The literature search has been classified into various sections such as
Section A: Studies related to prevalence and severity of asthma among children.
Section B: Studies related to effect of breathing exercise on asthmatic children.
2.1 Section A: Studies related to prevalence and severity of asthma among children.
Maria Cheraghi, et al., (2012) conducted a cross sectional study to find prevalence and risk factors of childhood asthma in Pune city, India. The findings showed that the prevalence of asthma was 7% among 6-7yrs old and 6.7% among 13-14yrs old. Asthma was more common among boys (81%) than girls (49%) and more frequent in students studying in private school (7.3%)than in those studying in public schools (5.8%).The study concluded that there was a high prevalence of childhood asthma associated with genetic and environmental risk factors.
Zubair Kabir, Patrick, J., et al., (2011) conducted a cross sectional self administered questionnaire survey on prevalence of symptoms of severe asthma and allergies in Irish school children as an ISSAC protocol study from 1995 -2007.The study concluded that there was significant increase in symptoms of severe asthma among children in the age group of 12-14 years from 12% to 15.3%.
John T. McBride, MD (2011) conducted a cross sectional studied on epidemiology of asthma in children that involved 122 centers in 54 countries. The investigator rigorously identified children with wheezing and asthma symptoms, prevalence nearly 30% among them of all between 13 -14 years and in 6-7years olds the risk of current asthma was increased.
Pradeepa P, et al., (2010) conducted a epidemiological study on prevalence of asthma in school children in rural areas of Karnataka state, India. Study population included school children between the age group of 10 -18 years, the total number of sample was 573. Overall, there were 55.1 % males and 44.9%females. The prevalence of ever wheezes was 8.4% and current wheezes was 5.2%. The wheezing was more prevalent among the 10-12 years age group (11.5%) compared to others.
Daljit Singh, et al., (2010) conducted a epidemiological study on prevalence of asthma in rural children between the age group of 1-15years in Ludhiana. The study results showed that 2.6% of rural children was significant with association of history of allergy and exposure to smoking.
Sang II Lee, (2010) conducted an epidemiological studies in 1995 to 2000 on the prevalence of asthma symptoms in Korean children, was highly significant in junior high school who over five years. However, in elementary school children, the prevalence of asthma symptoms decreased, although the prevalence of diagnosis of asthma, ever and treatment of asthma, last 12 months increased. In addition, it was found that various factors, such as obesity, passive smoking, dietary habits, raising pets at home, and fever/antibiotic use during infancy were associated with childhood asthma.
Gnanase Karan S, Subramani, Thaninum Asari A, et al., (2010) conducted an epidemiological study on atmospheric air pollution and incidence of bronchial asthma and the severity form in asthmatic centers at Vellore district. The findings identified that the air pollutants and their effects found in the affected children of 10 – 15% among the selected population.
Paramesh H (2008) conducted a epidemiological study on prevalence of asthma in India. The study findings revealed that the study among 20,000 children under the age of 18years in the city of Bangalore showed a prevalence of 90%(1979) , 10.5%(1984), 18.5%(1989) , 24.5% (1994) and 29.5%(1999).In rural areas showed 5.7% in children of 6-15years.The persistent asthma also showed an increase from 20%to27.5% and persistent severe asthma 4%to 6.5%.
Gupta D, et al., (2008) conducted a descriptive study on prevalence of asthma and its association with environmental factors. The study indicates that there is high prevalence of asthma in school children in a rural area, where male children’s had more prevalence than female.
Sidney S Burman, et al., (2008) conducted a study on global prevalence, morbidity, mortality and economic burden associated to asthma over the last 40 years particularly in children. The findings of the study data revealed that worldwide 300 million had asthma and the prevalence increased by 50% in children every decade.
Shah JR, Ambedkar YK, Mathew RS, et al., (2007) conducted a study on prevalence of asthma among children in India. The findings of the study was revealed that there was high prevalence seen in districts of Madras, Delhi and Kottaya centers.
Shally Awasthi, Ekta Kalra, Siddhartha Roy and Saumya Awasthi (2007) conducted a descriptive study on prevalence of asthma, wheeze and risk factors associated with it in school going children aged 6-7yrs and 13 to 14yrs at Lucknow, U.P., India. The findings indicated that prevalence of asthma and wheeze reported were 2.3% and 6.2%, respectively, in age group 6-7 years and 3.3% and 7.8%, respectively, in age group 13-14 years. On the basis of adjusted odds ratio, risk factors for wheeze /asthma were tertiary education of mother, antibiotic use in the first year of life, eating pasta or fast-food or meat once or more/week and exercise once or more/week while the protective factors were intake of vegetables once or more and fruits thrice or more per week.
Rosalind L Smyth (2007) conducted a epidemiological study on incidence, prevalence and mortality of childhood asthma in UK. The study identified that childhood asthma rates was increased in English speaking countries ( UK, New Zealand, Australia and North America ) and some Latin American countries (Peru and Costa Rica), and lowest in Russia, Indonesia, and Albania. The incidence accounted for a weekly new case rate of approximately 60 -70 for pre school children,40 – 50 for children aged 5-14 years and 20-25 for people older than 15years.
Goy DY, et al., (2007) conducted a cohort study to evaluate the epidemiology of asthma and allergic disease in that a written questionnaire was administered to 6238 school chidren. The prevalence of doctor diagnosed asthma was 20% among them. More severe asthma related symptoms were present in Malays and Indians than in the Chinese.
Richard Beasley, et al., (2007) conducted an epidemiological study on international patterns of the prevalence of pediatric asthma in clinics of North America. The preliminary results from 156 centers in 56 countries and involving more than 750,000 children showed striking international differences in the prevalence of asthma symptoms . The prevalence of self-reported wheezing in the previous 12 months in 13- to 14-year-old children varied from 1.6% to 36.7% in different centres . The corresponding prevalence for parent-reported wheezing for the 6- to 7-year-old age group was 0.8% to 32.1%. Although there are limitations in international prevalence comparisons of this kind, a number of observations that can be made from the ISAAC findings have important implications for future asthma research.
2.2 Section B: Studies related to effect of breathing exercise on asthmatic children.
Agency of Heath Care Research Center (2012) conducted a randomized controlled study of effectiveness of breathing exercises and or retraining techniques in the treatment of asthma in US. In research group trained a Buteyko breathing technique for period of 4 weeks. The result showed there is an improvement in lung function and decrease of asthmatic symptoms significantly.
Tarun Saxena and Saxena (2009) studied the effect of various breathing exercises in patients with bronchial asthma of mild to moderate severity. The sample size was 50 they were trained to perform omkara yoga at high pitch which prolonged exhalation for 12 weeks. The result showed significant improvement in symptoms, FEV1(force expiratory volume) and PEFR (peak expiratory flow rate). The study concluded that breathing exercise mainly expiratory exercises improved lung function subjectively and objectively and recommended it should be a regular part of therapy.
Opat AJ, Cohen MH, Baily, et al., (2009) conducted a randomized study on clinical trial of Buteyko breathing technique in asthma as taught by video, was a efficacious asthma therapy in Australia. The sample size 36 adult subject with mild to moderate asthma randomized and allowed to watching video twice per day and practice for 4 weeks. Asthma related quality of life, peak expiratory flow, symptoms and asthma medication intake were assessed both before and after intervention. The results demonstrated a significant improvement in quality of life at p =0.043 as well as reduction in inhaled bronchodilator at p=0.08.
Chen TL, Mao HC, Lai CH, et al., (2009) conducted quasi-experimental study on effect of yoga exercise intervention on health related physical fitness in school-age asthmatic children. The sample size was 31 voluntary children, 16 are in experimental group and 15 are control group aged 7 to 12 years from one public elementary school in Taipei country. The result showed after 2 weeks of self practice at home, Yoga exercise continued to improve BMI, flexibility, muscular strength and cardiopulmonary fitness.
Cooper S, Oborne J, Newton S, et al., (2009) conducted a randomized controlled study of effect of buteyko and pranayama techniques in 90 patients who inhaled corticosteroids with mild stable asthma were trained buteyko and pranayama techniques for 2 weeks and subjects practised the techniques at home twice daily for 6 months. The results showed that the symptoms score significantly improved in buteyko group.
Sander A, Gyorile, Martin H Brutsche (2009) conduct a study on complementary and alternative technique such as breathing or retraining exercises need to be studied over the next few years to establish the additive role in the treatment of asthma because which showed significant improvement in the lung function and quality of life.
Ramazazo Dlu YM, Kraemer R (2008) conducted a study on relationship of physical exercise to changes in static lung volume (hyperventilation)and airway dynamics as well as to ventilator gas exchange, heart rate reserve, breathing reserve and working capacity of at a heart rate of 170/min was evaluated in 23 children between 6 to 15years of age who had asthma. Lung function test was performed before and after a 15 week period of physical training. The result indicated that there is a significant (p=0.05) improvement in both hyperventilation and specific airways conductance.
Cibella, et al., (2007) conducted a study on lung function decline in bronchial asthma. The investigator identified that FEV1 had linear decay with aging in each subject.FEV1 decay was significantly higher among younger asthmatics with power baseline functional condition.