STOP-BANG Score of 3: Interpretation and Clinical Significance
A STOP-BANG score of 3 indicates intermediate risk for obstructive sleep apnea (OSA) and warrants further diagnostic testing, as this score demonstrates high sensitivity but moderate specificity for detecting OSA. 1
Understanding the STOP-BANG Questionnaire
The STOP-BANG questionnaire is a validated screening tool for OSA that consists of eight dichotomous (yes/no) items:
- Snoring
- Tiredness/fatigue during daytime
- Observed apnea
- High blood Pressure
- BMI > 35 kg/m²
- Age > 50 years
- Neck circumference > 40 cm
- Male Gender
Each positive response contributes one point to the total score (range: 0-8) 1
Clinical Significance of a Score of 3
Risk Stratification
- A STOP-BANG score of 3 falls in the intermediate risk category for OSA 2
- Sensitivity for detecting moderate-to-severe OSA (AHI ≥ 15) is approximately 93% 2
- Negative predictive value for moderate-to-severe OSA is approximately 90% 2
- The probability of moderate-to-severe OSA with a score of 3 is approximately 25% in sleep clinic populations 3
- The probability of severe OSA (AHI ≥ 30) with a score of 3 is approximately 15% in surgical populations 3
Diagnostic Accuracy
- The STOP-BANG questionnaire has high sensitivity but low specificity for detecting OSA 1
- A score of ≥3 has excellent sensitivity (>90%) to detect moderate-to-severe and severe OSA 4
- The negative predictive value for severe OSA (AHI ≥ 30) is approximately 91% 4
- The diagnostic accuracy varies by geographic region, with AUC >0.80 in most regions except East Asia (0.52) 4
Clinical Approach for Patients with a Score of 3
Recommended Next Steps
- Further diagnostic testing is required as screening tools alone cannot definitively diagnose OSA 1
- Consider home sleep apnea testing (HSAT) for patients with high pretest probability 1
- In-laboratory polysomnography (PSG) remains the gold standard for diagnosis 1
- For patients with nondiagnostic HSAT (technically inadequate or AHI <5 events/hour), repeated testing with either HSAT or PSG should be done 1
Important Considerations
- The STOP-BANG questionnaire should not be used as a standalone diagnostic tool due to its limited specificity 1
- The number of potential false negative results limits the use of STOP-BANG as an instrument to definitively diagnose individual patients with OSA 1
- In patients with an uncertain diagnosis or for whom treatment proves challenging, consultation with a sleep specialist is recommended 1
Special Populations
- In the general population, a STOP-BANG score of ≥3 has a sensitivity of 66.2% for detecting AHI ≥15 and 69.2% for detecting AHI ≥30 5
- In Asian populations, using the standard BMI cutoff of >35 kg/m² is appropriate, as lower BMI cutoffs did not significantly improve questionnaire performance 6, 5
- For surgical patients, a score of 3 indicates a 15% probability of severe OSA 3
Clinical Pitfalls to Avoid
- Do not rely solely on the STOP-BANG score for diagnosis without confirmatory testing 1
- Do not dismiss patients with a score of 3 as "low risk" - they require further evaluation 2, 3
- Recognize that while STOP-BANG has high sensitivity, its specificity is low, leading to potential false positives 1
- Be aware that the questionnaire's performance may vary across different populations and clinical settings 4