Studying the status of asthma in students at primary and secondary schools in Thai Nguyen city and the effectiveness of controlling asthma with ICS + LABA

To describe the status of pupils of primary schools and secondary schools with bronchial asthma in Thai Nguyen city.. To identify some risk factors of BA for pupils of primary and second

1

BACKGROUND

Bronchial asthma (AB) is a fairly common disease among respiratory tract diseases in our country as well as many countries around the world Bronchial asthma (AB) is caused by many factors and tend to increase gradually According to the World Health Organization 2004 (WHO), the world has more than 300 million patients of Bronchial asthma There are 6-8% of adults, over 10% of children under 15 years old It is to estimate that this number will increase to 400 million in 2025

The Western Pacific and South East Asia regions, the situation of

BA of children within 10 years (1984-1994) had increased considerably, such as in Japan from 0.7% to 8%, Singapore from 50-20%, Indonesia 2.3 to 9,8%, the Philippines from 6 to 18.8% In Viet Nam, the average rate of BA accounts for 5-6% of BA population, in which, there are 5% in adults, 10% of children under 15 years old, and

it depends on regional changes and environmental pollution

Recently, the prevention and treatment of BA complied with instruction from the GINA (Global Initiative for Asthma) has achieved good results However, many research results have showed that the control and treatment of BA is still to have shortcoming, many patients diagnosed BA is only treated to stop BA without prophylactic treatment

of BA Therefore, frequently BA recurrent attacks cause more severe disease and take more cost for treatment of BA It increases the rate of emergency hospital admissions, and effect of BA treatment is not high

In Thai Nguyen, there is not any research on this issue Therefore, we carry out this research with 3 following objectives:

1 To describe the status of pupils of primary schools and secondary schools with bronchial asthma in Thai Nguyen city

2 To identify some risk factors of BA for pupils of primary and secondary schools in Thai Nguyen city

3 To evaluate BA control effectiveness by ICS + LABA (Seretide) for pupils of primary and secondary Schools in Thai Nguyen city

2

NOVEL CONTRIBUTIONS OF THE THESIS

Determination BA rate of pupils of primary schools and secondary schools with bronchial asthma in Thai Nguyen city

Identification of some risk factors of BA for pupils of primary and secondary schools in Thai Nguyen city

Giving evidences of positive effect of asthma control with ICS + LABA (Seretide) in the community

Use of Peak flow meter to follow up changes of indexes of PEF morning, PEF evening, variation of PEF morning and PEF evening in the diagnosis and monitoring of asthma control in community

Application of ACT scores to assess the results of asthma control in community

THE STRUCTURE OF THE THESIS

The main part of the thesis consists 107 pages It includes the following sections:

Introduction: 2 pages

Chapter 1 - Overview: 29 pages

Chapter 2 - Subjects and research methods: 22 pages

Chapter 3 - Outcomes of the study: 19 pages

Chapter 4 - Comments: 32 pages

Conclusions and Recommendations: 3 pages

The thesis has 35 tables, 7 charts and 129 literature references, of which, there are 37 Vietnamese literature references, 92 English references

3

Chapter 1 OVERVIEW 1.1 Epidemiology of Bronchial Asthma

1.1.1 The circulation of Bronchial Asthma

Bronchial asthma (AB) is a chronic lung disease and the most common disease in the world BA happens in all ages and in all countries Within 20 years, the recent incidence is increasing more and more, especially in children The percentage of children with symptoms

of BA changes from 0 to 30% It is depended on the survey in each region in the world

According to GINA 2004, the global percentage of BA are as follows: 12 countries with rate of BA above 12%, 16 countries with rate of BA from 8-12%, 23 countries with rates of BA between 5-8% ,

33 countries with rate of BA below 5% High rate of BA focuses on European countries such as Scotland, Giosey, Guosey, Wales, Isle of Man, England, Newzeland and Australasia (Australia) Lowe rates of

BA are Russia, China, Anbania, Indonesia, Macao etc…

Asia - Pacific regions, recently, epidemiologists have studied showed that the rates of BA of pupils at the 6-7 years old in Bangkok increases from 11.0% in 1995 to 15.0% in 2001 and those in Chiang Mai increase from 5.5% in 1995 to 7.8% in 2001.The rates of BA of pupils at the age of 13 and 14 in Chiang Mai increases from 12.7% in 1995 and 8.7% in 2001 and those in Bangkok increase from 13.5% in 1995 and 13.9% in 2001 Pupils at the 12-15 years old in Taiwan, the rate of BA diagnosed physicians was 4.5% in 1995 and 6% in 2001 , in Singapore from 1994 to 2001, the rate of asthma at the age from 12 to 15 increase from 9.9 % to 11.9% However, the rates of BA decrease from 16.6 to 10.2% at the age of 6 and 7 In Hong Kong, the group of the 13-14 years old diagnosed asthma was 11.2% in 1995 and 10.2% in 2002 The rate of asthma of Japanese children was 7.6%

4 Vietnam is a country of Southeast Asia Region and has a accelerated rate of BA in recent years The rate of BA of children under

15 years old in some residential areas in Hanoi in 1998 was 2.7% Recent studies on the rate of BA of pupils at school age, the rate of BA

in Hai Phong in 2002 was 9.3% BA percentage of pupils at school age

in urban and suburbs of Hanoi in 2005 was 10.42% Studies of pupils at some secondary schools in Ha Noi in 2003 and in 2006 were 10.3% and 8.74% consecutively

1.1.2 The burden of Bronchial Asthma

The burden from BA is for not only patients, but also affects to economics, well-being of families and the burden of the whole society For patients with negative health affects to study, work and work, affects to quality of life and happiness for themselves and their families, many cases are death or disability

Study of AIRIAP in Asia and Pacific region, including Vietnam, shows that proportion of patients leave school and leave of work in a year is 30-32% (16-34% in Viet Nam) and the ratio of emergency hospital admission is 34% (of which, that in Vietnam is 48%); patients with insomnia in the four weeks was 47% (71% in Vietnam)

Factors affecting development and expression

of Bronchial Asthma

- Subject factors

• Gene

- Gene creating atopy allergy

- Gene creating allergic increase response of the airway

• Obesity

- Outside the house: pollen, mold, fungi and spores

• Infections (predominantly viral)

• Allergens from work

• Tobacco smoke: Passive and active

• Air pollution inside and outside of the house

• Diet

Mechanisms affecting development process and manifestation of

BA of factors are complex and they interact with each other Many multi-gene patterns related to susceptibility to asthma and allergies Complex interaction between genes and environment seem to play a key role in formation of the disease

1.3 Prophylactic treatment (control) of Bronchial Asthma (BA)

1.3.1 The aims of control treatment (prevention) of BA: According to

GINA 2006

- Gaining and maintaining control of symptoms of BA

- Maintaining normal activities, including to make efforts

- Upholding lung function as close as to normal lung function as possible

- Preventing from a paroxysmal attack of BA

- Avoiding adverse effect of drugs used to treat BA

- To prevent deaths from BA

1.3.2 Treatment of control of Bronchial Asthma (BA)

Novel concepts in prophylaxis treatment of BA: Prophylactic treatment of BA is mainly with mild and moderate types in communities Several and critical types of BA are treated in hospitals Drugs for the preventive treatment are used daily prolonged medications to control of BA primarily through anti-inflammatory effects of drugs

6 Prophylaxis drug include glucocorticoid (ICS) for inhaling and entire body, transformed drug leukotriene, Long Acting β2 Agonist combining with ICS, theophylline released slowly, Cromone, anti-IgE, and treatments of symptoms of other entire body

ICS is the sole drug inhibiting inflammation in a effective way ICS reduces the increase of reaction of the respiratory tract, controls inflammation, relieves symptoms and paroxysmal attacks leading to reduce needs of relieve medications Today, ICS is recommended as the first choice in controlling Bronchial Asthma

Recent studies show that BA patients do not controlled by low or high doses Combination with LABA (Long Acting β2 Agonist) has more effective than increase of ICS dose Effect of LABA is bronchodilator for 12 hours and ICS is used twice per day So, two combinated drugs are well suited to control better clinical symptoms of

BA patients without increase ICS dose or maintain the control status of

BA symptoms when reduction of ICS dose

1.3.3 Seretide is a medication of effective coordination in prophylaxis treatment of Bronchial Asthma (BA)

Ingredients of Sertide composed of Salmeterol and Fluticasone propionate Salbutamol Contains Salmeterol (belonging to LABA group ) and Fluticasone propionate (belonging to ICS group) Both substances have effects on the various aspects of BA pathogenesis: Salmeterol is to control symptoms, while Fluticasone propionate

prevents BA recurrent attacks by controlling inflammation

7

Chapter 2 RESEARCH OBJECTS AND METHODOLOGY

2.4 Phương pháp nghiên cứu

2.1 Subjects of study

Pupils at primary and secondary schools (from 6 to 15 years old) Parents or careers of pupils (in the case of pupils from 6 to 7 years old)

2.2 Duration of study: From October 2007 to October 2010

2.3 Research location: Primary and secondary schools of Thai Nguyen city 2.4 Research Methodology

2.4.1 Research of description: Design of cross-sectional descriptive

study to determine BA percentage of pupils at primary and secondary schools in Thai Nguyen city in 2008

Sample size: Applying the formula for sample size for described study

( ) 2

2 2

pq Z

n is minimum number of pupils from 6 to 15 years old to research

Z2(1- α /2): coefficient of confident limit (with α = 0,05, Z2(1- α /2) = 1,96)

p : ratio of pupils with BA estimated 10%

q = 1-p; d: desired error = 1%

Since then we have: 0 , 1 0 , 9 3457

01 , 0

96 , 1

2

2

2.4.2 Research of disease symptom: Applying the formula for sample

size of disease symptom study to identify risk factors

( )2 2 1

2 2 2 1 1 ) 1 ( 2

/

p p

p p p p Z p p

Z

n

−

−+

−+

−

n is sample size needed in each group

α = 0,05 , Z 1- α /2 = 1,96, β = 0,2, Z 1- β = 0,84

8

( ) ( ) 0,75

1.2 2

2

−+

=

p p

OR

p OR

67,02

2

p

p1 is the rate of exposure to risk factors of BA group

p2 is the rate of exposure to risk factors in the control group (about 60% of exposure to tobacco smoke without BA)

OR odds ratio expected is 2

6 , 0 1 6 , 0 75 , 0 1 75 , 0 84 , 0 67 , 0 1 67 , 0 2 96

,

1

−

− +

− +

−

=

n

Replacing the formula, we calculate 152 students

To fix BA groups/ control group is 1/2, we have a sample size to study: BA group is 152 pupils and the control group is 304 pupils (sampling rate at schools are 161 pupils of BA group and 322 pupils of the control group)

2.4.3 Intervention study: formula for calculating sample size of

intervention

( )2 2 1

2 2 1 1 2 ) , (

11

p p

p p p p Z n

−

−+

−

= αβ

n is the minimum sample size to calculate

α is statistical significance and probability of a error type 2 it is estimated 0.01

Z2 is looked up the table of value with α= 0,01, β = 0.1; Z(2α,β) = 14 , 9

β is probability of a error type 2 It is estimated 0.01

p1 is the rate of patients estimated asthma control of pretreatment It is estimated 30%

p2 is proportion of patients estimated after treatment Estimation is 30%

3,005,0

3,013,005,0105,09,14

−

−+

−

=

n

9

- From then, it is calculated n = 61 (estimated 10% give up, n chosen is 68)

2.5 The studied criteria

- The group of criteria on the status of BA

- The group of criteria on risk factors

- The group of criteria on intervention effect

+ Assessing effectiveness of asthma control according to GINA criteria + Assessing the effectiveness of BA control according to tools of assessment of asthma controlling ACT (Asthma Control Test), the acceptance of patients

2.6 Diagnostic criteria of Bronchial Asthma (BA) according to GINA 2004

2.7 Methods and techniques of data collection

Collecting screened information through forms of surveys: All pupils (or parents) are given a questionnaire and instructed answer to questions (Appendix 1)

Interview, examination, measurement of respiratory function: pupils, having one of six questions to be answered “yes”, are invited to visit medical doctor, asked disease history, measurement of respiratory function (PEF) to diagnose BA (the Appendix 2)

Những học sinh ở nhóm nghiên cứu bệnh chứng ñược phỏng vấn theo phiếu ñiều tra (phụ lục 3 và 4)

Những bệnh nhân can thiệp: Khám làm bệnh án, khám lại sau 2 tuần, 4 tuần, 8 tuần, 12 tuần (phụ lục 5)

Pupils in the disease group were interviewed by questionnaire (Appendix 3 and 4)

The patients of intervention: Take medical records and re- examine after 2 weeks, 4 weeks, 8 weeks and 12 weeks (Appendix 5)

2.8 Data processing

Analysis and data processing by in medical statistical methods using

the software of Epi-Info 6.04 and SPSS 13.0 version

10

Chapter 3 RESULTS OF STUDY 3.1 Percentage of Bronchial Asthma (BA)

Table 3.1 Percentage of Bronchial Asthma (BA) by gender: Number

of questionnaires forms distributed are 4329 and these collected are 4329 There are 4292 questionnaires forms full enough information processed Overall morbidity rate was 9.5% The rate of BA in boy pupils is 10.4% and is higher than that girl pupils (8.6%) with p <0.05

Table 3.2 Percentage of Bronchial Asthma (BA) by age: The rate of

BA of the groups of 6-10 yeas old and the 11-15 years old group are 10.1% and 9.0% (p> 0.05) consecutively

Table 3.3 The rate of asthma according to asthma status

The rates of BA at level 1, level 2, level 3 are 66.7%, 20.8% and 12.5% consecutively

Table 3.6 Knowledge of patients with BA on BA control and BA control status: Rates of patients knowing drugs cutting BA attacks, BA

being a disease able to be controlled are 64.9% and 3.4% consecutively The rate of patients has been treated control by physicians is 1.9%

Rate of patients off shool Rate of patients admitted ICU

Figure 3.2 The rate of pupils being off school and admitted ICU due to

asthma in last year 3.2 Some risk factors cause Bronchial Asthma (BA)

Table 3.8 Family history has persons with BA

11

Status of BA

Family history

BA (n=161)

Without

BA (n=322)

Without

BA (n=322)

Without

BA (n=322)

12

- Tar odor substances: aromatic oils, paint 30 18.6

- Removers and washing substances with smelly 22 13.7

Table 3.13 Allergens causing onset of BA attacks: Allergens causing

onset of BA attack: house dusts (34.8%) and animal hairs (30.4%) account for high percentage

3.3 Effect of BA control with ICS + LABA HPQ (seretide):

Through studying 68 patients with BA together with 12-week intervention with ICS + LABA, we obtain following results:

3.3.1 Characteristics of studied subjects

Table 3.14 General characteristics of studied subjects

Age in average (years) 9.8 ± 2.4

13 symptoms of those patients decrease 39, 7% and 91.2% consecutively The difference is statistically significant with p <0.05

Table 3.18 Number of days with symptoms in average per patient

After 4 weeks (X±SD)(3)

Changes (1&2)

p 1&2

Leve 2 (n=35) 9.0 ± 1.8 1.0 ± 1.5 0 8.0 < 0.05 Leve 3 (n=33) 13.3 ± 3.4 4.5 ± 2.5 0.5 ± 1.1 8.8 < 0.05 Total (68) 11.1 ± 3.4 2.7 ± 2.7 0.2 ± 0.8 8.4 < 0.05

Table 3.19 Percentage of BA patients with symptoms at the night after treatment

Pretreatment of BA, after two weeks and 4 weeks, there are 69.1%, 27.9 % and not any patients having symptoms at night consecutively The difference is statistically significant with p<0.05

Table 3.20 Average number of nights with symptoms per patient

Point of time

BA level

Pretreatment (X±SD)

After 2 weeks (X±SD)

After 2 weeks

Chan ges

p

BA level2 (n=35) 1.5 ± 1.9 0.1 ± 0.2 0 1.4 <0.05

BA level3 (n=33) 5.2 ± 2.5 0.9 ± 1.1 0 4.3 <0.05 Total (n =68 ) 3.3 ± 2.9 0.5 ± 0.9 0 2.8 <0.05

Table 3.21 The percentage of patients using drugs to cut BA attacks

Before treatment, 100% of patients have to use drugs for cutting BA attacks, after 2 weeks and 4 weeks, there are 52.9% and after 4 weeks

of treatment , there are not any patient taking medicine to cut BA attacks with p <0.05

Table 3.22 Average number of medicine used to cut BA attack per patient per day