Factors associated with quality of life in patients with severe asthma: the impact of pharmacotherapy

OBJECTIVE To identify, characterize, and quantify associations of various factors with quality of life (QoL) in patients with asthma, according to the pharmacotherapy employed. METHODS This was a cross-sectional study involving 49 patients (≥ 18 years of age) with severe uncontrolled or refractory asthma treated at a specialized outpatient clinic of the Brazilian Unified Health Care System, regularly using high doses of inhaled corticosteroids (ICs) or other medications, and presenting comorbidities. At a single time point, QoL was assessed with the Asthma Quality of Life Questionnaire (AQLQ). The overall AQLQ score and those of its domains were correlated with demographic variables (gender and age); Asthma Control Questionnaire score; pharmacotherapy (initial IC dose, inhaler devices, and polytherapy); and comorbidities. RESULTS Better AQLQ scores were associated with asthma control--overall (OR = 0.38; 95% CI: 0.004-0.341; p < 0.001), "symptoms" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001), and "emotional function" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001)-and with IC dose ≤ 800 µg--"activity limitation" domain (OR = 0.249; 95% CI: 0.070-0.885; p = 0.029). Worse AQLQ scores were associated with polytherapy--"activity limitation" domain (OR = 3.651; 95% CI: 1.061-12.561; p = 0.036)-and number of comorbidities ≤ 5--"environmental stimuli" domain (OR = 5.042; 95% CI: 1.316-19.317; p = 0.015). CONCLUSIONS Our results, the importance of this issue, and the lack of studies taking pharmacotherapy into consideration warrant longitudinal studies to establish a causal relationship between the identified factors and QoL in asthma patients.