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.