Hypertension Prevalence, Awareness, Treatment, and Control in Egypt
Results From the Egyptian National Hypertension Project (NHP)
Abstract This report from the Egyptian National Hypertension Project presents national estimates of the prevalence of hypertension and the extent to which high blood pressure is being detected, treated with medications, and controlled in the Egyptian population. The results are based on findings from a national probability survey of adults ≥25 years of age conducted in six Egyptian governorates. With the use of a stratified multistage probability design, 6733 people (85% response rate) were examined. Hypertension was defined as systolic pressure ≥140 mm Hg, and/or diastolic pressure ≥90 mm Hg, and/or reported treatment with one or more antihypertensive medications. Overall, the estimated prevalence of hypertension in Egypt was 26.3%. Hypertension prevalence increased progressively with age, from 7.8% in 25- to 34-year-olds to 56.6% in those 75 years or older. Hypertension was slightly more common in women than in men (26.9% versus 25.7%, respectively). Overall, 37.5% of hypertensive individuals were aware that they had high blood pressure, 23.9% were being treated with antihypertensive medications, and 8.0% were under control (systolic pressure <140 mm Hg and diastolic pressure <90 mm Hg). Hypertension prevalence as well as awareness, treatment, and control rates varied by region, with Cairo having the highest prevalence (31.0%) and the Coastal Region having the highest control rate (15.9%). Rates of awareness, treatment, and control tended to be lowest in areas of lower socioeconomic status. Our results indicate that hypertension is highly prevalent in Egypt and that the rates of hypertension awareness, treatment, and control are relatively low. These findings argue for a nationwide effort to prevent and control high blood pressure in Egypt in order to avert an epidemic of cardiovascular disease.
The improved control of infectious and parasitic diseases and the sharp decrease in infant mortality during recent decades has dramatically changed the health profile of many economically developing countries.1 This is reflected in a prolongation of life expectancy and the emergence of cardiovascular disease as a leading cause of morbidity and mortality in such countries.2 Statistics from the Egyptian Ministry of Health and the Egyptian Central Agency for Public Mobilization and Statistics3 indicate that between 1960 and 1990 the average life expectancy of Egyptians increased from 51.6 to 62.8 years for men and from 53.8 to 66.4 years for women. In 1970, cardiovascular disease accounted for 12.4% of all deaths in Egyptians, whereas two decades later it was responsible for 42.5% of the nation’s mortality.3
Recognizing the rapid emergence of cardiovascular disease as a clinical and public concern in Egypt, the Egyptian National Hypertension Project (NHP) was initiated in 1991 to assess the prevalence and health consequences of hypertension in Egypt. Additional goals were to explore the role of social and environmental factors as causes of hypertension and to develop a national infrastructure to enhance hypertension treatment and prevention efforts in Egypt. This article documents results from the hypertension prevalence survey, ie, phase I of the NHP.
A detailed description of methods used in the NHP is published concurrent with this article.4 In brief, phase I was a hypertension prevalence survey conducted in 6 of Egypt’s 26 governorates. Each governorate represented a distinct region of the country: Cairo (urban, capital), Bani Sweif (Northern Upper Egypt), Aswan (Southern Upper Egypt), Sharkia (Delta), Port Said (Coastal), and El Wadi El Gedid (Frontier). Subsequent steps of the multistage sampling procedure are detailed in the accompanying article.4
Four blood pressure (BP) measurements were obtained from each participant according to a standardized protocol.4 5 6 Based on the average of these four measurements the BP status of each participant was classified according to criteria established by the Fifth Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC V).7 Hypertension was defined as an average systolic BP ≥140 mm Hg, and/or diastolic BP ≥90 mm Hg, and/or self-reported treatment with antihypertensive medications.
For estimation of the overall prevalence of hypertension, the prevalence estimates for each of the regional samples were weighted according to the age, sex, and urban-rural population distributions of the total population for the region they represented. This was accomplished with the use of data from the most recent (1986) Egyptian census and extrapolation of the results to 1990.8 Awareness of hypertension was defined as self-report of a high BP measurement in the past. Specifically, participants were asked, “Have you ever had your blood pressure checked?” If yes, they were asked, “Was it normal or high?” Treatment of hypertension was defined as a positive response to the question, “Do you currently use drugs for treatment of high blood pressure?” Control of hypertension was defined as an average systolic BP <140 mm Hg and an average diastolic BP <90 mm Hg with the use of antihypertensive medications. Analyses of awareness, treatment, and control of hypertension were weighted as previously described to provide representative national and regional estimates. Except for response rates and demographic characteristics, weighted estimates rather than crude sample data are presented.
The sample frame consisted of 3600 households in which there were 7915 adult residents. A total of 6733 residents in 3359 of the households participated in the survey. The overall response rate by household was 93.9% and exceeded 90% in all governorates except for Cairo (79.3%). The corresponding response rates for individuals ranged from 81.5% in Bani Sweif to 89.3% in El Wadi El Gedid.
The mean age of the survey participants was 45.6 years (range, 25 to 95 years). The age distribution varied by governorate, with the Cairo sample having the oldest mean age (50.1 years) and the El Wadi El Gedid sample the youngest (42.7 years). A majority of the survey participants were women (56.5%). Approximately half (50.9%) were homemakers, students, or retirees who were not employed outside of the home. Of the remainder, 18% were engaged in manual labor, 16.6% in office work, and 13.9% in a profession. Seventy-three percent of the participants lived in an urban area.
BP distributions were approximately Gaussian, with a rightward skew (Fig 1⇓). Mean (±SD) systolic and diastolic BP values were 128.9±21.6 and 79.1±12 mm Hg, respectively. Fig 2⇓ displays weighted national estimates of mean systolic and diastolic BPs by age and sex. Mean systolic BP rose progressively across the entire age range. The pattern for mean diastolic BP was similar at younger ages, but the average level of diastolic BP plateaued between 45 and 64 years of age and decreased at older ages. Systolic BP was higher in men than in women before the age of 45, whereas the reverse was true later in life. At every age, diastolic BP was greater in men than women.
Prevalence of Hypertension
Table 1⇓ displays weighted national estimates of the prevalence of elevated systolic BP, elevated diastolic BP, medication use, and hypertension by age and sex. Hypertension prevalence increased progressively with age, with the exception of the oldest age group (≥75 years). In the youngest age group (25 to 34 years) hypertension was present in 7.8% of the population, whereas the prevalence rate was 59.4% in the 65-74 age group. The weighted national prevalence estimates suggest that 26.3% of all Egyptian adults 25 years of age and older were hypertensive.
Hypertension appeared to be slightly more common in Egyptian women (26.9%) then men (25.7%). However, the difference in prevalence between men and women changed with age and type of BP elevation (systolic versus diastolic). In the youngest age groups (25 to 34 and 35 to 44 years) systolic hypertension was more common in men than women, but the reverse was true in the older age groups. Diastolic hypertension was consistently more common in men than women.
Table 2⇓ displays the estimated prevalence of hypertension by region. Four regions (Cairo, Coastal, Northern Upper Egypt, and Southern Upper Egypt) had an estimated prevalence in excess of 25%. Of these, Cairo had the highest prevalence (31.0%), largely reflecting a relatively high prevalence of reported treatment with antihypertensive medications. Treatment with antihypertensive medications was uncommon (<5%) except in Cairo and the Coastal Region.
Classification of BP Status
Classification of BP according to JNC V indicates that 58.3% of all Egyptians ≥25 years of age had a normal BP; 17.5% had a high normal BP; and 14.7% had stage I, 6.2% stage II, 2.6% stage III, and 0.7% stage IV hypertension (Table 3⇓). Hypertension severity varied by region, with the highest prevalence of stage III and stage IV hypertension noted in Northern (4.9%) and Southern (4.3%) Upper Egypt. Normal BP readings were most prevalent in the Frontier Region (65.8%).
Hypertension Awareness, Treatment, and Control
Our results show that slightly more than one third (37.5%) of all Egyptians who could be classified as hypertensive were aware that they had high BP. Rates of awareness increased steadily with progressively higher stages of hypertension (25.9%, 38.9%, 43.0%, and 63.2% for hypertension stages I, II, III, and IV, respectively). Awareness also varied by region (Table 4⇓). The highest rates of awareness were noted in the Coastal Region and Cairo (56.5% and 56.0%, respectively), and the lowest rates were found in Northern (20.3%) and Southern (31.8%) Upper Egypt. Women (46.3%) were more aware of their diagnosis than men (28.0%), and those in the 55-64 age group (43.5%) were more aware than their counterparts in either the youngest (20.7%) or oldest (34.3%) age group.
The estimated percentage of hypertensive individuals receiving pharmacological treatment in Egypt was 23.9%. The percentage being treated with antihypertensive agents rose steadily with increasing severity of hypertension (13.4%, 20.2%, 22.7%, and 30.3% for stages I, II, III, and IV, respectively). Likewise, the percentage of participants being treated with antihypertensive medications varied by region (Table 4⇑), with the rate being highest in the Coastal Region and Cairo (43.3% and 40.4%, respectively) and lowest in Northern Upper Egypt (10.8%).
The estimated percentage of hypertensive individuals whose BPs were under control (systolic BP <140 mm Hg and diastolic BP <90 mm Hg) was 8.0%. The best control rates were noted in the Coastal Region and Cairo (15.9% and 14.9%, respectively), and the lowest control rates were observed in Northern and Southern Upper Egypt (0.9% and 2.8%, respectively). The percentage of hypertensive individuals with satisfactorily controlled BP was lowest in the 25-34 age group (3.7%) and highest in the ≥75 age group (12.6%). Control rates were higher in women than men (10.9% and 4.8%, respectively).
The NHP findings provide an unusual opportunity for comment on the prevalence of hypertension and the extent and adequacy of treatment in a large economically developing country. Specifically, NHP results indicate that the overall prevalence of hypertension in Egypt, estimated to be 26.3%, exceeds that of the United States (24%)9 and is certainly one of the world’s highest.10 11 12 13 This is especially noteworthy because of the comparatively young age of Egypt’s adult population. Clearly, such results have important clinical and public health implications for Egypt and potentially for other economically developing countries that are experiencing a decline in mortality from acute and parasitic diseases.
Certain NHP findings replicate patterns observed in other BP surveys. For instance, the general pattern of an increasing average systolic BP and increasing prevalence of systolic hypertension with age (except in the oldest age groups) has been well recognized in previous studies.14 Likewise, the pattern of an age-related increase in diastolic BP and diastolic hypertension until a plateau is reached in middle age followed by a decline in the older age groups (particularly in women) has been the norm in most surveys.
One of the most intriguing NHP findings was regional variation in hypertension prevalence. Two regions (the Delta and Frontier Regions) had a prevalence of hypertension less than 20%, whereas the prevalence was close to 30% in the other four regions. In part, this finding may have occurred as a result of variability in treatment with antihypertensive medication. However, there was an approximately twofold difference in the prevalence of elevated systolic and diastolic BPs between Northern Upper Egypt and the Frontier Region. Furthermore, between 4% and 5% of the populations in Northern and Southern Upper Egypt had stage III or IV hypertension, whereas this was the case for only 1.7% of the population in the Frontier Region. To what extent well-established risk factors for hypertension, such as age, weight, sodium intake, physical inactivity, and alcohol consumption, account for the observed regional variation in hypertension prevalence and severity is an important issue worthy of additional investigation. The role of these and other possible risk factors for hypertension, such as ethnicity, skin color, socioeconomic status, dietary constituents, and schistosomias, will be explored in the NHP data set.
Regional variation in rates of awareness, treatment, and control was also prominent. The region of Northern Upper Egypt stood apart from the other regions. In this mixed urban-rural region, only 20.3% of the hypertensive individuals were aware of their diagnosis, only 10.8% were on medication, and less than 1% were controlled. The predominantly urban areas of Cairo and the Coastal Region had the best rates of awareness, treatment, and control, but these were still far from ideal. For instance, in Cairo only slightly more than half (56.0%) of the hypertensive individuals were aware of their condition, and only 14.9% were controlled. Even in the more developed regions, such as Cairo and the Coastal Region, in which there is greater access to health care than in other regions, our data indicate the need for substantial additional efforts to increase the extent of awareness, treatment, and control of hypertension.
The extremely high prevalence of hypertension coupled with the disturbingly low prevalence of awareness, treatment, and control has important implications for health-care providers, public health officials, and health policy decision makers in Egypt. Because cardiovascular diseases such as acute myocardial infarction and sudden death often strike without prior warning, efforts directed toward the treatment and prevention of hypertension, as well as other atherosclerotic cardiovascular disease risk factors, should be a particularly important component of atherosclerotic cardiovascular disease prevention strategies. Education for health-care providers at all stages of professional training will be especially important. Such efforts should be guided by additional research to determine the attitudes, knowledge, and beliefs of clinical practitioners. In addition, the development of professional societies that focus on education and research in hypertension will be of enormous value. In this regard, the newly formed Egyptian Hypertension League is taking a leading role in the coordination and facilitation of hypertension research and teaching initiatives in Egypt.
The public health community must also be alerted to the emergence of hypertension as an important health problem in Egypt. Traditionally, public health workers have focused their efforts almost entirely on infectious and parasitic diseases and on maternal and child health. In the future, identification and treatment of chronic conditions such as hypertension must become an increasingly important focus of their health promotion and disease prevention efforts. Indeed, hypertension treatment and prevention initiatives implemented through existing community-based health-care clinics managed by the Ministry of Health should be an important component of the response by the public health community. Such endeavors must be carefully integrated with the efforts of individual clinicians and other health-care providers. Finally, health policy makers must be alerted to the clinical, public health, and economic consequences of hypertension, as well as risk factors for other emerging chronic conditions in Egypt, to guide them as they develop policy and ensure appropriate allocation of resources.
Such involvement will be especially important because the high prevalence of hypertension mandates both a population-based strategy, to reduce BP and prevent this condition, and a complementary high-risk strategy, to treat those people with established hypertension.15 A population-based strategy is especially important because the risk relationship between BP and atherosclerotic cardiovascular disease is direct and progressive (without a threshold) throughout the range of BP values. Hence, efforts to reduce BP-related atherosclerotic cardiovascular disease must be broad based, achieving BP reductions in normotensive and hypertensive individuals. Successful implementation of both strategies will require coordinated efforts across a number of institutions and organizations. Such efforts include use of the mass media to educate the general population, instruction in medical schools to educate students, leadership from professional organizations to promote research and provide continuing education programs, and encouragement of pharmaceutical companies to support research and education initiatives as well as provide medications to the indigent.
Egypt can benefit from the experiences of other nations that have designed and implemented successful efforts that ultimately led to a reduction in atherosclerotic cardiovascular disease and its risk factors.16 17 18 These prior initiatives provide a useful road map. However, the response in Egypt will have to reflect the special needs of a nation with diverse social, economic, and health priorities. In this regard, initiatives developed in Egypt could serve as a model for other economically developing countries, especially those in the Arab world.
In summary, survey results from the Egyptian NHP provide compelling evidence that hypertension is an extremely common and underserved health problem in Egypt. There is an urgent need for nationwide efforts to prevent and control hypertension in Egypt in order to avert an epidemic of BP-related atherosclerotic cardiovascular disease.
This research was sponsored by the US Agency for International Development; the National Heart, Lung, and Blood Institute; and the Egyptian Ministry of Health and Education.
- Received February 13, 1995.
- Revision received March 23, 1995.
- Accepted July 11, 1995.
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