What is OSA?
Obstructive sleep apnea-hypopnea (OSAHS) is a common sleep disorder characterized by recurrent upper airway collapse during sleep, leading to apnea or hypopnea.
During sleep, apnea caused by upper airway collapse and obstruction is usually accompanied by breathing pauses, snoring, decreased blood oxygen saturation, and daytime sleepiness.
Furthermore, it can cause various complications, leading to coronary heart disease, hypertension, cerebrovascular disease, diabetes, and more. In severe cases, it can cause sudden death during sleep, posing a significant health threat.
What is OSA screening scale?
Screening scales are tools to help quickly identify the risk of sleep apnea, acting as a simple “initial screening checkpoint.” Their purpose is to identify high-risk individuals through a few short questions, allowing for recommendations for more detailed testing.
Currently, there are many commonly used screening questionnaires, among which the NoSAS score and SBQ scale are widely used; the Berlin questionnaire and STOP questionnaire are also frequently used. For assessing daytime sleepiness, the Epworth Sleepiness Scale (ESS) is commonly used.
NoSAS Score Scale
| NoSAS | Item | Answer | Score |
|---|---|---|---|
|
N=Neck circumference |
How many centimeters is your neck circumference? |
_____cm |
|
|
O=Obesity |
BMI (body mass index) |
BMI=_____ |
|
|
S=Snoring |
Do you snore? |
Yes/No |
|
|
A=Age |
Age |
_ years old |
|
|
S=Sex |
Gender |
Male/Female |
|
The meaning of NoSAS: N=Neck circumference O=Obesity S=Snoring A=Age S=Sex
Scoring method: This scoring scale has 5 items, which can be used for preliminary screening, with a total of 17 points. The following is a detailed classification of each item.
Scoring:
① If the neck circumference is >40 cm, 4 points, otherwise 0 points.
② BMI score calculation: BMI less than 25, 0 points; BMI greater than or equal to 25, less than 30, 3 points; BMI greater than or equal to 30, 5 points.
③ Snoring “yes” gets 2 points, “no” gets 0 points.
④ Age, age greater than 55 years old gets 4 points, less than or equal to 55 years old gets 0 points.
⑤ Gender, male gets 2 points, female gets 0 points.
The score's meaning
The NoSAS (No Sleep Apnea Scale) has a total score of 17. If your score is 8 or higher, it indicates a higher risk of sleep apnea, and it is recommended that you consult a doctor for further professional examination.
Two important points to understand:
It may not be suitable for everyone: This scale is primarily designed for people with thick necks and who are overweight. If you have a thin neck or are slim, even if your score is low, you may still be at risk, and the scale may miss you.
A score of 7 is also a warning sign: Recent research has found that lowering the warning line from 8 to 7 can identify more at-risk individuals, but it may also lead to misdiagnosis of a small number of people who are not actually affected.
Overall, a score of 7 may be more practical as a warning line. Therefore, if your score is 7, it is worth paying attention to.
The meaning of STOP-BANG: S=Snoring T=Tired O=Observe P=Blood pressure B=BIM A=Age N=Neck circumference G=Gender
| STOP-BANG | Item |
|---|---|
|
S=Snoring |
Do you snore loudly (louder than talking or loud enough to be heard through closed doors) |
|
T=Tired |
Do you often feel tired, fatigued, or sleepy during daytime? |
|
O=Observe |
Has anyone observed you stop breathing during your sleep? |
|
P=Blood pressure |
Do you have or are you being treated for high blood pressure? |
|
B=BMI |
BMI? |
|
A=Age |
Age? |
|
N=Neck circumference |
Neck circumference? |
|
G=Gender |
Gender? |
Scoring method: This scale has a total of 8 points, each item can get a maximum of 1 point or 0 points, and the scores are divided as follows;
① For the first question, answer “yes” to get 1 point, answer “no” to get 0 point.
② For the second question, answer “yes” to get 1 point, answer “no” to get 0 point.
③ For the third question, answer “yes” to get 1 point, answer “no” to get 0 point.
④ For the fourth question, answer “yes” to get 1 point, answer “no” to get 0 point.
⑤ For the fifth question, A BMI greater than 35 was assigned a point of 1, and a BMI less than or equal to 35 was assigned a point of 0.
⑥ For the sixth question, Age greater than 50 years was assigned a score of 1, and age less than or equal to 50 years was assigned a score of 0.
⑦ For the seventh question, answer “male” to get 1 point, answer “female” to get 0 point.
The score's meaning
The assessment method for this scale is simple: a total score of 3 or higher indicates a high risk of obstructive sleep apnea-hypopnea syndrome (OSAHS). Studies show that this scale is easy to use and quite accurate.
This is a simple questionnaire to assess your level of drowsiness in daily life. It asks you how likely you are to doze off in eight different scenarios, ranging from “never” to “very likely,” on a scale of 0-3.
You need to answer how likely you are to doze off or fall asleep during each activity based on your usual behavior over the past few months. A total score above 10 usually indicates a significant daytime sleepiness problem.
Its advantages are its simplicity, speed, and ability to reflect your daytime drowsiness with a specific score. However, its limitation is that it cannot diagnose any disease (such as sleep apnea); a doctor must combine it with other examinations for a comprehensive assessment.
| Situation | Answer | |||
|---|---|---|---|---|
|
1.Sitting and Reading |
Never |
Rarely |
Sometimes |
Often |
|
2.Watching TV |
Never |
Rarely |
Sometimes |
Often |
|
3.Sitting inactive in a public place (e.g. a theatre or meeting) |
Never |
Rarely |
Sometimes |
Often |
|
4.As a passenger in a car without break |
Never |
Rarely |
Sometimes |
Often |
|
5.Lying down to rest during the day when circumstances permit |
Never |
Rarely |
Sometimes |
Often |
|
6.Sitting and talking to someone |
Never |
Rarely |
Sometimes |
Often |
|
7.Sitting quietly after lunch without alcohol |
Never |
Rarely |
Sometimes |
Often |
|
8.In a car, while stopped for a few minutes in traffic |
Never |
Rarely |
Sometimes |
Often |
The score's meaning
The ESS rating scale uses options such as “0 = Never”, “1 = Rarely”, “2 = Sometimes”, or “3 = Often”. This scale is primarily used to assess the severity of your daytime sleepiness.
The total score ranges from 0 to 24 points; a higher score indicates a more pronounced tendency to be sleepy during the day.
Generally, a total score ≥11 points is considered to indicate excessive sleepiness. A total score ≥9 points suggests an increased risk of obstructive sleep apnea-hypopnea syndrome (OSAHS).
The detailed score ranges and their meanings are as follows:
0-5 points: Normal daytime alertness
6-10 points: Some daytime drowsiness, but generally normal
11-12 points: Mild excessive sleepiness
13-15 points: Moderate excessive sleepiness
16-24 points: Severe excessive sleepiness
Core reference standards:
6 points: Indicates the presence of sleepiness
11 points: Indicates excessive sleepiness
16 points: Indicates dangerously severe sleepiness
Note: This questionnaire can usually be completed in 2-3 minutes. Please note that this score is mainly used to assess the degree of sleepiness and cannot be used alone to diagnose any disease.
A comprehensive judgment by a doctor, combined with other examinations, is required.
Other methods for diagnosing OSA
1. Polysomnography (PSG)
Polysomnography (PSG) is the gold standard for diagnosing sleep apnea.
It requires an overnight stay in a hospital sleep lab, monitoring multiple indicators such as electroencephalography (EEG), electrocardiography (ECG), respiration, and blood oxygenation to accurately calculate the apnea-hypopnea index and comprehensively assess sleep structure.
However, this method is expensive, and some patients may experience sleep disturbances due to unfamiliarity with the environment, leading to inaccurate results.
2. Home Sleep Apnea Test (HSAT)
Home-based sleep apnea testing offers a more convenient initial screening option.
Patients can use portable devices to monitor key indicators such as nighttime breathing and blood oxygenation, completing the test at home.
It is relatively inexpensive and particularly suitable for the initial assessment of suspected moderate to severe cases.
However, its limitation lies in its inability to monitor brain waves, which may cause it to miss some cases of central sleep apnea or milder conditions.
3. Clinical Evaluation and Imaging Examination
In addition, clinical evaluation and imaging examinations are also crucial. Doctors will combine the patient’s medical history and physical examination (such as measuring neck circumference and assessing facial structure).
They will also use imaging techniques such as nasopharyngoscopy, CT, or MRI to determine if there are specific structural problems, such as enlarged tonsils or posterior displacement of the tongue base.
This method can clarify the cause, which is especially important for patients requiring surgery. However, it cannot directly quantify the frequency of breathing events during sleep, so it usually needs to be used in conjunction with the aforementioned functional examinations.
Conclusion
Screening scales are effective tools for early detection of sleep apnea, but their results need to be combined with objective examinations to improve diagnostic accuracy.
While polysomnography (PSG) in hospitals is the “gold standard” for diagnosis, its high cost and requirement for hospitalization limit its use. Home sleep monitoring offers a more convenient and economical alternative, particularly suitable for use at home or in situations with limited medical resources.
Through a “stratified screening” strategy, high-risk individuals are initially screened using scales, followed by sleep monitoring to confirm the diagnosis, and imaging studies when necessary to identify the underlying cause.
This significantly reduces missed diagnoses, helps in developing more appropriate treatment plans, and ultimately improves patients’ quality of life and long-term health.
In the future, further improvements to the screening effectiveness of scales and the promotion of more convenient monitoring technologies are needed to truly achieve “early detection and early treatment” of sleep apnea.
