Changing patterns of hospital admission for asthma, 1981-97.

BACKGROUND Hospital admission rates for asthma have stopped rising in several countries. The aim of this study was to use linked hospital admission data to explore recent trends in asthma admissions in Scotland. METHODS Linked Scottish Morbidity Records (SMR1) for asthma (ICD-9 493 and ICD-10 J45-6) from 1981 to 1997 were used to describe rates of first admissions and readmissions by age and sex. As a measure of resource use, annual trends in bed days used were also explored by age and sex. RESULTS There were 160 039 hospital admissions for asthma by 82 421 individuals in Scotland during the study period. The overall hospital admission rate increased by 122% (from 106.7 to 236.7 per 100 000 population) but this varied by sex, age, and admission type. First admissions rose by 70% from 73.2 per 100 000 in 1986 to 124.8 per 100 000 in 1997 while readmissions fell. Children (<15 years) experienced a decline in overall admissions after 1992 due to falls in both new admissions and readmissions. By 1997 the ratio of female to male admissions was 0.57 in children, but 1.50 above 14 years of age. Mean lengths of stay fell from 10.7 days to 3.7 days between 1981 and 1997 and bed days used showed little change except for a decline after 1992 in children. CONCLUSIONS After a period of increasing hospitalisation for asthma in Scotland, rates of admission among children have begun to fall but among adults admissions continue to rise.