Analysis and Incidence Calculation of Snowmobile Injuries Identified in a Rural Wisconsin Health Care System Over Five Years

Jennifer P. King, Center for Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, Wisconsin.
Oluwatosin Olaiya, Center for Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, Wisconsin.
Daniel C. Cullinane, Center for Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, Wisconsin, daniel.cullinane@mainehealth.org.

Abstract

BACKGROUND: Current estimates of snowmobile-related injuries are largely based on inpatient data from trauma centers. These centers care for severely injured patients and may not capture treatment information and outcomes for minor snowmobile-related injuries, therefore underestimating their volume and overestimating patient acuity. METHODS: Medically attended snowmobile injuries were identified retrospectively from inpatient and outpatient records from a health system in north-central Wisconsin using a hierarchical method of International Classification of Diseases external cause codes and text searches for key words. Manual reviews of the medical record collected information on patient characteristics, accident details, and clinical information. Descriptive analyses, comparisons between hospital admitted and nonadmitted cases, and calculations of seasonal incidence rates were conducted. RESULTS: From November 1, 2013, through April 30, 2018, there were 1013 snowmobile-related injuries, with 264 (26%) cases hospitalized and 749 (74%) treated as outpatients. Text search alone identified 61% of all incidents and about a quarter (26%) of hospitalized incidents. Inpatients were older and a higher percentage wore helmets, sustained multisystem trauma, sustained more fractures, more organ injuries, and had higher need surgery and intensive care. Mortality was 1%. The average annual injury incidence rate was 313 per 100,000 snowmobiles registered. CONCLUSIONS: Currently available studies of snowmobile-related injuries have underestimated their number and burden. Studies combining datasets from health systems in the state and statewide mortality records for cases who died prior to care could elucidate the full statewide impact of snowmobile-related injuries in Wisconsin, leading to better assessment of prevention efforts and staffing in rural trauma systems.