Long COVID and episodic disability: advancing the conceptualisation, measurement and knowledge of episodic disability among people living with Long COVID – protocol for a mixed-methods study http://orcid.org/0000-0002-1632-6537Kelly K O'Brien1,2,3,4, http://orcid.org/0000-0002-4956-243XDarren A Brown5,6, http://orcid.org/0000-0002-6651-1132Colm Bergin7,8, http://orcid.org/0000-0003-0808-6729Kristine M Erlandson9, http://orcid.org/0000-0002-1165-0573Jaime H Vera10,11,...