BACKGROUND: The present study validates and evaluates the sensitivity and 
specificity of four internationally popular questionnaires, translated into 
Chinese, for assessing suspected obstructive sleep apnea (OSA) patients, namely, 
the Berlin questionnaire, the ASA checklist, the STOP questionnaire and the 
STOP-BANG questionnaire. Their predictive values in OSA risks in patients 
presenting with OSA symptoms are examined. Questionnaires may be helpful in 
prioritizing polysomnography (PSG) and in treatment for the more severe cases.
METHODS: All patients attending our sleep laboratory for overnight PSG were 
recruited. They were asked to complete three questionnaires (Berlin, ASA 
checklist and STOP) 2 weeks before and on the same night as the PSG. STOP-BANG 
questionnaire, an extended STOP with demographic data, 'B'-body mass index 
(BMI), 'A'-age, 'N'-neck circumference and 'G'-gender was completed by our 
technologists using the patient's completed STOP.
RESULTS: A number of 141 patients were recruited. The sensitivities and 
specificities for STOP-BANG with cutoffs at PSG's RDI=5, RDI=15 and RDI=30 were 
81% to 86% and 34% to 57%, respectively. The high-risk group patients identified 
by STOP-BANG had significantly higher respiratory disturbance index and lower 
minimum oxygen saturation than the low-risk group patients.
CONCLUSION: Among the four questionnaires studied, STOP-BANG, with only eight 
questions and the highest sensitivity, is the best questionnaire of the four for 
OSA screening. This can potentially assist in prioritizing PSG and can be 
helpful in clinical or self-evaluation by the general public.