Clinical Significance of the STOP-BANG Score in Assessing Obstructive Sleep Apnea
The STOP-BANG questionnaire is a validated screening tool with high sensitivity but low specificity for detecting obstructive sleep apnea (OSA), making it valuable for initial risk stratification but insufficient as a standalone diagnostic tool. 1, 2
Understanding the STOP-BANG Questionnaire
- STOP-BANG consists of eight dichotomous (yes/no) items: Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index >35 kg/m², Age >50 years, Neck circumference >40 cm, and male Gender 2
- Each positive response contributes one point to the total score, ranging from 0 to 8 2
- The questionnaire was specifically developed to meet the need for a reliable, concise, and easy-to-use screening tool for OSA 3
Risk Stratification Based on STOP-BANG Score
- Patients with a STOP-BANG score of 0-2 can be classified as low risk for moderate-to-severe OSA (AHI ≥15), with a negative predictive value of 90% 3, 4
- A STOP-BANG score of 3-4 indicates intermediate risk for OSA and warrants further diagnostic testing 2, 5
- Patients with a STOP-BANG score of 5-8 can be classified as high risk for moderate-to-severe OSA 3, 6
- As the STOP-BANG score increases from 0-2 to 7-8, the probability of moderate-to-severe OSA increases from 18% to 60%, and the probability of severe OSA rises from 4% to 38% 3
Diagnostic Accuracy of STOP-BANG
- The sensitivity of a STOP-BANG score ≥3 to detect moderate-to-severe OSA (AHI >15) and severe OSA (AHI >30) is 93% and 100%, respectively 3, 7
- For a STOP-BANG score of 5, the odds ratio for moderate/severe and severe OSA is 4.8 and 10.4, respectively 6
- For STOP-BANG scores of 7-8, the odds ratio for moderate/severe and severe OSA increases to 6.9 and 14.9, respectively 6
- The diagnostic accuracy of a STOP-BANG score ≥3 to detect moderate-to-severe OSA is high (>0.80) in most global regions, with some variation noted in East Asia 7
Clinical Application and Limitations
- The American Academy of Sleep Medicine states that the STOP-BANG questionnaire should not be used as a standalone diagnostic tool due to its limited specificity 1, 2
- For patients with intermediate scores (3-4), additional criteria can improve risk stratification: a STOP score ≥2 plus BMI >35 kg/m², male gender, or neck circumference >40 cm indicates higher risk for moderate-to-severe OSA 5
- Serum bicarbonate ≥28 mmol/L in patients with a STOP-BANG score ≥3 can further classify them as high risk for moderate-to-severe OSA 5
- The American College of Physicians recommends further diagnostic testing for patients with positive screening results, as screening tools alone cannot definitively diagnose OSA 1, 2
Recommended Diagnostic Approach
- For patients with low STOP-BANG scores (0-2), OSA is unlikely and further testing may not be necessary unless clinically indicated 3, 4
- For intermediate scores (3-4), consider additional risk factors and either home sleep apnea testing (HSAT) or in-laboratory polysomnography (PSG) 2, 8
- For high scores (5-8), proceed with diagnostic testing, with PSG remaining the gold standard for diagnosis 2, 6
- Consider adding nightly pulse oximetry in patients with a STOP-BANG score of 2-5 when screening for sleep apnea, as it can provide additional diagnostic information 4
Common Pitfalls to Avoid
- Do not rely solely on the STOP-BANG score for diagnosis without confirmatory testing 1, 2
- Recognize that while STOP-BANG has high sensitivity, its low specificity leads to potential false positives 1, 2
- Be aware that the STOP-BANG questionnaire was primarily validated in middle-aged, predominantly male populations, which may affect its accuracy in other demographic groups 8
- Do not use clinical questionnaires, morphometric models, or clinical prediction rules as the sole means to diagnose OSA, as they have insufficient sensitivity and specificity 1