Stop Bang Score Calculator

Screen for obstructive sleep apnea risk using the STOP-BANG questionnaire. Enter values for instant results with step-by-step formulas.

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Formula

STOP-BANG Score = S + T + O + P + B + A + N + G (each 0 or 1, total 0-8)

Eight yes/no questions scored 0-1 each. STOP = Snoring, Tiredness, Observed apnea, blood Pressure. BANG = BMI>35, Age>50, Neck>40cm, Gender (male). Score 0-2 = Low risk, 3-4 = Intermediate risk, 5-8 = High risk for OSA.

Worked Examples

Example 1: Preoperative Patient with High Risk

Problem: A 55-year-old male patient scheduled for knee surgery reports loud snoring, daytime tiredness, and his wife has observed him stop breathing during sleep. He has treated hypertension, BMI of 38, and neck circumference of 43 cm.

Solution: STOP-BANG Score:\nS (Snoring) = Yes (1)\nT (Tired) = Yes (1)\nO (Observed) = Yes (1)\nP (Pressure) = Yes (1)\nB (BMI > 35) = Yes (1)\nA (Age > 50) = Yes (1)\nN (Neck > 40cm) = Yes (1)\nG (Male) = Yes (1)\nTotal = 8/8

Result: STOP-BANG Score: 8/8 (High Risk) - Very high probability of severe OSA. Polysomnography and anesthesiology consultation essential before surgery.

Example 2: Low Risk Screening Patient

Problem: A 35-year-old female patient presents for routine health screening. She does not snore, has no daytime sleepiness, no observed apneas, normal blood pressure, BMI of 24, and neck circumference of 34 cm.

Solution: STOP-BANG Score:\nS (Snoring) = No (0)\nT (Tired) = No (0)\nO (Observed) = No (0)\nP (Pressure) = No (0)\nB (BMI > 35) = No (0)\nA (Age > 50) = No (0)\nN (Neck > 40cm) = No (0)\nG (Male) = No (0)\nTotal = 0/8

Result: STOP-BANG Score: 0/8 (Low Risk) - Very low probability of OSA. No sleep study indicated at this time.

Frequently Asked Questions

What is the STOP-BANG questionnaire and what does it screen for?

The STOP-BANG questionnaire is an eight-item screening tool designed to identify patients at risk for obstructive sleep apnea (OSA). Developed by Dr. Frances Chung and colleagues at the University of Toronto in 2008, it was originally created for preoperative screening but has since been widely adopted in primary care and other clinical settings. The acronym represents eight risk factors: Snoring, Tiredness, Observed apnea, blood Pressure, BMI, Age, Neck circumference, and Gender. Each item is scored as yes (1 point) or no (0 points), yielding a total score of 0 to 8. The questionnaire takes less than two minutes to complete and requires no special equipment or training.

How are STOP-BANG scores interpreted for OSA risk stratification?

STOP-BANG scores categorize patients into three risk groups for obstructive sleep apnea. A score of 0 to 2 indicates low risk, with a high negative predictive value of approximately 90 percent for moderate-to-severe OSA. A score of 3 to 4 indicates intermediate risk, where further clinical evaluation and possible sleep testing may be warranted. A score of 5 to 8 indicates high risk, with strong predictive value for moderate-to-severe OSA. Studies have shown that higher scores correlate with greater OSA severity, with scores of 7 to 8 having very high probability of severe OSA (AHI greater than 30). The simple scoring makes it practical for rapid clinical decision-making in various healthcare settings.

Why is BMI greater than 35 specifically chosen as the cutoff in STOP-BANG?

A BMI greater than 35 kg/m2 was selected as the STOP-BANG threshold because it represents Class II obesity, which is associated with substantially increased risk of obstructive sleep apnea. Excess adipose tissue in the upper airway region, including the tongue, soft palate, and lateral pharyngeal walls, narrows the airway and increases collapsibility during sleep. Studies have demonstrated that the prevalence of OSA increases progressively with BMI, with approximately 70 to 80 percent of morbidly obese patients having some degree of OSA. The relationship between obesity and OSA is bidirectional, as untreated OSA can promote weight gain through metabolic dysregulation, sleep fragmentation, and decreased physical activity. Weight loss of 10 to 15 percent can significantly reduce OSA severity.

How does the STOP-BANG compare to other sleep apnea screening tools?

The STOP-BANG questionnaire has been compared extensively to other OSA screening tools including the Berlin Questionnaire, Epworth Sleepiness Scale, and the STOP questionnaire (the first four items only). Multiple systematic reviews have found that the STOP-BANG has the highest sensitivity among available screening tools, ranging from 83 to 100 percent for moderate-to-severe OSA at the cutoff of 3 or higher. However, its specificity is relatively lower, ranging from 37 to 56 percent, meaning it produces more false positives than some alternatives. The Berlin Questionnaire may have higher specificity but lower sensitivity and takes longer to administer. The STOP-BANG strikes the best balance between simplicity, speed, and sensitivity for a screening tool in clinical practice.

Why is the STOP-BANG particularly important for preoperative screening?

Preoperative screening for OSA using the STOP-BANG is critical because undiagnosed OSA significantly increases perioperative risk. Patients with untreated OSA are at higher risk for difficult intubation, postoperative respiratory complications, cardiac arrhythmias, and intensive care unit admission. General anesthesia and opioid analgesics further compromise upper airway patency in OSA patients, increasing the risk of postoperative airway obstruction and oxygen desaturation. The American Society of Anesthesiologists guidelines recommend screening surgical patients for OSA, and the STOP-BANG is specifically endorsed for this purpose. Identifying high-risk patients preoperatively allows anesthesiologists to plan appropriate airway management, monitoring, and postoperative care strategies.

What is the difference between the STOP portion and the BANG portion of the questionnaire?

The STOP and BANG portions capture different types of risk information for obstructive sleep apnea. The STOP portion (Snoring, Tiredness, Observed apnea, blood Pressure) consists of symptom-based and clinical history questions that reflect current manifestations of possible OSA. These are subjective or clinically identified signs that suggest the presence of sleep-disordered breathing. The BANG portion (BMI, Age, Neck circumference, Gender) consists of demographic and anthropometric risk factors that are objective and easily measured. When used alone, the STOP questions have moderate sensitivity and specificity. Adding the BANG criteria significantly improves the sensitivity of the tool, particularly for detecting moderate-to-severe OSA, at the cost of somewhat reduced specificity.