Screening Tools for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) refers to interruption in the normal breathing pattern by partial or complete obstruction of the air passage during sleep. It is characterized by snoring, oxygen desaturations, hypopneas, episodes of apnea and excessive daytime sleepiness. According to National Healthy Sleep Awareness Project, OSA now affects 25 million adults in the US alone. This increased prevalence is a major public health concern since untreated OSA can have serious short-term and long-term consequences. Untreated OSA carries an increased risk of hypertension, stroke, depression, and headaches, to name a few. Hence, it is imperative to diagnose and prevent OSA for deep, restful sleep. Recently, there has been an increased importance of early sleep apnea detection. Early detection of OSA means prompt treatment and therefore facilitates reduction in mortality and morbidity usually associated with OSA. This can be especially important in commercial vehicle drivers or heavy machine operators since symptoms such as daytime fatigue and sleepiness, can be dealt with sooner than later.

Overnight polysomnography or a sleep study is the gold standard test to detect OSA. Since sleep studies are elaborate, expensive and time-consuming, a number of screening tools have been developed.

Screening for OSA

Early detection of OSA is facilitated by the development of several clinically tested screening tools. These screening measures if used by a family doctor at regular medical checkups can screen for severe or moderately severe OSA. A history of loud snoring and excessive daytime fatigue is suggestive of some sort of sleep apnea. These symptoms coupled with obesity and family history of OSA can put one at a higher risk. Such individuals would be ideal candidates for the screening tools to diagnose OSA and get appropriate treatment.

According to an expert analysis by the American College of Cardiology, there are a number of screening tools that are sensitive and highly specific and at the same time are relatively easy to administer in a clinical setting. STOP, STOP-BANG, Epworth Sleepiness Scale and Berlin Questionnaire are a few of the most specific and sensitive tools available currently. STOP and STOP-BANG questionnaires have been reported much more in research and tested clinically far more times than the others, due to their simplicity in administering.

STOP Questionnaire

This screening tool is one of the most commonly used questionnaires due to its easy administration. STOP consists of four yes or no questions. It assesses snoring (S), tiredness (T), observed apneas (O) and high blood pressure (P).

A yes answer on any two questions indicates high risk for sleep apnea.

STOP-BANG Questionnaire

This screening tool consists of eight yes or no questions. It assesses snoring (S), tiredness (T), observed apneas (O) and high blood pressure (P), similar to the STOP questionnaire. The BANG part of this tool includes BMI > 35 kg/m² (B), age > 50 years (A), neck circumference > 40 cm (N) and male gender (G).

A yes answer on any three questions indicates high risk for sleep apnea. STOP-BANG demonstrates high sensitivity in individuals with moderate to severe OSA.

Epworth Sleepiness Scale

Murray Johns created the Epworth Sleepiness screening tool in 1990. It assesses daytime somnolence or sleepiness due to inadequate sleep the night before. It is a self-report questionnaire consisting of eight questions of common scenarios, like reading a book, for instance. The answers range from zero (indicates no chances of dozing off) to three (always dozing).

The score of 10 or more on the Epworth Sleepiness Scale indicates excessive daytime sleepiness. This screening tool shows highest specificity in patients with moderate to severe OSA.

Berlin Questionnaire

Developed in 1996, Berlin Questionnaire is a screening tool that consists of three categories of questions: snoring, daytime sleepiness and hypertension and BMI.

In the first and the second categories, a response of frequent symptoms (>3-4 times/week) for snoring and daytime sleepiness is considered positive. The third category is considered positive if there is positive history of hypertension or a BMI of greater than 30 kg/m². Individuals are considered high risk for OSA if they are positive in two or more categories.

Conclusion

Untreated OSA greatly impacts the quality of life and can have serious implications. Needless to say, early detection by a simple way of a screening tool is hopeful in prompt diagnosis. Perhaps, general physicians could incorporate one of these screening tools during routine physical examinations for their patients. This could help in highlighting suspected OSA and such patients can receive treatment far earlier and avoid complications.

However, it must be emphasized that these questionnaires, though highly specific and sensitive are only suggestive of OSA. A positive on one or two screening tools is not a conclusive diagnosis of OSA. Further monitoring by polysomnography and assessment by a clinician may be required to confirm diagnosis of OSA.

References

• https://aasm.org/rising-prevalence-of-sleep-apnea-in-u-s-threatens-public-health/
• Colvin, L. J., & Collop, N. A. (2016). Commercial motor vehicle driver obstructive sleep apnea screening and treatment in the United States: an update and recommendation overview. Journal of clinical sleep medicine, 12(01), 113-125.
• https://www.acc.org/latest-in-cardiology/articles/2015/07/14/11/04/screeing-tools-for-the-obstructive-sleep-apnea-for-the-cardiovascular-clinician
• El-Sayed, I. H. (2012). Comparison of four sleep questionnaires for screening obstructive sleep apnea. Egyptian Journal of Chest Diseases and Tuberculosis, 61(4), 433-441.
• https://www.sciencedirect.com/science/article/pii/S0422763812000453
• https://medlineplus.gov/ency/article/003932.htm

 

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