We conducted an exploratory analysis of several prospectively obtained objective measures of disease activity to derive a predictive model of hospitalization for asthma among 310 adults, ages 18 to 50 yr, with moderate to severe asthma. Baseline characteristics associated with increased risk of hospitalization in the succeeding year include (1) prior year hospitalization, (2) moderate or severe respiratory impairment, (3) a medication regimen consistent with severe asthma, (4) a history of significant systemic steroid use, (5) maximum overnight PEF variability > 40%, and (6) mean evening PEF < 60% of predicted (relative risk = 6.5, 6.9, 8.1, 3.7, 3.0, and 3.2, respectively). Recursive partitioning analysis, depicted as a "classification tree," provided a more sensitive (94%) and specific (68%) multivariate description of the data set than either logistic regression (87 and 48%, respectively) or a simple additive risk model (46 and 93%, respectively). Patients with very high (> 50%), moderately elevated (10 to 15%), and very low (< 5%) risk of hospitalization were identified on the basis of particular combinations of prior hospitalization history, level of respiratory impairment, and medication regimen. Overnight variability and mean evening PEF measured at home over a 2-wk period proved less informative for risk stratification than respiratory impairment determined once at baseline by office spirometry. The findings warrant replication and extension in other populations with the goal of developing decision rules for risk stratification and effective interventions for risk reduction.
We conducted an exploratory analysis of several prospectively obtained objective measures of disease activity to derive a predictive model of hospitalization for asthma among 310 adults, ages 18 to 50 yr, with moderate to severe asthma. Baseline characteristics associated with increased risk of hospitalization in the succeeding year include (1) prior year hospitalization, (2) moderate or severe respiratory impairment, (3) a medication regimen consistent with severe asthma, (4) a history of significant systemic steroid use, (5) maximum overnight PEF variability > 40%, and (6) mean evening PEF < 60% of predicted (relative risk = 6.5, 6.9, 8.1, 3.7, 3.0, and 3.2, respectively). Recursive partitioning analysis, depicted as a "classification tree," provided a more sensitive (94%) and specific (68%) multivariate description of the data set than either logistic regression (87 and 48%, respectively) or a simple additive risk model (46 and 93%, respectively). Patients with very high (> 50%), moderately elevated (10 to 15%), and very low (< 5%) risk of hospitalization were identified on the basis of particular combinations of prior hospitalization history, level of respiratory impairment, and medication regimen. Overnight variability and mean evening PEF measured at home over a 2-wk period proved less informative for risk stratification than respiratory impairment determined once at baseline by office spirometry. The findings warrant replication and extension in other populations with the goal of developing decision rules for risk stratification and effective interventions for risk reduction.
Children born into allergic families, with two allergic parents, are at high risk of developing allergy within the first 5 years of life. In order to observe possible external factors in the sensitization process, a prospective study of 13 such children was done, in which serial clinical and immunologic observations were made at 3- to 6-month intervals over a period of 1 to 4 yr. Eleven of these children are now clinically allergic; 5 have asthma. Immunologic evidence for allergic sensitization was observed in these 11 children by RAST, antigen-induced leukocyte histamine release, lymphoblastogenesis, and rise in serum IgE. Upper respiratory infections (URI) occurred in these 11 allergic children 1 to 2 months prior to the onset of allergic sensitization. In 10 of these 11 URI children, complement-fixing antibodies to viruses (parainfluenza, RSV, CMV) increased in the same blood samples in which immunologic allergic sensitization was first evidenced. This coincidence suggests that certain viruses may contribute to the allergic sensitization process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.