Independent risk factors of asthma exacerbations: 3-year follow-up in a single-center prospective cohort study.

Background: Because minimizing future risk is the goal of asthma chronic asthma management, it is particularly important to identify risk factors. We conducted this 3-year single-center prospective cohort study to determine the independent risk factors of asthma exacerbations (AEs).

Methods: We performed this prospective, longitudinal, observational study with a 3-year follow-up on 257 patients aged 18-81 years with at least a 1-year history of asthma. Follow-up visits are conducted through regular annual phone calls, and the primary endpoints were AE.

Results: The uncontrolled group was more likely to develop AE than the well-controlled group [odds ratio (OR): 6.34, 95% confidence interval (CI): 1.14-35.21, P<0.05]. Patients with low Asthma Quality of Life Questionnaire (AQLQ) scores were more likely to develop AE than these with high AQLQ scores (OR: 0.59, 95% CI: 0.35-0.99, P<0.05). AQLQ and Asthma Control Questionnaires (ACQ) were both strong independent risk factors within 3 years of enrollment; the cut-off values (COV) of the AQLQ and the ACQ (uncontrolled) that better evaluated the risk with the AE were ≤5.4 and >1, respectively. The AQLQ scores had a sensitivity of 79.07% and a specificity of 59.09% [area under curve (AUC): 0.70, P<0.0001], and the ACQ (uncontrolled) had a sensitivity of 81.4% and a specificity of 52.29% (AUC 0.68, P<0.0001).

Conclusions: The findings of this study suggest that patients with uncontrolled asthma and a diminished health-related quality of life had an increased risk of exacerbations in the future. Defining these risk factors associated with AE is important as it will identify these at the highest risk to patients and may guide future interventions.