“…In the other 49 studies (61%), a total of 22 different definitions of CPIP were identified. Almost half (n = 23) of these studies applied the definition provided by the IASP, which is ‘chronic pain is pain that persists beyond three months post-operatively' [39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62]. The remaining half (n = 26) used multiple definitions of CPIP, which can be categorized and summarized as follows.…”