Skip to main content

Table 1 Number needed to treat in ventilator-associated pneumonia

From: Number needed to treat and cost-effectiveness in the prevention of ventilator-associated pneumonia

  Relative risk reduction
  5% 10% 15% 20% 25% 30% 35% 40% 45% 50%
Baseline VAP rate           
1% 2,000 1,000 667 500 400 333 286 250 222 200
2% 1,000 500 333 250 200 167 143 125 111 100
4% 500 250 167 125 100 83 71 63 56 50
6% 333 167 111 83 67 56 48 42 37 33
8% 250 125 83 63 50 42 36 31 28 25
10% 200 100 67 50 40 33 29 25 22 20
15% 133 67 44 33 27 22 19 16.7 15 13
20% 100 50 33 25 20 17 14 12.5 11 10
  1. Number needed to treat (NNT) was calculated as: NNT [relative risk of event] = 1/(pc × RRR), where pc is the proportion of control group subjects who suffer an event and RRR is relative risk reduction. These NNTs are based on events per 10 days of mechanical ventilation, meaning that more than one event can occur in a single patient who is ventilated for more than 10 days. VAP, ventilator-associated pneumonia.