Sri Lanka - epidemiology, Prevalence, Cross-Sectional Studies, Residence Characteristics - statistics & numerical data, Humans, Risk Factors, Child, Preschool, Female, Male, Poverty Areas, Respiratory Sounds, Asthma - epidemiology, Caregivers, Pediatrics, Cooking, Income, Wheezing, Males, Multivariate analysis, Confidence intervals, Toys, Illnesses, Populati...