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A CROSS-SECTIONAL STUDY ON KNOWLEDGE, ATTITUDE AND PRACTICE

REGARDING HYPERTENSION AMONG THE POPULATION AGE 18 YEARS OLD

AND ABOVE IN THE AREA OF SUNGAI KERUBONG, SARIKEI

FROM 6TH JULY TO 29TH AUGUST 2008.

AUDREY ALBERT RADIN (13762), AZWAN BIN RAHAMAN (13793), FATIM ZULAIKA (14022), HENRIETTA ALBELA (14118), KHO SZE SHYANG (14285), LAU EE HUA (14325),

MOHAD SUHAIMI BIN SULAIMAN (14478), NGUA CHEN WEN (14678), NORAIN BINTI OMAR (14785), NUR AIMI BINTI JADDIL @ ZAIDEL (14887),

NURUL AIZAM BT MOHD AZMI (14976), SITZ SANAA B1INTI WAN AZMAN (15303), TEE VERN JUN (15404), TENG HUNG XIN (15407), WONG JIA HUEY (15508), GIN CHAT ZHEN (15708), MOHD HISYAMUDIN BIN HARIS PADILAH (12419)

DEPARTMENT OF COMMUNITY MEDICINE & PUBLIC HEALTH FACULTY OF MEDICINE & HEALTH SCIENCES

UNIVERSITI MALAYSIA SARAWAK

2008

rusar "mmat iv, aa}umx,. tu. äuc. uu.

U1VMRSTTI MALAYSIA SARAWAK

DECLARATION

We declare that this research originates from our own effort, except for certain facts and citations with which the sources have been clearly listed in the bibliography.

13762 Audrey Albert Radin

13793 Azwan bin Rahaman

14022 Fat im Zulaika

14118 Henrietta Albela

14285 Kho Sze Shyang

14325 Lau Ee Hua

14478 Mohad Suhaimi bin Sulaiman

14678 Ngua Chen Wen

14785 Norain binti Omar

14887 Nur Aimi Binti Jaddil @ Zaidel

14976 Nurul Aizam Bt Mohd Azmi

15303 Siti Sanaa Binti Wan Azman

15404 Tee Vern Jun

15407 Teng Hung Xin

15508 Wong Jia Huey

15708 Gin Chai Zhen

12419 Mohd Hisyamudin bin Haris Padilah

i

ACKNOWLEDGEMENTS

This research will not be going so smoothly without the full cooperation of

villagers from Sungai Kerubong. Firstly, we would like to thank the villagers from all

11 longhouses from Sungai Kerubong, namely Rumah Jawa, Rumah Insol, Rumah

Meringgai, Rumah Puin, Rumah Lanyaw, Rumah Usin, Rumah Anggey, Rumah

Manggang, Rumah Patrick, Rumah Mudam and Rumah Moses. Special appreciation

to Tuai Rumah Jawa ak Drahman, who provided us full cooperation for coordinating

our research activities and being very caring to all of us. Not forgetting our

respondents who are willing to spare their precious time for our survey.

Apart from that, we would like to thank Universiti Malaysia Sarawak for

subsidizing our research activities and give us a chance to interact with local

longhouse community. We would also like to thank our posting coordinator, Mr.

Cliffton Akoi ak Pangarah, for his hard work and professional advice to us during the

posting. Not forgetting our appreciation to Associate Prof Dr. Kamaluddin Bakar,

Head of Department of Community Medicine & Public Health, Prof Dr. Mohd. Raili

Suhaili, Associate Prof. Dr. Mariah Ahmad, Dr. Haironi Yusof, Dr. Aye Aye Aung,

Mdm Cheah Whye Lian, Miss Zainab Tambi and other lecturers or staff.

Our appreciation also extends to Tan Sri Datu Professor Dr. Haji Mohd Taha

Arif, Dean of the Faculty of Medicine and Health Sciences, all the lecturers and staff

of the faculty for their assistance in completing our study and intervention programme

successfully. Special appreciation to Mr Sukran bin Kana, officer of community

development, who dealt with student welfare and accommodation. We would like to

thank the medical laboratory technicians of UNIMAS immensely for their assistance

during our intervention programme.

We would also like to thank Sarikei Divisional Health Officer, Dr. Haji Mohd.

Asri, all the health staff from Sarikei and Bintangor Health Clinics, Sarikei District

Council, Jabatan Penerangan Malaysia, Public Works Department, UNIMAS drivers

for their contribution and support throughout our community posting. Their constant

effort has had a significant impact on the final make-up of this dissertation.

11

ABSTRACT

Hypertension is becoming an increasingly common health problem globally.

In 2002, WHO estimated that there are a staggering 1 billion individuals with

hypertension and 7.1 million deaths yearly attributed to hypertension. Currently, it is

estimated that the number of hypertensive patients in Malaysia is 4.8 million

(Ministry of Health 2008). It is even more disquieting that approximately two-thirds

of individuals with hypertension in Malaysia were unaware that they were

hypertensive (NHMS3 2006). Evaluation of knowledge, attitudes and preventive

practices (KAP) is an essential component of hypertension control. Thus, a population

based cross-sectional study was conducted on a stratified random sample of 169

adults aged 18 and above from 11 Than long houses at Sungai Kerubong area, Sarikei

from 6th July to 29`h August 2008. The research objective was to study the KAP

regarding hypertension among the community. It was assessed from a pre-tested

interview-guided questionnaire. The prevalence of hypertension was 24.9%. For

assessment of knowledge, a total of 10 questions were asked. Only 16.0% of the

respondents had adequate knowledge regarding hypertension. On the contrary, 85.8%

of the respondents had positive attitude. Also, out of the 169 respondents, 131 had

good practices on hypertension prevention. In addition, there was weak positive

correlation between knowledge and attitude level and between attitude and practice

level. These data point that although knowledge is positively correlated with attitude,

it is not a dominating factor. Thus, besides aiming to improve their knowledge,

awareness and promoting healthy lifestyle must not be neglected to maintain and

hopefully to increase their attitude and practice.

iii

ABSTRAK

Penyakit tekanan darah tinggi (atau hipertensi) semakin menular sebagai

masalah kesihatan umum pada peringkat dunia. Pada tahun 2002, WHO

menganggarkan kira-kira I bilion individu yang mempunyai hipertensi dan 7.1 juta

kematian setiap tahun dikaitkan dengan penyakit darah tinggi. Kini, jumlah pesakit darah tinggi di Malaysia adalah lebih kurang 4.8 milion (Kementerian Malaysia

2008). Perkara yang lebih merunsingkan adalah kira-kira dua pertiga daripada pesakit hipertensi tidak sedar bahawa mereka menghidap hipertensi (NHMS3 2006).

Penilaian tentang pengetahuan, sikap dan amalan pencegahan (KAP) adalah komponen penting dalam mengawal penyakit tekanan darah tinggi. Dengan itu,

sebuah kajian keratan rentas berdasarkan populasi yang diipilih berteraskan

persampelan berperingkat secara rawak telah dijalankan ke atas 169 dewasa yang berumur 18 tahun dan ke atas dari 11 rumah panjang Than dari kawasan Sungai

Kerubong, Sarikei bermula dari 6 Julai hingga 29 Ogos 2008. Objektif penyelidikan ini bertujuan untuk mengkaji paras pengetahuan, sikap dan amalan tentang penyakit darah tinggi di kalangan komuniti. Ini telah dijalankan melalui temuramah berdasarkan soal selidik yang telah diuji terlebih dahulu. Kajian menunjukkan 24.9%

responden menghidapi hipertensi. 10 soalan telah ditanya untuk bahagian

pengetahuan. Hanya 16.0% responden didapati mempunyai pengetahuan yang

mencukupi berkenaan hipertensi. Akan tetapi, 85.8% responden berjaya mencapai

skor sikap positif. 131 daripada 169 reponden didapati mempunyai amalan yang baik

berkenaan cara-cara mencegah hipertensi. Analisis kajian telah menunjukkan terdapat hubungan positif antara paras pengetahuan dengan paras sikap dan antara paras sikap dengan paras amalan. Data-data ini menunjukkan walaupun pengetahuan mempunyai hubungan positif dengan paras sikap, pengetahuan bukan merupakan penentu utama. Oleh itu, selain berusaha untuk meningkatkan tahap pengetahuan mereka, penekanan harus diberikan terhadap kesedaran dan pengamalan gaya hidup sihat agar dapat

mengekalkan dan moga-moga dapat meningkatkan lagi paras sikap dan amalan

mereka.

iv

Pusat Khidmat Maklumat Akademik UNIVERSiT[ MALAYSIA SARAWAK

TABLE OF CONTENTS

Declaration

Acknowledgements

Abstract

Abstrak

Table Of Contents

List Of Tables

List Of Figures

Chapter 1 Introduction And Background Information

1.1 Introduction

1.2 Background Information

Chapter 2 Statement Of Problem, Literature Review And

Conceptual Framework

2.1 Statement Of Problem

2.2 Literature Review

2.3 Conceptual Framework

Chapter 3 Objectives & Hypotheses

3.1 General Objective

3.2 Specific Objectives

3.3 Hypotheses

Page

1

11

111

iv

V

viii

X

I

3

5

8

16

18

19

20

V

Chapter 4 Research Methodology

4.1 Research Design & Setting

4.2 Population & Sampling

4.3 Inclusion Criteria

4.4 Exclusion Criteria

4.5 Variables

4.6 Study Instruments

4.7 Data Entry And Analysis

4.8 Operational Definitions

4.9 Research Methodology Flow Chart

Chapter 5 Results

5.1 Introduction

5.2 Socio-demographic Factors

5.3 Hypertension Profile

5.4 Knowledge

5.5 Attitude

21

21

21

22

22

22

23

24

27

28

29

34

36

49

5.6 Practice 62

5.7 Relationship Between Knowledge Level with Attitude Level 74

5.8 Relationship Between Attitude Level with Practice Level 77

Chapter 6 Discussion

6.1 Introduction

6.2 Knowledge

6.3 Attitude

80

81

87

vi

6.4 Practice 92

6.5 Relationship Between Knowledge Level with Attitude Level 97

6.6 Relationship Between Attitude Level with Practice Level 100

Chapter 7 Limitations, Recommendation And Conclusion

7.1 Conclusion

7.2 Limitations

7.3 Recommendations

101

104

105

References 107

Appendices

1. Appendix A- Pre-Intervention Questionnaire

II. Appendix B- Census Form

III. Appendix C- Map of Sungai Kerubong

113

119

120

vii

LIST OF TABLES

Items

Table 2.1

Table 5.1

Table 5.2

Table 5.3

Table 5.4

Table 5.5

Table 5.6

Table 5.7

Table 5.8

Table 5.9

Table 5.10

Table 5.11

Table 5.12

Table 5.13

Table 5.14

Title Page

Manifestation of Target Organ Damage Due To Hypertension 12

Assessment of knowledge on hypertension among respondents 37

(N=169)

The difference between gender and knowledge levels 40

The difference between age group and knowledge levels 42

The difference between education levels and knowledge levels 44

The difference between socioeconomic status and knowledge 46

levels

The difference between family history and knowledge levels 47

Assessment of attitude regarding hypertension among respondents 51

(N = 169)

The difference between gender and attitude levels 54

The difference between age group and attitude levels 56

The difference between education levels and. attitude levels 57

The difference between socioeconomic status and attitude levels 59

The difference between family history and attitude levels 60

Assessment of practice regarding hypertension among

respondents (N = 169)

The difference between gender and practice levels

63

66

viii

Table 5.15 The difference between age group and practice levels 68

Table 5.16 The difference between education levels and practice levels 69

Table 5.17 The differences between socioeconomic status and practice levels 71

Table 5.18 The difference between family history and practice levels 73

Table 5.19 The Relationship between Overall Knowledge and Overall 74

Attitude Levels

Table 5.20 Spearman Rank Correlation between knowledge and attitude total 76

score

Table 5.21 The Relationship between Overall Attitude and Overall Practice 77

Levels

Table 5.22 Spearman Rank Correlation between attitude and practice total 78

score

ix

LIST OF FIGURES

Items

Figure 5.1

Figure 5.2

Figure 5.3

Figure 5.4

Figure 5.5

Figure 5.6

Figure 5.7

Figure 5.8

Figure 5.9

Figure 5.10

Figure 5.11

Figure 5.12

Figure 5.13

Figure 5.14

Figure 5.15a

Figure 5.15b

Title Page Pie chart of percentage of gender among respondents (N = 169) 29

Pie chart of percentage of each age group among respondents 30

(N = 169)

Pie chart of percentage of education among respondents (N = 169) 31

Pie chart of percentage of each education level among respondents 32 (N = 169)

Pie chart of percentage of each socioeconomic group among 33

respondents (N = 169)

Pie chart of percentage of hypertensive and non-hypertensive 34

among respondents (N = 169)

Pie chart of percentage of respondents with or without family 35

history of hypertension (N = 169)

Bar graph showing knowledge level among respondents (N = 169) 36

Bar graph showing the percentage of the respondent with adequate 38

and inadequate knowledge in each category (N= 169)

Bar graph showing the knowledge level of male and female 41

respondents (N = 169)

Bar graph showing knowledge level among each age group 43

(N = 169)

Bar graph showing knowledge level among each education group 45

(N = 169)

Bar graph showing knowledge level among each socioeconomic 46

group (N = 169)

Bar graph showing knowledge level among respondents with 48

positive and negative family history of hypertension (N = 169)

Bar graph showing the percentage of respondents with positive 49

and negative attitude in each category (N = 169)

Bar graph showing the percentage of respondents with positive 52

and negative attitude in each category (N=169)

X

Figure 5.16

Figure 5.17

Figure 5.18

Figure 5.19

Figure 5.20

Figure 5.21

Figure 5.22

Figure 5.23

Figure 5.24

Figure 5.25

Figure 5.26

Figure 5.27

Figure 5.28

Figure 5.29

Figure 5.30

Figure 5.31

Bar graph showing attitude level among male and female 54

respondents (N = 169)

Bar graph showing attitude level among each age group (N = 169) 56

Bar graph showing attitude level among each education level 58 (N = 169)

Bar group showing attitude level among each socioeconomic 59

group (N = 169)

Bar graph showing attitude level among respondents with positive 61

and negative family history of hypertension (N = 169)

Bar graph showing practice level among respondents (N = 169) 62

Bar graph showing the percentage of the respondent with good 64

and poor practice in each category (N=169)

Bar graph showing practice level among male and female 67

respondents (N = 169)

Bar graph showing practice level among each age group (N = 169) 68

Bar graph showing practice level among each education group 70

(N = 169)

Bar graph showing practice level among each socioeconomic 72

group (N = 169)

Bar graph showing practice level among respondents with positive 73

and negative family history of hypertension (N = 169)

Bar graph showing the relationship between level knowledge level 75

and attitude level (N = 169)

Scatterplot showing correlation between knowledge and attitude 76

total score

Bar graph showing the relationship between attitude level and 78

practice level

(N = 169)

Scatterplot showing correlation between practice and attitude total 79

score

X1

CHAPTERI

INTRODUCTION AND BACKGROUND INFORMATION

1.1 INTRODUCTION

Hypertension is defined as the persistent elevation of systolic blood pressure of 140

mmHg or greater and/or diastolic blood pressure of 90 mmHg or greater. Patients with

hypertension are usually asymptomatic. However, if uncontrolled, hypertension can lead to

life threatening complications such as heart failure, stroke, renal failure and many more.

Sometimes, patients are unaware that they have been hypertensive for a long time, and thus

unaware of the complications due to prolonged uncontrolled hypertension.

The World Health Report (2002) stated that the prevalence of hypertension worldwide

is estimated to be 1 billion individuals, and 7.1 million deaths per year may be attributable to

hypertension. In Malaysia, the prevalence of hypertension is 32.2% in patients aged 18 and

above, as revealed by the third National Health and Morbidity Survey (NHMS) (Ministry of

Health, 2006). Furthermore, a surveillance conducted by the Disease Control Division

(2006) estimated that a total of 456,132 people aged 25 to 64 years in Sarawak have

increased blood pressure. It was also pointed out that the prevalence in Sarawak was the

second highest among the states. The high prevalence of hypertension has made it one of the

most common non-communicable diseases in the world hence greatly affecting overall

morbidity and mortality rate worldwide.

Nevertheless, it is well known that hypertension is a condition, which is preventable

in the non-hypertensive and controllable in hypertensive individuals. According to Clinical

Practice Guidelines (2008), one of the objectives of the evaluation of hypertensive patients is

I

to assess lifestyle and identify other cardiovascular risk factors or concomitant disorders that

affect risk factors in order to plan an effective management plan. From the public health

perspective in particular, this is done primarily through lifestyle modifications. These

lifestyle modifications which include dietary change, weight control, reduction in

consumption of alcohol and regular physical activities have been shown to help reduce blood

pressure in hypertensives and prevent the occurrence of hypertension in normal individuals

(Whelton P. K. et al, 2002).

For this reason, assessment of knowledge, attitude and practice of the community on

hypertension and subsequently implementation of health intervention programmes are

essential. Health interventions can help the community to better understand hypertension and

thus enable them to change their way of life for the better.

Furthermore, the low level of awareness and knowledge regarding hypertension

among Malaysians in general is another good enough reason for study and intervention.

(Ministry of Health, 2006). Better knowledge and awareness of hypertension ensure better

control of the disease through lifestyle modification as well as help prevent its development

and progression. In a study conducted by Muntner et al. (2004) 50.2% of hypertension

patients that were aware of their hypertensive status have keenly made lifestyle modifications

to control their blood pressure. This demonstrates that awareness and knowledge of

hypertension is crucial in instilling positive attitude and creating good practice to prevent and

control hypertension better. Eventually, these will lead to reduced prevalence of hypertension

and hopefully, influence the community to embrace the need to seek knowledge and adopt a

lifelong healthy lifestyle which will help to prevent and cope with not only hypertension, but

many other diseases and illnesses that may affect them.

2

1.2 BACKGROUND INFORMATION

Sarikei is the sixth administrative division in Sarawak. It has a total area of 4,332.4

square kilometres with a population of 110,695 people (Information Department of Sarikei,

2007). The society is culturally varied, with Iban, Melanau, Malay and Chinese forming the

majority of the population. The economy of Sarikei is primarily agricultural, in which its

main commodities are pineapple and pepper.

This study is conducted in 11 Than long houses at Sungai Kerubong area in Sarikei,

which is about 15 kilometres from the main road of Kuching-Sarikei. Driving from Sarikei

town will take about 30 minutes via tarred road. These long houses include Rumah Jawa,

Rumah Lanyaw, Rumah Insol, Rumah Puin, Rumah Meringgai, Rumah Usin, Rumah Moses,

Rumah Mudam, Rumah Patrick, Rumah Anggey and Rumah Manggang. The total estimated

population are 758 people with a total of 141 doors.

Breakdown of population in each long house is as follows: Rumah Jawa with 25 doors

and 147 residents; Rumah Lanyaw with 20 doors and 103 residents; Rumah Insol with Il

doors and 81 residents; and Rumah Puin with 29 doors and 148 residents; Rumah Meringgai

with 11 doors and 58 residents; Rumah Moses with 3 doors and 17 residents; Rumah Anggey

with 12 doors and 61 residents; Rumah Manggang with 4 doors and 16 residents; Rumah

Patrick with 6 doors and 24 residents; Rumah Usin with 12 doors and 46 residents and

Rumah Mudam with 12 doors and 57 residents. The residents work as farmers, fishermen,

government servants and some of them work at the factory nearby.

The electricity of the long house is supplied by Sarawak Electricity Supply Company

(SESCO). Besides that, proper water supply is provided by the local authority and from the

3

nearby river. In addition, there is a public phone in Rumah Jawa only. Most of the primary

school students study at S. K. Jawa, which is located 300 metres from Rumah Jawa. However,

there is no secondary school in that area. The nearest government health clinic is Sarikei

Health Clinic which is 35 km from this area.

4

Pnsot K6idmat Maklumat Alcademix yjVtvERSrfl MAi., AYSU sARAWAK

CHAPTER II

STATEMENT OF PROBLEM, LITERATURE REVIEW AND CONCEPTUAL

FRAMEWORK

2.1 STATEMENT OF PROBLEM

At present, hypertension is becoming an increasingly common health problem

worldwide, primarily because of increasing longevity and commonness of contributing

factors such as obesity, physical inactivity and unhealthy diet (Singh et aL, 2000). In 2006,

the NHMS ascertained that the national prevalence of hypertension was 32.2%. The authors

also found that it was significantly more prevalent in the rural areas (36.9%) compared to

urban subjects (29.3%). This figure is disquieting and more measures need to be taken to put

a stop to this trend especially in the rural population.

In Sarawak, the Disease Control Division (2006) estimated that 38.6% of the

population were hypertensive. By comparison with the other states, Sarawak has a higher

prevalence of hypertension. From the latest statistics provided by the Sarawak Health

Department (2007), the total attendance in outpatient clinic for respondents aged 20 and

above is 5.8%. Moreover, indigenous people from Sarawak (Sarawak Bumiputeras) are found

to have a higher prevalence of hypertension in comparison with the Malays, Chinese, Indians

and other minority ethnic groups in Malaysia (Rampal et al, 2008). It is also necessary to

ascertain the effects of their lifestyle and diet to hypertension. As such, a study regarding

hypertension followed by health intervention is much needed and valuable to this particular

community.

S

According to the statistics provided by Sarikei Division Health Office, the number of

hypertension cases in Sarikei was 19 865 in 2006 and increased to 20 693 cases in 2007. In

Sarikei Health Clinic, the total attendance of hypertension patients in the hypertension and

heart disease clinic amounted to 9057 in 2007. Majority of the patients were Iban, with a

number of 4851 cases (53.6%). Thus, the community in Sungai Kerubong area is an ideal

population to conduct the survey as it comprises of an Than community, which is the main

indigenous group in Sarawak. Besides, its locality is strategic. It is situated at the rural area of

Sarikei.

Besides, uncontrolled hypertension has caused increasing morbidity and mortality due

to low level of awareness of its complications and poor control (Rampal et al, 2008). For

example, more than one-third of premature mortality is due to coronary heart disease and a

greater proportion due to stroke (Ministry of Health, 1999). It is also an important risk factor

for premature mortality in heart and kidney failures. This scenario could be solved if

continuous and comprehensive health education is implemented into the community.

Furthermore, as stated by Mohamad Taha (2003), the public health approach of

primary prevention of hypertension has been accepted to be the most cost-efficient and

sustainable method to manage the increasing prevalence of hypertension worldwide.

Educating the community about all the risk factors and teaching them how they can modify

these risk factors can help them to better understand hypertension and overall adopt a

healthier lifestyle for the prevention and better control of hypertension.

Taking into account the facts mentioned above that is, the higher prevalence of

hypertension in Sarawak and among the rural ethnic groups; the severity of the complications

of uncontrolled hypertension; and the easiness and effectiveness of prevention through

6

lifestyle modifications, it is clear that a study on the knowledge, attitude and practice in this

community is undeniably important and beneficial to the study and the participants. This

study will provide an opportunity to gain information about the knowledge and attitude of the

community in order to come up with constructive recommendations and strategies to address

the issue. Furthermore, it is hoped that this study can create higher awareness, better attitude

and more effective preventive practice regarding hypertension and thus contribute towards a

better quality of living in the community.

7

2.2 LITERATURE REVIEW

2.2.1 Definition of Hypertension

Blood pressure in a population is a continuum, which is represented by Gaussian

distribution. According to Malaysian Clinical Practice Guidelines (2008) on management of

hypertension, hypertension is the persistent elevation of systolic blood pressure of 1 40 mmHg

or greater and/or diastolic blood pressure of 90 mmHg or greater. In 2003, the Seventh

Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment

of High Blood Pressure has defined blood pressure of 120/80 mmHg to 139/89 mmHg as

"prehypertension". Prehypertension is not a disease category but it is used to identify

individuals who are at high risk of developing hypertension. To diagnose hypertension, two

properly taken blood pressure on two different occasions have to show blood pressure above

140/90 mmHg. However, if there is target organ damage, or the blood pressure is greater than

210/120 mmHg, only one occasion is needed to diagnose hypertension.

2.2.2 Classification of Hypertension

Generally, hypertension can be classified into essential hypertension, secondary

hypertension and malignant hypertension. In essential hypertension, no definable cause can

be found and its cause is multifactorial. It is attributable to a variety of factors such as genetic

causes, insulin resistance, environment and many more. On the other hand, in secondary

hypertension, a specific cause can be found. This is important as the cure to the underlying

disease may cure the hypertension. Examples of underlying conditions which may cause

hypertension are renal disorders, endocrine disorders, cardiovascular disorders, drugs and

pregnancy. In malignant hypertension, the diastolic blood pressure is greater than 130 mmHg

with associated papilloedema and retinal haemorrhages and exudates. Besides, there are

8

manifestations of hypertensive encephalopathy, such as. severe headache, vomiting, visual

disturbances, transient paralyses, convulsions, stupor, and coma.

2.2.3 Epidemiology of Hypertension

According to Jones & Hall (2007), there are about 972 million people suffering from

hypertension in 2000. By the year 2025, the number of hypertensive individuals is projected

to increase up to 1.56 billion persons. There are two main factors contributing to the rapid

growth of hypertension: the increased aging population and the rapid growth in the rate of

obesity. And in most parts of the world, hypertension is the most important reversible risk

factor for cardiovascular disease which has replaced infectious disease as the leading cause of

death worldwide. According to Sarawak Health Department (Health Facts 2008), the total

number of outpatient attendances was 22,627 in 2006. This number increased by 1,040

patients in 2007.

The Third National Health and Morbidity Survey (2006) shows that the prevalence of

hypertension among adults 18 years and above in Malaysia is 32.2%. There are about 4.8

million hypertensive individuals in Malaysia. A surveillance conducted by the Disease

Control Division (2006) demonstrated that those in the age group of 55-64 years old have a

higher prevalence of raised blood pressure, followed by the age group 45-54 years old.

In NHMS 2006, comparison between the sexes revealed no significant difference in

prevalence between males (33.3%) and females (31.0%). However, in a national study of

16,440 subject aged 15 and above, hypertension was significantly more prevalent among

males in the age group of 15-39 years old but there was no significant difference in

prevalence of hypertension in males and females in those aged 40 years and above. In both

sexes, it was found prevalence of hypertension increases with age (Rampal et al, 2008).

9

It was also discovered that hypertension was significantly more prevalent in rural

groups (36.9%) in contrast to urban areas (29.3%) (Ministry of Health, 2006). Concerning

ethnicity, the Malays have a higher prevalence (33.9%) as compared to the other two major

ethnic groups namely Chinese and Indian, with prevalence of 32.4% and 29.4% respectively.

However, Rampal et al (2008) showed dissimilarity in which prevalence of hypertension

between the three major races is highest among the Chinese population (30.6%), followed by

the Malays (26.7%) and the Indians (25.1%). Furthermore, the authors established that the

indigenous people from Sarawak (Sarawak Bumiputeras) had a higher prevalence of

hypertension overall (31.1%) compared with the three major ethnic groups and other ethnic

groups as well.

2.2.4 Risk Factors

There are many established risk factors contributing to hypertension. These various

risk factors can be divided into non-modifiable and modifiable. Non-modifiable risk factors

include age, gender, race and family history. As age increases, the risk of hypertension

clearly increases. As claimed by Mohd Yunus (1999), there is significant increase in

hypertension prevalence particularly after twenties. The highest prevalence of hypertension is

found among those aged 60 years and above (57.3%) and 50 to 59 years old (53.3%).

Beevers, Lip & O'Brien (2001) also found that men were at a higher risk of getting

hypertension compared to women up to post-menopausal age. In a study by Roncaglioni et al.

(1992), it was discovered that those with one relative who has premature coronary artery

disease has a relative risk of 2. Whereas, those with two or more relatives has a relative risk

of 3.

Modifiable risk factors comprise of smoking, hyperlipidaemia, diabetes, sedentary

lifestyle and obesity. The correlation between both smoking and hyperlipidaemia can be seen

10

in Multiple Risk Factor Intervention Trial, in which a mild hypertensive subject who smokes

and have normal serum cholesterol level has a much lower cardiovascular risk compared to a

mildly hypertensive subject who also smokes and have raised serum cholesterol (Beevers,

Lip & O'Brien, 2001).

2.2.5 Consequences of Hypertension

The main complications of hypertension are target organ damages like cardiac,

cerebrovascular, peripheral vascular, renal and retinal disorders as stated above.

Cardiovascular disease, one of the leading causes of death worldwide, is eminently

preventable by lowering blood pressure. According to World Health Organisation, about 50%

of the coronary heart disease and 75% of stroke are due to hypertension. Lewington et al

(2002) in his report showed that higher blood pressure is associated with a higher risk of

cardiovascular disease such as heart attack and heart failure, stroke and renal failure. Besides,

the authors found out that every increment of 20mmHg in systolic BP or 10mmHg in

diastolic BP doubles the risk of cardiovascular disease in adults aged 40-70 years old. Stroke

is another devastating consequence of hypertension. In Beevers' (2001), men aged 40- 59

years with 160- 180 mmHg systolic blood pressure are at about 4 times higher risk of stroke

compared to those with lower blood pressure during coming 8 years. Hypertensive

individuals have 3 times more risks of peripheral vascular diseases compared to normotensive

individual. Renal dysfunction and retinal vascular changes are often expected in hypertensive

individuals.

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