Social Determinants of Poor Outcomes Following Frostbite Injury: A Study of the National Inpatient Sample

Severe frostbite injury can result in significant disability from amputation of limbs and digits which may be mitigated through prompt medical care. The reported rates of amputation vary widely between centers. Our aim was to describe the incidence and factors associated with amputation secondary to frostbite injury in the United States using a national sample of hospitalizations. Admissions for frostbite injury were identified in the National Inpatient Sample (2016-2018). Factors associated with amputation were assessed by multivariable logistic regression and clustered by hospital. The overall incidence of frostbite injury in the United States is 0.83 of 100,000 people. Of the social factors associated with frostbite injury, homelessness and the black race were independently associated with a higher likelihood of amputation at the primary admission. Diagnosis of cellulitis was a predictor of amputation. Homeless frostbite patients were more frequently discharged against medical advice and were less likely to discharge with supportive medical care, despite having a higher rate of more severe injury. Disability from amputation following frostbite injury affects at least 20% of frostbite-injured patients and disproportionally affects the homeless population. Further study is needed to ascertain the decision making that leads to early amputation following frostbite injury, especially in the homeless and black population. Outreach and education efforts should be initiated to promote salvage of functional limb length following frostbite injury.