What do systematic reviews say?

Interventions vs placebo or no prophylaxis

Interventions showed no clear difference in nosocomial pneumonia compared with placebo or no prophylaxis (low certainty).

• Interventions for preventing upper gastrointestinal bleeding in people admitted to intensive care units 2018 · Cochrane Headline outcomes only
  RR 1.15 [0.9, 1.48]
  9 studies · 1331 participants
  Low