| Category | Concept |
| Anxiety and discomfort associated with masks | Feeling blockage and pressure by the mask was uncomfortable. |
| The contact with the mask was painful. | |
| I avoided moving because I was worried that the mask would be displaced. | |
| I wondered if air was leaking. | |
| Discomfort associated with air pressure | Feeling my mouth dry due to the strong wind pressure was uncomfortable. |
| The NPPV exerts strong wind pressure and made me feel uncomfortable. | |
| Insomnia with anxiety or discomfort | I could not sleep because of anxiety or discomfort caused by the mask and wind pressure. |
| Because the mask worried me and I had difficulty moving, my sleep was fragmented. |