Michel Joffres

Hypertension Treatment and Control in Five European Countries, Canada, and the United States

Abstract—Levels of hypertension treatment and control have been noted to vary between Europe and North America, although direct comparisons with similar methods have not been undertaken. In this study, we sought to estimate the relative impact of hypertension treatment strategies in Germany, Sweden, England, Spain, Italy, Canada, and the United States by using sample surveys conducted in the 1990s. Hypertension was defined as a blood pressure of 160/95 mm Hg or 140/90 mm Hg, plus persons taking antihypertensive medication. “Controlled hypertension” was defined as a blood pressure less than threshold among persons taking antihypertensive medications. Among persons 35 to 64 years, 66% of hypertensives in the United States had their blood pressure controlled at 160/95 mm Hg, compared with 49% in Canada and 23% to 38% in Europe. Similar discrepancies were apparent at the 140/90 mm Hg threshold, at which 29% of hypertensives in the United States, 17% in Canada, and ≤10% in European countries had their blood pressure controlled. At the 140/90 mm Hg cutpoint, two thirds to three quarters of the hypertensives in Canada and Europe were untreated compared with slightly less than half in the United States. Although guidelines vary among countries, resulting in different case definitions, this does not account entirely for the varying success of different national control efforts. Low treatment and control rates in Europe, combined with a higher prevalence of hypertension, could contribute to a higher burden of cardiovascular disease risk attributable to elevated blood pressure compared with that in North America.

A comparative evaluation of waist circumference, waist-to-hip ratio and body mass index as indicators of cardiovascular risk factors. The Canadian Heart Health Surveys.

OBJECTIVE: To comparatively evaluate cut-off points of waist circumference, body mass index and waist to hip ratio with respect to their ability to predict other individual and multiple cardiovascular disease risk factors.DESIGN: Population-based, cross-sectional surveys.SUBJECTS: A total of 9913 men and women aged 18–74, selected using health insurance registries from five Canadian provinces.MEASUREMENTS: Anthropometric measures, other cardiovascular risk factors, receiver operating characteristic curves, sensitivity, specificity, positive and negative predictive values.RESULTS: Waist circumference may be the best single indicator of other individual and multiple cardiovascular risk factors. Optimal cut-off points of all anthropometric measures are dependent on age, sex and the prevalence of the risk factor(s) being considered. For waist circumference, cut-off points of ≥90 cm in men and ≥80 cm in women may be most appropriate for prediction of individual and multiple risk factors in Caucasian populations.CONCLUSION: Health professionals should incorporate the use of waist circumference measurements in their routine clinical examination of adult patients.

Awareness, Treatment, and Control of Hypertension in Canada ☆

The Canadian Heart Health Surveys are cross-sectional, population-based cardiovascular disease risk factor surveys that took place in each of the 10 Canadian provinces between 1986 and 1992. Hypertension awareness, treatment, and control status are examined. Of 23,129 randomly selected, noninstitutionalized respondents aged 18 to 74 years, 85% had four blood pressure (BP) measurements taken under standardized conditions, two at home during a home interview and two at a following clinic visit. The mean of all available measurements was used to determine hypertension status. Estimates are weighted and represent population values. Only 2% of respondents had never had their BP checked, and 73% had had their BP checked in the last 12 months. A systolic or diastolic BP > or = 140/90 mm Hg was found in 22% of participants (26% of men, 18% of women), representing 4.1 million Canadians. Overall, 16% of participants were treated and controlled; 23% were treated and not controlled; 19% were not treated and not controlled; and 42% were unaware of their hypertension (47% of men and 35% of women). Among hypertensives 18 to 34 years old, 64% of men and 19% of women were unaware of their hypertension. Among treated and not controlled hypertensives 63% had a mean systolic BP > or = 150 mm Hg, and 29% a diastolic BP > or = 95 mm Hg, suggesting that an important number of Canadians treated for hypertension are still at increased risk. Despite frequent interactions with the health care system, too many Canadians are still not well controlled or are unaware of their hypertension.

Distribution of blood pressure and hypertension in Canada and the United States.

BACKGROUND Two North American population based surveys, the Third National Health and Nutrition Examination Survey (NHANES III) and the Canadian Heart Health Surveys (CHHS) have similar time frames and methods that allow comparisons between these countries in terms of the distribution of systolic (SBP) and diastolic (DBP) blood pressure and the levels of hypertension awareness, treatment, and control. METHODS Cross-sectional population surveys using similar methods conducted home interviews and clinic visits (CHHS), and medical examinations (NHANES III). The CHHS included the ten Canadian provinces (1986-1992) and NHANES III, a representative sample of the United States population (1988-1994). Blood pressure measurements were available for 23,111 Canadians (age 18-74 years), and restricted to the 15,326 US participants in the same age range (age 18-74 years) with both systolic and diastolic mean values. Standardized techniques were used for BP measurements. Mean of all available measurements was used from four measurements for the CHHS and six measurements for NHANES III. A mean SBP/DBP of 140/90 mm Hg or treated with medication defined hypertension. All measures were weighted to represent population values. RESULTS Both surveys showed similar trends in mean BP by age, with slightly higher levels in the CHHS. Hypertension prevalence using the same definitions and the same age range (18-74 years) was NHANES III: 20.1%, CHHS: 21.1%. Although the prevalence of isolated systolic hypertension (ISH) was similar in both studies, around 8% to 9%, the CHHS had higher ISH prevalence than NHANES III in the younger age groups and lower prevalence in the older age groups. Elevated SBP dominated the prevalence figures after the 1950s in both studies. Compared to NHANES III, the CHHS showed a lower proportion (43% v 50%) of individuals with optimal BP (< 120/80 mm Hg) and a very low proportion of hypertensives under control (13% v 25%). About half of diabetic participants were hypertensive (using 140/90 mm Hg) in both countries with a very low level of control in Canada (9%) v the US (36%) for ages 18 to 74 years. CONCLUSIONS The results of these two surveys highlight the importance of SBP, in the later decades of life, an overall low control of hypertension in both countries, and a better overall awareness, treatment, and control of hypertension in the US than in Canada for that period. Dissemination of hypertension guidelines and a more aggressive focus on SBP are urgently needed in Canada, with special attention to diabetics.

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.

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.

An international comparative study of blood pressure in populations of European vs. African descent

BackgroundThe consistent finding of higher prevalence of hypertension in US blacks compared to whites has led to speculation that African-origin populations are particularly susceptible to this condition. Large surveys now provide new information on this issue.MethodsUsing a standardized analysis strategy we examined prevalence estimates for 8 white and 3 black populations (N = 85,000 participants).ResultsThe range in hypertension prevalence was from 27 to 55% for whites and 14 to 44% for blacks.ConclusionsThese data demonstrate that not only is there a wide variation in hypertension prevalence among both racial groups, the rates among blacks are not unusually high when viewed internationally. These data suggest that the impact of environmental factors among both populations may have been under-appreciated.

Estimate of the benefits of a population-based reduction in dietary sodium additives on hypertension and its related health care costs in Canada

BACKGROUND Hypertension is the leading risk factor for mortality worldwide. One-quarter of the adult Canadian population has hypertension, and more than 90% of the population is estimated to develop hypertension if they live an average lifespan. Reductions in dietary sodium additives significantly lower systolic and diastolic blood pressure, and population reductions in dietary sodium are recommended by major scientific and public health organizations. OBJECTIVES To estimate the reduction in hypertension prevalence and specific hypertension management cost savings associated with a population-wide reduction in dietary sodium additives. METHODS Based on data from clinical trials, reducing dietary sodium additives by 1840 mg/day would result in a decrease of 5.06 mmHg (systolic) and 2.7 mmHg (diastolic) blood pressures. Using Canadian Heart Health Survey data, the resulting reduction in hypertension was estimated. Costs of laboratory testing and physician visits were based on 2001 to 2003 Ontario Health Insurance Plan data, and the number of physician visits and costs of medications for patients with hypertension were taken from 2003 IMS Canada. To estimate the reduction in total physician visits and laboratory costs, current estimates of aware hypertensive patients in Canada were used from the Canadian Community Health Survey. RESULTS Reducing dietary sodium additives may decrease hypertension prevalence by 30%, resulting in one million fewer hypertensive patients in Canada, and almost double the treatment and control rate. Direct cost savings related to fewer physician visits, laboratory tests and lower medication use are estimated to be approximately

Prevalence of mental disorders among children exposed to war: a systematic review of 7,920 children

430 million per year. Physician visits and laboratory costs would decrease by 6.5%, and 23% fewer treated hypertensive patients would require medications for control of blood pressure. CONCLUSIONS Based on these estimates, lowering dietary sodium additives would lead to a large reduction in hypertension prevalence and result in health care cost savings in Canada.

Should active recruitment of health workers from sub-Saharan Africa be viewed as a crime?

Worldwide, millions of children are affected by armed conflict. However, data on the prevalence of mental disorders among these children is sparse. We aimed to determine the prevalence of mental disorders among children affected by war using a systematic review and meta-regression analysis. We systematically reviewed existing literature to identify studies on prevalence of post-traumatic stress disorder (PTSD), anxiety, depression and psychosis among children exposed to armed conflict. We searched electronic databases and references listed in studies to obtain eligible studies. We pooled studies using the random-effects method and explored heterogeneity using meta-regression analysis. Seventeen studies met our inclusion criteria. Studies included 7,920 children. Sample sizes ranged from 22 to 2,976. Four studies were conducted during a conflict and others during post-conflict. All the studies reported PTSD as the primary outcome ranging from 4.5 to 89.3%, with an overall pooled estimate of 47% (9% CI: 35–60%, I 2 = 98%). Meta-analysis heterogeneity was attributable to study location (OR 1.33, 95% CI: 1.27–1.41), method of measurement (OR 1.36, 95% CI: 1.29–1.44) and duration since exposure to war (coefficient 0.17, 95% CI: 0.94–0.25). In addition, four studies reported elevated depression that allowed pooling (43%, 95% CI: 31–55%) and three studies reported elevated anxiety disorders allowing pooling (27%, 95% CI: 21–33%). Our systematic review suggests a higher prevalence rate of mental disorders among children exposed to conflict than among the general population. Given the number of current conflicts, there is a paucity of information regarding mental disorders among children affected by war.