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

59 patients were included (61% with COPD and 39% with ILD). BPNES factor scores were not significantly different between raters' assessments ( > 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.