Alarming Prevalence of Emergency Hypertension Levels in the General Public Identified by a Hypertension Awareness Campaign

Abstract

BACKGROUND

Hypertension is a major cause of mortality and morbidity today. The “silent” nature of hypertension makes it critical to determine its prevalence and its severity in the general public and to identify strategies to identify people unaware of its presence. A mobile hypertension awareness campaign was created to: (i) determine the prevalence and types of hypertension in an urban North American center, (ii) increase hypertension awareness, and (iii) identify reasons for lack of therapy adherence.

METHODS

Mobile clinics were provided at shopping malls, workplaces, hospitals, and community centres to measure blood pressure in the public. Blood pressure recordings were done on a voluntary basis.

RESULTS

Of 1097 participants, 50% presented with high blood pressure which was higher than expected. Of particular clinical significance, an unexpectedly large number of participants (2%) exhibited a hypertensive urgency/emergency. Most of these people were not adherent to medications (if their hypertension was detected previously), were unaware of their hypertensive state, and/or unwilling to acknowledge or ignored the clinical significance of the extremely high blood pressure readings. Reasons for lack of adherence included: denial, being unaware of health consequences, and proper management of hypertension.

CONCLUSIONS

A relatively large segment of an urban population lives unaware of severe emergency levels of hypertension. A public mobile hypertension clinic provides a valuable strategy for identifying hypertension in the general public and for knowledge translation of hypertension management.

Hypertension has a staggering impact on the quality of life and risk of morbidity and mortality worldwide. Hypertension is attributed to approximately 54% of strokes and 47% of ischemic heart disease cases every year.¹ As a result in 2013, hypertension was deemed the number one risk factor associated with mortality in the world.²

The Canadian average for the prevalence of hypertension (i.e., on antihypertensive medications or blood pressure ≥140/90 mm Hg) is 22.6% in adults.³ In the province of Manitoba, the prevalence of diagnosed hypertension is similar to the national average—20.3%.⁴ First Nations (Aboriginal Canadians) and Métis (of French–Canadian and Aboriginal ancestry) populations in Manitoba have an incidence of hypertension of 35 and 28%, respectively.^5,6 The rate of untreated hypertension in those with previously diagnosed hypertension is 13% in Canada with significant regional variations.⁷ However, these results have been limited to primarily self-reporting or medical records. As well, the process of assessing the burden of hypertension in any population is not a static process but a dynamic one that requires continual monitoring.⁸

As a result, a hypertension awareness campaign was designed to generate recent data relevant to the prevalence of high blood pressure in an urban center, Winnipeg, Manitoba, Canada (population: ~718,000). The objectives of the hypertension awareness campaign were to: (i) determine the prevalence of high blood pressure in the general public through mobile clinics, (ii) increase hypertension awareness and management for the public, and (iii) gain knowledge on reasons for lack of therapy adherence.

METHODS

The mobile clinic was created through a collaboration of graduate students, nurses, dietitians, physicians, and technicians. The clinics were based at various locations including shopping malls, workplaces, community events, Aboriginal campuses, and hospitals. The greatest number of individuals screened occurred at workplaces. Interested participants would either sign up for an appointment or drop in to the mobile clinic. Men and women of different ethnic backgrounds, occupations, socioeconomic status, and age were included. Ethnicities included: First Nations, Caucasian, African–Canadian, East Indian, Philipino, Korean, Chinese, Japanese, and South American. The age range of people who participated in the clinics was wide—from 16 to 92 years old. The sex distribution of the participants was fairly even with 49% males and 51% females tested. Occupations were also numerous including but not limited to: homemakers, cooks, students, lawyers, healthcare professionals, engineers, carpenters, managers, and unemployed. A significant proportion of the population (~15%) did not have a family physician. All participants participated voluntarily and provided informed consent. University of Manitoba Research Ethics Board, Health Sciences Centre Research, and St. Boniface Hospital Research Review Committee approvals were obtained.

Blood pressure was measured according to the Canada Hypertension Guidelines on proper blood pressure measurement.⁹ Blood pressure was measured either through auscultatory and oscillometric (using a BPTru instrument) methods or just oscillometric (BPTru) after sitting at rest for at least 3 minutes. Approximately 30 percent of the readings were obtained using both blood pressure measurement methods. Oscillometric measurements were used as the sole measurement method when Hypertension Canada in 2016 deemed that automated devices were the preferred method.¹⁰ Blood pressure measurements were performed in quiet and private locations, i.e., empty offices, cubicles, and curtained private spaces. Two blood pressure readings were taken in each arm at 1 minute intervals. The first reading would be excluded for determination to which blood pressure category the participant belonged, i.e., (i) normotensive/prehypertensive/controlled hypertension, (ii) uncontrolled hypertension, (iii) high blood pressure and undiagnosed/yet to be treated, (iv) hypertensive emergency/urgency. Blood pressure was defined according to Hypertension Canada guidelines.⁹ Prehypertension was defined as 121/81 mm Hg—139/89 mm Hg. High blood pressure (uncontrolled blood pressure) was defined as ≥140/90 mm Hg. An urgency/emergency blood pressure measurement was defined as ≥180/110 mm Hg.⁹ A hypertensive urgency was defined as blood pressure ≥180/110 mm Hg with no signs of organ damage whereas a hypertensive emergency was defined as blood pressure ≥180/110 mm Hg with signs of organ damage according to Canada Hypertension Education Program guidelines.⁹ Examples of organ damage included acute coronary syndrome, acute ischemic stroke, and hypertensive encephalopathy to name a few.⁹ Signs and symptoms of these included chest pain, back pain, retinal hemorrhages, severe headache, dizziness, blurred vision, and/or slurred speech. Data collected included the category to which their blood pressure belonged, diagnosis of hypertension, and qualitative information on obstacles to therapy adherence. A mean of the blood pressure readings for all participants was not collected. Following the blood pressure measurement, the participant would meet briefly with a healthcare professional to discuss ways to help manage or prevent hypertension.

RESULTS

From July 2014 to May 2016, 1097 individuals participated in the hypertension awareness mobile clinic. Of the 1097 participants seen, 50% presented with normotension or prehypertension and 50% were hypertensive (Figure 1). Surprisingly, 2% of participants presented with a hypertensive urgency/emergency. Those exhibiting a hypertensive urgency/emergency were asked if they had a prescription for antihypertensive medication. Participants responded with (i) no, they have never been prescribed an antihypertensive (n = 4), (ii) they have an antihypertensive medication and take it regularly (n = 4), or (iii) they have an antihypertensive medication but reported not taking it regularly (n = 14). The majority of these people with emergency/urgency levels of high blood pressure had no realization that their blood pressure was abnormal. They reported their health as “normal.” Participants that presented with a hypertensive emergency were advised to go immediately to the Emergency Department of the nearest Hospital. Approximately 25% of those with a hypertensive urgency/emergency dismissed the results and the advice they were given during the appointment.

Figure 1.

Percentage of individuals by blood pressure category (n = 1097). Prehypertension was defined as 121/81–139/89 mm Hg. High blood pressure was defined as ≥140/90 mm Hg. A hypertensive urgency was defined as blood pressure ≥180/110 mm Hg with no signs of organ damage. A hypertensive emergency was defined as blood pressure ≥180/110 mm Hg with signs of organ damage.

To the group of those with a hypertensive urgency that were previously diagnosed with hypertension and stopped taking their antihypertensive medications, they were asked to provide reasons for the discontinuance of hypertensive medication. The respondents identified experiencing side-effects from the medications, forgetting to fill the prescription once it was completed, feeling good without the medication, dismissing the clinical significance of high blood pressure readings, and trying to control their blood pressure by alternative approaches (life style, nutrition, behavioral changes) instead of using the antihypertensive drugs.

DISCUSSION

The quantitative and qualitative data collected from the hypertension awareness clinic provide an important insight into the prevalence of high blood pressure in a relatively large urban North American city. The findings demonstrate that 50% of the population surveyed required medical attention due to uncontrolled hypertension. The remaining 50% of the population presented with controlled or normal blood pressure. The results collected during this study on the prevalence of high blood pressure are about twice as high as previously reported national and provincial reports for Canada.^3,4 The difference in findings could be explained by means of data collection. The national statistics were based on 3 different databases:³ (i) Canadian Health Measures Survey, (ii) the National Population Health Survey and the Canadian Community Health Survey, and (iii) the Canadian Chronic Disease Surveillance System. The means by which these 3 databases collected the results were different: (i) self-reported diagnosis or prescription of antihypertensive drugs, (ii) blood pressure measurement using a BPTru machine, (iii) a database that determined a diagnosis of hypertension with 2 physician claims within 2 years or an in-patient hospitalization.³ Information collected in the current report were not collected based on medical records, but rather on blood pressure readings that day. Findings from a Stroke Prevention Clinic in another urban Canadian center reported that ~50% of patients referred to the clinic had uncontrolled systolic blood pressure.¹¹ Our findings are similar in proportion but very different in terms of population distribution. The Stroke Prevention Clinic is for individuals with risk factors for a stroke. Our population included a heterogeneous group of individuals at all risk levels.

It is arguable whether the data collected from mobile clinics is more accurate than self-reporting or physician claims in a database. Clearly, one important limiting factor in the collection of the present data is that the mobile clinics are limited to individuals interested in having their blood pressure measured. Despite this limitation, 29% of the population included individuals with previously diagnosed hypertension and uncontrolled blood pressure (>140/90 mm Hg). This is more than twice the national average of 13%.⁷

A key finding includes the 2% of the population that exhibited an asymptomatic hypertensive urgency/emergency. The population prevalence is likely to be even higher than 2%. Of the 22 individuals with a hypertensive urgency/emergency, 7 individuals were under the age of 40 years old. The only location where these particular individuals (<40 years of age) were observed was at their workplace. This illustrates the crucial need for hypertension awareness, particularly among young individuals. Workplace mobile health clinics appear to be a very effective way to reach people who may otherwise be uninterested in having their blood pressure measured, too busy or without access to a physician. The detection of hypertension in the workplace has large implications not only for companies interested in workplace safety but will be of special significance for life insurance companies involved with insuring workplace health. In future studies of hypertension prevalence in the general public, it may be important to focus exclusively on workplace measurements to obtain representative estimates.

Lack of therapy adherence was a common observation during the campaign. It has been previously reported that only 8.1% of patients adhere to their antihypertensive medications ≥80% of the time.¹² This suggests that a large proportion of the population are at risk for target organ damage and cardiovascular events. The overarching theme of responses for not taking antihypertensive medications included a lack of awareness for the consequences of hypertension and effective means to manage hypertension. It is for these reasons that mobile clinics offer an important means to increase knowledge and awareness.

This information has health implications for the general public. The mobile clinics offer a strategy for knowledge translation to the public. In addition, these results have identified areas of need that require further attention. The mobile clinics and the hypertension campaign provided increased awareness to populations unaware of significant impending medical need. It is recommended that this type of approach could and should be implemented on a regular basis throughout North America.

It is also important to discuss these data in relation to the Canadian context of diagnosis, treatment, and control of hypertension. Although Canada has been recently applauded for its hypertension control rates (68%),¹³ the low prevalence of hypertension (13–22%^7,13) and its treatment strategies for hypertension, our data would argue that considerable work still needs to be done. There may be many reasons for the apparent discrepancy. Campbell and Feldman¹³ recently pointed out that the “careful detailed analysis of hypertension surveys indicate many of those who are undiagnosed and uncontrolled are not within the health care system.” Our data would not have this limitation. They also suggested that very successful community programs to improve hypertension have not been disseminated widely throughout Canada. In addition, public health efforts to prevent and control hypertension have met with limited success in Canada.¹³ They concluded, as have others,³ that further coordinated efforts are still required to improve the treatment and control of hypertension in Canada. Our data are consistent with this need and further emphasizes the potential urgency of the demand.

DISCLOSURE

The authors declared no conflict of interest.