Seasonal variations in hospital admissions for asthma in Malta

The seasonality of asthma exacerbations may reflect varying exposure to triggers. This study retrospectively analyzes the seasonality of asthma hospital admissions, at all ages, in a population-based study. Analysis of the seasonality of asthma admissions and correlation with temperature was carried out ill the setting of a regional hospital covering all acute asthma admissions ill all island population. Admissions were divided into pediatric (1994-8) and adult (1989-8) cases. Both pediatric (0-14 years; n = 2916) and adult (15-59 years; n = 1269) admissions showed a peak ill January and a trough ill August. The seasonality ill pediatric admissions was far more pronounced than ill adults. Both cohorts exhibited a second, smaller peak ill spring. In school-aged children, the end of school ill June was associated with a sharp (91%) drop ill admissions, and restarting school ill October was associated with all even sharper rise (165%). A negative correlation was found between admissions and mean monthly ambient temperatures, and this was most pronounced ill the pediatric age groups. This marked seasonality may indicate that temperature is a proxy for the total time spent indoors. Both the start and end of school had a profound impact oil pediatric admission rates. Prospective studies are necessary to establish the role of viral infections and the influence of indoor and outdoor aeroallergens oil the seasonality of hospitalization rates for asthma ill the local setting.