Cultural adaptation and evaluation of the measurement properties of the Berlin Questionnaire for Brazil

Abstract Objective to produce the Brazilian version of the Berlin Questionnaire (BQ) with evidence of reliability and validity. Method The cultural adaptation was carried out in the following stages: translation, synthesis of translations, back-translation, evaluation by an expert committee and pre-test with 30 participants. Next, the psychometric properties were evaluated with 104 participants who answered the Brazilian version of the BQ and underwent polysomnography (PSG). They also completed a sociodemographic and clinical characterization instrument and the Epworth Sleepiness Scale. Reliability was assessed concerning homogeneity of the items (internal consistency), and criterion validity was tested by comparing the Brazilian version of the BQ with the apnea and hypopnea index (AHI) obtained through PSG. Results The Brazilian version of the BQ presented evidence of semantic-idiomatic, conceptual and cultural equivalence, with good acceptability and feasibility. The findings demonstrated the reliability of the measure (Cronbach's alpha 0.74). The instrument presented a sensitivity of 81.3%, 86.2%, and 93.8%, and specificity of 82.5%, 54.7% and 50.0% for the risk stratification of obstructive sleep apnea according to the AHI ≥5, ≥15 and ≥ 30 events per hour, respectively. It should be emphasized that the BQ is a screening instrument for obstructive sleep apnea (OSA) and should be combined with a clinical evaluation and later confirmed with PSG. Conclusion The Brazilian version of the Berlin Questionnaire was reliable and valid in the study population.