“…Other studies only considered objective parameters from sleep study. The polysomnographic parameters considered were AHI less than 5–15 events/hour (10 studies) [24,25,27,28,31,32,34,35,37,38] , RDI<5–10 events/hour (3 studies) [29,30,33] , RDI>5 events/hour (2 studies) [31,35] , Pes more negative than 10 or 20 mmH 2 O (8 studies) [1,23,24,27,29,30,33,35] , total arousal index (TAI)>5–15 events/hour (7 studies) [1,24,25,33,34,35,38] , the presence of excessive daytime sleepiness or fatigue or snoring (9 studies) [22,25,26,29,30,32,33,36,38] and presence of RERA or flow limitation (3 studies). [25,27,28] …”