Are paper-based and telephone interview equivalent modes of administrating the COPD Assessment Test, the Functional Assessment of Chronic Illness-Fatigue Subscale and the St. George's Respiratory Questionnaire?

Abstract

Introduction: The COVID-19 pandemic brought numerous challenges, and novel methods for monitoring symptoms and quality of life of people with chronic obstructive pulmonary disease (COPD) are now required. The COPD Assessment Test (CAT), the Functional Assessment of Chronic Illness-Fatigue-Subscale (FACIT-FS) and the St. George’s Respiratory Questionnaire (SGRQ) paper-based measures are commonly applied in clinical practice. Nevertheless, it is unknown if follow-up monitoring using telephone interview is equivalent to in person paper-based forms. Objectives: This study aimed to compare validity and reliability of follow-up monitoring using CAT, FACIT-FS and SGRQ when administered by paper-based forms and telephone interview in people with COPD. Methods: Data from an observational 6-month prospective study including people with stable COPD followed up monthly was analysed. At follow-up six, participants answered to CAT, FACIT-FS and SGRQ questionnaires in person during a home visit and by telephone with an interval maximum of 48-hours. Participants were randomly selected to answer first to the paper version followed by telephone or vice versa. Validity was assessed with the Spearman correlation (rs). Reliability measures included Intraclass Correlation Coefficient (ICC), standard error of measurement (SEM), Bland and Altman 95% Limits of Agreement (BA95%LoA) and internal consistency with Cronbach’s alpha. Results: Twenty-one people with COPD (17 men; 65 ± 8 years; FEV1 65.1 ± 21.2%predicted) were included. Strong positive correlations (rs 0.85-0.98, p < 0.001) between the scores of CAT, FACIT-FS and SGRQ applied by both methods were found. Test-retest reliability was excellent, with an ICC of 0.94 (95%CI: 0.85-0.98), 0.99 (95%CI: 0.96-0.99) and 0.98 (95%CI: 0.94-0.99) for CAT, FACIT-FS and SGRQ total scores. The SEM showed a low level of associated measurement error, ranging between 0.40 in FACIT-FS to 4.68 in SGRQ symptoms subscale. The BA95%LoA ranged from -1.13 to 0.80, illustrating a good level of agreement between both administration modes, with no evidence of bias. The internal consistency was similar between paper and telephone versions (Cronbach’s alpha of 0.72/0.71, 0.34/0.21 and 0.85/0.86 for CAT, FACIT and SGRQ total scores). Conclusions: In a context where personal contact should be reduced, telephonic administration of CAT, FACIT-FS and SGRQ showed to be a valid and reliable alternative approach to paper-based forms for monitoring symptoms and health-related quality of life in people with COPD.