Pre-race screening and stratification predicts adverse events-A 4-year study in 29585 ultra-marathon entrants, SAFER X.

Background: Pre-race screening and risk stratification in recreational endurance runners may predict adverse events (AEs) during a race.

Aim: To determine if pre-race screening and risk stratification predict AEs during a race.

Methods: A total of 29 585 participants (Male 71.1%, average age = 42.1 years; Female 28.9%, average age = 40.2 years) at the Two Oceans ultra-marathon races (56 km) completed a pre-race medical screening questionnaire and were risk stratified into four pre-specified groups [very high risk (VHR; existing cardiovascular disease-CVD:3.2%), high risk (HR; risk factors for CVD:10.5%), intermediate risk (IR; existing other chronic disease, medication use or injury:53.3%), and low risk (LR:33.0%)]. Race starters, finishers, and medical encounters (ME) were recorded. Did-not-start (DNS) rate (per 1000 entrants that did-not-start), did-not-finish (DNF) rate (per 1000 starters that did-not-finish), AE rate [per 1000 starters that either DNF or had an ME], and ME rate (per 1000 starters with an ME) were compared across risk categories.

Results: Adverse events were significantly higher (per 1000 starters; 95%CI) in the VHR (68.9; 52.4-89.9:P = .0407) compared with the LR (51.3; 46.5-56.7). The DNS rate was significantly different between the IR (190.3; 184.0-196.9) and LR (207.4; 199.2-216.0: P = .0011). DNF rates were not different in the VHR (56.4; 41.9-75.9) compared to LR (44.2; 39.7-49.1: P = .1295), and ME rate was also not different between risk categories, however, VHR (12.9; 7.0-23.9) was approaching significance compared to LR (6.9; 5.2-9.1: P = .0662).

Conclusion: Pre-race medical screening and risk stratification may identify athletes at higher risk of AEs. Further studies should be performed in larger cohorts to clarify the role of pre-race medical screening in reducing AEs in endurance runners.