Reliability and validity of the London Chest Activity of Daily Living scale for adults with asthma.

Introduction Dyspnoea during activities of daily living (ADL) is frequently reported by adults with asthma. However, instruments that specifically assess that in people with asthma have not yet been validated. Objectives: To investigate the validity and reliability, including standard error of measurement (SEM) and Minimum Detectable Change (MDC), of the London Chest Activity of Daily Living (LCADL) scale for adults with asthma. Methods: Adults with asthma answered the LCADL scale which was performed twice by the same rater. Spirometry, 6-minute walk test (6MWT), St George's Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) dyspnoea scale, Asthma Quality of Life questionnaire (AQLQ), Asthma Control Test (ACT), and Glittre-ADL test were assessed. For statistical analyses, Spearman correlation, Wilcoxon test, Intraclass Correlation Coefficient (ICC), Cronbach's alpha coefficient, SEM, MDC were performed. Results: Seventy participants were included (30% men, 44 ± 15 years old, BMI 27[23-31]kg/m 2 , FEV 1 80 ± 17%predicted). For convergent validity, the LCADL scale was moderately correlated with SGRQ, AQLQ, and Glittre-ADL (r= 0.57, -0.46, and 0.41 respectively; P < 0.0001). The LCADL scale correlated weakly with the mMRC scale, ACT, and spirometry measures (-0.23 < r < 0.39; P < 0.001). Weak to strong correlations between the domains of the LCADL scale and the domains of the SGRQ were observed (0.26 < r < 0.73; P < 0.001). There was no difference between the test-retest of the scale (p= 0.65) and reliability analysis shows an ICC 3 of 0.71, a Cronbach's alpha coefficient of 0.87, an SEM of 6.23 points, and an MDC of 17.27 points. Conclusion: The LCADL scale is valid and reliable for assessing dyspnoea during ADL in adults with asthma.