American University of Armenia Cross-sectional Survey on Hypertension Prevalence, Frequency of ...

48 Pages·2001·0.12 MB·English

American University of Armenia

Department of Public Health

Cross-sectional Survey on Hypertension Prevalence, Frequency of
Risk Factors and Compliance Practices in Armenia.

(Research Grant Proposal)

Lusine Saroyan
MPH candidate

Yerevan 2001
Table of Contents

Executive summary -------------------------------------------------------------------------- 3
Background information -------------------------------------------------------------------- 4
Pilot study -------------------------------------------------------------------------------------- 9
Specific aims and objectives of the study ----------------------------------------------- 10
Methods --------------------------------------------------------------------------------------- 11
Target population ------------------------------------------------------------------ 12
Sample size and sampling methodology --------------------------------------- 13
Study limitations ---------------------------------------------------------------------------- 16
Study strengths ------------------------------------------------------------------------------ 16
Data analysis --------------------------------------------------------------------------------- 17
Human subject and ethical considerations --------------------------------------------- 18
Time frame for the project ----------------------------------------------------------------- 19
Budget ----------------------------------------------------------------------------------------- 19
Personnel responsibilities ------------------------------------------------------------------ 20
Project feasibility ---------------------------------------------------------------------------- 21
Acknowledgements -------------------------------------------------------------------------- 23
References ------------------------------------------------------------------------------------ 24
Appendices ----------------------------------------------------------------------------------- 27

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Executive summary
Hypertension is one of the major public health problems in the world. It is one of the
major risk factors for cardiovascular mortality. Because of hypertension's central role in
coronary heart disease and stroke, one of the biggest challenges facing public health authorities
and medical practitioners is the control of hypertension worldwide.
According to data of Armenian Republican Health Information Analytic Center
(RHIAC) in 1999 there were 1166 people per 100,000 population who suffer from
hypertension. The incidence rate of hypertension has grown constantly since 1985.
To assess the hypertension prevalence in Armenia and to obtain precise information
about compliance with hypertension treatment and the frequency of various hypertension risk
factors, a survey of the Armenian population is recommended. The design of the study is cross-
sectional observational survey. The main tool to conduct this quantitative study is a personal
interview with the study population using a questionnaire and measuring blood pressure.
Respondents will be selected using multistage cluster sampling (probability proportional to size).
One thousand seventy five men and women aged 19 and above from Yerevan, Armavir and
Aragatsotn will participate in the survey.
Statistical analysis will be done using STATA statistical package. The prevalence of
diagnosed hypertensives, of those with elevated blood pressure and the prevalence of
hypertensives that comply with treatment will be calculated. Also 2x2 tables and logistic
regression model will be used to compare risk factors to hypertension, and to evaluate
interaction between variables.
The overall duration of the study is six months. The overall estimated budget is
approximately nineteen thousand ($19,104).
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Background information
Hypertension is one of the major public health problems in the world. According to the
World Health Organization (WHO), hypertension is “a disorder characterized by high blood
pressure which includes systolic blood pressure higher than 140mm/Hg and diastolic blood
pressure over 90mm/Hg” [1]. To diagnose hypertension, these numbers should be validated by
three measurements of blood pressure over a period of three months [1,2]. On average, people
with uncontrolled high blood pressure are: seven times more likely to have a stroke, six times
more likely to develop congestive heart failure, and three times more likely to have a heart
attack [3].
Based on data provided by the Centers for Disease Control and Prevention, and the
National Center for Health Statistics, as many as 50 million Americans have high blood pressure
(HBP). Among people aged 65 years and older, about 40 percent of whites and 50 percent of
blacks have HBP. Blood pressure increases with age, but the onset of hypertension most often
occurs during the third, fourth, and fifth decades of life [4]. HBP was listed on death certificates
as the primary cause of death of 42,565 Americans in 1997. HBP was listed as a primary or
contributing cause of death in about 210,000 of the more than 2,000,000 U.S. deaths that year
[5].
The costs of hypertension are alarming. It was estimated to be $30 billion in the United
States (US) in 1997 alone. Drug treatment covers nearly a third or $7 billion of the $22 billion in
direct costs, which also includes the cost for hospitalizations and doctor visits [6].
The authors of the article “State of the art and perspectives in hypertension”[7],
reported that as a whole 1/2 of hypertensives remain undiagnosed; 1/4 are not treated despite
awareness of hypertension; 1/8 know they have hypertension but are not satisfactory treated;
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and only the last 1/8 of patients are diagnosed and treated with sufficient blood pressure control.
This fact was confirmed by other studies [8,9].
The WHO provides information that cardiovascular disease is rapidly becoming an
important factor in developing countries and in the newly independent states of the former
Soviet Union. It is projected that death and disability from coronary heart disease and
cerebrovascular disease are now increasing so quickly in these parts of the world that they will
rank as first and fourth, respectively, among the causes of the global burden of disease by 2020.
Because of hypertension's central role in coronary heart disease and stroke, one of the biggest
challenges facing public health authorities and medical practitioners is the control of hypertension
[8].
A number of epidemiological studies have identified risk factors that increase the
likelihood of developing hypertension [1]. However, the association with these risk factors does
not necessarily imply an etiologic role [1]. Those risk factors are family history of hypertension
and cardiovascular diseases, family and personal history of hyperlipidemia, family and personal
history of diabetes mellitus, high salt (sodium chloride) intake, obesity, smoking, excessive
alcohol intake, and lack of physical activity. A family history of hypertension, namely having
hypertensives among first-order adult relatives (parents and siblings) is one of the strongest risk
factors for developing hypertension [1]. Family and personal history of hiperlipidemia and
obesity are also strongly associated with developing hypertension. The proportion of
hypertension attributable to obesity has been estimated to be 30-65 percent in Western
populations. Multivariate regression analysis of hypertension data indicates a rise of 2-3 mm Hg
systolic blood pressure and 1-3 mm Hg diastolic blood pressure for each 10 kg increase in
weight [1,10]. A number of experimental and observational studies show that the intake of
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sodium chloride, in excess of physiological requirements, is associated with high blood pressure.
The results of the interpopulation study “Intersalt” revealed that “a 100 mmol/day lower intake
of sodium chloride over a lifetime would result in a 9 mm Hg smaller rise in systolic pressure
from 25 to 55 years of age” [11].
Alcohol consumption has also been related to high blood pressure. “Two or more
drinks consumed per day increases systolic blood pressure by 1.0 mm Hg and diastolic blood
pressure by 0.5 mm Hg per alcoholic drink” [12]. Individuals with sedentary life style (no
activity or any physical activity for less than 20 minutes or less than three times per week) have
a 20-50 percent increased risk of developing hypertension when compared with more active
people [13]. The National Institutes of Health in the US recommend adults to have at least 30
minutes of moderate activity most days of the week to promote cardiovascular fitness.
Moderate activities include walking, gardening, yard working, moderate-to-heavy house
working, dancing, or home exercising [14]. The association between the aforementioned risk
factors and hypertension is supported by many other studies conducted in the world [15, 16,
17, 18, 19, 20, and 21].
One of the largest projects in the US related to hypertension was the National Health
and Nutrition Examination Surveys (NHANES I, II, III, IV). These studies were conducted by
the National Center for Heath Statistics, and the Centers for Disease Control and Prevention,
during four separate periods of time: 1960-1962, 1971-1974, 1976-1980, and 1988-1991.
Due to significant improvement in awareness, treatment and control of hypertension, the
prevalence of the disease has declined since 1971. Age-adjusted prevalence rates have
declined from 36.3% to 20.4% (I-III). Age-adjusted mean systolic pressure declined from 134
mm Hg at NHANES I to 119 mm Hg at NHANES III. During the interval between the
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NHANES II and III, the threshold for defining hypertension changed from 160/95 to 140/90
mm Hg. Despite this favorable trend, many people with hypertension are unaware of their
condition, and many more are untreated or inadequately treated [22, 23]. Current management
of the disease is characterized by underdiagnosis, misdiagnosis, undertreatment, overtreatment
and misuse of medications. As a result, 75 percent of the estimated hypertensives increase their
risk for vascular complications [9].
In order to avoid possible complications, hypertension should be under strict control
and monitoring. Even after diagnosis and adequate control and treatment, the risk for coronary
heart disease and renal disease continues to be elevated. Thus, early treatment of elevated
blood pressure may reduce the incidence of clinical manifestations of hypertension and decrease
long-term consequences of the disease [24].
Despite decades of attention to fight noncompliance with treatment of hypertension, the
problem remains a significant factor in the control of blood pressure [25, 26]. There are several
reasons for not complying with treatment and low utilization of health services. In addition to
drug side effects and costs, the most common reason that the treatment fails is the poor patient-
physician relationship. Recent studies suggest that improving the effectiveness of provider-
patient contacts would improve the treatment of hypertension [27].
According to 1999 data from the Armenian Republican Health Information Analytic
Center (RHIAC), there were 1,164 people per 100,000 population who suffer from
hypertension. The incidence rates of hypertension and patients mortality have consistently grown
since 1985. Mortality from HBP in 1985 was 52.8 per 100,000 population, while in 1999 it
was 75.4 per 100,000 population [28]. Stroke is one of the severe complications of
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hypertension. According to RHIAC, in 1998 mortality due to stroke was 85.17 per 100,000
[28].
The problem with these figures is they were calculated using unreliable population data.
The official population of the country is still reported to be 3.5 million people. However, there
has been large migration of the population of Armenia during the last years and according to
non-official sources, it may be less than 2 million people. Moreover, the data provided by
RHIAC are based on cases registered upon referral for specialized medical care. Taking into
account poor socioeconomic conditions of a large proportion of the population, and the
negative attitude towards primary health care, it can be assumed that there are many people
who do not access appropriate care. Also, due to lack of knowledge of the importance of
hypertension, Armenians may not seek care for the problem. The estimation of the real
prevalence of hypertension among Armenians is hindered also because during the first stages of
hypertension, there are no symptoms. An individual can have HBP and still feel well. All these
reasons indicate Armenians not know they have HBP and among those that know, many are
self-treating the problem. Self treatment not only worsen the situation with hypertension, but
could also increase the risk of developing serious complications such as stroke, heart attack,
kidney diseases, and other serious complications. Taking into account already mentioned data, it
can be assumed that the actual figures on hypertension prevalence in Armenia are likely to be
appreciably higher. In effect, the prevalence is not really known. No large national studies have
been undertaken.

Pilot Study
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To obtain preliminary data on the hypertension situation in Armenia and to test the study
instrument (hypertension questionnaire), a small study was conducted among the adult
population from several districts in Yerevan. The study included 50 people aged 19 years and
older. The sampling methodology for the pilot study was convenience sampling, and one
individual from every third apartment in a specific location was interviewed. The interview lasted
approximately 10 minutes. An additional 10 minutes was needed to take the blood pressure
measurement. The blood pressure reading was taken twice: before and after conducting the
interview. As a result of the pilot, the questionnaire was minimally changed. Changes consisted
of changing the sequence of questions and reorganizing some of the skipping patterns used in the
original instrument.
The following groups of people were identified during the pilot study:
1) People with normal blood pressure (N=32): 64% (95% CI: 50.7% - 77.3%)
2) People with diagnosed hypertension (N= 13): 26% (95% CI: 14%-38%)
3) People not previously diagnosed with hypertension, but with high blood pressure readings
(N=5):10% (95% CI: 1.7% - 18%)
Among those with diagnosed hypertension 61.5 percent (N=8) were complying with the
prescribed treatment. Five or 38.5 percent of the hypertensives were not complying with
treatment (95% CI: 12% - 65%). However, even among the eight people who reported that
they were following their doctor's prescriptions, none had blood pressure less than 140/90 mm
Hg.
Although these data are not representative and could not be generalizable to the whole
population, it provided further justification to conduct a large-scale study.

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