Predictors of asthma-related quality of life in a large cohort of asthmatics: A cross-sectional study in a secondary care center.

Background In recent decades, asthma-related quality of life questionnaires have joined objective clinical indicators as important outcome measures. In this study, we sought to investigate the predictors of asthma-related quality of life in a large cohort of patients recruited from a secondary care center. Methods We conducted a cross-sectional study on asthmatics (N = 1301) recruited from the Liege University Hospital asthma clinic (Belgium). After performing a descriptive analysis highlighting the distribution of scores from the Mini Asthma Quality of Life Questionnaire (Mini AQLQ) and its four dimensions (symptoms, activity limitation, emotional function, and environmental stimuli), we did multiple regression analysis to identify the independent predictors of AQLQ. Results Multiple regression beta analysis showed that AQLQ and its four dimensions were primarily associated with asthma control (p < 0.0001 in all instances). Female gender was associated with a lower score for the AQLQ's activity and environmental dimensions (p < 0.05 for both), while current smokers had a higher score on the AQLQ's environmental dimension (p < 0.0001). The burden of asthma treatment was associated with a lower score for the AQLQ's emotional (p < 0.05) and environmental (p < 0.05) dimensions. BMI was associated with a lower score in the AQLQ's activity dimension (p < 0.0001), while the opposite was true for the FeNO test (p < 0.0001). Sputum neutrophils were inversely related to the score for the AQLQ's symptom dimension (p < 0.05), whereas post-bronchodilator FEV1 showed a positive relationship for that same dimension (p < 0.05). Conclusion Asthma control is the main predictor of AQLQ score and impacts all its dimensions, but demographic, functional, and airway inflammatory parameters may also influence some dimensions of the AQLQ.