“…Fourteen studies (82%) were undertaken in Europe, and the studies analyzed nine different skills related to resuscitation. Fourteen studies 12 , 21 , 22 , 24 , 25 , 26 , 28 , 29 , 30 , 32 , 33 , 34 , 35 , 36 reported short term outcomes (up to less than 3 months), while five studies 23 , 27 , 31 , 32 , 35 reported mid- to long-term retention (from 3 months up to 6 months post training). We found a wide range of target populations with 15 studies investigating various groups of healthcare professionals, 12 , 21 , 22 , 23 , 24 , 25 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 and two studies investigating lay persons 26 , 27 ( Table 1 , Table 2 ).…”