Data from uncontrolled studies suggested that NIV might have been effective and safe in the management of some patients with SARS [45], while others highlighted concerns of increased SARS transmission risk to healthcare workers [46]. In a multicenter cohort of 302 MERS critically ill patients, NIV was used initially in 35% of patients, but the vast majority of them (92.4%) required conversion to invasive mechanical ventilation; however, NIV was not independently associated with 90-day mortality [47].