Reliability and validity of dyspnea numeric rating scales as a patient-reported outcome in pulmonary rehabilitation of COPD

Patient-reported outcomes (PRO’s) are important in clinical decision making. Common PRO’s for COPD may provide limited insight into specific aspects of dyspnea or can be time-consuming to administer. We evaluated the use of 4 Dyspnea Numeric Rating Scales (NRS), measuring intensity and unpleasantness of dyspnea during both rest and activity as a PRO in pulmonary rehabilitation (PR) of COPD patients.Patients (n=379, FEV1%=55±17) completed Dyspnea NRS, COPD Assessment Test (CAT), Saint-George Respiratory Questionnaire (SGRQ), 2 weeks before (T0), at the start (T1) and end (T2) of PR. Spirometry and 6 min walking test (6MWT) was performed at T1 and T2. Global Rating of Change (GRC) was provided at T2. We assessed factor structure, reliability and validity of the NRS, assessed sensitivity to change, and estimated MCID.Single- and 2-factor solutions (rest and activity), explained 69% vs. 93% of variance, and had good internal consistency (αtotal=.85, αrest=.92, αactivity=.93). NRStotal had good test-retest reliability (ICC=.74). Correlations with SGRQ were high (rtotal=.75, rrest=.61, ractivity=.67); comparable to CAT-SGRQ correlations (r=.78). Change in NRS was associated with change in CAT (r=.52) and SGRQ (r=.51). None of the PRO’s correlated with changes in 6MWT or FEV1. NRS, CAT and SGRQ showed similar sensitivity to change (d=.74, .81, .76). Criterion- and reliability-based methods led to similar MCID estimates for NRS (GRC: 3-5, SE...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Physiotherapists Source Type: research