Recent trends in the prevalence and severity of childhood asthma

Abstract

Objective: To examine changes in the prevalence and distribution of childhood asthma and its relationship with various measures of children's health and functioning between 1981 and 1988. It was hypothesized that there would be an increase in the prevalence of asthma, especially among black children, and that available measures would suggest a deterioration in the health and functioning of children with asthma over this period.

Design: Analyses of data from the Child Health Supplements to the National Health Interview Survey.

Setting and sample: Nationally representative random sample of 15,224 children aged 0 to 17 years in 1981 and 17,110 in 1988.

Main outcome measures: Changes in (1) the prevalence and distribution of asthma, and (2) among children with asthma, the percentage of children hospitalized, days spent in bed, school days lost in the year prior to survey, and parent ratings and reports of children's overall health status and behavior problems.

Results: The estimated prevalence of childhood asthma increased from 3.1% in 1981 to 4.3% in 1988 (P < .0001), with similar increases for children, adolescents, and both sexes. Increases occurred among white children (2.7% to 4.1%; P < .0001) but not black children (5.3% vs 5.1%; not significant). Among those with asthma in 1988 compared with 1981, there was better overall health status (11% vs 24% fair/poor; P < .0001) and fewer with 30 or more days spent in bed in the last year (3.9% vs 7.2%; P < .04). We also observed trends toward a lower rate of hospitalization in the last year (10% vs 14%; P = .07), fewer school days missed (2% vs 6% with > 30 days; P = .08), and a lower rate of extreme behavior problem scores (13% vs 18%; P = .09) in 1988 compared with 1981. Reductions were similar among both black and white children.

Conclusions: These results indicate that the estimated prevalence of asthma among children in the United States increased by almost 40%, and that although the increase occurred exclusively among white children, the prevalence of asthma still remains higher in black children than in white children. There was no support for increasing asthma severity and functional impact among either black or white children with asthma in 1988 compared with 1981. These findings provide no evidence to support the beliefs that asthma prevalence is increasing largely among black children or that the severity of asthma among most children in the United States is increasing.