Pre-Race Risk Screening and Stratification Predicts Adverse Events - SAFER Study In 76654 Distance Runners

Abstract

PURPOSE: The purpose of this study was to determine if a pre-race medical screening and risk stratification program predicts adverse events (ability of a runner to finish the race, or develop a medical complication) during an endurance running event. METHODS: This prospective study, conducted during the Two Oceans marathon races (21.1km and 56km) in South Africa over 4 years, involved 76654 consenting race entrants. Race entrants completed a pre-race medical screening questionnaire at registration (3-4 months before the race), and were risk stratified into four groups: very high risk (VHR; existing cardiovascular disease - CVD), high risk (HR; risk factors for CVD), intermediate risk (IR; existing other chronic disease, medication use or injury), and low risk (LR). All runners in the VHR and HR categories were provided with educational information to decrease the risk of medical complications, and were also advised to undergo a pre-race medical assessment. Runners were tracked from registration to starting and finishing the race, and medical encounters (ME) were documented. Main outcome variables were the did-not-start rate (DNS; % runners registering but not starting) and the adverse event rate (AE) [defined as % starters that did-not-finish (DNF) or had an ME] in each risk category. RESULTS: The DNS rate (%: 95% CI) for runners was similar in all risk categories (VHR=19.5; 17.9-21.2, HR=18.8; 18.0-19.7, IR=18.4; 18.0-18.9, and LR=18.6; 18.2-19.1)(p=0.604). The DNF rates in the VHR (2.2; 1.6-3.0)(p=0.005), HR (1.8; 1.5-2.1)(p=0.017), and IR (1.9; 1.8-2.1)(p<0.001) were significantly higher compared to the LR (1.4; 1.2-1.5). The overall AE rates for runners in the VHR (2.3; 1.8-3.0)(p=0.0017), HR (1.8; 1.5-2.1)(p=0.0323), and IR (2.0; 1.9-2.2)(p<0.001) were significantly higher compared to the LR (1.5; 1.3-1.6). CONCLUSIONS: A pre-race medical screening, risk stratification and educational intervention program did not change the DNS in the risk categories. However, runners in the higher risk categories, that chose to start the race, were more likely to suffer an adverse event (not finish the race or present with a medical encounter) compared with runners in the lowest risk category.