A study of the psychometric properties of the Brazilian...Portuguese version of Bronchiectasis Health Questionnaire.

INTRODUCTION AND OBJECTIVE: The Bronchiectasis Health Questionnaire (BHQ) is a simple, repeatable, and self-reporting health status questionnaire for bronchiectasis. This study aims to cross-culturally adapt the BHQ into Brazilian Portuguese and evaluate its measurement properties. METHODS: The participants answered the Saint George...s Respiratory Questionnaire (SGRQ) and the modified Medical Research Council (mMRC) scale for dyspnea. The Brazilian-Portuguese version of the Bronchiectasis Health Questionnaire (BHQ-Brazil) was used at baseline (test) and after 14 days (retest). The psychometric analyses included internal consistency, test-retest reliability, and construct validity: factorial validity, convergent validity, and discriminative validity, agreement, and ceiling and floor effects. RESULTS: The BHQ-Brazil demonstrated adequate internal consistency (Cronbach...s alpha...=...0.92) and substantial reliability (intraclass correlation coefficient...=...0.86; 95%CI: 0.79...0.90). The exploratory factorial analysis was considered suitable. All items presented a factorial load >0.40. The convergent validity of the BHQ-Brazil with mMRC was moderate (r...=......0.53, p...<...0.001), while concurrent validity with the SGRQ was strong (symptoms: r...=......0.72, activities: r...=......0.60, impact: r...=......0.60, total score: r...=......0.75, all p...<...0.001). The standard error of measurement was 4.81 points. The discriminative validity demonstrated that individuals with more pulmonary exacerbations, colonization by Pseudomonas aeruginosa, worst dyspnea, and a higher number of affected lung lobes presented the lowest quality of life. No floor or ceiling effects were observed. CONCLUSION: The BHQ-Brazil presents adequate measurement properties to evaluate the impact of bronchiectasis on health-related quality of life, and can be used in clinical and research settings.

Reproducibility, validity, and reliability of the incremental step test for subjects with moderate to severe asthma.

OBJECTIVE: We investigated the measurement properties of the incremental step test in subjects with moderate to severe asthma. METHODS: Subjects with moderate to severe persistent asthma were recruited from a tertiary university hospital specializing in treating severe asthma. All subjects performed one cardiopulmonary exercise test (CPET) and two incremental step tests (IST) in random sequences. Pulmonary gas exchange was measured during all exercise tests. The measurement properties investigated were reliability by intraclass correlation coefficient (ICC), measurement error by the standard error of measurement and minimum detectable difference, construct validity by Pearson's correlation, and interpretability by the ceiling and floor effects. RESULTS: Fifty subjects (38 females, mean [SD], age 43.7 [11.6] yr, % FEV1 70 [14.3], BMI 28.5 [5.3] kg/m2) completed the study. The peak oxygen uptake (peak VO2) for the CPET was 27.6 [±6.8] ml/kg/min, for the first IST was 22.3 [±5.3] ml/kg/min and for the second IST was 23.3 [±5.3] ml/kg/min. The IST presented excellent reliability (ICC=0.93, CI95% 0.88-0.96), very good measurement error (2.5%), and construct validity for peak VO2 measurement compared to the CPET (r = 0.85; p < 0.001) to assess exercise capacity in subjects with moderate to severe asthma, with appropriate ceiling (10%) and floor (0%) effects. CONCLUSION: The IST presented excellent reliability and very good measurement error and validity to assess exercise capacity in subjects with moderate to severe asthma, without ceiling or floor effects.