MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH THE NATIONAL INSTITUTE OF HYGIENE AND EPIDEMIOLOGY ---***--- ĐANG HUONG GIANG EPIDEMIOLOGICAL CHARACTERISTICS OF ASTHMA IN 13-14-
Trang 1MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH THE NATIONAL INSTITUTE OF HYGIENE AND EPIDEMIOLOGY
-*** -
ĐANG HUONG GIANG
EPIDEMIOLOGICAL CHARACTERISTICS OF ASTHMA
IN 13-14-YEAR-OLD CHILDREN AND THE EFFECTS OF HEALTH EDUCATION INTERVENTION IN TWO
DISTRICTS OF HANOI
Science: Epidemiology Code: 62 72 01 17 SUMMARY OF THE DOCTORAL DISSERTATION
Trang 2The project was completed at the
National Institute of Hygiene and Epidemiology
The scientific advisors:
2 Prof Đang Đuc Anh
The dissertation is available at:
1 The National Library
2 The National Institute of Hygiene and Epidemiology
Trang 3LIST OF THE PUBLICATIONS BY THE
AUTHORS RELATED TO THE DISSERTATION
1 Đang Huong Giang, Nguyen Tien Dung, Đang Đuc Anh (2011),
"Quality of life of children with asthma in Bach Mai and Saint Paul
hospitals, Hanoi in 2010-2011", Journal of preventive Medicine, No
7(125), Set XXI, pp 22-27
2 Đang Huong Giang, Nguyen Tien Dung, Đang Đuc Anh (2014),
"The status of asthma knowledge among 13-14-year-old children with asthma at Thanh Xuan and Long Bien districts in Hanoi, 2012",
Journal of preventive Medicine, No 1(149), Set XXIV, pp 58-63
3 Đang Huong Giang, Nguyen Tien Dung, Đang Đuc Anh (2014),
"Effectiveness of school-based education program for 13-14-year-old schoolchildren with asthma at Thanh Xuan and Long Bien districts in
Hanoi, 2012-2013", Journal of preventive Medicine, No 1(149), Set
XXIV, pp 64-70
Trang 41 Introduction
Asthma is a common chronic respiratory disease, affecting people of all ages particularly of childhood The predominant symptoms such as wheezing, cough, breathlessness and chest tightness are intermittent, more severe at night and early morning, affecting on daily life and sometimes fatal The prevalence and morbidity rates due to asthma are rising in many areas in the world
Although there are no cure for asthma but we can control disease and maintain control it for a long period of time by conducting health education programs
In Viet Nam, the statistics of the national survey demonstrated that the prevalence associated with asthma in adults was 4.1%, 64.9% among patients visited emergency departments, more than 80% of asthmatic children under fifteen has never been treated with preventor while some studies revealed that knowledge of parents on asthma was impaired
Studying epidemiological characteristics of asthma and carrying out the interventions in communities to manage asthma and to improve quality
of life of patients is practical and essential research Thus, we conducted the study "Epidemiological characteristics of asthma in 13-14-year-old children and the effects of educational intervention at two districts in Ha Noi" The study objectives were
1 To describe some epidemiological characteristics of asthma in 14-year-old children at Thanh Xuan and Long Bien districts in Ha Noi in 2012
13-2 To assess the effeciveness of educational intervention in two researched districts
2 New scientific contributions
Trang 5- The study defined the prevalences of diagnosed asthma in 13-14-year-old children at two districts in Ha Noi and discribed some common trigger factors
- This study is the first for establishing the modern asthma management for schoolchildren and assessing the effects of health education intervention with outcomes: asthma status, school absenteeism, knowledge about asthma and quality of life of the children
3 Practical value of the study
-The results of study about the prevalences of asthma in children helped physicians realize the popularity of asthma in communities Furthermore, the information about the asthmatic trigger factors permitted doctors choose the suitable intervention to control those factors
- The study affirmed the effects of health education intervention on controlling asthma symptoms, school absenteeinsm due to asthma and improving the asthmatic knowledge and demonstrated that this method could be applied in many schools
4 The structure of the dissertation: The dissertation consists of 126
pages including, introduction 2 pages, literature review 32 pages, objectives and methods 19 pages, results 27 pages; discussion 29 pages, conclusions 2 pages and recommendation 1 page There are 23 tables, 13 charts and 3 pictures, 118 references including 25 in Vietnamese and 93 in English
Chapter 1 Literature review 1.1 Epidemiology of asthma: There are three methods of identifying
cases of asthma that being used commonly in epidemiological researchs in the world: asking directly patients for self-reporting of the asthma dianognosis and/or the most common sypmtoms of asthma such as wheezing and assessment of bronchial reactivity of the airway to exercise
1.1.1 Epidemiology of asthma in the world
1.1.1.1 Prevalence
- The prevalence of asthma in childhood: the prevalences of
13-14-year-old children being diagnosed asthma varied between 1.6% to 28.2% and
Trang 6they were lower than having wheezing In 6-7-year-old children the prevalences of being diagnosed asthma ranged from 1.4% to 27.2% The difference of the prevalences of wheezing and asthma between countries is larger than within country
- The prevalence of asthma in adulthood: in 64 coutries in adults aged
18-99- years the prevalence of doctor-diagnosed asthma was lowest in Viet Nam (1.8%) and highest in Australia (32.2%) According to the World Health Organization, the variation in the prevalence of asthma between different countries is 21-fold
1.1.1.2 Factors influencing the prevalence of asthma
- Environmental factors: The indoor factors (fungi, domestic dust, insects,
cockroaches, tobacco smoke) and outdoor factors (air pollution, dust and smoke) influence the prevalences of asthma Some jobs associated with higher risk for occupational asthma are farming work, painting, cleaning solution and plastic manufacturing
- Host factors: the factors such as sex, weight, atopy have been considered
as asthma risk factors Male sex is a risk factor for asthma in childhood, and people who have BMI≥25 seem to have asthma with 1.51 fold higher than those with a average-weighted The risk of asthma among children whose parents had atopic diseases are 3.29 times higher than other children
1.1.1.3 Times trends of asthma: In United State, Australia, some
European developed countries (Finland, Sweeden, Newziland, the UK) and Asian countries such as Hongkong, Singapore, Thailand the prevalences of asthma and wheezing are rising
1.1.1.4 Incidence: Currently, there are no methods to measure the
incidence of asthma accurately In the UK, the incident of asthma was high (136.6/10.000/year), The American statistics showed that incidence of asthma was 3.8/1000/year, during one year new onset rates were highest in Auturm and Winter
1.1.1.5 Asthma mortality: in 2000 mortality among American patients
hospitalized for asthma were 0.5% In some countries such as Switzerland,
Trang 7Portugal and Japan the reduction in asthma mortality have appeared by increasing use of inhaled corticoides
1.1.2 Epidemiology of asthma in Viet Nam
In our country statistics data on prevalence and mortality of asthma
is lack In 2003, the prevalence of asthma among children in Ha Noi was 12.56% in urban areas and 7.52% in rural areas In 2007, the prevalence of diagnosed asthma among 13-14-year-old children in Can Tho was 1.4% The prevalence of asthma in Vietnamese adults was 4.1%; the rates of asthma in male was higher in female However, Viet Nam has ackowledged that the rates of asthma mortality were increasing
1.2 Asthma and wheezing symptom
1.2.1 Asthma
1.2.1.1 Definition: Asthma is a chronic inflammatory disorder of the
airway in which many cells and cellular elements play a role The chronic inflammation is associated with airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning These episodes are usually associated with widespread, but variable, airflow obstruction within the lung that is often reversible either spontaneously or with treatment
1.2.1.2 Mechanisms of asthma: there are three main disease progressions
of asthma: airway chronic inflammation, airway narrowing and airway hyperresponsiveness
1.2.1.3 Causal and risk factors: including host factors and environmental
factors
- Host factors consist of genetic, obesity, sex and age
- Environmental factors consist of allergens (domestic allergens, furred animals, pollen, fungi), respiratory inflammation, air pollution, tobacco smoke, food, drugs
- Another factors: endocrin, climate, exercise, stress
1.2.1.6 Asthma treatments: In GINA asthma treatment steps the education
is the first
Trang 81.3 The role of education in asthma preventional strategy: The experts
evaluated that asthma education is a cheap and effective intervention in asthma management and prevention
1.3.1 The activities of education: multiple educational methods have been
used such as exchange information, discussion, asthma consultant, asthma clubs
1.3.2 Effectiveness of education interventions: There have been many
studies about effectiveness of education on asthma
- The effectiveness on asthma symptoms: education intervention for parents reduced visits to emergency room, admissions to hospital and attacks of asthma compared with the control group
- The effectiveness on school absenteeism: education for primary schoolchildren eliminated days of school missed due to asthma
- The effectiveness on keeping well treatment: education helped patients to realize the significance and essential of follow-up treatment, therefore this could reduce the number of children who were unschedules doctors visits
- The effectiveness on children’s knowledge of asthma: education in the schools improved schoolchildren’s knowledge, using inhaler skill, helped children to choose activity and increased asthmatic knowledge of caregivers
- The effectiveness on quality of life: asthma impairs the quality of life of the patients According to researchers, the effects of education on patients' quality of life were not clear and this should be investigated in more studies
Chapter 2 RESEARCH METHODOLOGY
Sample and setting
- The sample for objective 1: The 13-14-year-old schoolchildren have been studying 7-8th grade from the secondary schools at two districts Thanh Xuan and Long Bien
Trang 9- The sample for objective 2: the asthmatic children of two districts Thanh Xuan and Long Bien who participated in the characteristic epidemiological study
- Inclusion criteria: The children who enrolled in the intervention study
were asthmatic children based on the criteria of the International study of asthma and allergy in childhood (ISAAC), the physician-diagnosed asthma
- Exclusion criteria
+ The children without agreed to participate in the study
+ The children transfered to another school which is out side of study's setting
- The setting: the study was conducted at two districts Thanh Xuân and Long Bien in Ha Noi Two districts were chosen purposively because of differences in geography and level of urbanization
2.2 Methodology
2.2.1 Study designs
- Cross-sectional survey
- Longitudinal intervention community study with control group
2.2.2 Sample sizes and sampling methods
2.2.2.1 Sample size and sampling method for objective 1
- Sample size: using the formula for estimating population proportion
2
2 2 / 1
)1(
p
p p z
Trang 10- Sampling method: purposive and simple random sampling The
sampling based on instruction of ISAAC, in each geographical area the sampling unit will be a school
Step 1: districts Thanh Xuan and Long Bien were chosen purposively Step 2: choosing the schools randomly by making a table sample of each
districts, the schools were selected in study by randomly drawing school
by school untill there were at least 3000 13-14-year-old children
Step 3: whole 13-14-year-old children in selected schools were enrolled in
study Actually, in each district 8 schools were selected
2.2.2.1 Sample sizes and sampling methods for objective 2
- Sample sizes: there were 4 outcomes in the study: asthma statusincluding day and night symptoms, asthma control test score; school absences; knowledge of asthma and quality of life Untill now there has been no study knowledge of asthma among schoolchildren so this study used three outcomes including school absences, asthma control test score and quality
of life score to calculate sample size for intervention objective
+ Outcome is school absences, using the formula estimating the difference between two proportions
2 2 1
2 2 1 1 2 ,
) (
) 1 ( ) 1 ( (
p p
p p p p z n
at 0.2% corresponding to power 80%, we have z α,β = 7.9 Hence, a required minimum sample size was 77 children Providing for 10% of drop-out study participants sample size was 85 children in each group
Trang 11+ Outcome is quality of life and asthma control test score, using the formula estimating the difference between two means
2 2 1
2 2)(
)(2
Sample size for quality of life: δ variance from the previous study was
1.25; with expecting to find out the difference between means of quality of life scores was 0.5, thus we chosed μ1 – μ2 = 0.5; α = 0.05 corresponding to
zα=1.96 and β = 0.2 corresponding to zβ=0.84 Thus, n=98 children Providing for 10% of drop-out study participants sample size was 108 children in each group
- Sample size for asthma control test score: δ - variance from the previous
study was 3.2; with expecting to find out the difference between means of asthma control test score was 1.4, thus we chosed μ1 – μ2 = 1.4; α = 0.05 corresponding to zα=1.96 and β = 0 2 corresponding to zβ=0.84 Hence, n=82 children Providing for 10% of drop-out study participants sample size was 91 children in each group
Combined the results of calculating sample size, a sample of 108 children should be studied in each of two groups
- Sampling methods: purposively sampling
+ Choosing the subjects for intervention study: Actually, 133 children with diagnosed asthma in Thanh Xuân district and 126 children with diagnosed asthma were found out from cross-sectional study, these children were enrolled in the intervention study and followed in one year
+ Assignment to groups: purposively selected Thanh Xuan district in the intervention group and Long Bien district in the control group Thus, 126 children with diagnosed asthma in Long Bien district belonged to the
Trang 12control group and 133 children with diagnosed asthma in Thanh Xuan district belonged to the intervention group
2.2.3 Study contents
2.2.3.1 Study contents in objective 1
- Study variables: prevalences of asthma, wheezing, the risk factors,
characteristics of indoor and outdoor
- Instruments: used the ISAAC questionnaire including 8 questions in
40 minute each, provided at 1 month intervals from September to December in 2012
- Variables: asthma status, school absence, asthma knowledge and quality
of life
- Isntruments
+ Knowledge questionnaire consisted of 20 questions
+ Asthma control test for 12 year old and over contained 5 statements + Quality of life questionnaire comprised 23 items in 3 domains: activity limitation, symptoms and emotional function
- Procedure
+ In September 2012 (t0) children were surveyed knowledge, asthma control test, quality of life This was baseline information
Trang 13+ In September, October and November children were attended educational sessions three times, 1 month interval The information from these surveys was used to guide the chilren how to evaluate and monitor asthma themselves
+ In December 2012 and May, September 2013 (t1, t2 and t3) children were surveyed knowledge, asthma control test, quality of life This was posttest intervention information
2.2.5 Statistical methods: Statistical analysis was performed using Epidata
3.1, and Stata.11.1 We performed statisticcal test such as chi-square test, Fisher's exact test, Mann-Whitney test and Generalized Estimating Equations
Chapter 3 RESULTS
6701 schoolchildren from two districts were surveyed
Epidemiological characteristics of asthma
Table 3.3 District distribution of children with diagnosed asthma
Characteristics Total Thanh Xuân
district
(n=3118)
Long Biên district
(n=3583)
p value