Abstract
Background he 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 he 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.
Footnotes
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Conflict of interest: N. Karlsson is an employee of AstraZeneca.
Conflict of interest: M.J. Atkinson reports payment as an independent consultant to Evidera for activities contracted by AstraZeneca associated with psychometric evaluation of the RSQ, outside the submitted work.
Conflict of interest: H. Müllerová is an employee of AstraZeneca.
Conflict of interest: Dr. Alacqua reports she is an AstraZeneca employee.
Conflict of interest: Dr. Keen reports and Christina Keen is a permanent full time employee at AstraZeneca.
Conflict of interest: Dr. Hughes reports personal fees from AstraZeneca UK, during the conduct of the study;.
Conflict of interest: Dr. Janson reports personal fees from AstraZeneca, personal fees from Chiesi, personal fees from GlaxoSmithKline, personal fees from Boehringer Ingelheim, personal fees from Novartis, personal fees from Teva, outside the submitted work;.
Conflict of interest: Dr. Make reports grants, non-financial support and other from Astra Zeneca, non-financial support from Spiration, grants, non-financial support and other from Glaxo Smith Kline, grants, non-financial support and other from Sunovion, other from Mt. Sinai, other from Web MD, other from National Jewish Health, other from Novartis, other from American College of Chest Physicians, other from Projects in Knowledge, other from Hybrid Communications, grants from Pearl Research, other from Medscape, other from Verona, other from Boehringer Ingelheim, other from Theravance, other from Ultimate Medical Academy, non-financial support and other from Circassia, personal fees and non-financial support from Third Pole, non-financial support and other from Shire, non-financial support and other from Phillips, other from Eastern Pulmonary Society, other from Catamount Medical, other from Science 24/7, other from Eastern VA Medical Center, other from Academy Continued Health Care Learning, grants from NHLBI, personal fees from Takeda, other from Wolters Kluwer Health, outside the submitted work;.
Conflict of interest: Dr. Price reports grants from AKL Research and Development Ltd, personal fees from Amgen, grants and personal fees from AstraZeneca, grants and personal fees from Boehringer Ingelheim, grants from British Lung Foundation, grants and personal fees from Chiesi, grants and personal fees from Circassia, personal fees from Cipla, personal fees from GlaxoSmithKline, personal fees from Kyorin, personal fees from Merck, grants and personal fees from Mylan, grants and personal fees from Mundipharma, grants and personal fees from Napp, grants and personal fees from Novartis, grants and personal fees from Pfizer, grants and personal fees from Regeneron Pharmaceuticals, grants from Respiratory Effectiveness Group, grants and personal fees from Sanofi Genzyme, grants and personal fees from Teva, grants and personal fees from Theravance, grants from UK National Health Service, grants and personal fees from Zentiva (Sanofi Generics), non-financial support from Efficacy and Mechanism Evaluation programme, non-financial support from Health Technology Assessment, outside the submitted work; and stock/stock options from AKL Research and Development Ltd which produces phytopharmaceuticals; and owns 74% of the social enterprise Optimum Patient Care Ltd (Australia and UK) and 74% of Observational and Pragmatic Research Institute Pte Ltd (Singapore).
Conflict of interest: H.K. Reddel reports that this study is funded by AstraZeneca. She received reimbursement from AstraZeneca for time spent working on the study but not for manuscript preparation. Medical writing support was provided by AstraZeneca, as stated in the support statement. She also reports a data and safety monitoring board (DSMB) and advisory boards for, and and an unconditional research grant and an honorarium for providing independent medical education from AstraZeneca; a DSMB and advisory boards for, and an unconditional research grant, an honorarium for providing independent medical education and a grant for a registry from GlaxoSmithKline; a DSMB for Merck; a DSMB and an advisory board for, and a grant for a registry from Novartis; an honorarium for providing independent medical education from Teva; an honorarium for providing independent medical education from and an advisory board for Boehringer Ingelheim; and advisory boards for Sanofi Genzyme and Chiesi, all outside the submitted work.
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- Received November 6, 2020.
- Accepted November 12, 2020.
- Copyright ©ERS 2020
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