Differences in need for antihypertensive drugs among those aware and unaware of their hypertensive status: a cross sectional survey

BACKGROUND: Lack of antihypertensive use among hypertensive individuals is a major public health problem. It remains unclear as to how much of this lack of treatment is because of failure to diagnose hypertension or failure to initiate drug treatment for those with a diagnosis of hypertension. The primary aim of this study was to determine the proportion of those untreated individuals who would be recommended to start drug therapy for control of blood pressure among those aware or unaware of their diagnosis of hypertension. METHODS: The Canadian Heart Health Surveys (1986 – 1992), a national, cross-sectional descriptive survey (n = 23 129), was used to determine the proportion of individuals who were untreated, yet satisfied the 2004 Canadian hypertension guidelines for initiating drug therapy. Patients were divided into subgroups of those aware and unaware of having a diagnosis of hypertension according to self reported awareness from the survey. RESULTS: Of those with untreated hypertension (= 140/90 mmHg), only 37% were aware of their diagnosis. 74% of untreated individuals aware of their diagnosis of hypertension would require drug therapy, compared to 57% of those who were unaware. Of those >65 years of age, 52% of aware individuals needed drug therapy whereas only 34% of unaware elderly would need drug treatment. CONCLUSION: In both unaware and aware subgroups, the majority of patients with untreated hypertension would benefit from antihypertensive drug therapy according to the 2004 Canadian Hypertension recommendations. The proportion of untreated patients that still need drug therapy was higher among those who were aware compared to those who were unaware. This finding suggests that the major gap in hypertension control may be in initiating drug therapy rather than in diagnosing hypertension. Further studies are needed to confirm these results to ultimately help strategize public health efforts in controlling hypertension

Heart and Stroke Foundation of Ontario (HSFO) high blood pressure strategy's hypertension management initiative study protocol

<p>Abstract</p> <p>Background</p> <p>Achieving control of hypertension prevents target organ damage at both the micro and macrovascular level and is a highly cost effective means of lowering the risk for heart attack and stroke particularly in people with diabetes. Clinical trials demonstrate that blood pressure control can be achieved in a large proportion of people. Translating this knowledge into widespread practice is the focus of the Hypertension Management Initiative, which began in 2004 with the goal of improving the management of this chronic health condition by primary care providers and patients in the community.</p> <p>Methods</p> <p>This study will test the effect of a systems change on the management of high blood pressure in real world practice in primary care in Ontario, Canada. The systems change intervention involves an interprofessional educational program bringing together physicians, nurses and pharmacists with tools for both providers and patients to facilitate blood pressure management. Each of two waves of subjects were enrolled over a 6 month period with the initial enrollment between waves separated by 9 months. Blood pressure will be measured with the BpTru ^®automated blood pressure device. To determine the effectiveness of the intervention, a before and after analysis within all subjects will compare blood pressure at baseline to annual measurements for the three year study. To assess whether the intervention has an impact on blood pressure control independent of community trends, a betwen group comparison of baseline blood pressures in the delayed wave will be made with the immediate wave during the same time period, so that the immediate wave has experienced the intervention for at least 9 months. The total enrollment goal is 5,000 subjects. The practice locations include 10 Family Health Teams (FHTs) and 1 Community Health Centre (CHC) and approximately 49 primary care physicians, 15 nurse practitioners, 37 registered nurses and over 150 community pharmacists across the 11 communities throughout the province of Ontario. The 11 primary care sites will be divided into immediate and delayed groups based on geography and the use of an electronic versus a traditional chart patient record.</p> <p>Discussion</p> <p>Initial consideration was given to randomizing the groups, however, for a number of reasons, this was deemed to not be possible. In order to ensure that the sites in the immediate intervention and delayed intervention groups are not different from each other, the sites will be assigned to the intervention groups manually to ensure a distribution of the variables as evenly as possible.</p> <p>Given that HSFO approached this particular group of health care providers to participate in a program relating to hypertension, this may have heightened their awareness of the issue and affected their management of patients with hypertension. Thus, data will be collected to allow an assessment of previous practice patterns and determine any impact of the Hawthorne Effect.</p> <p>Trial registration</p> <p>Clinicaltrials.gov NCT00425828</p

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

Background: The 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. Methods: Using a standardized analysis strategy we examined prevalence estimates for 8 white and 3 black populations (N = 85,000 participants). Results: The range in hypertension prevalence was from 27 to 55% for whites and 14 to 44% for blacks. Conclusions: These 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

A randomized trial of mail vs. telephone invitation to a community-based cardiovascular health awareness program for older family practice patients [ISRCTN61739603]

BACKGROUND: Family physicians can play an important role in encouraging patients to participate in community-based health promotion initiatives designed to supplement and enhance their in-office care. Our objectives were to determine effective approaches to invite older family practice patients to attend cardiovascular health awareness sessions in community pharmacies, and to assess the feasibility and acceptability of a program incorporating invitation by physicians and feedback to physicians. METHODS: We conducted a prospective randomized trial with 1 family physician practice and 5 community pharmacies in Dundas, Ontario. Regular patients 65 years or older (n = 235) were randomly allocated to invitation by mail or telephone to attend pharmacy cardiovascular health awareness sessions led by volunteer peer health educators. A health record review captured blood pressure status, monitoring and control. At the sessions, volunteers helped patients to measure blood pressure using in-store machines and a validated portable device (BPM-100), and recorded blood pressure readings and self-reported cardiovascular risk factors. We compared attendance rates in the mail and telephone invitation groups and explored factors potentially associated with attendance. RESULTS: The 119 patients invited by mail and 116 patients contacted by telephone had a mean age of 75.7 (SD, 6.4) years and 46.8% were male. Overall, 58.3% (137/235) of invitees attended a pharmacy cardiovascular health awareness session. Patients invited by telephone were more likely to attend than those invited by mail (72.3% vs. 44.0%, OR 3.3; 95%CI 1.9–5.7; p < 0.001). CONCLUSION: While the attendance in response to a telephone invitation was higher, response to a single letter was substantial. Attendance rates indicated considerable interest in community-based cardiovascular health promotion activities. A large-scale trial of a pharmacy cardiovascular health awareness program for older primary care patients is feasible

Epidemiology of cardiovascular risk factors in Greece: aims, design and baseline characteristics of the ATTICA study

BACKGROUND: In an attempt to evaluate the levels of several cardiovascular risk factors in Greece we conducted a population-based health and nutrition survey, the "ATTICA study". In this work we present the design and the methodology of the study, as well as the status of various baseline characteristics of the participants. METHODS: From May 2001 to December 2002 we randomly enrolled 1514 adult men and 1528 adult women, stratified by age – gender (census 2000), from the greater area of Athens. More than 300 demographic, lifestyle, behavioral, dietary, clinical and biochemical variables have been recorded. RESULTS: Regarding the frequency of the classical cardiovascular risk factors we observed that 51% of men and 39% of women reported smokers (p < 0.05), 37% of men and 25% of women were defined as hypertensives (p < 0.05), 46% of men and 40% of women had total serum cholesterol levels above 200 mg/dl (p < 0.05) and 8% of men and 6% of women had history of diabetes mellitus. Moreover, 20% of men and 15% of women were obese (p < 0.05), while men were more physically active as compared to women (42% vs. 39%, p < 0.05). 19% of men and 38% of women had mild to severe depressive symptoms (p < 0.01). Finally, 72 men (5%) and 45 (3%) women reported history of coronary heart disease at entry evaluation. CONCLUSIONS: The prevalence of the common cardiovascular risk factors in our population seems high. As a consequence a considerable proportion of Greek adults are at "high-risk" for future cardiovascular events

The influence of calcium and magnesium in drinking water and diet on cardiovascular risk factors in individuals living in hard and soft water areas with differences in cardiovascular mortality

BACKGROUND: The role of water hardness as a risk factor for cardiovascular disease has been widely investigated and evaluated as regards regional differences in cardiovascular disease. This study was performed to evaluate the relation between calcium and magnesium in drinking water and diet and risk factors for cardiovascular disease in individuals living in hard and soft water areas with considerable differences in cardiovascular mortality. METHODS: A random sample of 207 individuals living in two municipalities characterised by differences in cardiovascular mortality and water hardness was invited for an examination including a questionnaire about health, social and living conditions and diet. Intake of magnesium and calcium was calculated from the diet questionnaire with special consideration to the use of local water. Household water samples were delivered by each individual and were analysed for magnesium and calcium. RESULTS: In the total sample, there were positive correlations between the calcium content in household water and systolic blood pressure (SBP) and negative correlations with s-cholesterol and s-LDL-cholesterol. No correlation was seen with magnesium content in household water to any of the risk factors. Calcium content in diet showed no correlation to cardiovascular risk factors. Magnesium in diet was positively correlated to diastolic blood pressure (DBP). In regression analyses controlled for age and sex 18.5% of the variation in SBP was explained by the variation in BMI, HbA1c and calcium content in water. Some 27.9% of the variation in s-cholesterol could be explained by the variation in s-triglycerides (TG), and calcium content in water. CONCLUSIONS: This study of individuals living in soft and hard water areas showed significant correlations between the content of calcium in water and major cardiovascular risk factors. This was not found for magnesium in water or calcium or magnesium in diet. Regression analyses indicated that calcium content in water could be a factor in the complexity of relationships and importance of cardiovascular risk factors. From these results it is not possible to conclude any definite causal relation and further research is needed

Acute and Chronic Impact of Dynamic Exercise on Arterial Stiffness in Older Hypertensives

Arterial stiffness increases with ageing and hypertension. Regular physical activity has been recommended as an important management component of hypertension. The purpose of this study was to examine the acute impact of maximal dynamic exercise and the effect of 20 weeks of aerobic exercise on arterial stiffness of the carotid and brachial arteries in older hypertensives. Nine previously sedentary and treated older hypertensives (2 men and 7 women, age 68.2 ± 5.4 yrs) performed maximal treadmill exercise to volitional fatigue while arterial stiffness indices (arterial distensibility and β stiffness index) were measured prior to, immediately (about 10 min) following, and 24 h following maximal exercise. These measurements were repeated following 20 weeks of moderate intensity aerobic exercise training. Maximal exercise had no impact on arterial stiffness indices immediately and 24 h following exercise intervention. Following 20 weeks of training, arterial stiffness indices remained unchanged at rest and following maximal exercise. These data show that, in older hypertensives, 1) acute maximal dynamic exercise had no impact on arterial stiffness of the carotid and brachial arteries, and 2) 20 weeks of moderate intensity aerobic exercise training failed to modify arterial stiffness

Quality of care for hypertension in the United States

BACKGROUND: Despite heavy recent emphasis on blood pressure (BP) control, many patients fail to meet widely accepted goals. While access and adherence to therapy certainly play a role, another potential explanation is poor quality of essential care processes (QC). Yet little is known about the relationship between QC and BP control. METHODS: We assessed QC in 12 U.S. communities by reviewing the medical records of a randomly selected group of patients for the two years preceding our study. We included patients with either a diagnosis of hypertension or two visits with BPs of ≥140/90 in their medical records. We used 28 process indicators based on explicit evidence to assess QC. The indicators covered a broad spectrum of care and were developed through a modified Delphi method. We considered patients who received all indicated care to have optimal QC. We defined control of hypertension as BP < 140/90 in the most recent reading. RESULTS: Of 1,953 hypertensive patients, only 57% received optimal care and 42% had controlled hypertension. Patients who had received optimal care were more likely to have their BP under control at the end of the study (45% vs. 35%, p = .0006). Patients were more likely to receive optimal care if they were over age 50 (76% vs. 63%, p < .0001), had diabetes (77% vs. 71%, p = .0038), coronary artery disease (87% vs. 69%, p < .0001), or hyperlipidemia (80% vs. 68%, p < .0001), and did not smoke (73% vs. 66%, p = .0005). CONCLUSIONS: Higher QC for hypertensive patients is associated with better BP control. Younger patients without cardiac risk factors are at greatest risk for poor care. Quality measurement systems like the one presented in this study can guide future quality improvement efforts

The potential savings of using thiazides as the first choice antihypertensive drug: cost-minimisation analysis

BACKGROUND: All clinical practice guidelines recommend thiazides as a first-choice drug for the management of uncomplicated hypertension. Thiazides are also the lowest priced antihypertensive drugs. Despite this, the use of thiazides is much lower than that of other drug-classes. We wanted to estimate the potential for savings if thiazides were used as the first choice drug for the management of uncomplicated hypertension. METHODS: For six countries (Canada, France, Germany, Norway, the UK and the US) we estimated the number of people that are being treated for hypertension, and the proportion of them that are suitable candidates for thiazide-therapy. By comparing this estimate with thiazide prescribing, we calculated the number of people that could switch from more expensive medication to thiazides. This enabled us to estimate the potential drug-cost savings. The analysis was based on findings from epidemiological studies and drug trials, and data on sales and prescribing provided by IMS for the year 2000. RESULTS: For Canada, France, Germany, Norway, the UK and the US the estimated potential annual savings were US$13.8 million, US$37.4 million, US$72.2 million, US$10.7 million, US$119.7 million and US$433.6 million, respectively. CONCLUSIONS: Millions of dollars could be saved each year if thiazides were prescribed for hypertension in place of more expensive drugs. Our calculations are based on conservative assumptions. The potential for savings is likely considerably higher and may be more than US$1 billion per year in the US

Identifying priorities in methodological research using ICD-9-CM and ICD-10 administrative data: report from an international consortium

BACKGROUND: Health administrative data are frequently used for health services and population health research. Comparative research using these data has been facilitated by the use of a standard system for coding diagnoses, the International Classification of Diseases (ICD). Research using the data must deal with data quality and validity limitations which arise because the data are not created for research purposes. This paper presents a list of high-priority methodological areas for researchers using health administrative data. METHODS: A group of researchers and users of health administrative data from Canada, the United States, Switzerland, Australia, China and the United Kingdom came together in June 2005 in Banff, Canada to discuss and identify high-priority methodological research areas. The generation of ideas for research focussed not only on matters relating to the use of administrative data in health services and population health research, but also on the challenges created in transitioning from ICD-9 to ICD-10. After the brain-storming session, voting took place to rank-order the suggested projects. Participants were asked to rate the importance of each project from 1 (low priority) to 10 (high priority). Average ranks were computed to prioritise the projects. RESULTS: Thirteen potential areas of research were identified, some of which represented preparatory work rather than research per se. The three most highly ranked priorities were the documentation of data fields in each country's hospital administrative data (average score 8.4), the translation of patient safety indicators from ICD-9 to ICD-10 (average score 8.0), and the development and validation of algorithms to verify the logic and internal consistency of coding in hospital abstract data (average score 7.0). CONCLUSION: The group discussions resulted in a list of expert views on critical international priorities for future methodological research relating to health administrative data. The consortium's members welcome contacts from investigators involved in research using health administrative data, especially in cross-jurisdictional collaborative studies or in studies that illustrate the application of ICD-10