A Study of Correlation between Asthma Control Test and Lung Function Parameters

Introduction: Asthma control is the extent of observed asthma symptoms in patients and reduction in symptoms after treatment. Simple screening tools are available to assess asthma control. Asthma control test is a simple numerical scoring system that can be easily used on a routine basis. Latest Global Initiative for Asthma (GINA) guidelines stress that asthma control is the main objective of asthma treatment. In this COVID-19 pandemic situation, there is an hesitancy in performing and undergoing pulmonary function tests among physicians and the patients. Hence, in this study it was planned to correlate the asthma control test values with FEV1 and other parameters like Peak Expiratory Flow Rate (PEFR), Absolute Eosinophil Count (AEC) and serum magnesium. Aim: To study the correlation between asthma control test and FEV1; to study the correlation between asthma control test and other parameters like PEFR, AEC and Serum magnesium. Materials and Methods: This was a cross-sectional observational study done from February 2019 to January 2020 conducted at Department of Pulmonary Medicine. A total of 55 patients of Bronchial asthma in line with GINA Guidelines were included in the study. Asthma control test questionnaire was administered to all the patients. Routine blood investigations like Total Leucocyte Count (TLC), Differential Leucocyte Count (DLC), Absolute Eosinophil Count (AEC), serum magnesium levels were done. Pulmonary function parameters like FEV1 and PEFR were measured. Results: Asthma control test had positive correlation with FEV1 with a spearman’s correlation of 0.2758 and p-value of 0.0414 which was statistically significant. The spearman’s correlation between asthma control test and AEC was -0.4583 with a p-value of <0.001, which was significant. The correlation of asthma control test with serum magnesium was 0.3414 with a p-value of 0.010. Conclusion: Asthma control test score had a significant positive correlation with FEV1 and serum magnesium levels. It also had significant negative correlation with AEC (inflammatory marker). Hence, asthma control test can be used as tool for treatment response in the current COVID-19 pandemic situation and also in resource limited settings.