“…Over half of studies of clown intervention lasted less than 15 minutes [3,4,12,15,16,21,22,25,[27][28][29][30][31][32][33][34]. For seventy one percent of the studies the intervention is realized by one clown at one visit [4,5,9,11,15,16,19,21,[23][24][25][26][27][28][29][30][31][32][33] and in twenty nine percent of the studies the clowns intervention is realized by two clown at one visit [10,[12][13][14]17,18,22,34]. …”