Differences in screening and treating relative energy deficiency in sport between the United States of America and Japan

BACKGROUND: The diagnosis and treatment of relative energy deficiency in sport (RED-S) are challenging owing to variations in symptoms and the absence of specific guidelines. This study aimed to investigate differences in the diagnosis and follow-up of RED-S, its consequences, and related factors among sports medicine physicians with different backgrounds in Japan and the USA and examine the differences between the two countries.METHODS: An anonymous survey regarding the diagnosis and treatment processes of RED-S was distributed to sports medicine physicians via email. Respondents included 58 sports medicine physicians from the USA and 241 from Japan.RESULTS: The findings showed that 77.6% of the US physicians screened athletes for RED-S, whereas 17.5% of their Japanese counterparts did so. Moreover, 98.3% and 36.7% of the US and Japanese physicians, respectively, answered that they screened athletes for eating disorders upon suspicion of low energy availability. Logistic regression analysis revealed that the number of US sports medicine physicians who screened athletes for the female athlete triad (Triad) and RED-S (odds ratio [OR] = 12.78, P<0.001) and adhered to specific criteria for athlete suspension and return-to-play (OR=33.67, P<0.01) was higher than that of their Japanese counterparts.CONCLUSIONS: The prevalence of RED-S-related screening and treatment differed between US and Japanese sports medicine physicians. Educating sports medicine physicians about the diagnosis and treatment of athletes with possible signs of RED-S is important in treating female athletes and further investigations are required to identify why the physicians screened/not screened the athletes.