrolled high blood pressure (among those treated for hypertension). RESULTS: Older age, lowest income, and less than high school education were associated with presence of hypertension. Men (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.2) and adults < 60 years (OR, 1.7; 95% CI, 1.1-2.6) were more likely than others to be unaware. Among those aged 60+ years, women were more likely than men to have uncontrolled high blood pressure (OR, 2.4; 95% CI, 1.1-5.2) despite treatment. Elevated systolic blood pressure was the issue in over 90% of women and 80% of men with uncontrolled hypertension. Depending on the definition employed, 4.4% (95% CI, 2.4-6.4) to 7.8% (95% CI, 6.0-9.6) of the population with hypertension had resistant hypertension. CONCLUSIONS: Messaging or interventions encouraging screening may be helpful for all younger Canadian adults and men; programs encouraging blood pressure control may help older women.

Prevalence, awareness, treatment, and control of hypertension among Canadian adults with diabetes, 2007 to 2009.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Acute care hospital days and mental diagnoses.

BACKGROUND: 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.

Changes in the rates of awareness, treatment and control of hypertension in Canada over the past two decades.

BACKGROUND: Analyses of medication databases indicate marked increases in prescribing of antihypertensive drugs in Canada over the past decade. This study was done to examine the trends in the prevalence of hypertension and in control rates in Canada between 1992 and 2009. METHODS: Three population-based surveys, the 1986-1992 Canadian Heart Health Surveys, the 2006 Ontario Survey on the Prevalence and Control of Hypertension and the 2007-2009 Canadian Health Measures Survey, collected self-reported health information from, and measured blood pressure among, community-dwelling adults. RESULTS: The population prevalence of hypertension was stable between 1992 and 2009 at 19.7%-21.6%. Hypertension control improved from 13.2% (95% confidence interval [CI] 10.7%-15.7%) in 1992 to 64.6% (95% CI 60.0%-69.2%) in 2009, reflecting improvements in awareness (from 56.9% [95% CI 53.1%-60.5%] in 1992 to 82.5% [95% CI 78.5%-86.0%] in 2009) and treatment (from 34.6% [95% CI 29.2%-40.0%] in 1992 to 79.0% [95% CI 71.3%-86.7%] in 2009) among people with hypertension. The size of improvements in awareness, treatment and control were similar among people who had or did not have cardiovascular comorbidities Although systolic blood pressures among patients with untreated hypertension were similar between 1992 and 2009 (ranging from 146 [95% CI 145-147] mm Hg to 148 [95% CI 144-151] mm Hg), people who did not have hypertension and patients with hypertension that was being treated showed substantially lower systolic pressures in 2009 than in 1992 (113 [95% CI 112-114] v. 117 [95% CI 117-117] mm Hg and 128 [95% CI 126-130] v. 145 [95% CI 143-147] mm Hg). INTERPRETATION: The prevalence of hypertension has remained stable among community-dwelling adults in Canada over the past two decades, but the rates for treatment and control of hypertension have improved markedly during this time.

Population-based analysis of class effect of ß blockers in heart failure.

The long-term use of ß blockers has been shown to improve the outcomes of patients with heart failure (HF). However, it is still disputed whether this is a class effect, and, specifically, whether carvedilol or bisoprolol are superior to metoprolol. The present study was a comparative effectiveness study of ß blockers for patients with HF in a population-based setting. We conducted an observational cohort study using the Quebec administrative databases to identify patients with HF who were prescribed a ß blocker after the diagnosis of HF. We used descriptive statistics to characterize the patients by the type of ß blocker prescribed at discharge. The unadjusted mortality for users of each ß blocker was calculated using Kaplan-Meier curves and compared using the log-rank test. To account for differences in follow-up and to control for differences among patient characteristics, a multivariate Cox proportional hazards model was used to compare the mortality. Of the 26,787 patients with HF, with a median follow-up of 1.8 years per patient, the crude incidence of death was 47% with metoprolol, 40% with atenolol, 41% with carvedilol, 36% with bisoprolol, and 43% with acebutolol. After controlling for several different covariates, we found that carvedilol (hazard ratio [HR] 1.04, 95% confidence interval [CI] 0.97 to 1.12, p = 0.22) and bisoprolol (HR 0.96, 95% CI 0.91 to 1.01, p = 0.16) were not superior to metoprolol in improving survival. Atenolol (HR 0.82, 95% CI 0.77 to 0.87, p <0.0001) and acebutolol (HR 0.86, 95% CI 0.78 to 0.95, p = 0.004) were superior to metoprolol. In conclusion, we did not find evidence of a class effect for ß blockers in patients with HF.

Thirty-day in-hospital revascularization and mortality rates after acute myocardial infarction in seven Canadian provinces.

BACKGROUND: Recent clinical trials have demonstrated benefit with early revascularization following acute myocardial infarction (AMI). Trends in and the association between early revascularization after (ie, 30 days or fewer) AMI and early death were determined. METHODS AND RESULTS: The Statistics Canada Health Person-Oriented Information Database, consisting of hospital discharge records for seven provinces from the Canadian Institute for Health Information Hospital Morbidity Database, was used. If there was no AMI in the preceding year, the first AMI visit within a fiscal year for a patient 20 years of age or older was included. Times to death in hospital and to revascularization procedures were counted from the admission date of the first AMI visit. Mixed model regression analyses with random slopes were used to assess the relationship between early revascularization and mortality. The overall rate of revascularization within 30 days of AMI increased significantly from 12.5% in 1995 to 37.4% in 2003, while the 30-day mortality rate decreased significantly from 13.5% to 10.6%. There was a linearly decreasing relationship - higher regional use of revascularization was associated with lower mortality in both men and women. CONCLUSIONS: These population-based utilization and outcome findings are consistent with clinical trial evidence of improved 30-day in-hospital mortality with increased early revascularization after AMI.

HISTORIQUE: De récents essais cliniques ont démontré l'avantage d'une revascularisation précoce après l'infarctus aigu du myocarde (IAM). Les tendances quant à la revascularisation précoce (c.-à-d., après 30 jours ou moins) dans l'IAM et son lien avec la mortalité précoce ont été déterminés. RÉSULTATS: Les auteurs ont utilisé la Base de données sur la santé orientée vers la personne de Statistique Canada, composée des dossiers de congés hospitaliers pour sept provinces de la Base de données sur la morbidité de l'Institut canadien d'information sur la santé. En l'absence d'IAM au cours de l'année précédente, les premières visites pour IAM à l'intérieur d'une année fiscale pour les patients de 20 ans ou plus ont été compilées. Le temps avant décès à l'hôpital ou avant revascularisation a été calculé à partir de la date de l'admission lors d'une première visite pour IAM. Les auteurs ont procédé à des analyses de régression selon un modèle mixte avec courbes aléatoires afin d'évaluer le lien entre la revascularisation précoce et la mortalité. Le taux global de revascularisation dans les 30 jours suivant l'IAM a significativement augmenté, de 12,5 % en 1995 à 37,4 % en 2003, tandis que le taux de mortalité à 30 jours a significativement diminué de 13,5 % à 10,6 %. On a noté un lien linéairement décroissant ­ l'utilisation régionale plus élevée de la revascularisation a été associée à une mortalité moindre chez les hommes et chez les femmes. CONCLUSIONS: Ces résultats basés dans la population sur l'utilisation et l'issue de l'intervention concordent avec les conclusions des essais cliniques quant à l'amélioration de la mortalité perhospitalière dans les 30 jours associée à un taux plus élevé de revascularisation précoce après l'IAM.

Identification of factors driving differences in cost effectiveness of first-line pharmacological therapy for uncomplicated hypertension.

BACKGROUND: Published practice guidelines and economic evaluations have come to different conclusions regarding optimal pharmacotherapy for the treatment of uncomplicated hypertension. The drivers of these disparities are not clear. Greater understanding is needed for clinicians, researchers and policy makers to determine the most effective and sustainable strategies. OBJECTIVES: To identify how cost and cost-effectiveness considerations are used to generate recommendations by major hypertension guidelines, and determine key drivers of cost-effectiveness conclusions in available economic evaluations. METHODS: A systematic search and narrative review of major hypertension guidelines and health technology assessments of first-line antihypertensive therapy were performed. RESULTS: Of the eight guidelines identified, formal cost-effectiveness analysis was rarely integrated in the formulation of recommendations. When guidelines considered costs, recommendations remained incongruent. Two economic evaluations were identified (United Kingdom and Canada); however, these differed in their conclusion of the most cost-effective agent and attractiveness of calcium channel blockers. Review of these economic evaluations suggests that cost-effectiveness conclusions are strongly influenced by relative costs of drug classes; when relative differences in drug costs are lower, the impact on associated conditions such as heart failure and diabetes influences cost-effectiveness conclusions. CONCLUSION: In the setting of finite health care resources and significant budget impact due to high population prevalence, cost effectiveness is an important consideration in the treatment of uncomplicated hypertension. Identification of key drivers of cost effectiveness will assist interpretation and conduct of current and future economic evaluations.

Blood pressure in Canadian adults.

BACKGROUND: Hypertension is estimated to cause more than one-eighth of all deaths worldwide. In Canada, the last national surveys to include direct measures of blood pressure (BP) took place over the years 1985-1992; hypertension was estimated at 21%. DATA AND METHODS: Data are from cycle 1 of the Canadian Health Measures Survey, conducted from March 2007 through February 2009. The survey included direct BP measures using an automated device. Weighted frequencies, means and cross-tabulations were produced to estimate levels of hypertension awareness, treatment and control in the population aged 20 to 79 years. RESULTS: Among adults aged 20 to 79 years, hypertension (systolic BP higher than or equal to 140 or diastolic BP higher than or equal to 90 mm Hg, or self-reported recent medication use for high BP) was present in 19%. Another 20% had BP in the pre-hypertension range (systolic 120 to 139 or diastolic 80 to 89 mm Hg). Of those with hypertension, 83% were aware, 80% were taking antihypertensive drugs, and 66% were controlled. Uncontrolled hypertension was largely due to high systolic BP. INTERPRETATION: Hypertension prevalence is similar to that reported in 1992. Since then, the level of hypertension control has increased considerably.

In-hospital mortality in 13,263 survivors of out-of-hospital cardiac arrest in Canada.

BACKGROUND: There is a substantial mortality rate in patients admitted alive after out-of-hospital cardiac arrest. The primary objective of our study was to examine trends in in-hospital survival in out-of-hospital cardiac arrest survivors in Canada between 1994 and 2004. The secondary objective was to examine predictors of in-hospital survival in these patients. METHODS: Data on hospital admissions from April 1, 1994, to March 31, 2004, were obtained from the Health Person-oriented Information Database, maintained by Statistics Canada. We included all patients with a primary diagnosis of cardiac arrest who survived to hospital admission. We assessed survival to hospital discharge in all patients admitted alive. RESULTS: In Canada, 13,263 patients survived community arrest between 1994 and 2004. The annual incidence of hospital admission after out-of-hospital cardiac arrest decreased by 33%, from 5.37 per 100,000 in 1994 to 3.63 per 100,000 in 2004 (P < .0001 for trend). Subsequently, 5,045 patients (38.03%) survived to hospital discharge. The survival rate did not change during the duration of the study. Invasive coronary artery disease management was associated with a greatly increased chance of survival (odds ratio 21.98, 95% CI 17.62-27.42). Also male gender, heart failure, and acute myocardial ischemia were independent positive predictors of survival to hospital discharge; greater age and comorbidities were negative predictors of survival. Finally, there were significant interprovincial variations in survival rates. CONCLUSIONS: Our study, the largest of its kind, has 4 main findings. Firstly, between 1993 and 2004, there was a significant and steady decline in admission rates after community cardiac arrest. Second, there was no change in the in-hospital survival rates. Thirdly, invasive management of coronary artery disease was associated with a greatly improved chance of survival, and finally, there were important regional variations in survival rates.

School-based influenza vaccine delivery, vaccination rates, and healthcare use in the context of a universal influenza immunization program: an ecological study.

Influenza vaccines are universally funded in Ontario, Canada. Some public health units (PHUs) vaccinate children in schools. We examined the impact of school-based delivery on vaccination rates and healthcare use of the entire population over seven influenza seasons (2000-2007) using population-based survey and health administrative data. School-based vaccination was associated with higher vaccination rates in school-age children only. Doctors' office visits were lower for PHUs with school-based vaccination for children aged 12-19 but not for other age groups. Emergency department use and hospitalizations were similar between the two groups. In the context of universal influenza vaccination, school-based delivery is associated with higher vaccination rates and modest reductions in healthcare use in school-age children.