Related Experiment Video
Updated: Oct 19, 2025

Inverse Probability of Treatment Weighting Propensity Score using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Heads-Up: Risk-Specific Neurodegenerative Mortality and Years-Saved Analysis on the US Olympian Cohort
Moi Yamazaki1, Quentin De Larochelambert1, Guillaume Sauliere1
1Institute of Biomedical and Epidemiological Research in Sport (IRMES), National Institute of Sport, Expertise, and Performance (INSEP), Paris, France.
Abstract:
Purpose: This study aimed to identify the risk of neurodegenerative death (ND) that former Olympians endure due to their participation in sports grouped based on presumed repeated shocks to the head, and to understand the impact of their participation in such elite sports on their total longevity. Materials and Methods: The cohort included all former US Olympians, who participated in the Olympic Games (OG) between 1948 and 1972, and whose vital status and causes of death were verified (n = 2,193). Olympic sports were classified into three categories of exposure: Collision (the highest presumed risk of repeated shocks to the head), Contact, and No-Contact. The Fine-Gray competing risk regression model was used to compare the risk of ND where the No-Contact category was a reference group. The years-saved analysis was performed to quantify the number of years saved or lost to ND and total longevity compared with the US general population. Results: A total of 65 NDs were identified. Collision sports Olympians had a 3.11 (95% CI: 1.31-7.40) higher risk of ND while the Contact group showed a risk of 0.56 (95% CI: 0.21-1.48) compared with the No-Contact sports Olympians. Compared with the general population, the Collision group lost 0.61 (95% CI: -1.16-0.06) years of life from ND, while the Contact group saved 0.4 (95% CI: 0.26-0.54) and the No-Contact group saved 0.09 (-0.09-0.28) years of life up to the age of 90. Regarding the total longevity, Collision, Contact, and No-Contact groups saved 4.67 (95% CI: 3.13-6.22), 5.8 (95% CI: 4.93-6.67), and 6.24 (95% CI: 5.57-6.92) years of life, respectively, from all causes of death. Conclusion: There is an elevated risk of ND among US Olympians, who engaged in sports with the highest presumed risk of repeated shocks to the head compared with those exposed to no such hazard. Such risk does not jeopardize the total longevity among Olympians in Collision sports.
Related Concept Videos
Actuarial Approach
Consider the example of a high-risk surgical procedure with significant early-stage mortality. A two-year clinical study is conducted,...
Cancer Survival Analysis
Comparing the Survival Analysis of Two or More Groups
Assumptions of Survival Analysis
Relative Risk
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...

