Epidemiology of Obstructive Sleep Apnea
OSA is common sleep disorder gaining increased recognition and attention. OSA is prevalent in both children (1-5%) and adults (10-30%). OSA is more prevalent in men (22%) than women (17%) and the risk of developing OSA increases with advancing age and higher body mass index (BMI).6
There are predisposing risk factors for OSA which include maxillary and/or mandibular hypoplasia, macroglossia, tonsillar hypertrophy, Mallampati classification and a narrow oropharyngeal airway and endocrine disorders such as hypothyroidism. However a commonly used screener for assessing OSA risk involves the STOP-Bang mnemonic.
S – Snoring
T – Tiredness
O – Observed apnea
P – Pressure; blood pressure elevated
B – BMI > 35 kg/m
A – Age > 50 years
N – Neck circumference; > 17” for males or 16” for females
G – Gender, male
Snoring: does the patient snore loudly enough to be heard through a closed door or loud enough requiring a bed partner to poke or elbow the patient? Note that snoring is not synonymous with OSA.
Tiredness: does the patient report excessive daytime sleepiness? Excessive sleepiness can be measured by a questionnaire tool called the Epworth Sleepiness Scale (ESS). A score of ten or greater may warrant a physician to evaluate for a sleep disorder. A positive ESS is not synonymous with OSA as other sleep disorders may also yield a positive ESS such as primary insomnia.
Observed apnea: has a bed partner witnessed the patient struggling to breathe while sleeping, such as choking or gasping sounds or long periods of time between breaths?
Pressure, elevated blood pressure is both a risk factor of and consequence of OSA.
BMI: increased weight is a well-known risk factor for OSA. Online BMI calculators are available to assess this metric by entering patient height and weight.
Age: individuals over the age of 50 years old have higher OSA prevalence than younger people. The soft tissue laxity of aging may contribute to oropharyngeal airway collapsibility.
Neck circumference: another correlate with obesity. Neck size of 17” or more in males or 16” or more in females puts a check in this box.
Gender: males have higher OSA risk than females.
OSA - Low Risk : Yes on 0 - 2 questions
OSA - High Risk : Yes on 3 or more questions
A recent study found that patients with a STOP-Bang score of 3 had a 25% probability of a severe OSA. For each additional STOP-Bang point there was another 10% increase in severe OSA probability.7 STOP-Bang does not diagnose patients with OSA, however it triggers a need for a sleep referral and an eventual sleep study, which is the gold standard in diagnosing the presence of OSA and other sleep disorders.