Objectives: To determine the prevalence of self-reported pre-race chronic medical conditions and allergies in ultramarathon race entrants and to explore if these are associated with an increased risk of race-day medical encounters (MEs).
Methods: Data from two voluntary open-ended pre-race medical screening questions (Q1 - history of allergies; Q2 - history of chronic medical conditions/prescription medication use) were collected in 133641 Comrades Marathon race entrants (2014-2019). Race-day ME data collected prospectively over 6 years are reported as incidence (per 1000 starters) and incidence ratios (IR: 95%CI's).
Results: Pre-race medical screening questions identified race entrants with a history of chronic medical conditions and/or prescription medication use (6.9%) and allergies (7.4%). The % entrants with risk factors for cardiovascular disease (CVD) was 30% and being older (>45 years) or male (27.5%) were the most frequent CVD risk factors. 0.3% of entrants reported existing CVD. The overall incidence of MEs was 20/1000 race starters. MEs were significantly higher in race entrants reporting a 'yes' to Q1 (allergies) (IR = 1.3; 1.1-1.5) (p = 0.014) or Q2 (chronic medical conditions and/or prescription medication use) (IR = 1.3; 1.1-1.5) (p = 0.0006).
Conclusions: Voluntary completion of two open-ended questions identified chronic medical conditions and/or prescription medication use in 6.9% and allergies in 7.4% of ultramarathon race entrants. This is lower than that reported for other races that implemented compulsory completion of a more comprehensive pre-screening questionnaire. Despite potential under-reporting, a pre-race self-reported history of chronic medical conditions and allergies was associated with a higher risk of race-day MEs.
Keywords: Running; cardiovascular disease; chronic disease; pre-participation medical screening; risk factors.