1. Pulmonology Department, Hospital Prof. Doutor Fernando Fonseca, EPE, Amadora, Lisbon, Portugal
2. Faculdade Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
3. The University Sleep Disorders Center, Riyadh, Saudi Arabia
4. Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
5. Strategic Technologies Program of the National Plan for Sciences and Technology and Innovation in the Kingdom of Saudi Arabia, Riyadh, Saudi Arabia
6. Intensive Care Unit, Hospital Morales Meseguer, Murcia, Spain