“…A definition of CPIP was lacking in 31 (39%) of the studies (table 2) [8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38]. In the other 49 studies (61%), a total of 22 different definitions of CPIP were identified.…”