How Should We Quantify Asthma Control?

Background: Current asthma guidelines suggest a series of criteria to assess if asthma is controlled. However, there is a need to develop a simple and practical method to quantify the degree of such control, both in clinical practice and research. Study objectives: This report describes a new method to quantify asthma control based on a percentage score. It also aims at comparing the percentage scores obtained with patient's self-evaluation of asthma control and a current validated Mini Asthma Quality of Life (MAQOL) questionnaire. Setting and subjects: Forty-two subjects (25 female and 17 male patients) with asthma of different severity recruited from a tertiary center asthma clinic. Methods: The asthma scoring method provided a percentage control for symptoms, baseline expiratory flows and, an optional parameter, for airway inflammation assessed from inducedsputum eosinophil count. These control parameters were compared to an overall assessment of asthma control by the patient (also on a 100% scale) and the score obtained from a validated MAQOL questionnaire. Results: Mean ± SEM scores for symptoms, expiratory flows, and airway eosinophilia (last 2 weeks) were 87.8 ± 1.4%, 88.6 ± 1.8%, and 66.2 ± 3.9%, respectively. No significant correlation was found between these three parameters (p > 0.05). The mean global asthma control score and the score estimated by the patient were 80.9 ± 1.5% and 91.7 ± 1.5%, respectively (not significantly different). There was a significant correlation between asthma control score (percentage) and percentage symptom score (p < 0.001), while it almost achieved significance for FEV[sub 1] (p = 0.05). Only symptom scores correlated with the MAQOL questionnaire. Conclusions: We developed a simple easy-to-use asthma control scoring system based on a percentage of optimal control. The percentage symptom score but not the global control score of this new method correlated with patient's global... [ABSTRACT FROM AUTHOR]