Impact of school opening on asthma hospital admissions in New York State

Asthma is believed to peak in autumn, but seasonal variation by age group has rarely been examined. The impact of returning to school on children's asthma admissions has also not been well explored. The objectives of this study are to determine how the return to school affects asthma hospital admissions and to assess the timing and magnitude of admissions following school vacations among different age groups.This time-series study compared asthma admissions on the first day of school to those on subsequent days in the school session following four school breaks (summer, Christmas, winter, spring). Data included hospital admissions due to asthma from 1991-2001 in New York State. A generalized additive model assessed the risk associated with school return among different age groups (2-4, 5-11, and 12-17 years old) while adjusting for long term trends, day-of-the-week, holidays, daily ozone level, temperature, and humidity. Adults (18-65 years) and elders (> 65 years) were the comparison groups. There was a significant increase in hospital admissions (6% - 254%) associated with the return to school after each break for all children. Peak asthma admissions occurred from 17-30 days after the first day of school. Stronger associations were found following summer vacation and for children aged 5-11 years. Smaller or no increases were observed in adults and elders. Returning to school after vacations substantially increases the risk of asthma admissions in children, especially among elementary school children. Intervention focused on the period of return to school may reduce the asthma burden in children.