Translation, cross-cultural adaptation, reliability, and construct validity of the Brazilian Portuguese version of the Basic Psychological Needs in Exercise Scale

This study aims to translate, culturally adapt, and test the reliability and construct validity of the Brazilian Portuguese version of the Basic Psychological Needs in Exercise Scale (BPNES) for patients with Chronic Obstructive Pulmonary Disease (COPD) and Interstitial Lung Disease (ILD). Pulmonary function, dyspnea, quality of life, anxiety and depression symptoms, and functional status were assessed, and two raters independently applied the BPNES. BPNES scores were compared between raters' applications to assess reliability, internal consistency, and agreement. Confirmatory Factor Analysis was used to assess the factor structure of the BPNES model.Results: 59 patients were included (61% with COPD and 39% with ILD). BPNES factor scores were not significantly different between raters' assessments (p > 0.05). The internal consistency was 0.70 for autonomy, 0.76 for competence, and 0.80 for relatedness. Inter-rater and test-retest reliability were good to very good for autonomy (ICC = 0.78, 95%CI 0.62-0.87; ICC = 0.75, 95%CI 0.57-0.86, respectively), competence (ICC = 0.81, 95%CI 0.68-0.89; ICC = 0.65, 95%CI 0.43-0.80, respectively), and relatedness (ICC = 0.79, 95%CI 0.65-0.88; ICC = 0.70, 95%CI 0.50-0.83, respectively). Significant correlations were observed between BPNES factors and quality of life, anxiety, depression, and functional status. In conclusion, this study confirmed the reliability and construct validity of the Brazilian Portuguese version of the BPNES in patients with COPD and ILD.