a decreasing trendp < 0.001
In the 30 s timepoint analysis, the estimated means of compression depth, rate and number of effective compressions showed a decreasing trend that was not dependent on PPE: comparing the first 30 s with the last 30 s, depth decreased from 55 (54–57) mm to 52 (50–54) mm ( p < 0.001), the rate decreased from 120 (117–122) to 117 (115–120) compressions per minute ( p < 0.001) and the number of effective CCs decreased from 50 (45–56) to 37 (31–44) ( p < 0.001).