Assessing the impact of comorbidity on asthma severity and asthma control in adult asthma patients

Introduction: Asthma is commonly co-existent with several comorbidities, mainly gastroesophageal reflux disease, obesity, diabetes mellitus and cardiovascular diseases. The management of asthma becomes difficult in asthma patients living with these comorbidities.

Objectives: The aim of this study was to determine the impact of comorbidities on asthma severity and asthma control in asthma patients. 

Study Design: In this cross-sectional study, 55 adult asthma patients were enrolled from Hospital Selayang, Malaysia.

Methods: The asthma control was assessed by administering the Malaysian version of asthma control test (ACT) to the patients. The lung function testing was performed by CosMed^® spirometer. The clinical and functional criteria for asthma diagnosis and severity were used according to Global Initiative for Asthma (GINA) guidelines. The socio-demographic data and comorbidities were recorded from patients’ medical records. Patients were grouped into two categories; asthma patients without comorbidities and asthma patients with comorbidities. The data were analyzed by Statistical Package for Social Sciences (SPSS)^® for independent t-test.

Results: The mean age of the asthma patients were 53.21 ± 16.45. The results of independent t-test showed that the mean score of asthma control was significantly higher in group of asthma patients without comorbidities (20.17 ± 3.70) than asthma patients with comorbidities (i.e. 17.15 ±3.17; t = 2.959 (53), p = 0.005). Whereas the mean FEV₁ % values were not significantly different in groups of asthma patients without comorbidities (68.96 ± 17.16) and patients with comorbidities i.e. 60.98 ± 17.19; t = 1.698 (53), p = 0.095). 

Conclusions: The asthma control showed a significant difference between asthma patients with comorbidities and asthma patients without comorbidities. But the values of FEV₁ % were not significantly different between two groups. The association of comorbidies with asthma outcomes should be explored in other populations with greater sample size to address the issues of generalizability of the findings.