Discrepancies between the asthma control test and quality of life scores among biologic- and nonbiologic-treated asthma patients

Abstract

Background: In the era of asthma remission, quality of life (QOL) in daily activities is increasingly valued in addition to exacerbation control. However, the value of the Asthma Control Test (ACT) for assessing QOL remains unclear. This study compared the use of the ACT with the Asthma Quality of Life Questionnaire (AQLQ), with a focus on activity limitations.

Methods: We first analyzed biologic-treated asthma patients who were attending our institution and assessed the relationship between stable-phase ACT scores and AQLQ scores (including both overall scores and domain-specific scores). Receiver operating characteristic (ROC) curves were analyzed to identify the optimal ACT threshold for predicting favorable AQLQ scores. The findings were subsequently validated in a nonbiologic-treated group.

Results: Among biologic-treated patients (n = 69), the median ACT and AQLQ scores were 22 (IQR: 18-25) and 5.5 (IQR: 4.7-6.4), respectively. Discrepancies between the ACT and AQLQ were most evident in the activity limitation domain. Half of the patients with well-controlled ACT scores (≥20) reported difficulty with high-intensity exercise and avoiding environmental triggers, regardless of asthma duration. ROC curve analysis revealed that an ACT score ≥23 predicted favorable AQLQ activity limitation scores (≥6) (AUC: 0.83; sensitivity: 86 %; specificity: 76 %). Favorable scores were more commonly observed in the ACT ≥23 group than in the 20-22 group (p < 0.01). Similar findings were observed in the nonbiologic group (n = 123).

Conclusions: A cutoff score of ≥23 for the ACT may better reflect patient-perceived QOL than the conventional cutoff score of 20.