Patient selection: burn victim
Outcome: mortality
Risk factors for mortality:
(1) burn size >= 35% (relative risk 96; relative risk for size 20-34% 18; relative risk for size 10-19% 6.6)
(2) age > 48 years (relative risk 7.3; relative risk 2-3 if 21 to 48 years old)
(3) inhalation injury (relative risk 3.6)
(4) female gender (relative risk 1.8)
where:
• The relative risk is influenced by the fact that the mortality rate is now so low for many burns. According to Figure 1 the mortality rate at 35% total burn surface area is 5-10%.
Factors reducing the risk of mortality:
(1) skin graft operation (relative risk 0.11; not getting skin graft surgery increases risk of mortality with relative risk 9)
(2) burn limited to the arm only (relative risk 0.53)
Other factors not listed:
(1) significant concurrent trauma
(2) significant comorbid conditions