Background: Berlin Questionnaire (BQ), an English language screening tool for obstructive sleep apnea (OSA) in primary care, has been applied in tertiary settings, with variable results.
Aims: Development of BQ Portuguese version and evaluation of its utility in a sleep disordered breathing clinic (SDBC).
Material and methods: BQ was translated using back translation methodology and prospectively applied, previously to cardiorespiratory sleep study, to 95 consecutive subjects, referred to a SDBC, with OSA suspicion. OSA risk assessment was based on responses in 10 items, organized in 3 categories: snoring and witnessed apneas (category 1), daytime sleepiness (category 2), high blood pressure (HBP)/obesity (category 3).
Results: In the studied sample, 67.4 % were males, with a mean age of 51 ± 13 years. Categories 1, 2 and 3 were positive in 91.6, 24.2 and 66.3 %, respectively. BQ identified 68.4 % of the patients as being in the high risk group for OSA and the remaining 31.6 % in the low risk. BQ sensitivity and specificity were 72.1 and 50 %, respectively, for an apnea-hipopnea index (AHI) > 5, 82.6 and 44.8 % for AHI > 15, 88.4 and 39.1 % for AHI > 30. Being in the high risk group for OSA did not influence significantly the probability of having the disease (positive likelihood ratio [LR] between 1.44-1.49). Only the items related to snoring loudness, witnessed apneas and HBP/obesity presented a statistically positive association with AHI, with the model constituted by their association presenting a greater discrimination capability, especially for an AHI > 5 (sensitivity 65.2 %, specificity 80 %, positive LR 3.26).
Conclusions: The BQ is not an appropriate screening tool for OSA in a SDBC, although snoring loudness, witnessed apneas, HBP/obesity have demonstrated being significant questionnaire elements in this population.