The Asthma Control Test is a poor measure of asthma control in a modern cohort of clinically uncontrolled asthma patients.

The Asthma Control Test (ACT) is a recommended assessment tool for asthma. In patients with severe asthma, the presence of co-existing reflux, obesity & anxiety may act as confounders, lowering the ACT score & making the patient appear less likely to achieve control. In this study, we tested this hypothesis in a cohort of less severe asthma & used a cohort of patients subsequently identified as not having asthma as a control group. Participants with a clinical diagnosis of asthma and persistent respiratory symptoms were recruited to a 12-week study, undergoing simultaneous diagnostic testing & remote monitoring. Lung function, type 2 inflammation & ACT were recorded at 4 visits over 12 weeks. Results from the first 100 participants are presented. Asthma was diagnosed in 54 subjects, an alternative diagnosis was made in the remaining 44, while two withdrew from the study. Individuals with asthma had a lower mean ACT at enrolment (16 vs 18, p<0.05), though this did not meet the minimum significant clinical difference. Similarly, individuals with asthma had lower FEV1% predicted than controls (78% vs 102%, p<0.01). Correlation between eosinophil count & FEV1 was noted (visit 1 r=-0.36, p<0.01). In patients with asthma, the ACT score correlated with number of co-morbidities (visit 1, r=-0.31, p<0.05), with multi-morbid patients showing the lowest ACT score across all visits. No correlation was noted for FEV1 or T2 biomarkers. In patients who did not have asthma, ACT showed a similar correlation with number of non-asthma diagnoses (visit 1 r =-.39, P<0.01). In conclusion, the ACT score is lower in the presence of comorbidities in both individuals with & without asthma.