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3
Asia-Pacific Journal of Public Health 2006 Vol. 18 No. 1
increased from 512 in 1999 to 1,313
in 2003
7
. It is the Thai Ministry of
Public Health policy that every
Provincial Health Office must
conduct a periodical survey for
screening and early detection of
hypertension cases. Therefore, this
study aimed to assess health risk
behaviours, and measured the
prevalence, awareness, treatment,
and control of hypertension and
associated factors among people
aged 35-60 years in a rural area of
Muang District, Chachoengsao
Province.
Materials and Methods
This investigation was carried out
in Chachoengsao Province, 82
kilometers from Bangkok. In 2003,
there were 10 districts and 1 semi-
district. Two-stage systematic
sampling was used to recruit the
study subjects (Figure 1). The
sample size was estimated using the
single proportion formula, with 95%
confidence interval. A sample size
of 527 cases was calculated based
Health Risk Behaviours,
Awareness, Treatment and
Control of Hypertension
among Rural Community
People in Thailand
N Howteerakul
1
, PhD
N Suwannapong
1
, PhD
R Sittilerd
2
, MSc
P Rawdaree
3
, MD, MSc
1
Faculty of Public Health, Mahidol University, Bangkok, Thailand
2
Office of the Permanent Secretary, Ministry of Public Health, Thailand
3
Bangkok Metropolitan Medical College, Bangkok Medical Association,
Thailand
Address for correspondence:
Dr Nopporn Howteerakul
Department of Epidemiology,
Faculty of Public Health,
Mahidol University,
420/1 Rajvithi Road, Bangkok
10400, Thailand.
Tel: + 66 (0) 2354-8541
Fax + 66 (0) 2354-8567
Email: npp92432@yahoo.com
Introduction
Hypertension remains a significant
public health issue in Thailand
and worldwide
1,2
. It is also a major
risk factor for cardiovascular,
cerebrovascular and renal diseases
2
.
The Second Thai National Health
Examination Survey (NHES II),
in 1996, showed that Central
Thailand had the highest pre-
valence of hypertension (14.7%).
Of these, 26.6% were aware of
their high blood pressure, and
50.8% of treated persons achieved
blood pressure control
3
. Most
uncomplicated hypertension is
asymptomatic. In some cases people
live for 10-20 years unaware that
they are affected. Mortality from
cardiovascular disease due to the
complications of hypertension can
be found at age 40 years
4-6
.
Chachoengsao is a province in
Central Thailand. Rapid economic
and lifestyle changes have affected
the burden of non-communicable
diseases in this province. The
number of hypertension cases
Abstract
This cross-sectional study aimed
to assess health risk behaviours,
prevalence, awareness, treatment,
and control of hypertension and
associated factors among Thai
rural community people. 527
people, aged 35-60 years, were
randomly sampled and inter-
viewed. Two blood pressure (BP)
measurements were assessed by
standardized protocol. Hyper-
tension was defined as a mean
systolic BP>140 mmHg or diastolic
BP>90 mmHg. 76.9% lacked
regular exercise, 28.5% were
current alcohol drinkers, and
23.7% were current smokers.
The prevalence of hypertension
was 17.8%. Among the hyper-
tensive cases, 64.9% (61/94) were
aware of their high BP, 42.6%
(26/61) were treated, and 42.3%
(11/26) achieved BP control (<140/
90 mmHg). Multiple logistic
regression analysis indicated four
variables significantly associated
with hypertension: age >40 years
(adjusted OR=4.20, 95%CI 1.93-
9.11), married status (adjusted
OR=0.48, 95%CI 0.26-0.89),
family history of hypertension
(adjusted OR=2.39, 95%CI 1.40-
4.07), and BMI >23.0 kg/m
2
(adjusted OR=3.41, 95%CI 1.80-
6.45). Lifestyle modification
programs are needed to prevent
hypertension. Asia Pac J Public
Health 2006; 18(1): 3–9.
Keywords: Health risk behaviours,
awareness, treatment, control,
hypertension, Thailand.
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4
was used to measure BP. All
participants were seated during BP
measurement, with their left arms
on the table. Also, they were asked
to sit quietly without talking or
crossing their legs for 15 minutes
before their BP was recorded.
Cigarette smokers were also asked
to refrain from smoking for at least
30 minutes prior to BP measure-
ment. All subjects were asked to
abstain from alcohol in the evening
before measurement. BP measure-
ment was performed from 1.00 p.m.
to 6.00 p.m. each day, since that was
the period when BP was stable
6
. The
BP of all participants was measured
twice, with 5-minute spacing, at the
mid-point of the left arm, positioned
at the level of the heart. The mean
of these two measurements was
used as the subject’s BP. One
researcher only conducted all BP
measurements.
Definitions
Hypertension was defined as an
average systolic BP (SBP) >140
mmHg or an average diastolic BP
(DBP) >90 mmHg, according to
the Seventh Report of the Joint
National Committee on Detection,
Evaluation and Treatment of High
Blood Pressure, JNC VII
8
. Good
physical exercise referred to body
exercise, such as jogging, walking,
aerobics that caused the body to
move continuously for >20 minutes
and >3 days per week. Smoking
was categorized as current, former
(not for >1 year), and non-smoker.
Alcohol consumption was
categorized as current, former (not
for >1 year), and non-drinker.
Awareness of hypertension was
defined as self-reported history of
hypertension, or high BP by a
healthcare professional. Treatment
of hypertension was defined as
using antihypertensive drug(s)
prescribed by a healthcare
professional at the time of interview.
Control of hypertension was defined
as a subject who was receiving
treatment for hypertension and kept
BP normal (SBP <140 mmHg and
DBP <90 mmHg).
Statistical analysis
General characteristics and study
variables were described by
percentage, mean, and standard
deviation. Inter-group comparison
for risk factors among subjects
was performed using t-test for
continuous variables and Chi-square
test for two proportions. Logistic
regression was used to obtain odds
ratios (ORs) and 95% confidence
intervals. The significance level was
set at P <0.05.
Results
Of the 527 respondents, 58.4% were
female. Ages ranged from 35-60
years, with a mean age of 45 years.
About 81% were married; 75%
completed elementary school;
46.1% were agriculturists. Average
monthly incomes ranged from
1,000-60,000 Baht, with a median
of 5,500 Baht (40 Baht = 1US$).
26.9% had a family history of
hypertension. BMI ranged from
14.7-51.5 kg/m
2
with a mean of
24.99 kg/m
2
. 51.1% were overweight
(BMI 23.1-30.0 kg/m
2
), and 11.2%
were obese (BMI >30.0 kg/m
2
).
Health risk behaviours
Of the 527 respondents, 76.9%
lacked regular exercise and 23.7%
were current smokers. The smoking
duration of the 125 current smokers
on a rate of 14.7% hypertension
from NHES II in the central region
3
.
Precision was set at 3%. The
inclusion criteria were people aged
35-60 years, who lived in the study
area for at least six months prior to
conducting this survey; they were in
the household during the survey
although their names were not listed
in the house registration. Pregnant
women or persons who were drunk
on the interview day were excluded.
The Ethical Review Committee of
Mahidol University approved the
research protocol. Written consent
was gained from all participating
subjects before data collection.
Instruments
Questionnaire
The survey instrument was a four-
part questionnaire. The first part
comprised closed-ended questions
about the study subjects’ general
characteristics. The second part was
concerned with data on any history
of sickness, hypertension, kidney
disease, diabetes mellitus, heart
disease, gout, smoking, alcohol
drinking, physical exercise and
family history of hypertension. The
third part comprised height, weight,
BMI and blood pressure level
data. The fourth part dealt with
awareness, treatment and control of
hypertension data.
BP measurement
A mercury sphygmomanometer
Figure 1. Two-stage systematic sampling procedure
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5
Asia-Pacific Journal of Public Health 2006 Vol. 18 No. 1
ranged from 2-44 years, with a
median of 20 years; 40.0% smoked
>10 cigarettes/ day. About 28.5%
were current alcohol drinkers. Of
the 150 drinkers, 28% consumed
>30 grams of alcohol per day
(Table 1).
Distribution of blood pressure
Figure 2 shows the distributions
of systolic and diastolic BP,
which were approximately normal
distribution, with a rightward skew.
Mean systolic and diastolic BP
(mmHg) was 127.54 ± 14.91 and
83.13 ± 11.19 for men; and 126.35
± 19.80 and 81.41 ± 13.96 for
women, respectively. The mean
systolic and diastolic BP were
higher in men than women.
However, no significant difference
was found (p=0.433 and p=0.117,
respectively).
Prevalence of hypertension
Table 2 shows age and sex-specific
BP distribution classification
according to the JNC VII criteria
8
.
Overall, 65.8% of men and 51.7%
of women were prehypertensive.
The overall prevalence of hyper-
tension was 17.8%. The proportion
of hypertension was slightly higher
among women than men (18.8 vs.
16.4%). The prevalence of hyper-
tension increased with age in both
men and women (Table 3).
Table 1. Prevalence of health risk behaviours among 527 respondents
Variable Number %
Physical exercise
Good 122 23.1
Need for improvement 405 76.9
Smoking status
Non-smoker 353 67.0
Former smoker 045 09.3
Current smoker 125 23.7
Duration of smoking in years (n=125)
≤ 10 028 22.4
11 - 20 054 43.2
> 20 043 34.4
Median = 20 Range = 2 – 44 years
Number of cigarettes/day on
the smoking day (n = 125)
≤ 10 075 60.0
> 10 050 40.0
Median = 10 Range = 4 to 60 cigarettes
Alcohol drinking
Non-drinking 348 66.0
Formerly drinking 029 05.5
Currently drinking 150 28.5
Volume of alcohol intake
(grams/day) n=150
≤ 30 108 72.0
> 30 042 28.0
Median = 15 Range = 0.3 - 165.5 grams/days
Figure 2. Distribution of (a) systolic and (b) diastolic blood pressures of 527 respondents
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Table 2. Percentage distribution of BP level
a
by age and sex of 527 respondents
Normotensive or Controlled Hypertensive Hypertensive
Age, yrs
Normal Prehypertension Stage 1 Stage 2
SBP, mmHg < 120 and 120 – 139 or 140 – 159 or > 160 or
DBP, mmHg < 80 80 - 89 90 – 99 > 100
Total 24.7 57.4 8.8 9.1
Men 17.8 65.8 7.3 9.1
Women 29.5 51.7 9.7 9.1
a
Based on categories established in JNC VII
8
.
Table 3. Prevalence of hypertension by age 35-60 years, and sex (n=527)
Men Women All
Age group
n % n % n %
35 – 39 3/68 4.4 6/80 7.5 9/148 6.1
40 – 44 8/48 16.7 6/61 9.8 14/109 12.8
45 – 49 8/33 24.2 12/65 18.5 20/98 20.4
50 – 54 7/31 22.6 14/54 25.9 21/85 24.7
55 – 60 10/39 25.6 20/48 41.7 30/87 34.5
Crude prevalence 36/219 16.4 58/308 18.8 94/527 17.8
Hypertension, diastolic blood pressure > 90 mmHg or systolic blood pressure > 140 mmHg or treatment with antihypertensive medication
Awareness, treatment and control
of hypertension
Table 4 shows that 64.9% of
respondents with a diagnosis of
hypertension were aware of their
high BP. More women than men
were aware of their hypertension
(79.3 vs. 41.7%; p <0.001). The
estimated proportion of male
respondents being treated was
higher than female (53.3 vs. 39.1%),
but no significant difference was
found (p=0.334). The proportion of
hypertensive cases who were treated
and had controllable BP (systolic BP
<140 mmHg and diastolic BP <90
mmHg) was 42.3%. Better treatment
and control were also more common
among women than men (44.4 vs.
37.5%), but no significant difference
was found (p=0.741).
Factors associated with
hypertension
All variables were simultaneously
analysed by multiple logistic
regression. After adjustment for
all other variables in the model,
four variables were statistically
associated with hypertension: age
>40 years; married status; family
history of hypertension; and BMI
>23.0 kg/m
2
(Table 5).
Discussion
The mean SBP and DBP in this
study were 126.84 mmHg and 82.12
mmHg, respectively, which were
similar to the findings of studies in
Korea
9
and China
10
. However, it
was higher than the finding (119.9
mmHg, 73.6 mmHg) of the Central
Region people in the NHES II
study
3
. The prevalence of hyper-
tension was also slightly higher than
the finding of the Central Region
people in the NHES II study (17.8
vs. 14.7%). The reason was that
previous studies found that BP
increased with age
5,11,12
. The
NHES II involved a higher
proportion of younger age groups
than the present study. Considering
the age-sex specific prevalence of
hypertension (Table 3), the
prevalence of hypertension in men
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Asia-Pacific Journal of Public Health 2006 Vol. 18 No. 1
aged <50 years was higher than
women of the same age, which
might be due to more males being
exposed to risk behaviours for
hypertension. Several previous
surveys found that the proportion of
male smokers and drinkers was
much higher than females
13,14
. In
contrast, the prevalence of hyper-
tension in men aged >50 years
was lower than in women of the
same age. One possible explanation
was the influence of changing
hormone levels due to menopause in
women
6
.
The awareness of high BP
among women was quite a lot
higher than men (79.3%, 46/58
vs. 41.7%, 15/36; p <0.001). A
possible explanation is that the
study area for this investigation
was located near the city. The
respondents could conveniently
access the health services provided
by the government. Generally, the
proportion of women utilizing health
care services is higher than men
15
.
In this study the proportion of
hypertension awareness was 64.9%
which was a discrepancy with the
high mean BP as shown in Figure 2
and much higher than 20.8% in the
report of Suriyawongpaisal, et al.
16
in 1991 and 26.6% in the NHES II
study
3
in 1996. Two possible reasons
can explain this: 1) awareness of
Table 5. Crude and adjusted odds ratios (ORs) from multiple logistic regression analysis of the respondents’
general characteristics, health risk behaviours and hypertension (n=527)
Crude Adjusted
a
P-value
Variable
OR 95% CI OR 95% CI
Age (years)
< 40 1.00 1.00
> 40 4.47 2.18-9.14 4.20 1.93-9.11 < 0.001
Marital status
Single/widowed 1.00 1.00
Married 0.58 0.34-0.97 0.48 0.26-0.89 0.019
Family history of hypertension
No 1.00 1.00
Yes 2.27 1.43-3.62 2.39 1.40-4.07 0.001
BMI (kg/m
2
)
< 23.0 1.00 1.00
> 23.0 3.37 1.90-5.97 3.41 1.80-6.45 < 0.001
a
adjusted for all other variables in the model.
Table 4. Prevalence of hypertension, awareness, treatment and control, by sex (n=527)
Men Women Total P-value
Variable
n % n % n %
Prevalence 36/219 16.4 58/308 18.8 94/527 17.8 0.479
Awareness
a
15/36 41.7 46/58 79.3 61/94 64.9 < 0.001
Treatment
b
8/15 53.3 18/46 39.1 26/61 42.6 0.334
Control
c
3/8 37.5 8/18 44.4 11/26 42.3 0.741
a
the number of hypertensive persons who were diagnosed before;
b
the number of hypertensive persons who used anti-hypertension drugs;
c
the number of hypertensive persons who kept blood pressure normal (diastolic blood pressure
<90 mmHg and systolic blood pressure <140 mmHg) during treatment
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hypertension in present study was
defined as self-reported history of
hypertension, or high BP by a
healthcare professional; 2) the
healthcare services in the current
study period were much better than
in the previous studies. In addition,
some public health education
programs aimed to increase people’s
awareness and prevention of
hypertension were introduced in the
study period.
Like treatment, control of
hypertension by antihypertensive
drug therapy was 42.3%. The
control rate was higher than the
finding of 20.0% by Suriyawong-
paisal, et al.
16
, but it was lower than
the finding (50.8%) of NHES II
3
.
Several reasons can explain this:
first, it might be lack of
aggressiveness in treating patients
9
;
Second, the patient compliance with
taking antihypertensive drugs was
poor. Wiwatkunoopakarn, et al
reported that only 72% of essential
hypertensive patients at Nan
Provincial Hospital, Thailand had a
good level of drug compliance
15
. It
was a hospital-based study.
Therefore, the drug compliance
should be higher than this figure.
Third, the side-effects of the
currently available antihypertensive
drugs in the study area might affect
the low drug compliance rate and
fail to achieve the goal of BP
control.
This study confirmed the
findings of previous studies, that
the prevalence of hypertension
increases with age, family history
of hypertension, high BMI and
married status
9,11,12,17-20
. Married
respondents were less likely to
develop hypertension than those
single or widowed (OR=0.58, 95%
CI 0.34-0.97), as support from the
family can reduce stress, which is a
risk factor for high BP
22
.
Respondents who had a family
history of hypertension were more
likely to develop hypertension than
those who had no family history of
hypertension (OR=2.27, 95% CI
1.43-3.62), which may be due to
genetic determinants and similar
patterns of eating in the same
family
5,18
. In this study, a BMI of
>23.0 kg/m
2
was considered
overweight. Research conducted in
10 countries—Hong Kong, India,
Thailand, Malaysia, Fiji, Indonesia,
Singapore, China, South Korea, and
the Philippines—indicated that
Asians had more fat content
compared with Caucasians, which
meant that a BMI of 25.0 kg/m
2
was
inappropriate for measuring Asian
overweight. In other words, an
Asian and a Caucasian may be the
same weight and height, but the
Asian has a greater risk of fat-
related illness, such as hypertension
and diabetes
21
. In the present study,
the respondents with BMI >23.0 kg/
m
2
were more likely to develop
hypertension than those with BMI
<23.0 kg/m
2
(OR=3.37, 95% CI
1.90-5.97). It is possible that higher
BMI generally indicates higher
serum cholesterol and triglyceride
levels, which are related to high
blood pressure
22
. This finding
corresponded with the findings of
others
9,15,20
.
However, no health risk
behaviour factors were statistically
associated with hypertension
(p>0.05). Only univariate analysis
found that drinkers of >30 grams
of alcohol per day were 2.5 times
more likely to develop hypertension
than those who drank ≤30 grams
(OR=2.5, 95%CI 1.01-6.33), but it
was not statistically significant for
multivariate analysis (data not
shown). One possible reason might
be that the volume of health risk
practices relied on self-reports. The
number and volume of cigarette-
smoking and alcohol-drinking per
day, as well as the duration of these
practices, did not reach the
threshold for hypertension
23
.
The strengths of this study
included a convenient, unobtrusive,
and standardized measurement
of BP. Limitations included: 1)
the modest sample size which
represented only rural community
people in Chachoengsao Province;
2) the self-report questionnaire; and
3) the cross-sectional study design,
which cannot determine whether the
associations between significant
predictors and hypertension were
causal.
In conclusion, the prevalence
of health risk behaviours and
hypertension is quite high among
rural community people. Lifestyle
modification programs targeting BP
reduction in hypertensive cases are
needed to prevent the complications
of hypertension. Participatory health
education programs aimed at
increasing people’s awareness and
prevention of hypertension should
be introduced.
Acknowledgements
The authors would like to thank the
staff of Muang District Health
Office and the Chachoengsao
Provincial Chief Medical Officer for
their support during fieldwork.
References
1. Division of Health Statistics,
Ministry of Public Health.
Public Health Statistics, 1997.
Bangkok: Veteran Organization
Press; 1998:153-97.
2. Feldman RD, Campbell N,
Larochelle P, et al. 1999
Canadian recommendations for
the management of hyper-
tension. Task Force for the
Development of the 1999
Canadian Recommendations
for the Management of
Hypertension. CMAJ 1999;
161(Suppl 12): S1-17.
3. Choprapawon C. Thai Health
Status, 2000. Bangkok: Usa
Press; 2000: 233-25.
4. Beevers G, Lip YHG, O’Brien
E. Clinical review, ABC of
hypertension, The patho-
physiology of hypertension.
BMJ 2001; 322: 912-6.
5. Sing RB, Suh IL, Sing VP, et al.
Hypertension of stroke in
Asia: prevalence, control and
strategies in developing
at Mahidol University on June 25, 2015aph.sagepub.comDownloaded from
9
Asia-Pacific Journal of Public Health 2006 Vol. 18 No. 1
countries for prevention. J Hum
Hypertens 2000; 14: 749-63.
6. Whitworth JA. World Health
Organization, International
Society of Hypertension
Writing Group. 2003 World
Health Organization (WHO)/
International Society of
Hypertension (ISH) statement
on management of hypertension.
J Hypertens 2003; 21: 1983-92.
7. Chachoengsao District Health
Office. Non-communicable
disease report, 2003.
8. Chobanian AV, Bakris GL,
Black HR, et al. The Seventh
Report of the Joint National
Committee on Prevention,
Detection, Evaluation, and
Treatment of High Blood
Pressure: the JNC 7 report.
JAMA 2003; 289: 2560-72.
9. Jo I, Younjhin A, Jungbok L,
Kyung RS, Hong KL, Chol S.
Prevalence, awareness, treat-
ment, control and risk factors of
hypertension in Korea: the
Ansan study. J Hypertens 2001;
19(9): 1523-32.
10. Gu D, Reynolds K, Wu X, et al.
Prevalence, awareness, treat-
ment, and control of hyper-
tension in China. Hypertension
2002; 40: 920-7.
11. Percy C, Freedman SD, Gilbert
JT, White L, Ballew C, Mokdad
A. Prevalence of hypertension
among Navajo Indians: findings
from the Navajo Health and
Nutrition Survey. J Nutri 1997;
127(10 Suppl): 2114S-2119S.
12. Tate RB, Manfreda J, Krahn
AD, Cuddy TE. Tracking of
blood pressure over a 40-year
period in the University of
Manitoba follow-up study,
1948-1988. Am J Epidemiol
1995; 142: 946-54.
13. Supawongse C, Buasai S.
Smoking Behaviour of Thai
Youths: A National Survey.
Bangkok: Health Research
Institute; 1996.
14. National Statistics Office of
Thailand, Office of the Prime
Minister. Report of the Health
and Welfare Survey, 1996.
15. Wiwatkunoopakarn S, How-
teerakul N, Suwannapong N,
Sooksriwongse C. Drug
compliance among essential
hypertensive patients at Nan
Hospital. J Public Health 2001;
31(2): 114-25.
16. Suriyawongpaisal P, Under-
wood P, Rouse LI, Mungkarasiri
R. An investigation of hyper-
tension in a slum of Nakhon
Ratchasima. Southeast Asian J
Trop Med Public Health 1991;
22(4): 586-94.
17. Voravong R, Patumanond J,
Tawichasri C. Hypertension in
rural elderly and its associated
factors. Bull Dept Med Serv
1999; 24: 469-76.
18. Charles MA, Pettitt DJ, Hanson
RL, et al. Familial and meta-
bolic factors related to blood
pressure in Pima Indian
children. Am J Epidemiol 1994;
140: 123-31.
19. Swaddiwudhipong W, Chaova-
kiratipong C, Nguntra P,
Mahasakpan P, Jaisaard W,
Tatip Y. Prevalences of hyper-
tension, diabetes mellitus, and
hypercholesterolemia between
Thai-yais and Thais: a survey in
Mae Sot District, Tak Province,
1999. Bull Dept Med Serv
2000; 25: 71-7.
20. Quasem L, Shetye SM, Alex
CS, Kumar Nag A, Sarma PS,
Thankappan KR. Prevalence,
awareness, treatment and
control of hypertension among
the elderly in Bangladesh and
India: a multicentre study. Bull
World Health Organ 2001;
79(6): 490-500.
21. Asians on a different obesity
scale. Health. October 16,
2002. Available from: http://
www.cbsnews.com/stories/
2002/10/16/health/
main525887.shtml [Accessed
2003 Nov 4].
22. Beilin LJ, Puddey IB, Burke V.
Lifestyle and hypertension. AJH
1999; 12: 934-45.
23. Kaplan MN, Lieberman E,
editors. Clinical Hypertension.
6
th
ed. Maryland, USA: Williams
& Wilkins, 1994.
at Mahidol University on June 25, 2015aph.sagepub.comDownloaded from