Validation of the dyspnoea-12 scale into Portuguese speaking COPD patients

Background and aims: Dyspnoea-12 assesses dyspnea based on the physical and affective components of the symptom. The aim of this study was to translate the Dyspnoea-12 into Portuguese, and to obtain validation data regarding the use of this tool in patients with chronic obstructive lung disease (COPD). Methods: The English version of the scale Dyspnoea-12 underwent a formal translation process into Portuguese as spoken in Brazil with the final version being called Dyspnoea-12-Pt. The latter was applied to 51 Portuguese-speaking patients with COPD (33 men; age: 66.4 ± 8.1 years; FEV₁: 48.7% ± 17.2% pred). Participants also completed the Medical Research Council dyspnea scale (MRC), the Baseline Dyspnea Index (BDI), the Hospital Anxiety and Depression scale, the Saint George's Respiratory Questionnaire (SGRQ) and performed spirometry and the Six-Minute Walk Test (6 MWT). Forty-five volunteers in stable clinical conditions also completed the Dyspnoea-12-Pt scale approximately 2 weeks after the first evaluation. Results: Dyspnoea-12-Pt showed significant correlations with the scales MRC (r = 0.494), BDI (r = −0.511), SGRQ (r = 0.806), Anxiety (r = 0.471), Depression (0.414) and walked distance in the 6 MWT (r = 0.329). Cronbach's alpha of Dyspnoea-12-Pt total was 0.921 and the intraclass correlation coefficient between sequential measures was 0.829. Conclusion: The scale Dyspnoea-12-Pt exhibits acceptable psychometric properties and may be used as an evaluation tool of dyspnea in Portuguese speaking COPD patients.