Inter-Day Test–Retest Reproducibility of the CAT, CCQ, HADS and EQ-5D-3L in Patients with Severe and Very Severe COPD

Henrik Hansen,1 Nina Beyer,2 Anne Frølich,3,4 Nina Godtfredsen,1,2 Theresa Bieler5 1Department of Respiratory Medicine, Respiratory Research Unit, Hvidovre University Hospital, Hvidovre, Denmark; 2Institute for Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; 3Innovation and Research Centre for Multimorbidity, Slagelse Hospital, Slagelse, Denmark; 4Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark; 5Department of Physical & Occupational Therapy, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, DenmarkCorrespondence: Henrik HansenDepartment of Respiratory Medicine, Respiratory Research Unit, Hvidovre University Hospital, Kettegård Alle 30, Center 2, Section 255, Hvidovre, 2650, DenmarkTel +45 28946780Email henrik.hansen.09@regionh.dkIntroduction: In patients with COPD, the COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ), Hospital Anxiety and Depression Scale (HADS) and EuroQol 5D (EQ-5D-3L) are widely used patient reported outcome measures (PROMs) of respiratory symptoms, anxiety, depression and quality of life. Despite established validity, responsiveness and minimal important change (MIC), the reproducibility and especially important agreement parameters remain unreported in these frequently used PROMs. The aim of this study was to investigate the inter-day test–retest reliability and agreement of the CAT, CCQ, HADS and EQ-5D-3L in patients with severe and very severe COPD (FEV1 < 50%) eligible for hospital-based pulmonary rehabilitation.Patients and Methods: Fifty patients (22 females, mean [SD] age 67 [9] yrs.; FEV1 32[9] %; 6-minute walk distance 347 [102] meters; CAT 21 [6] points; BMI: 26 [6] kg/m2) completed the questionnaires (CAT, CCQ, HADS, EQ-5D-3L) in combination with functional performance test instructed by one assessor on test-day one (T1) and by another assessor 7– 10 days later on test-day two (T2).Results: The inter-day test–retest reliability ICC was 0.88 (LL95CI: 0.80) for CAT; 0.69 (LL95CI: 0.46) for CCQ; 0.86 (LL95CI: 0.75) and 0.90 (LL95CI: 0.82) for HADS-anxiety (A) and depression (D) and 0.87 (LL95CI: 0.76) for EQ-5D-VAS. The corresponding agreements within a single measurement (standard error of measurement, SEM) and for repeated measurement errors (smallest real difference, SRD) were respectively 2.1 and 2.9 points for CAT; 0.5 and 0.7 points for CCQ total; 1.3 and 1.9 points for HADS-A; 0.9 and 1.3 points for HADS-D and 6.8 and 9.7 VAS-score for EQ-5D-3L, respectively. Ceiling/flooring effect was present in < 5% for all questionnaires.Conclusion: In patients with severe and very severe COPD, the CAT, CCQ, HADS and EQ-5D-3L questionnaires presented moderate to excellent inter-day test–retest reliability, and no floor or ceiling effect was documented for any of the questionnaires. Only CAT and HADS had an acceptable SRD below the established MIC for assessing change over time on group level, and none of the PROMS were fit to assess individual changes over time.Keywords: COPD, questionnaires, patient reported outcomes, reproducibility of results