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Comment on: “Comparison of Female Athlete Triad Coalition and RED-S risk assessment tools”

Recently, Koltun et al. (2019) published a comparison of the risk assessment tools and return to play (RTP) guidelines developed by the Female Athlete Triad Coalition (Triad CRA; De Souza, Nattiv, et al., 2014) and International Olympic Committee (IOC) Relative Energy Deficiency in Sport (RED-S) Working Group (RED-S CAT; Mountjoy et al., 2015) for exercising women. The authors found that the RED-S CAT classified many more women (71.7%) than the Triad CRA (25.3%) as fully cleared for sporting activities (Koltun et al., 2019). Comparing the two tools is an important step for understanding how athletes may be cleared for sport when facing an energy deficit based on which tool was used. Prior to the publication by Koltun et al. (2019) we published a similar comparison (Holtzman et al., 2019) and found conflicting results: Triad CRA fully cleared 28.9% of athletes and RED-S CAT fully cleared 3.8% of athletes. While the two studies agree with Triad CRA scores, the RED-S CAT scores are divergent and a comment on the cause of this divergence is warranted. Unfortunately, Koltun et al. (2019) incorrectly implemented the RED-S guidelines. Throughout the study, outdated RTP guidelines (Mountjoy et al., 2014) were used instead of the current RED-S CAT (Mountjoy et al., 2015). The RED-S RTP guidelines were revised significantly with publication of the RED-S CAT, and these changes could affect the outcomes of the study. Most notably for this comparison, the criteria for defining menstrual dysfunction were altered: the current REDS CAT defines primary amenorrhoea as failure to achieve menarche by age 15 and secondary amenorrhoea as functional hypothalamic amenorrhoea (FHA) lasting >3 months, while the original guidelines use age 16 for primary amenorrhoea and secondary amenorrhoea as FHA >6 months. Koltun et al. (2019) note that “an important difference in the risk factors identified by each tool” is the primary amenorrhoea criterion, yet this difference is erroneously produced. Had the authors used the most up-to-date guidelines (Mountjoy et al., 2015), they would have found harmony on both the primary and secondary amenorrhoea items. In our study (Holtzman et al., 2019), we faithfully reproduced the RED-S CAT’s suggestions for age of menarche and length of secondary amenorrhoea. Koltun et al. additionally made several errors in their evaluation of bone health for both the Triad CRA and RED-S CAT. For athletes <20 years, Koltun et al. measured bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) at the total body and lumbar spine. Despite their statement to the contrary, this is not consistent with current International Society for Clinical Densitometry (ISCD) guidelines (Gordon et al., 2014; Lewiecki et al., 2016), which recommend measuring the total body less head – not the total body – in addition to the lumbar spine in patients <20 years. Furthermore, the authors cite the 2007 ISCD guidelines (Lewiecki et al., 2008) instead of the more recent 2013 paediatric ISCD guidelines and 2015 ISCD guidelines (Lewiecki et al., 2016). In evaluating bone health for the purposes of the RED-S CAT, Koltun et al. only considered L2–L4 lumbar spine measurements, invoking “alarm criteria” from an IOC Medical Commission position statement published in 2013 (Sundgot-Borgen et al., 2013). Under ISCD guidelines, measurement of the L1–L4 region should be used for the lumbar spine and vertebrae should only be excluded should they have local structural change or artefact (Lewiecki et al., 2016). The original RED-S Consensus Statement (Mountjoy et al., 2014) further states that the total body less head can be used in adolescents, and references the 2014 Female Athlete Triad Coalition Consensus Statement (De Souza, Nattiv, et al., 2014) for DXA BMD measurement, which indicates lumbar spine, total hip, and femoral neck as sites for measurement in adults. These errors alone do not entirely account for the divergence in results between the Koltun et al. study and ours. First, sample ages were different: Koltun et al. included women 18–35 years while we evaluated girls and women 15–30 years. Second, Koltun et al. excluded anyone with a current eating disorder or other psychiatric diagnosis. Our study was intended to reflect typical clinical population of athletes without strict exclusion criteria, and these eating disorder/psychiatric disorder patients were included in our sample. Additionally, the Koltun et al. study recruited healthy women completing ≥2 h/week of purposeful physical activity; our sample had a ≥4 h/week threshold for exercise, all participants reported participating in a sport, and all were recruited in a sports medicine clinical setting. Thus, our sample more accurately represented a population of athletes, though this group could potentially be a sample of a sicker population. In terms of methodology, Koltun et al. did not evaluate the “prolonged relative energy deficiency” RED-S risk factor. In our study, we used restrictive dietary habits or self-reported disordered eating (current or past history) as a proxy for this marker, and it was by far the most inclusive moderate risk criterion, with 77.0% of our moderate risk athletes screening positive. While we did not evaluate the duration of these behaviours in our study, in our clinical practice, a patient reporting such behaviours acutely raises our suspicion of energy deficiency. Many other moderate risk RED-S risk factors were not evaluated by Koltun et al., but this item represented the starkest difference. In Figure 2 of the Koltun et al. report, the authors note a number of RED-S CAT moderate risk criteria as “Not Applicable” and in the text remark that some of these markers are not specifically defined by the RED-S CAT. However, the authors do not comment on their exclusion of ECG (which, in the RED-S CAT, is a high-risk criterion, not moderate risk) or JOURNAL OF SPORTS SCIENCES 2020, VOL. 38, NO. 9, 994–995 https://doi.org/10.1080/02640414.2020.1738119