Mortality, hospital admission, and healthcare cost due to injury from venomous and non-venomous animal encounters in the USA: 5-year analysis of the National Emergency Department Sample

Abstract

BackgroundInjuries due to encounters with animals can be serious, but are often discussed anecdotally or only for isolated types of encounters. We sought to characterize animal-related injuries presenting to US emergency departments (ED) to determine the impact of these types of injuries.MethodsAll ED encounters with diagnosis codes corresponding to animal-related injury were identified using ICD-9-CM codes from the 2010 2014 National Emergency Department Sample (NEDS). Outcomes assessed included inpatient admission, mortality, and healthcare cost. Survey methodology was applied to univariate and multivariate analyses. Weighted numbers are presented.ResultsThere were 6 457 534 ED visits resulting from animal-related injuries identified. Bites from non-venomous arthropods (n=2 648 880; 41%), dog bites (n=1 658 295; 26%) and envenomation from hornets, wasps or bees (n=812 357; 13%) constitute the majority of encounters. There were 210 516 patients (3%) admitted as inpatients. Inpatient admission was most common for those suffering from venomous snakes or lizard bites (24%, n=10 332). Death was infrequent occurring in 1162 patients (0.02% of all ED presentations). The greatest number of deaths was due to bites from non-venomous arthropods (24% of deaths, n=278) whereas rat bites proved the most lethal (6.5 deaths per 10 000 bites). Among persons aged 85 years or greater, odds of hospital admission for any animal-related injury was 6.42 (95% CI 5.57 to 7.40) and the OR for death was 27.71 (95% CI 10.38 to 73.99). Female sex was associated with improved survival (OR 0.55, 95% CI 0.41 to 0.73) and lower rates of hospital admission (OR 0.77, 95% CI 0.75 to 0.79). The total healthcare cost for these animal encounters during the observed time period was $5.96 billion (95% CI $5.43 to $6.50 billion).ConclusionThe morbidity, mortality, and healthcare cost due to animal encounters in the USA is considerable. Often overlooked, this particular mechanism of injury warrants further public health prevention efforts.Level of EvidenceLevel IV.