Cold weather injuries among patients at an urban safety net hospital, Boston, MA

Abstract

Background: Disadvantaged urban populations, particularly low-income and homeless individuals, are vulnerable to negative health effects from extreme weather exposure. Cold weather exposures and injury among these populations have received limited attention. We characterized incidence and risk factors for cold weather injuries (CWIs) among patients at Boston Medical Center (BMC), an urban safety-net hospital, over a ten year period.Methods: A case-control study was conducted using BMC emergency department (ED) records. Cases included all patients who presented to the ED from November 1, 2005, to March 31, 2015, with ICD-9/10 codes reflecting injury from exposure to extreme cold weather (e.g. hypothermia, trench foot, frostbite, chilblains). Incidence of CWI by month and year were calculated and stratified by sex, age, and race. Conditional multivariable logistic regression was used to identify risk factors for CWI, including race/ethnicity, homelessness, and mental and physical health comorbidities.Results: Incidence of CWIs from 2005-2015 was 1.2 cases per 1,000 persons (n=817 cases). January had the highest monthly incidence of cold-weather injuries (n=22±15). Cases were predominantly male (n=614; 75%), and approximately 44% were African American. Twenty-eight percent of cases had ≥2 CWI admissions. In multivariable analyses, non-white Hispanic/Latinos experienced 2.0x the odds of CWI compared to others (OR: 2.0, 1.3, 3.1; p=0.002). Homelessness was associated with reduced odds of CWI (OR: 0.05; 0.03, 0.08; p=<0.001.) Comorbid mental health conditions and substance abuse were not associated with increased odds of CWI. Conclusions: Increased CWI risk among Hispanic/Latinos may reflect language barriers to accessing prevention. Reduced risk among persons experiencing homelessness may indicate that service providers in Boston are protecting at-risk individuals, or that such injuries are underreported. CWIs should be further assessed among marginalized urban populations.