Medical Incidents and Evacuations on Wilderness Expeditions for the Northwest Outward Bound School

Outdoor education (OE) expeditions travel far from definitive care and have unique epidemiology. Most OE expedition studies have examined a single organization and results may not generalize. This study examines the injuries, illnesses, medical evacuations, and nonmedical incidents of the Northwest Outward Bound School (NWOBS) to broaden our understanding and demonstrate commonalities within the field.

This retrospective database review examined incidents and evacuations on NWOBS expeditions from June 1, 2014 through October 31, 2016. Incident rates, evacuation rates, and incident type frequencies were calculated. Frequencies of incidents during different expedition time periods were compared with a 1-sample χ² test. The odds ratio that each type of incident would require evacuation was calculated and compared with other incident types using Fisher exact test.

The study period included 59,058 program days, 277 incidents, 143 medical incidents, 75 medical evacuations, and no fatalities. Injuries occurred at a rate of 1.64 per 1000 program days and illnesses at a rate of 0.78 per 1000 program days. The most common injuries were strains, sprains, and trauma or infection of the skin and soft tissue. Most injuries occurred while backpacking, hiking, or moving around camp. The most common illnesses were nausea, vomiting, diarrhea, abdominal pain, asthma, respiratory infections, and urinary tract infections. The medical incidents with the highest odds of evacuation were fractures, urinary tract infections, abdominal pain, and asthma.

Results from the NWOBS database are consistent with those from other expeditionary OE programs. These findings should guide risk-management strategies and staff medical training.