PubMed:: "Recurrence"[Mesh] OR recurr*[tiab] OR relaps*[tiab] OR recrudesc*[tiab];; Embase.com:: 'recurrence risk'/exp OR 'recurrent disease'/exp OR recurr*:ab,ti OR relaps*:ab,ti OR recrudesc*:ab,ti;; PsycInfo:: DE "Relapse (Disorders)" OR TI ( recurr* OR relaps* OR recrudesc* ) OR AB ( recurr* OR relaps* OR recrudesc* );; CINAHL:: (MH "Recurrence") OR TI ( recurr* OR relaps* OR recrudesc* ) OR AB ( recurr* OR relaps* OR recrudesc* );; Cochrane Library:: (recurr* OR relaps* OR recrudesc*):ti,ab,kw