Association between Childhood Asthma Control Test scores and lung pathophysiologic indicators in longitudinal measurements

Xiaoxing Cui; Xiaojian Zhou; Zhen Li; Yanbo Teng; Lili Lin; Qian Wang; Jianguo Hong; Yan Lin; Marilyn S Black; Michael H Bergin; Junfeng Zhang

doi:10.21037/jtd-22-1383

Association between Childhood Asthma Control Test scores and lung pathophysiologic indicators in longitudinal measurements

J Thorac Dis. 2023 Aug 31;15(8):4207-4215. doi: 10.21037/jtd-22-1383. Epub 2023 Jul 28.

Authors

Xiaoxing Cui^#¹, Xiaojian Zhou^#², Zhen Li², Yanbo Teng³, Lili Lin², Qian Wang², Jianguo Hong², Yan Lin⁴, Marilyn S Black⁵, Michael H Bergin⁶, Junfeng Zhang^{1

3

4}

Affiliations

¹ Nicholas School of the Environment, Duke University, Durham, NC, USA.
² Department of Pediatrics, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.
³ Global Health Research Center, Duke Kunshan University, Kunshan, China.
⁴ Duke Global Health Institute, Durham, NC, USA.
⁵ Chemical Safety Research, Underwriters Laboratories Inc., Marietta, GA, USA.
⁶ Department of Civil and Environmental Engineering, Duke University, Durham, NC, USA.

^# Contributed equally.

Abstract

Background: Childhood Asthma Control Test (C-ACT) is a well-validated questionnaire for asthma controls among 4-11 years old children. This study aims to examine if longitudinal C-ACT score changes could also reflect lung pathophysiologic changes.

Methods: Thirty-seven children (43% female) aged 5 to 10 years old with mild or moderate asthma were followed up for 6 weeks with bi-weekly assessments of C-ACT, airway mechanics, lung function and respiratory inflammation. Associations of longitudinal changes in C-ACT score with lung pathophysiologic indicators were evaluated using linear mixed-effects models.

Results: A two-point worsening of total C-ACT score (sum of child and caregiver-reported) was associated with significant decreases in forced expiratory volume during the 1^st second (FEV₁) by 1.7% (P=0.04) and forced vital capacity (FVC) by 1.6% (P=0.01) and increased total airway resistance [airway resistance at 5 Hz (R₅)] by 3.8% (P=0.05). A two-point worsening in child-reported score was significantly associated with 3.1% and 2.5% reductions in FEV₁ and FVC, respectively, and with increases in R₅ by 6.5% and large airway resistance [airway resistance at 20 Hz (R₂₀)] by 5.5%. In contrast, a two-point worsening of caregiver-reported score was associated with none of the concurrent lung pathophysiologic measurements. Worsening of total C-ACT score was significantly associated with increased respiratory inflammation [fractional exhaled nitric oxide (FeNO)] in a subset (n=23) of children without eosinophilic airway inflammation. C-ACT scores were associated with none of the small airway measures.

Conclusions: In children with mild or moderate asthma, longitudinal C-ACT score changes could reflect acute changes in large airway resistance and lung function. Measures of small airway physiology would provide valuable complementary information for asthma control. Asthma phenotype may affect whether C-ACT score could reflect respiratory inflammation.

Keywords: Airway mechanics; lung function; respiratory inflammation; small airway.