To develop a prognostic clinical index for adults with chronic stable asthma.
Design
Analysis of data from a 48-week randomized, crossover trial of regular vs as-needed inhaled β-agonist therapy.
Patients
Eligible patients included 70 men and women between the ages of 15 and 64 years with asthma for > 1 year.
Outcome measure
Asthma deterioration within 20 weeks, defined as either a marked decline in FEV1 (≥1.0 L or ≥30% from baseline) or initiation of systemic corticosteroid therapy for asthma exacerbation.
Results
Three baseline factors independently predicted asthma deterioration: frequent symptoms on waking in the 4 weeks before baseline, past hospitalization for asthma, and age 35 years or older. Based on cross-stratification and consolidation of these prognostic factors, an index was developed that stratified subjects into four risk groups with distinctive deterioration rates of 9%, 21%, 39%, and 67% (p<0.001).
Conclusion
For adults with chronic stable asthma, three simple clinical factors can be combined to stratify effectively for risk of subsequent asthma deterioration.
Key words
asthma
clinical severity
prognostic index
Cited by (0)
Dr. Beckett was supported in part by the National Heart, Lung, and Blood Institute, Division of Lung Diseases, Preventive Pulmonary Academic Award. The original trial that provided data for this study was funded by the Health Research Council of New Zealand.