Time trends in prevalence of symptoms of asthma in Indian children: ISAAC and GAN studies

Abstract

Aims and Objectives: The international study of asthma and allergies in childhood (ISAAC) I and III were conducted in India in 1994-95 and 2001-03 respectively with no further studies since. Global asthma network(GAN) was initiated with the aim to assess the change in prevalence of asthma across the world. Methods: The GAN was a questionnaire and school based study conducted in 9 centres across India from 2017-2018 with similar methodology as previous ISAAC studies for 6-7y and 13-14y old children. Prevalence per 1000 and 95% confidence intervals(95%CI) were calculated. Results: The prevalence of wheeze in the past 12 months for 6-7y group was 5.6%(N=31697), 5.3%(N=46761) and 3.2%(N=20084) for ISAAC phase I, III and GAN respectively. The prevalence in 13-14y group was 6% (N=37171), 5.8% (N=52098) and 3.7% (N=25887) respectively. Comparing GAN and ISAAC phase III, there was significant decrease in prevalence for all centres in both age groups except for 2 centres in 13-14years age group (Jaipur: little change, Pune: significant increase). Comparing ISAAC phase I and III, there was little change in 6-7y group in all cities except Pune (significant increase), for 13-14y group there was little change except Jodhpur and Delhi (significant decrease)(figure 1). Conclusion: The prevalence of asthma was lower in most of the centres across India in both age groups possibly reflecting evolution in environmental factors.