Differences in asthma clinical outcomes according to initial severity.

UNLABELLED: Information on asthma morbidity outcomes in relation to the initial degree of severity is scarce. OBJECTIVE: To determine the differences in asthma morbidity, quality of life (QOL), and lung function outcomes according to the initial severity of the illness. METHOD: A cohort of 235 (102 mild, 69 moderate, and 64 severe) asthma patients was followed up for 3 years. The following parameters were collected for all patients: asthma morbidity, clinical data, spirometry, and St. George's Respiratory Questionnaire (SGRQ). RESULTS: A significant reduction in asthma morbidity and an improvement in pulmonary function and QOL were observed in the total group 3 years later. However, when the sample was stratified according to the initial severity, differences were observed between means in the third year compared with the first year in the following: number of primary care visits (patient/year) due to asthma: mild -1 (95% CI: -1.42 to -0.56); moderate -0.9 (-.92 to 0.18); and severe 1 (-0.23 to 2.27) (p = 0.020); FEV, (%): mild 8.5 (-5.3 to 11.6), moderate -0.3 (-3.2 to 2.6), and severe -1.5 (-5 to 2) (p < 0.001); and total score of the SGRQ: mild -9.8 (-12.2 to -7.3), moderate -9.1 (-12.9 to -5.2), and severe -7.9 (-11.9 to -3.9) (p < 0.001). CONCLUSIONS: We conclude that asthma prognosis varies according to the initial severity. Clinical, QOL, and pulmonary function outcomes in the mild asthma group are better than in the moderate and severe groups.