Erratum to: Protocol for the End-of-Life Social Action Study (ELSA): a randomised wait-list controlled trial and embedded qualitative case study evaluation assessing the causal impact of social action befriending services on end of life experience. Issue 1 (December 2016) - Walshe, Catherine; Algorta, Guillermo; Dodd, Steven; Papavasiliou, Evangelia; Hill, Matthew; Ockenden, Nick; Payne, Sheila; Preston, Nancy