Tài liệu Epidemiological characteristics of asthma in 13-14-year-old children and the effects of health education intervention in two districts of hanoi

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-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 HA NOI - 2014 The project was completed at the National Institute of Hygiene and Epidemiology The scientific advisors: 1. Prof. Nguyen Tien Dung 2. Prof. Đang Đuc Anh Reviewer 1: Reviewer 2: Reviewer 3: The dissertation had defended at the meeting hall of the National Institute of Hygiene and Epidemiology. In ………………… The dissertation is available at: 1. The National Library 2. The National Institute of Hygiene and Epidemiology LIST 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. 1. 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 1314-year-old children at Thanh Xuan and Long Bien districts in Ha Noi in 2012. 2. To assess the effeciveness of educational intervention in two researched districts 2. New scientific contributions - 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-yearold children being diagnosed asthma varied between 1.6% to 28.2% and they 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, Portugal 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. 1.3 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. - 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 n  z12 / 2 p(1  p)  p 2 Where: p - prevalence of diagnosed-asthma among 13-14-year-old children estimated from the previous study=2.6%; α - significance level was chosen = 0.05%, z- corresponding to 95% confidence level = 1.96, ε- disired precision was chosen = 0.22. A required minimum sample size was 2973.4 children. In each district at least 3000 children would have enrolled. - 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 status including 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. n z2 , ( p1 (1  p1 )  p2 (1  p2 ) ( p1  p 2 ) 2 Where: n is the minimum sample size in each of intervention and control groups; p1 - proportion of children being abcent from school from the previous study =38.5%; p2 - proportion of children being absent from school was expected the result to be 18.5%; α- type I error was chosen at 0.05% corresponding to significant level 95%; β - type II error was chosen 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. + Outcome is quality of life and asthma control test score, using the formula estimating the difference between two means. n 2( z  z ) 2  2 ( 1   2) 2 Where: n is the minimum sample size in each of the two groups; δ variance; μ1 - μ2 -the expected difference between two means of two groups. - 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 control 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 Vietnamese. 2.2.3.2 Study contents in objective 2 - Intervention contents + Selected intervention district was Thanh Xuan. The intervention was performed in schools by healthcares and teachers of the schools who have exprienced in the training course about asthma. The control group was Long Bien, the asthmatic children were received the traditional health care and would received the intervention of the study one year later. The materials of intervention entailed booklets for children and for schools' healthcares which containing core contents about asthma and how to manage the asthma. The education program consisted of 4 sessions lasting 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. + 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 Diagnosed Total Thanh Xuân Long Biên p district district value (n=3118) (n=3583) test χ2 n % n % n % 260 3.9 134 4.3 126 3.5 0.1 asthma Table 3.3. shows that the prevalence of children with diagnosed asthma in Thanh Xuan district was as much as in Long Bien district with p>0.05. Table 3.4 Sex distribution of children with diagnosed asthma Characteristics Male Female p value (n=3485) (n=3216) test χ2 n n % % Diagnosed asthma 154 4.4 106 3.3 0.02 Table 3.4. shows that the prevalence of children with diagnosed asthma in males was significantly higher than females with p<0.05. Table 3.6 District distribution of children with wheezing Characteristics Current wheezing Thanh Xuân Long Biên p value (n=3118) (n=3583) test χ2 n % n % 248 8.0 369 10.3 0.001 Severe wheezing 119 3.8 138 3.9 0.94 Table 3.6. shows that compared with Thanh Xuan district, the prevalence of children with current wheezing in Long Bien district was greater with p<0.05. Table 3.10. Some characteristical outdoors of asthmatic children Characteristics Thanh Xuân Long Biên P district district value (n=133) (n=126) χ2 test n rate n rate % % House was influenced by smoke outside 47 35.6 64 50.8 0.01 School was influenced by dust, smoke and chemical 58 43.6 37 29.4 0.02 odour Table 3.10 shows that according to the children in Long Bien their houses were influenced by smoke outside more than in Thanh Xuan, conversely, the children in Thanh Xuan believed that smoke, dust and chemical odour have impacted on their schools more than in Long Bien (p<0.05) Table 3.11 The asthmatic trigger factors of children in the last 12 months Total Thanh Xuân Long Biên Factors (n=259) district district (n=133) (n=126) n rate % n rate % n rate % Climate change 146 56.4 75 56.4 71 56.3 Cold 69 26.6 37 27.8 32 25.4 Exercise 65 25.1 31 23.3 34 27.0 Tobacco smoke 63 24.3 38 28.6 25 19.8 Table 3.10 shows that the common asthmatic trigger factors of children in two districts were climate change, cold and exercise. 3.3 The effectiveness of educational intervention. Selected Thanh Xuan district in the intervention group and Long Bien in the control group. In September 2013 there were 7 children in two districts transfering their schools to another ones. 3.3.1 Characteristics of children with asthma at baseline - Characteristics of asthma status Table 3.13 Percentage of characteristics of asthma status at baseline (t0) Intervention Control district P value district (n=126) χ2 test Characteristics (n=133) n rate % n rate % Day-time symptoms 34 25.6 45 35.7 0.08 Night-time symptoms 20 15.0 26 20.6 0.24 Table 3.13 shows that there was no difference on the number of chidren having day-time and night-time symptoms between two districts with p>0.05 Table 3.13 Asthma control test of children at baseline (t0) Characteristics Asthma control test score ( x ± SD) Percentage of children with well-controlled asthma Intervention Control district (n=133) 23.1 ± 2.9 district (n=126) 22.5 ± 3.3 88.7 86.5 P value 0.11 0.12 Mann-Whitney test calculations for the difference between means of two groups and Chi-square calculations for the difference between two groups on proportion. Data in table 3.14 demonstrates similarities of asthma control test between two districts. - Characteristics of school absences Table 3.15 Percentage of children being absent from school at baseline (t0) Characteristics Intervention Control P value district district χ2 test (n=133) (n=126) n rate % n rate % Being absent from 15 11.3 11 8.7 0.32 school Data in table 3.15 demonstrates similarities of percentage of children being absent from school between Thanh Xuan and Long Bien districts. - Characteristics of knowledge on asthma Table 3.18 Asthma knowledge of the children at baseline (t0) Knowledge Knowledge score ( x ± SD) Percentage having a of good children level Intervention Control p value district district (n=133) (n=126) 8.0 ± 4.0 8.3 ± 3.6 0.52 2.3 0.8 0.33 of understanding asthma Mann-Whitney test calculations for the difference between means of two groups and Chi-square calculations for the difference between two groups on proportion. Table 3.18 shows no significant differences between two districts for asthma knowledge of chidren with p>0.05 - Characteristics of quality of life Table 3.19 Quality of life of the children at baseline (t0) Quality of life Intervention Control P value district district (Mann (n=133) (n=126) Whitney test) Activity limitation 30.3 ± 5.9 29.9 ± 5.5 0.23 Symptoms ( x ± SD) 60.5 ± 11.2 60.9 ± 9.9 0.72 Emotions fuction 49.4 ± 9.0 50.7 ± 6.9 0.93 140.2 ± 23.8 141.5 ± 20.3 0.76 ( x ± SD) ( x ± SD) Quality of life total score ( x ± SD) Data in table 3.19 demonstrates that no significant differences were found between two districts on quality of life in subscales and total scale at baseline. 3.3.2 Effectiveness of educational intervention - Effectiveness on asthma status P= 0.001+++ percentage of children having day symptoms P= 0.08+ P= 0.01+ P=0.08+ P= 0.001+ 50 intervention district control district 40 30 20 10 Times 0 t0 September 2 p from χ test; + t1 December +++ t2 May t3 September p from generalized estimating equations Chart 3.7 Effectiveness of education on percentage of children having day-time symptoms P=0.001+++ percentage of children having hight symptoms intervention district P=0.2 4+ 30 P=0.001+ P=0.02+ P=0.1+ control district 25 20 15 10 5 0 t0 September t1 December t2 May t3 September Times p from χ2 test; +++p from generalized estimating equations + Chart 3.8 Effectiveness of education on percentage of children having night-time symptoms Chart 3.7 and 3.8 show that there were significant diminution in day-time and night-time symptoms over time in the intervention district compared to the control district with p<0.05 Table 3.20 Effectiveness of education on percentage children with wellcontrolled asthma Percentage of children Intervention Control P value with well-controlled district district (χ2 test) asthma n % Times n % t0 September 118 88.7 109 86.5 0.59 t1 December 128 96.2 110 87.3 0.01 t2 May 125 94.0 113 89.7 0.21 t3 September 123 94.6 108 88.5 0.08 +++ p 0.02 +++ p: Generalized estimating equations Table 3.20 shows that in the intervention district the percentage of children with well-controlled asthma increased over time more significantly than it in the control district with p<0.05 - Effectiveness on absence from school Table 3.21 Effectiveness of education on percentage of children being absent from school Percentage of children Intervention Control being absent from district district school n % Times n % t0 September 15 11.3 11 8.7 t1 December 4 3.0 11 8.7 t2 May 5 3.8 13 10.3 t3 September 3 2.3 12 9.8 +++ p 0.02 +++ p: Generalized estimating equations P value (χ2 test) 0.32 0.04 0.03 0.01 Table 3.21 shows that in the intervention district the percentage of children being absent from school decreased over time. The decrease was significant compaired to the control district with p<0.05 - Effectiveness on asthma knowledge 20 knowledge score p=0.0001+++ 16 12 8 intervention district control district 4 t0 September t1 December t2 May t3 September Lần +++ p: Generalized estimating equations Chart 3.10 Effectiveness of education on knowledge score Chart 3.10 shows that children's knowledge score in the intervention district increased over time more significantly than in the control district with p<0.05 - Effectiveness on quality of life symptom quality of life score P=0.04+++ 70 68 66 64 62 60 58 intervention district control district 56 t0 September t1 December t2 May t3 September Times +++ p: Generalized estimating equations Chart 3.12 Effectiveness of education on quality of life symptoms domain score Chart 3.12 shows that the increase in quality of life symptoms domain score over time in the intervention district was faster than in the control district, the difference was significant with p<0.05 Total quality of life score 161 P=0.14+++ 158 155 152 149 146 143 140 intervention district control district 137 t0 September t1December t2 May t3 September Times +++ p Generalized estimating equations Chart 3.13 Effectiveness of education on total quality of life score Chart 3.13 shows that there was no significant difference of total quality of life score over time between two districts (p>0.05) L