SEASONAL-VARIATION IN CHILDHOOD ASTHMA HOSPITALIZATIONS IN FINLAND, 1972-1992

All hospital treatment periods caused by asthma in children under 15 y ears in Finland during 1972-1992 were examined. The data were obtained from the Hospital Discharge Register, covering all hospitalisations i n Finland. A total of 59,624 asthma related treatment periods were rec orded. The monthly variation in hospitalisations peaked in May (35.6% above the trend) and in autumn and early winter (41.3% above the trend in October), whereas the monthly variations were low in late winter a nd in summer. The overall profile of seasonal variation was similar in both sexes, although admissions were lower for boys than for girls in winter and higher in autumn. The average monthly deviation was highes t in the age group 0-4 years in May, 42.8% above the trend, and highes t in the age group 5-9 years in October, 53.9% above the trend. Closer examination of the seasonal variation gives indirect information on p ossible trigger factors for acute asthma. Conclusion A clear seasonal variation could be observed in childhood asthma hospital admissions, t ogether with age and sex-related differences in this seasonality. Prev entive treatment for asthma should be used effectively in order to avo id acute attacks leading to hospitalisation in children who are allerg ic to birch pollen and also at times of viral respiratory infections.