Screenings with overweight or obesity
Sleep apnea screening: STOP-Bang, Epworth and AHI explained
In obstructive sleep apnea (OSA), the airway closes off again and again during sleep, despite efforts to breathe. Common signs are daytime sleepiness, sleep that does not refresh, loud or irregular snoring, and choking or gasping while asleep. (USPSTF, 2022) This page covers who should be asked about it, what the questionnaires mean, and how the sleep test result is read.
Who should be checked
| Source | Who it covers | What it says |
|---|---|---|
| USPSTF, 2022 | Adults 18 and older without symptoms, or whose symptoms have not been noticed or raised | Evidence insufficient to recommend for or against screening (I statement). It does not apply to people who have symptoms or concerns about sleep apnea, children, teenagers, pregnant people, workplace fitness exams, or people with a condition such as a stroke that can trigger it. (USPSTF, 2022) |
| American Academy of Sleep Medicine (AASM), 2017 | Adults with signs and symptoms that point to moderate to severe sleep apnea | A sleep test (a sleep lab study, or a home test with an adequate device) to diagnose it, as part of a full sleep evaluation with follow-up. (AASM, 2017) |
Where they differ: the USPSTF looks at screening people who do not report symptoms, and found too little evidence either way. (USPSTF, 2022) The AASM guideline is about testing people who already have symptoms, and it recommends a sleep test for them. (AASM, 2017) So the USPSTF I statement is not a reason to skip testing if you have symptoms.
Risk factors listed by the USPSTF are male sex, age 40 to 70, being past menopause, a higher BMI, and differences in the face, jaw or upper airway, such as large tonsils. (USPSTF, 2022) In the AASM guideline, a high-risk picture is excessive daytime sleepiness plus at least 2 of these 3: regular loud snoring, someone seeing you stop breathing or gasp or choke in your sleep, or diagnosed high blood pressure. (AASM, 2017)
The questionnaires: STOP-Bang and Epworth
Neither questionnaire diagnoses sleep apnea. The AASM recommends that questionnaires and prediction tools not be used to diagnose it without a sleep test. (AASM, 2017) The USPSTF adds that none has been properly validated in the general primary care population. (USPSTF, 2022)
STOP-Bang
STOP-Bang has 8 yes-or-no items: snoring, tiredness, observed stopped breathing, high blood pressure, BMI, age, neck size and male sex. Each yes adds 1 point, so the total runs from 0 to 8. (Chung, 2016)
| Score | Risk of moderate to severe sleep apnea |
|---|---|
| 0 to 2 | Low |
| 3 or 4 | In the middle; other details, such as a BMI over 35, help sort the risk |
| 5 to 8 | High |
Source for the table: (Chung, 2016) A score of 3 or more picked up 93% of people with moderate to severe sleep apnea in the studies the authors summarize. (Chung, 2016) The catch is false alarms: in the AASM review, STOP-Bang had a sensitivity of 0.93 but a specificity of only 0.36, so many people who score high turn out not to have sleep apnea. (AASM, 2017)
Epworth Sleepiness Scale
The Epworth scale measures daytime sleepiness, not breathing. You rate your chance of dozing off in 8 everyday situations from 0 to 3, giving a total of 0 to 24. (Epworth Sleepiness Scale) The questions are copyrighted, so ask your doctor for the form.
| Total score | Daytime sleepiness |
|---|---|
| 0 to 5 | Lower normal |
| 6 to 10 | Higher normal |
| 11 to 12 | Mild excessive |
| 13 to 15 | Moderate excessive |
| 16 to 24 | Severe excessive |
Source for the table: (Epworth Sleepiness Scale) A normal Epworth score does not rule out sleep apnea: in the AASM review it missed many people who had it, with a sensitivity of 0.27 to 0.72. (AASM, 2017)
Home sleep test or sleep lab
| Sleep lab study (polysomnography) | Home sleep apnea test | |
|---|---|---|
| Where | Overnight in a sleep lab, with staff watching | At home, with fewer sensors and no staff present |
| What it measures | Brain waves, eye and chin muscle activity, airflow, breathing effort, oxygen level and heart rhythm | Breathing and oxygen level; most devices cannot tell sleep from wake |
| Main result | Apnea-hypopnea index (AHI), counted per hour of sleep | Respiratory event index (REI), counted per hour of recording, which can read lower than the true AHI |
| Who it suits | Anyone; preferred with significant heart or lung disease, nerve and muscle conditions, long-term opioid use, past stroke or severe insomnia | Adults without those conditions who have signs of moderate to severe sleep apnea |
Sources for the table: (AASM, 2017) (USPSTF, 2022) A home test can be more convenient, easier to get and lower cost. If a single home test is negative, unclear or technically poor, the AASM recommends a sleep lab study. If a first lab study is negative but sleep apnea is still suspected, it suggests a second one may be considered. (AASM, 2017)
Reading the AHI on your report
The AHI counts how many times per hour your breathing stops (apnea) or becomes shallow (hypopnea) during sleep. It is used to describe how severe sleep apnea is. (USPSTF, 2022)
| AHI | Usual label |
|---|---|
| Below 5 | Below the threshold for sleep apnea |
| 5 to under 15 | Mild |
| 15 to under 30 | Moderate |
| 30 or more | Severe |
Sources for the table: the AASM guideline uses AHI 5, 15 and 30 as its severity thresholds. (AASM, 2017) The USPSTF writes the same bands in whole numbers as mild 5 to 15, moderate 16 to 30 and severe more than 30, so a result of exactly 15 or 30 can be labeled one band lower there. (USPSTF, 2022) The diagnosis also depends on symptoms: the definition the AASM cites uses a closely related count, the respiratory disturbance index, of 5 or more events per hour with typical symptoms, or 15 or more even without symptoms. (AASM, 2017) Your doctor decides what your result means for you and what comes next.
Medicare coverage
Medicare Part B covers sleep tests (Types I, II, III and IV) if you have clinical signs and symptoms of sleep apnea and your doctor orders the test. After the Part B deductible you pay 20% of the Medicare-approved amount. Medicare covers a Type I (full lab) study only in a sleep lab facility. (Medicare.gov) The national coverage rule behind this has applied since March 3, 2009, and covers home tests (Types II and III, and Type IV devices with 3 or more channels including airflow) for people with signs and symptoms. (CMS, NCD 240.4.1) Neither page describes cover for testing people without symptoms.
Treatment is outside this page. The USPSTF and AASM documents also discuss treatment devices; ask your doctor.
Questions people ask
Should I be screened for sleep apnea if I have no symptoms?
The USPSTF found the evidence insufficient to recommend for or against screening adults without symptoms (an I statement, 2022). It is not a recommendation against it. If you have symptoms such as loud snoring, gasping in your sleep or daytime sleepiness, that is a reason to talk to your doctor about testing, not a screening question. (USPSTF, 2022)
Can a questionnaire tell me if I have sleep apnea?
No. The AASM recommends that questionnaires such as STOP-Bang and the Epworth scale not be used to diagnose sleep apnea without a sleep test. They help decide who should be tested. (AASM, 2017)
What does a STOP-Bang score of 3 or more mean?
STOP-Bang scores run from 0 to 8. A score of 0 to 2 is low risk for moderate to severe sleep apnea, 3 or 4 is in the middle, and 5 to 8 is high risk. A score of 3 or more catches most people with moderate to severe sleep apnea, but many people with that score do not have it. (Chung, 2016) (AASM, 2017)
Is a home sleep test as good as a sleep lab?
For adults without other major health problems who have signs of moderate to severe sleep apnea, the AASM says either a sleep lab study or a home test with an adequate device can be used. If a single home test is negative, unclear or technically poor, it recommends a sleep lab study. (AASM, 2017)
Does Medicare pay for a sleep study?
Medicare Part B covers sleep tests if you have clinical signs and symptoms of sleep apnea and your doctor orders the test. After the Part B deductible you pay 20% of the Medicare-approved amount. Medicare covers lab-based (Type I) studies only in a sleep lab facility. (Medicare.gov) (CMS, NCD 240.4.1)
Related
- Screenings if you have overweight or obesity
- Screenings if you have high blood pressure
- Annual physical tests
- Blood pressure screening: who and how often
- Medicare preventive screenings
- A sleep apnea risk check on our sister site Uncover My Risk