Topics in asthma - Part II. Problems and possibilities in understanding the natural history of asthma

In early life, asthma symptoms can occur intermittently or may not be sever e enough to limit normal activities, which makes it difficult for the clini cian to make reliable predictions and administer therapy with some precisio n. In the case of pediatric asthma, the identification of children who will experience the development of a clinically important illness that will imp air their quality of life can be a complex process. The usual methods for d escribing this information include the prognostic statistics of sensitivity , specificity, likelihood ratio, and positive predictive value. The sensiti vity, specificity, and likelihood ratio of various early markers of asthma have been calculated from several cohort studies.