IOC REDs CAT2 Severity/Risk Assessment tool that implements primary, secondary and potential indicators into a traffic-light criterion outlined in figure 6
| REDs indicator | References |
| Severe primary indicators (count as 2 primary indicators) | |
| Primary amenorrhoea (females: primary amenorrhoea is indicated when there has been a failure to menstruate by age 15 in the presence of normal secondary sexual development (two SD above the mean of 13 years), or within 5 years after breast development if that occurs before age 10); or prolonged secondary amenorrhoea (absence of 12 or more consecutive menstrual cycles) due to FHA | 6 141 286–288 |
| Clinically low free or total testosterone (males: below the reference range) | 49 92 121 289–291 |
| Primary indicators | |
| Secondary amenorrhoea (females: absence of 3–11 consecutive menstrual cycles) caused by FHA | 6 141 286 287 |
| Subclinically low total or free testosterone (males: within the lowest 25% (quartile) of the reference range) | 49 92 95 121 289–291 |
| Subclinically or clinically low total or free T3 (within or below the lowest 25% (quartile) of the reference range) | 49 219 290 |
| History of ≥1 high-risk (femoral neck, sacrum, pelvis) or ≥2 low-risk BSI (all other BSI locations) within the previous 2 years or absence of ≥6 months from training due to BSI in the previous 2 years | 206 286 292 |
|
Pre-menopausal females and males <50 years old: BMD Z-score* <−1 at the lumbar spine, total hip or femoral neck or decrease in BMD Z-score from prior testing Children/adolescents: BMD Z-score* <−1 at the lumbar spine or TBLH or decrease in BMD Z-score from prior testing (can occur from bone loss or inadequate bone accrual) | 119 120 123 293 |
| A negative deviation of a paediatric or adolescent athlete’s previous growth trajectory (height and/or weight) | 294 295 |
| An elevated score for the EDE-Q global (>2.30 in females; >1.68 in males) and/or clinically diagnosed DSM-5-TR-defined Eating Disorder (only one primary indicator for either or both outcomes) | 68 80 276 296–298 |
| Secondary indicators | |
| Oligomenorrhoea caused by FHA (>35 days between periods for a maximum of 8 periods/year) | 6 141 286 287 |
| History of 1 low-risk BSI (see high vs low-risk definition above) within the previous 2 years and absence of <6 months from training due to BSI in the previous 2 years | 206 286 292 |
| Elevated total or LDL cholesterol (above reference range) | 191 235 299 |
| Clinically diagnosed depression and/or anxiety (only one secondary indicator for either or both outcomes) | 296 300 301 |
| Potential indicators (not scored, emerging)†† | |
| Subclinically or clinically low IGF-1 (within or below the lowest 25% (quartile) of the reference range) | 11 168 290 |
| Clinically low blood glucose (below the reference range) | 11 80 |
| Clinically low blood insulin (below the reference range) | 45 127 290 |
| Chronically poor or sudden decline in iron studies (eg, ferritin, iron, transferrin) and/or haemoglobin | 169 302–304 |
| Lack of ovulation (via urinary ovulation detection) | 287 305–307 |
| Elevated resting AM or 24-hour urine cortisol (above the reference range or significant change for an individual) | 45 127 179 290 |
| Urinary incontinence (females) | 230 308 309 |
| GI or liver dysfunction/adverse GI symptoms at rest and during exercise | 8 214 310 |
| Reduced or low RMR <30 kcal/kg FFM/day or RMR ratio <0.90 | 9 219 311 312 |
| Reduced or low libido/sex drive (especially in males) and decreased morning erections | 108–111 |
| Symptomatic orthostatic hypotension | 294 313 314 |
| Bradycardia (HR <40 in adult athletes; HR <50 in adolescent athletes) | 294 295 313 |
| Low systolic or diastolic BP (<90/60 mm Hg) | 315 316 |
| Sleep disturbances | 50 76 317 |
| Psychological symptoms (eg, increased stress, anxiety, mood changes, body dissatisfaction and/or body dysmorphia) | 8 68 296 300 301 318 |
| Exercise dependence/addiction | 68 80 319 320 |
| Low BMI | 286 294 295 |
Every indicator above requires consideration of a non-LEA-mediated differential diagnosis. All indicators apply to females and males unless indicated. Menstrual cycle status and endogenous sex hormone levels cannot be accurately assessed in athletes who are taking sex hormone-altering medications (eg, hormone-based contraceptives), and thyroid hormone status indicators cannot be accurately assessed in athletes who are taking thyroid medications. All laboratory values should be interpreted in the context of age-appropriate and sex-appropriate and laboratory-specific reference ranges. Most REDs data and associated thresholds have been established in premenopausal/andropausal adults unless indicated. Disclaimer: this tool should not be used in isolation nor solely for diagnosis, as every indicator requires clinical consideration of a non-LEA-mediated differential diagnosis. Furthermore, the tool is less reliable in situations where it is impossible to assess all indicators (eg, menstrual cycle status in females who are using hormonal contraception). This tool is not a substitute for professional clinical diagnosis, advice and/or treatment from a physician-led team of REDs health and performance experts
Adolescent refers to <18 years of age.
*BMD assessed via DXA within ≤6 months. In some situations, using a Z-score from another skeletal site may be warranted (eg, distal 1/3 radius when other sites cannot be measured or including proximal femoral measurements in some older (>15 years) adolescents for whom longitudinal BMD monitoring into adulthood is indicated).119 321 A true BMD decrease (from prior testing) is ideally assessed in comparison to the individual facilities DXA’s LSC based on the facilities calculated coefficient of variation (%CV). As established by ISCD, at the very least, LSC should be 5.3%, 5.0% and 6.9% for the spine, hip and femoral neck to detect a clinical change.120 321
†Potential indicators are purposefully vague in quantification, pending further research to quantify parameters and cut-offs more accurately.
BMD, bone mineral density; BMI, body mass index; BP, blood pressure; BSI, bone stress injuries; DSM-5-TR, Diagnostic and Statistical Manual of Mental Disorders, fifth edition, text revision; DXA, dual-energy X-ray absorptiometry; EDE-Q, Eating Disorder Examination Questionnaire; FFM, fat-free mass; FHA, functional hypothalamic amenorrhoea; GI, gastrointestinal; HR, heart rate; IGF-1, insulin-like growth factor 1; ISCD, International Society for Clinical Densitometry; LDL, low-density lipoprotein; LSC, least significant change; RMR, resting metabolic rate; T3, triiodothyronine; T, testosterone; TBLH, total body less head.