Global burden of childhood asthma has increased in the last few decades particularly in low-income countries. In Pakistan there is a lack of community based epidemiological studies estimating the burden of asthma among children. Moreover, generalizability of such studies is also limited. This study determined the prevalence and predictors of asthma among children 3-17 years of age in Karachi, Pakistan.
Methods:
A two-stage community based representative cross-sectional survey was conducted in Karachi from March 2012-April 2013 comprising 1046 children aged 3-17 years. In the first stage, 80 clusters out of 7500 were randomly selected, and then within each cluster, line listing of 200–250 households was done. Out of these lines listed households, 15 households per cluster were selected and one child from each household was enrolled randomly in the study. A translated and pre-tested version of ISAAC (International Study of Asthma and Allergies in Children) questionnaire was administered. Multivariate logistic regression was done to generate adjusted odds ratios for predictors of asthma. P-value of < 0.05 was considered significant. Chi square test was applied to see the difference in prevalence of asthma with respect to age.
Results:
The overall prevalence of asthma among study participants was 10.2% (95% CI: 8.4-12.0), while among 3-7 year old children it was 14.7%, followed by 6.8% in 15-17 and 5.8% in 8-14 year old children (p < 0.05). Asthma was more likely to occur among boys (adj. OR: 2.5, 95% CI: 1.6-4.0), children in the younger age group (3-7 years) (adj. OR 2.9, 95% CI: 1.7-4.8), those living in households with ill-ventilated kitchens (adj. OR 1.8, 95% CI: 1.1-3.1), having family history of asthma (adj. OR 2.3, 95% CI: 1.3-3.9) and those of the Sindhi ethnicity (adj. OR 2.2, 95% CI: 1.1-4.4). In a separate model for 3-7 years age group, family history of asthma (adj. OR: 2.4, 95% CI: 1.3–4.5), boys (adj. OR: 2.1, 95% CI: 1.2-3.6) and allergy to dust mite (adj. OR: 2.3, 95% CI: 1.0-5.0) were regarded as important risk factors.
Conclusions:
This study is the first robust evidence regarding asthma among children in Pakistan, reporting a high burden in this group. Family history, male gender, Sindhi ethnicity and ill-ventilated kitchen were identified as important predictors of asthma. Targeted preventive measures and further intervention studies are required to better understand and reduce the burden of asthma among children in Pakistan.