[Diagnosis] FYI: OSA, Criteria for Diagnosis

[Gideon]

to provide some clarity to AB readers
from Clinical Guideline for the Evaluation, Management and Long-term Care of Obstructive Sleep Apnea in Adults

Obstructive sleep apnea (OSA) is a common disorder affecting at least 2% to 4% of the adult population and is increasingly recognized by the public. The signs, symptoms and consequences of OSA are a direct result of the derangements that occur due to repetitive collapse of the upper airway: sleep fragmentation, hypoxemia, hypercapnia, marked swings in intrathoracic pressure, and increased sympathetic activity. Clinically, OSA is defined by the occurrence of daytime sleepiness, loud snoring, witnessed breathing interruptions, or awakenings due to gasping or choking in the presence of at least 5 obstructive respiratory events (apneas, hypopneas or respiratory effort related arousals) per hour of sleep. The presence of 15 or more obstructive respiratory events per hour of sleep in the absence of sleep related symptoms is also sufficient for the diagnosis of OSA due to the greater association of this severity of obstruction with important consequences such as increased cardiovascular disease risk.1

[url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2699173/#B1][/url]

[Illorum]

I'd like to point out that the 2-4% prevalence is a very outdated figure - latest study I saw estimated 1 billion people when only looking at people 30-69 (3 billion people fall in that age range iirc).

The clinical guidelines have this more comprehensive OSA definition further below that I prefer since its more inclusive of UARS symptoms (fatigue & insomnia): 

The diagnosis of OSA is confirmed if the number of obstructive events (apneas, hypopneas + respiratory event related arousals) on PSG is greater than 15 events/hr or greater than 5/hour in a patient who reports any of the following: unintentional sleep episodes during wakefulness; daytime sleepiness; unrefreshing sleep; fatigue; insomnia; waking up breath holding, gasping, or choking; or the bed partner describing loud snoring, breathing interruptions, or both during the patient's sleep.1 OSA severity is defined as mild for RDI ≥ 5 and < 15, moderate for RDI ≥ 15 and ≤ 30, and severe for RDI > 30/hr (Consensus).