A survival analysis of dropout among French swimmers.
Level 3 - non-randomized controlled study
Retrospective cohort study (by design analogy, non-clinical sports epidemiology)
PubMed 40110418 · doi:10.3389/fspor.2025.1509306
What was done
Researchers analyzed dropout patterns using registry data from 160,861 French swimmers under 21 years of age. They evaluated the influence of performance level, sex, and relative age (birth quarter). Chi-squared tests assessed the relationship between birth quarter and performance, and Kaplan-Meier survival curves were used to model dropout trends across age and sex.
What was found
Dropout rates peaked at 13.16 years for girls and 17.50 years for boys. At age 13, dropout was 8.7% for top 10% females (9.9% for males) compared to 78.1% for bottom 10% females (69.3% for males). By age 17, top 10% dropout rose to 39.6% for females and 28.6% for males, while bottom 10% dropout reached 91.7% for females and 83.4% for males. After age 13, female dropout increased more sharply than male dropout, with the largest sex gap (4.8%) occurring at 17.9 years. Relative age disparities in dropout peaked at age 12.7 for girls (10%) and at 14.7 for boys (8.1%).
Why it matters
These findings identify precise age windows where attrition accelerates in youth sports, demonstrating that biological sex, relative age effects, and early performance stratifications strongly predict sports discontinuation.
Limits
The study is based solely on competitive swimmers in France, which may not generalize to other sports or sporting cultures. The dataset does not capture qualitative reasons for dropping out, such as coaching practices, academic burden, injuries, or socioeconomic factors.
Cited by
- supports Most kids drop out of organized sports by age 13.