Differences in Asthma Clinical Outcomes According to Initial Severity

Abstract

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 (− 1.92 to 0.18); and severe 1 (− 0.23 to 2.27) (p = 0.020); FEV1 (%): 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.