Assessing the Cushion Effect: A Systematic Review and Meta-Analysis of the Role of Obesity in Motor Vehicle Injuries and Fatalities

Abstract

Purpose: A systematic review and meta-analysis were done to evaluate the effect of obesity in injury and mortality due to motor vehicle accidents. Materials & Methods: The systematic review consisted of 20 studies meeting the inclusion criteria. The meta-analysis was conducted on these studies to analyze obesity as a risk factor for specific injuries, as well as overall injury and mortality compared to non-obese patients. Results: The data revealed that obesity was associated with increased lower extremity injuries (odds ratio [OR] = 1.44, 95% confidence interval [CI] = 1.19-1.69, P ≤ 0.05), neck injuries (OR = 3.38, 95% CI = 1.58-5.19, P ≤ 0.05), and overall mortality (OR = 1.51, 95% CI = 1.40-1.61, P ≤ 0.05). When stratified for obesity class with class I as BMI >30.1-34.9, class II BMI 35-39.9, and class III BMI >40, only class II (OR = 1.20, 95% CI = 1.15-1.24, P ≤ 0.05) and class III (OR = 1.49, 95% CI = 1.30-1.68, P ≤ 0.05) were associated with increased mortality risk. No significant differences were seen with head, upper extremity, thoracic, abdominal, or pelvic injuries. Conclusion: Obesity is a risk factor in motor vehicle accidents for fatality and injury, specifically lower extremity and neck injuries.