The STOP-BANG Questionnaire is a concise medical screening tool used to assess an individual’s risk of having Obstructive Sleep Apnea (OSA). This condition involves the repeated collapse of the upper airway during sleep, which can lead to significant health consequences. Healthcare providers employ this eight-item questionnaire in various clinical settings, including primary care offices and specialized sleep clinics, to quickly identify patients who may require further evaluation. It is also a standard part of pre-operative assessment to flag individuals who might need specific airway management precautions during and after surgery. The tool’s ease of administration and high sensitivity make it a practical first step in recognizing this common, yet often undiagnosed, sleep disorder.
The Eight Components of the Screening Tool
The questionnaire’s name is an acronym. The first four letters, S-T-O-P, relate to self-reported symptoms, and the last four, B-A-N-G, refer to physical and demographic risk factors associated with Obstructive Sleep Apnea.
Self-Reported Symptoms (S-T-O-P)
The S stands for Snoring, asking if a person snores loudly enough to disturb a bed partner or be heard through closed doors. T represents Tiredness, focusing on whether a person often feels fatigued, tired, or sleepy during the daytime. O is for Observed Apnea, questioning if anyone has witnessed the individual stop breathing, gasp, or choke during their sleep. P signifies high blood Pressure, asking if the person has hypertension or is currently being treated for the condition.
Physical and Demographic Factors (B-A-N-G)
The second part of the acronym, B-A-N-G, covers four objective measures. B refers to Body Mass Index (BMI), with a positive response recorded if the BMI is greater than 35 kg/m². A denotes Age, counting as a risk factor if the person is older than 50 years. N is for Neck circumference, with a positive result measured as greater than 40 centimeters (roughly 16 inches). G stands for Gender, with the risk factor being assigned if the individual is male.
Calculating and Interpreting the Risk Score
Calculating the STOP-BANG score involves tallying the number of “yes” answers to the eight questions. Each affirmative response is assigned one point, resulting in a total score that can range from zero to eight. This total score is used to stratify the patient into one of three distinct risk categories for having moderate or severe Obstructive Sleep Apnea.
A score between zero and two is classified as Low Risk for moderate to severe OSA, suggesting a low probability of the condition. An Intermediate Risk is assigned to a score of three or four, indicating an increased likelihood that warrants further consideration. A score of five or higher places the individual in the High Risk category for moderate or severe OSA.
There is also a more nuanced interpretation for patients who fall into the intermediate range. A person with a score of three or four is still considered High Risk if they meet specific criteria, such as having a BMI greater than 35 kg/m² or meeting at least two of the four “STOP” questions. As the total score increases from the low end to the high end, the probability of having moderate to severe OSA increases proportionally.
Clinical Application and Limitations of the Screening Tool
The STOP-BANG questionnaire functions as a triage tool to streamline the diagnostic process for sleep-disordered breathing. Its most common use is in the pre-operative setting, where identifying high-risk patients allows anesthesiologists to take special precautions regarding airway management and post-operative monitoring. Patients flagged as high-risk are known to have an increased rate of complications like desaturation and critical care admissions following surgery.
In general practice, the tool helps clinicians decide which patients to refer for definitive sleep testing, such as a full overnight polysomnography. The high sensitivity of the questionnaire means it is effective at identifying nearly all people who have the condition, and its high negative predictive value reliably rules out moderate-to-severe OSA in those with low scores.
The STOP-BANG is exclusively a screening instrument and cannot provide a formal diagnosis of Obstructive Sleep Apnea. The tool has a lower specificity, meaning it can sometimes flag individuals as high-risk who ultimately do not have the condition, potentially leading to unnecessary further testing. Therefore, a high score only indicates the need for a comprehensive sleep study, which remains the gold standard for diagnosis and determining the severity of OSA.