Abstract
Background: The Respiratory Symptoms Questionnaire (RSQ) is a novel, 4-item patient-reported diagnosis-agnostic tool designed to assess the frequency of respiratory symptoms and their impact
on activity, without specifying a particular diagnosis. Our objective was to examine its validity in patients with asthma and/or chronic obstructive pulmonary disease (COPD).
Methods: Baseline data were randomly sampled from patients who completed the RSQ in the NOVELTY study
(NCT02760329). The total sample (N=1530) comprised three randomly selected samples (N=510 each) from each physician-assigned diagnostic group (asthma, asthma+COPD,
COPD). The internal consistency and structural validity of the RSQ were evaluated using exploratory and confirmatory factor analyses; psychometric performance was observed using Classical Test Theory and Item Response Theory analyses.
Results: For the total sample, the mean RSQ score was 5.6 (SD 4.3; range: 0-16). Irrespective of diagnosis, the internal consistency of items was uniformly adequate (Cronbach’s alphas range: 0.76-
0.80). All items had high factor loadings, and structural characteristics of the measure were invariant across groups. Using the total sample, RSQ items informatively covered the theta score range of –2.0 to 2.8, with discrimination coefficients for individual items being high-to-very high (1.7-2.6). Strong convergent correlations were observed between the RSQ and St George’s Respiratory Questionnaire
(SGRQ; 0.77, p<0.001).
Conclusions: The RSQ is a valid, brief, patient-reported tool for assessing respiratory symptoms in patients across the whole spectrum of asthma and/or COPD, rather than using different
questionnaires for each diagnosis. It can be used for monitoring respiratory symptoms in clinical practice, clinical trials and real-world studies.
Original language | English |
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Article number | 00828-2020 |
Number of pages | 11 |
Journal | ERJ Open Research |
Volume | 7 |
Issue number | 1 |
Early online date | 1 Feb 2021 |
DOIs | |
Publication status | Published - 2021 |
Bibliographical note
ACKNOWLEDGEMENTSThe authors wish to acknowledge the work of the NOVELTY study investigators, who are listed in full in the supplementary material, and Sharon MacLachlan (Evidera, London, UK), who participated in the analysis of sections of the data. Medical writing support, under the direction of the authors, was provided by Lauren McNally, MSci, CMC Connect, McCann Health Medical Communications, and was funded by AstraZeneca, Cambridge, UK, in accordance with Good Publication Practice (GPP3) guidelines (Ann Intern Med 2015; 163: 461–464). Support statement: The NOVELTY study is funded by AstraZeneca