Individuals Experiencing Houselessness and Severe Frostbite in Edmonton and Calgary; a three-winter review

Abstract

Background: Edmonton and Calgary are Albertan cities with populations of over 1 million each and experience cold winter temperatures, making frostbite a common emergency departments (ED) presentation. In 2024 the estimated unhoused population was approximately 7000 across both cities. Our primary objective was to assess the frequency and severity of frostbite injuries in individuals experiencing houselessness (IEH) compared to those with housing.

Methods: This retrospective study of administrative data assessed patients treated in Edmonton and Calgary with severe frostbite over three winters. Data abstracted include patient characteristics, frostbite grade, and time between injury and ED presentation. Ambient temperatures at injury time were assessed from the Alberta Climate Information Service. IEH was determined via clinician notes. Descriptive analysis and statistical methods were used to compare housing status and the grade of injury and arrival time to the ED. The relationship between homelessness and time of injury to arrival at the hospital was examined using ordinal logistic regression. The dependent variable, Time of Injury to Arrival, was categorized as: <12 hours, 12 to 24 hours, 24 to 48 hours, 48 to 72 hours, and >72 hours.

Results: 257 cases of severe frostbite were abstracted. Mean age 42.5 (SD13.7), Sex male 208/257(80.9%). IEH comprised 140/257 (54.5%) of cases and unknown in 40/257(15.6%). Houselessness was a precipitating frostbite factor in 102/257(39.7%). IEH was not found to be a statistically significant predictor of frostbite grade (p = .109); OR = 1.55 (95% CI = 0.910 - 2.67). IEH experienced delays in arrival to the ED (p < .001, OR = 2.90, 95% CI = 1.73 - 4.91). IEH were nearly three times as likely to fall into a higher delay category of arrival time compared to non-IEH. Additionally, among the IEH population in this study, 43.48% of Grade 4, 25.86% of Grade 3, and 34.48% of Grade 2 cases occurred at temperatures warmer than -20 degrees Celsius.

Implication and lessons learned: Individuals experiencing houselessness had a threefold increase in the likelihood of delayed frostbite ED presentation. Additionally, a significant proportion of frostbite injuries occurred at temperatures warmer than -20C. This study suggests a need for current cold weather system responses to reexamine opportunities for prevention, proactive care, and the availability of shelter for IEH at temperatures warmer than -20C, which is warmer than many cities cold weather responses.