Eight-item screen for obstructive sleep apnea risk.
Source: Chung et al., Anesthesiology 2008.
What does the STOP-BANG score mean?
The STOP-BANG questionnaire is an eight-item tool developed by Chung and colleagues at the University of Toronto and published in Anesthesiology in 2008. It was designed for pre-operative screening of obstructive sleep apnea (OSA), a condition in which the upper airway repeatedly collapses during sleep, causing oxygen desaturation and arousal. Undiagnosed OSA carries significant peri-operative risk due to increased sensitivity to sedatives and opioids.
Each of the eight items contributes 1 point: Snoring (loud), Tiredness (daytime), Observed apnoea, blood Pressure (treated hypertension), BMI >35, Age >50, Neck circumference >40 cm, and Gender male. Total scores range from 0 to 8.
OSA affects an estimated 1 billion adults worldwide. It is significantly underdiagnosed, most people with moderate-to-severe OSA are unaware of the condition. Risk factors include male sex, obesity, large neck circumference, alcohol use, and anatomical features such as retrognathia or enlarged tonsils. OSA causes fragmented, unrestorative sleep, which leads to excessive daytime sleepiness, cognitive impairment, and increased cardiovascular risk including hypertension, atrial fibrillation, and stroke.
STOP-BANG is a sensitive screening tool but is not specific, many people with a score of 3 or above will not have OSA on formal testing. It should trigger a conversation with a doctor, not cause alarm.
Reference ranges
| Score | OSA risk | Suggested action |
|---|---|---|
| 0 – 2 | Low risk | Unlikely to have significant OSA |
| 3 – 4 | Intermediate risk | Discuss with GP; consider sleep study if symptomatic |
| 5 – 8 | High risk | Sleep study recommended; inform anaesthetist before surgery |
When should you see a doctor?
A STOP-BANG score of 3 or above, or any score combined with significant daytime sleepiness or witnessed apnoeas, warrants medical evaluation. If you are planning surgery, a high STOP-BANG score should be disclosed to your surgical and anaesthetic teams before the procedure. Effective CPAP therapy for confirmed OSA reduces cardiovascular risk, improves daytime alertness, and may lower blood pressure.
Frequently asked questions
What does STOP-BANG stand for?
STOP-BANG is an acronym: S = Snoring (do you snore loudly?), T = Tired (often tired/sleepy during daytime?), O = Observed (has anyone observed you stop breathing?), P = Pressure (treated or under treatment for high blood pressure?), B = BMI > 35, A = Age > 50, N = Neck circumference > 40 cm, G = Gender male. Each yes scores 1 point; maximum is 8.
What STOP-BANG score indicates high risk of sleep apnea?
A score of 0–2 is low risk for OSA. A score of 3–4 is intermediate risk. A score of 5–8 is high risk. For moderate-to-severe OSA specifically, a score of 5–8 has a sensitivity of about 83% and specificity of 56% in the original validation. Many anaesthesia departments use a score of 3 or above as the threshold for pre-operative sleep assessment.
What should I do if I have a high STOP-BANG score?
A high STOP-BANG score indicates you should discuss symptoms with your doctor, who may refer you for a sleep study (polysomnography or home sleep apnea testing). If you are having surgery, inform your anaesthetist, undiagnosed OSA significantly increases peri-operative risk. Effective treatment (CPAP, positional therapy, weight loss) can reverse most of the cardiovascular and metabolic consequences of OSA.