It hasn’t been easy for everyone to adapt to wearing face masks. Especially since for many, daily use has lead to health issues.

Introduction: NIV masks are a key to achieve patient’s adherence to treatment. The choice of the mask usually relies on clinical expertise. However, there is little data available regarding the side effects associated to NIV masks in home NIV users. Our primary aim was to assess the incidence of mask related SE. Our secondary aims were to describes incidence of pressure sore and its association with the type of mask used, the consequences of side effects to NIV compliance and quality of life. Methods: Retrospective review of all patients that attended our outpatient NIV clinic in 2018 with available data regarding mask and masks side effects. SE were grade as absent, mild, moderate, severe or very severe. Masks side effects taken into account were: pressure sore, pain, perceived leaks. Results: Data were available for 581 patients. Moderate to very severe SE were found in 305 (52%) patients when taking into account those, severe to very severe SE were found in 130 (22%) patients. Amongst severe to very severe SE, leaks SE occurred in 73 patients, pain in 41 and pressure sore in 37. Patients with at least a severe SE did not have a worse NIV compliance, quality of life assessed by the severe respiratory insufficiency questionnaire than those who did not (p=0.76 and 0.34). Daytime PaCO2 self-venting were significantly higher in patients with severe SE: 6.4±1.4 vs. 6.2±1.1 (p=0.01). The use of full-face mask was not associated to an increase of pressure sore (RR=0.95 \[0.89-1.03]). However, one full-face mask was associated to an increase risk of moderate to very severe pressure sore: RR=2.1 [1.0-4.5\] (p=0.04). Conclusion: Masks related side effects are common and seems to occur in more severe patients. Footnotes Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 1965. This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”. This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at [www.ers-education.org][1] (ERS member access only). [1]: http://www.ers-education.org