How this instrument works
STOP-Bang combines two four-item groups into one score. STOP covers what a patient reports: loud Snoring, daytime Tiredness, Observed pauses in breathing during sleep, and high blood Pressure. Bang covers four simple physical facts: BMI over 35, Age over 50, Neck circumference over 40 cm, and male sex. Each of the eight scores one point when present, for a total from 0 to 8, with higher totals indicating a greater probability of obstructive sleep apnea.
Frank Chung and colleagues built the STOP half first, publishing it in Anesthesiology in 2008 as a quick preoperative screen — anesthesiologists needed a fast way to flag patients whose undiagnosed sleep apnea might complicate surgery and recovery. A follow-up study in the British Journal of Anaesthesia in 2012 added the four Bang criteria and validated the combined eight-item version against sleep studies, showing that higher scores tracked with a higher probability of moderate or severe disease. The tool was built and validated for pre-surgical screening first, though it has since spread well beyond the operating room into general sleep-clinic and primary-care use.
The common convention splits the range into three bands: 0-2 is low risk, 3-4 is intermediate, and 5-8 is high risk for obstructive sleep apnea. STOP-Bang is deliberately generous with points — it would rather flag someone who turns out fine than miss someone who needs a sleep study — so a high score is a strong reason to pursue formal testing, not a diagnosis by itself; only overnight polysomnography or a comparable study can confirm obstructive sleep apnea.
- Answer the four STOP questions — Snoring, Tiredness, Observed apnea, and high blood Pressure — Yes or No.
- Answer BMI over 35 and Age over 50 based on the patient's current measurements.
- Answer Neck circumference over 40 cm, measured at the widest point.
- Answer Male, then read the total, 0 to 8, and its risk band.
Worked example — three totals across the range
Loud snoring, daytime tiredness, observed apnea, and high blood pressure all present, with none of the four Bang criteria: 1 + 1 + 1 + 1 + 0 + 0 + 0 + 0 = 4, landing in the intermediate-risk band (3-4).
Every one of the eight criteria present — all four STOP items plus BMI over 35, age over 50, a neck over 40 cm, and male sex — sums to 8, the maximum score and squarely in the high-risk band (5-8). At the other extreme, a patient who answers Yes only to Male and No to the remaining seven questions scores 0 + 0 + 0 + 0 + 0 + 0 + 0 + 1 = 1, in the low-risk band (0-2).
Questions
What do the STOP-Bang risk bands mean?
A score of 0-2 is generally read as low risk for obstructive sleep apnea, 3-4 as intermediate, and 5-8 as high risk, per the validation work by Chung and colleagues. Higher scores correlate with a higher probability of moderate-to-severe disease on formal sleep testing, but the score estimates probability — it does not replace a sleep study for anyone who needs a confirmed diagnosis.
What's the difference between STOP and STOP-Bang?
STOP is the original four-item questionnaire — snoring, tiredness, observed apnea, and blood pressure — published by Chung and colleagues in Anesthesiology in 2008. STOP-Bang adds four more objective criteria (BMI, age, neck size, sex), validated in a 2012 follow-up study, extending the range from 0-4 to 0-8 and improving how well the score separates low-risk patients from those likely to have moderate or severe sleep apnea.
Was STOP-Bang designed for surgery patients specifically?
Yes, originally — it was built and validated as a preoperative screen, so anesthesiologists could flag patients at risk of sleep-apnea-related complications like difficult airway management or post-operative respiratory depression before a procedure. It has since been adopted more broadly in sleep medicine and primary care, though its strongest validation evidence remains in the surgical population it was built for.
Does a high STOP-Bang score confirm sleep apnea?
No — it flags a high probability worth investigating, not a confirmed diagnosis. Obstructive sleep apnea is formally diagnosed with polysomnography, an overnight sleep study that directly measures breathing pauses and oxygen levels. A high score is a strong, well-validated reason to pursue that testing, not a substitute for it.
Why does male sex count as a risk factor on its own?
Because population studies consistently find obstructive sleep apnea more common in men than in women at a given age and body size, independent of the other seven factors — a pattern that held up in the Bang validation data. It's a statistical association, not a rule about any individual; a woman can score high through the other seven criteria and still carry meaningful risk.
How is neck circumference measured for this score?
At the widest point of the neck, typically just below the larynx, with the patient standing and looking straight ahead. A measurement over 40 cm (about 15.75 inches) counts as one point — it's used as a proxy for upper-airway soft tissue that can narrow the airway during sleep, which is harder to assess directly without imaging.
References
- Chung F et al. STOP questionnaire: a tool to screen patients for obstructive sleep apnea. Anesthesiology, 2008 (PubMed)
- Chung F et al. High STOP-Bang score indicates a high probability of obstructive sleep apnea. Br J Anaesth, 2012 (PubMed)
- American Academy of Sleep Medicine — What Is Sleep Apnea?
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.