A threshold model to determine the association between race rides and fall risk for early career (apprentice) jockeys.

Objectives: To identify descriptors associated with success in apprentice jockeys and to determine optimum numbers of jockeys for safer race riding.

Design: Retrospective cohort study.

Methods: Incidence-rates for jockey falls and success (wins per 1,000 race-starts), time and number of races spent at different apprentice levels were calculated for 807 apprentice and professional jockeys over 19 years of Thoroughbred flat racing in New Zealand (n = 524,551 race-starts). Survival analysis was used to compare career progression for jockeys that fell and those that did not, and individual seasonal fall incidence-rates were modelled.

Results: Apprentices had the highest fall incidence-rate in their first year of race riding (2.4, interquartile range 1.7-3.2 vs 1.1, interquartile range 1.0-1.2, p < 0.05) and a lower success incidence-rate compared to non-apprentice jockeys (71, interquartile range 67-75 vs 97 interquartile range 96-98, p < 0.05). Jockeys who fell during their apprenticeship rode in more race rides to progress towards professional status than those who did not. There was an inverse power relationship between fall incidence-rate and race rides per season for jockeys, with the inflection point at 33 rides per season. Half (48 %) of the jockeys rode fewer than 33 rides per season.

Conclusions: There is a surplus number of jockeys, riding at high fall risk, produced than is required by the number of race riding opportunities. Greater investment into the fitness, education and selection of a smaller cohort of dedicated apprentices, may be beneficial to reduce the risk of early career fall or injury in jockeys and requires further investigation.