Why use it

Obstructive sleep apnea affects 26–34% of adults in the general population and remains undiagnosed in approximately 82% of men and 93% of women with moderate-to-severe disease. Undiagnosed OSA significantly increases perioperative risk — including difficult airway, failed intubation, postoperative respiratory failure, cardiac arrhythmias, and ICU admission. The STOP-BANG enables rapid, evidence-based identification of patients who require formal sleep evaluation (polysomnography or home sleep apnea testing), CPAP titration, or enhanced perioperative monitoring. It requires no equipment or laboratory results, can be self-administered, and performs comparably to more complex multivariable prediction tools.

About

The STOP-BANG questionnaire is a validated eight-item screening tool for obstructive sleep apnea (OSA) developed by Chung and colleagues at the University of Toronto, published in Anesthesiology in 2008. It was originally developed for the preoperative setting — where undiagnosed OSA poses significant perioperative risk — and has since been extensively validated for general adult populations, bariatric surgery, cardiology, and primary care settings. The acronym STOP-BANG represents: Snoring (loud), Tired (daytime), Observed apnea, blood Pressure (high), BMI (>35 kg/m²), Age (>50 years), Neck circumference (>40 cm), and Gender (male). Each item is answered Yes or No, yielding a total score of 0–8. Scores are stratified into three risk categories: Low (0–2), Intermediate (3–4), and High (5–8). For moderate-to-severe OSA (AHI ≥15/hr), the STOP-BANG has a sensitivity of 93% and a specificity of 43% in the general population. Sensitivity increases to 97% at scores ≥3, making it highly useful as a screening (rule-out) test. A high score (5–8) has a positive predictive value of approximately 75–90% for severe OSA. The questionnaire is simple, quick to administer (<2 minutes), freely available, and has been translated and validated in over 20 languages. It is endorsed by the American Society of Anesthesiologists (ASA) and the Society of Anesthesia and Sleep Medicine (SASM) as a perioperative OSA screening instrument.

When to use

Preoperative assessment of adult patients scheduled for elective surgery — to identify those requiring enhanced perioperative airway management and monitoring
Primary care or outpatient medicine screening for OSA in adults with risk factors (obesity, hypertension, snoring, excessive daytime sleepiness)
Cardiology and heart failure clinics — OSA affects 50–60% of patients with heart failure and atrial fibrillation; undiagnosed OSA worsens cardiovascular outcomes
Bariatric surgery evaluation — OSA prevalence exceeds 70% in morbidly obese patients
Sleep medicine clinic triage to prioritize patients for polysomnography
Workplace and occupational health screening for safety-sensitive roles (commercial drivers, pilots, heavy machinery operators)
Patients presenting with resistant hypertension (OSA accounts for 30–40% of cases)
NOT validated for children or adolescents — use pediatric OSA screening tools instead
NOT a diagnostic tool — a positive screen (score ≥3) requires formal sleep evaluation for diagnosis

Formula

STOP-BANG SCORE = Number of YES answers (0–8) S — Snoring: Do you SNORE loudly (louder than talking, loud enough to be heard through closed doors)? T — Tired: Do you often feel TIRED, fatigued, or sleepy during the daytime? O — Observed: Has anyone OBSERVED you stop breathing during your sleep? P — Pressure: Do you have or are you being treated for high blood PRESSURE? B — BMI: BMI >35 kg/m²? A — Age: Age >50 years? N — Neck: NECK circumference >40 cm (>15.7 inches)? G — Gender: GENDER = Male? Risk Stratification: 0–2: Low Risk — OSA unlikely 3–4: Intermediate Risk — moderate suspicion for OSA 5–8: High Risk — high probability of moderate-to-severe OSA Sensitivity for moderate-to-severe OSA (AHI ≥15): Score ≥3: ~93–97% | Score ≥5: ~73–83% Specificity for moderate-to-severe OSA: Score ≥3: ~43–55% | Score ≥5: ~70–80%

Pearls & pitfalls

A STOP-BANG score ≥3 has a sensitivity of approximately 93–97% for moderate-to-severe OSA (AHI ≥15/hr) — it is an excellent rule-out tool at this threshold.
Scores ≥5 with a positive STOP component (any combination of snoring + sleepiness + observed apnea + hypertension) have a particularly high positive predictive value for severe OSA and should be prioritized for sleep referral.
Neck circumference threshold differs by sex in some clinical contexts: >40 cm for all adults in the original STOP-BANG; some updated guidelines use >43 cm for males and >41 cm for females for improved specificity.
BMI >35 kg/m² is the original STOP-BANG threshold; however, some clinical versions lower this to >30 or even >28 kg/m² for Asian populations, who have higher OSA risk at lower BMI values.
Male sex adds +1 point in the original STOP-BANG. This reflects the approximately 2-fold higher prevalence of OSA in men. However, postmenopausal women have substantially higher risk than premenopausal women — some experts recommend adjusting female scoring in clinical contexts.
The STOP-BANG does not assess for central sleep apnea (CSA) — which occurs in up to 30–40% of patients with advanced heart failure, stroke, or on chronic opioids — and scores low in these patients despite significant sleep-disordered breathing.
A STOP-BANG of 0 has a very high negative predictive value (NPV) for moderate-to-severe OSA (~99%) — OSA can be effectively excluded at this score in most clinical contexts.
The addition of serum bicarbonate (HCO₃⁻ >28 mEq/L) to a STOP-BANG score ≥3 substantially improves specificity for severe OSA (OHS — obesity hypoventilation syndrome) — consider measuring arterial or venous blood gas in high-risk patients.
OSA is bidirectionally associated with atrial fibrillation, resistant hypertension, type 2 diabetes, metabolic syndrome, and depressive disorders — positive screens should prompt cardiovascular risk factor assessment.
Even patients with low STOP-BANG scores who have excessive daytime sleepiness (Epworth Sleepiness Scale ≥11) should be referred for formal evaluation — the STOP-BANG may underperform in patients with CSA or severe insomnia.

Next steps

STOP-BANG 0–2 (Low Risk): OSA unlikely. Routine perioperative management. No formal sleep evaluation required unless clinical features suggest otherwise (e.g., witnessed apneas, marked daytime sleepiness). STOP-BANG 3–4 (Intermediate Risk): Moderate suspicion for OSA. Formal sleep evaluation recommended (polysomnography or home sleep apnea test if suspicion for moderate-to-severe OSA without co-morbidities). Preoperatively: inform anesthesia team; post-operative monitoring in a monitored setting for major surgery. Consider empirical CPAP if surgery is urgent. STOP-BANG 5–8 (High Risk): High suspicion for moderate-to-severe OSA. Strongly recommend formal sleep study before elective surgery if timing permits. Preoperatively: alert anesthesia and post-anesthesia care team; avoid sedating premedication; plan for difficult airway preparedness; post-operative monitoring in a monitored or HDU setting. Initiate CPAP/APAP therapy after polysomnography confirmation.

Evidence

Chung F et al. STOP questionnaire: a tool to screen patients for obstructive sleep apnea. Anesthesiology. 2008;108(5):812-821. PMID:18431116. Derivation n=2467 surgical patients. Sensitivity for AHI ≥5: 84%; for AHI ≥15: 93%; for AHI ≥30: 100%. Chung F et al. Validation of the Berlin questionnaire and American Society of Anesthesiologists checklist as screening tools for obstructive sleep apnea in surgical patients. Anesthesiology. 2008;108(5):822-830. Nagappa M et al. Validation of the STOP-Bang Questionnaire as a Screening Tool for Obstructive Sleep Apnea among Different Populations: A Systematic Review and Meta-Analysis. PLoS One. 2015;10(12):e0143697. PMID:26658438. Meta-analysis of 17 studies: sensitivity 90% for AHI ≥5, 94% for AHI ≥15, 96% for AHI ≥30.

References

Chung F et al. STOP questionnaire: a tool to screen patients for obstructive sleep apnea. Anesthesiology. 2008;108(5):812-821. — link
Nagappa M et al. Validation of the STOP-Bang Questionnaire as a Screening Tool for Obstructive Sleep Apnea among Different Populations: A Systematic Review and Meta-Analysis. PLoS One. 2015;10(12):e0143697. — link
Chung F et al. Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients with Obstructive Sleep Apnea. Anesth Analg. 2016;123(2):452-473. — link
American Society of Anesthesiologists Task Force. Practice Guidelines for the Perioperative Management of Patients with OSA. Anesthesiology. 2014;120(2):268-286. — link
Abrishami A et al. Predicting difficult mask ventilation and difficult intubation — the STOP-BANG questionnaire. Anesthesiology. 2010. — link

STOP-BANG Questionnaire

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