Asthma-induced hospitalizations among conscripts in Finland in 1982-1992

The purpose was to examine changes in the numbers of asthma-related hospitalizations among conscripts and possible seasonal fluctuations. Data on treatment periods for asthma among men aged 18-22 years at military hospitals in 1982-1992 were collected from the national hospital discharge register. Monthly numbers of hospitalizations were calculated for each year separately, together with the frequency of such periods per 1000 conscripts. Results. A total of 4894 asthma-related hospitalizations were recorded in 1982-1992, the frequency per 1000 conscripts increasing from 8.5 in 1982 to 27.7 in 1992. Evident seasonal fluctuations were observed in 1982-1989, the peaks being recorded for February (14% above the annual average), July (26%) and November (51%). A change in these seasonal fluctuations was observed in 1990-1992, however. The frequency of asthma-induced hospitalizations among conscripts tripled between 1982 and 1992, evidently indicating a real increase in the number of occurrences. The hospitalization peaks are located at the beginning of military service, a point at which factors tending to aggravate asthma exercise a major impact.