Medical Encounters Among 94,033 Race Starters During a 16.1-km Running Event Over 3 Years in the Netherlands: SAFER XXVI.

Background: There are limited data on the medical encounters (MEs) occurring during mass community-based running events of shorter distances (10-21.1 km). The aim of this study was to determine the incidence and nature of MEs during the largest mass participation running event in the Netherlands.

Hypothesis: We hypothesize that the incidence and nature of MEs will be similar to other running events.

Study Design: Descriptive epidemiological study over 3 years of a 16.1-km (10-mile) running event.

Level of Evidence: Level 4.

Methods: We investigated a total of 94,033 race starters at the 2017-2019 Dam tot Damloop (16.1 km), a point-to-point road race from Amsterdam to Zaandam, the Netherlands. All MEs were recorded by race medical staff on race day each year. MEs were retrospectively coded by severity, organ system, and final specific diagnosis (2019 consensus statement definition on mass community-based events). Incidence ( I ) per 1000 starters (95% CIs) were calculated for all MEs and serious/life-threatening MEs.

Results: The overall incidence (per 1000 starters) of all MEs was 2.75 (95% CI, 2.44-3.11), the overall incidence of serious/life-threatening MEs was 1.20 (95% CI, 1.00-1.45; 44% of MEs). Heat illnesses accounted for most MEs: hypothermia I = 0.54 (95% CI, 0.41-0.71) and hyperthermia I = 0.46 (95% CI, 0.34-0.62). Central nervous system MEs were also common (dizziness/nausea, I = 0.79; 95% CI 0.63-0.99), followed by the cardiovascular system MEs (exercise-associated postural hypotension, I = 0.36; 95% CI, 0.26-0.51).

Conclusion: The overall incidence of MEs was low compared with longer-distance races (21.1-90 km), but the incidence and relative frequency of serious/life-threatening MEs (44% of all MEs) was much higher. Heat illness (hypothermia and exertional heat stroke) accounted for most serious/life-threatening MEs.

Clinical Relevance: There is a need to implement prevention strategies and interventions by specialized medical practitioners in this and similar events.