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Prevalence of therapeutic use exemptions at the Olympic Games and Paralympic Games: an analysis of data from 2016 to 2022
  1. Alan Vernec1,
  2. David Healy1,
  3. Tamar Banon1,
  4. Andrea Petroczi2,3
  1. 1Science and Medicine, World Anti-Doping Agency, Montreal, Quebec, Canada
  2. 2School of Life Sciences, Pharmacy and Chemistery, Kingston University, Kingston, UK
  3. 3Institute of Health Promotion & Sport Sciences, Eötvös Loránd University, Budapest, Hungary
  1. Correspondence to Dr Alan Vernec, Science and Medicine, World Anti-Doping Agency, Montreal, Canada; alan.vernec{at}wada-ama.org

Abstract

Objectives The objectives of this study are to describe the prevalence of therapeutic use exemptions (TUEs) among athletes competing in four Olympic and four Paralympic games. The secondary objective was to present the prohibited substance and methods classes associated with TUEs.

Methods Data from the Anti-Doping Administration and Management System were extracted for this cross-sectional observation study. Eight cohorts were created to include athletes with TUEs who competed in the Rio 2016, Pyeongchang 2018, Tokyo 2020 and Beijing 2022 Olympic and Paralympic games. Prevalence of TUEs and proportion of prohibited substance and methods classes were defined as percentages among all athletes competing at each games.

Results 28 583 athletes competed in four editions of the Olympic games. Total prevalence of athletes with TUEs was 0.90% among all competitors. At the four Paralympic games, a total of 9852 athletes competed and the total TUE prevalence was 2.76%. The most frequently observed substances associated with TUEs at the Summer Olympics were glucocorticoids (0.50% in Rio) and stimulants (0.39% in Tokyo). At the Summer Paralympics, diuretics (0.79% in Rio) and stimulants (0.75% in Tokyo) were the most common. Winter games had somewhat similar trends, although TUE numbers were very low.

Conclusions The number of athletes competing with valid TUEs at the Olympic and Paralympic games was <1% and <3%, respectively. Variations in substances and methods associated with TUEs for different medical conditions were identified. Nevertheless, numbers were low, further reaffirming that TUEs are not widespread in elite sport.

  • Sports medicine
  • Athletes
  • Para-Athletes
  • Health
  • Doping in Sports

Data availability statement

No data are available. We are not able to share the data publicly as Therapeutic Use Exemptions data in ADAMS contain sensitive medical information and are subject to WADA’s International Standard for Protection of Privacy and Personal Information.

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WHAT IS ALREADY KNOWN ON THIS TOPIC

  • The therapeutic use exemption (TUE) system is globally used by athletes and sports authorities; however, research on TUE prevalence is sparse. A prior study in 2020 reported that the prevalence of TUEs among athletes competing in individual events at the Olympic games was below 1.0%.

WHAT ARE THE FINDINGS

  • Results suggest that the prevalence of TUEs among athletes at four Olympic and four Paralympic games between 2016 and 2022 was consistently low at 1.0%–3.0%, respectively. This is the first report of TUEs among Paralympic athletes.

HOW MIGHT IT IMPACT ON CLINICAL PRACTICE IN THE FUTURE

  • This study contributes to our understanding of TUE utilisation for Olympic and Paralympic athletes. The results provide evidence discrediting the notion that TUEs are prone to misuse or serve as a means for ‘legitimized’ doping.

Introduction

Sport promotes the ideals of fair competition, inclusion, integrity and promotion of health.1–3 However, some athletes have sought unfair advantages via performance-enhancing substances or methods. In the last century, several international federations (IF) and then the International Olympic Committee (IOC) created antidoping rules including a list of prohibited substances, which were in force for the first time at the 1968 Winter games. Since 2004, the ‘List of Prohibited Substances and Methods’ (List) has been managed by the World Anti-Doping Agency (WADA) and has continued to expand over the years to include many commonly used therapeutic agents.4 Thus, there is a need for a rigorous therapeutic use exemption (TUE) process to allow athletes with legitimate medical conditions to receive appropriate treatment while competing in sport.5 6

The TUE system, widely accepted and globally used by athletes and sports authorities, is a fundamental part of sport and the antidoping environment. The International Standard for Therapeutic Use Exemptions (ISTUE) provides the robust framework for which TUEs may be granted. It was first adopted by WADA in 2004 and is updated on a regular basis with stakeholder input.

On occasion, there have been some concerns related to transparency and potential misuse of the TUE system.7 8 Nevertheless, experts in antidoping have supported the TUE policy and highlighted the absence of substantiated proof supporting the exploitation of TUEs by elite athletes or their support personnel.9–11 These misconceptions, sometimes propagated due to political motives, pose a threat to the principle of inclusivity in sport and the integrity of the World Anti-Doping program.9 12 Furthermore, due to fear of facing public scrutiny, athletes might refrain from essential medical treatments to avoid being stigmatised as a cheater.13

These concerns were mitigated by an article published in 2020 that investigated the prevalence of TUEs and the association of TUEs and medals at five Olympic games between 2010 and 2018 among athletes competing in individual sports.14 The findings indicated that the percentage of athletes with a valid TUE, competing in individual events, was less than 1%. Further, there was no association between being granted a TUE and the likelihood of winning a medal.14 The present study is a continuation, in part, of the 2020 article.

The primary objective was to evaluate the overall prevalence of TUEs at the four most recent summer and winter Olympic games to increase awareness and improve transparency of the TUE process. In addition, for the first time, the prevalence of TUEs at four editions of the Paralympic games is investigated to address the scarcity of the current body of literature on Paralympic athletes and management of their medical treatment needs. Furthermore, the study describes the different prohibited substance classes associated with TUEs during each edition of the games.

Methods

Study design

Secondary data on TUEs from Olympic and Paralympic athletes, originally collected in Anti-Doping Administration and Management System (ADAMS) as per WADA protocol, were evaluated in a cross-sectional observation study to assess the prevalence of TUEs at multiple Olympic and Paralympic games. This research falls within the scope of Article 2.5 of the Canadian Tri-Council Policy Statement on the Ethical Conduct for Research Involving Humans and is considered a quality assurance study, and hence exempt from an ethical review board.15 ADAMS is a secure web-based system that consolidates doping control-related information, including athlete whereabouts, testing history, laboratory results and TUEs.16 In this study, an assessment of data on TUEs among elite athletes competing in eight games, two Winter and two Summer Olympic and Paralympic games was conducted. The evaluated games included Rio 2016, Pyeongchang 2018, Tokyo 2020 and Beijing 2022. Despite the Tokyo games being held in 2021, the event retained the ‘Tokyo 2020’ title for both the Olympic and Paralympic events. The majority of TUEs valid for the games were granted in advance by National Anti-Doping Organizations (NADOs) or IFs and recognised by the IOC and the International Paralympic Committee (IPC). During the games, new TUEs were granted by TUE Committees affiliated with the IOC or IPC.

Data definition

Data were extracted from the ADAMS database operated by WADA, a secure web-based system that centralises global doping control-related information such as athlete whereabouts, testing history, laboratory results and TUEs. Identification and collection of relevant TUE data for inclusion in the study are challenging. While numerous athletes’ TUEs were recorded in the ADAMS database for a specific Olympic or Paralympic event, the presence of such data in ADAMS did not guarantee the actual participation of each athlete in the competition. Therefore, it was necessary to conduct a thorough verification process of the ADAMS data, for each athlete, by validating results from the IOC and IPC websites and confirming whether athletes competed at each games.

Cohort definition

Prior to each games, a list of potential athletes that may be competing in the upcoming Olympics and Paralympics was shared with WADA and merged with the ADAMS database. Following the verification process, athletes with TUEs granted or recognised but who did not compete at the games were excluded from the study. The final cohort was categorised into eight groups representing four Olympic and four Paralympic games (figure 1).

Figure 1

Study flow chart. ADAMS, Anti-Doping Administration and Management System; TUE, therapeutic use exemption; WADA, World Anti-Doping Agency.

Measures

TUE prevalence was defined as the proportion of athletes with valid TUEs among all athletes participating at each games. Prohibited substances and methods were presented as classifications as defined in the List, where the proportion of substances associated with TUEs per games was described as percentage of athletes with TUE for the specific substance category among all participating athletes.

Data analyses

TUE prevalence

This study was descriptive in nature, and no formal hypotheses were tested. Owing to the relatively limited number of athletes possessing TUEs across each Olympic and Paralympic games, descriptive statistics were employed in this research, primarily focusing on TUE prevalence among athletes expressed as a percentage. Given the restricted size of the cohorts, no further statistical analyses were performed due to the insufficient statistical power for additional testing.

Prohibited substance class

Substances and methods were categorised as outlined in the List: S1 Anabolic Agents; S2 Peptide hormones, growth factors, and related substances; S3 Beta-2 agonists; S4 Hormone and metabolic modulators; S5 Diuretics and masking agents; S6 Stimulants; S7 Narcotics; S8 Cannabinoids; S9 Glucocorticoids; and M2 (prohibited method) Chemical and physical manipulation. The percentage of prohibited substances associated with TUEs was presented at each respective games.

Equity, diversity and inclusion statement

This study includes cohorts of Olympic and Paralympic athletes, which represent diverse groups of elite athletes including all genders, ages, nationalities and medical conditions. The research team consists of experienced and junior researchers from diverse disciplines and backgrounds.

Results

Overall prevalence of TUEs

Over the course of the four Olympic games, 28 583 athletes participated, with approximately three times as many athletes competing in the Summer games as in the Winter games. Results indicated the total prevalence of TUEs was 0.90% among all competitors across all Olympic games. Rio displayed the highest TUE prevalence at 1.06%, while the lowest was observed in Tokyo at 0.74%, as described in figure 2.

Figure 2

Therapeutic use exemption prevalence among athletes at eight games (two Summer and two Winter Olympic1 and Paralympic2 games). 1A total of 28 583 athletes competed at the Olympic games between 2016 and 2022: 11 303 in Rio, 2963 in Pyeongchang, 11 420 in Tokyo, and 2897 in Beijing. 2For the Paralympic games, 9852 athletes competed between 2016 and 2022: 4328 in Rio, 567 in Pyeongchang, 4393 in Tokyo, and 564 in Beijing.

In the four editions of the Paralympic games, a total of 9852 athletes competed. Similarly to the Olympics, more athletes took part in the Summer Paralympics. Results indicated the total TUE prevalence across all Paralympic games was 2.76%. Pyeongchang displayed the highest prevalence at 4.06%, while the lowest was observed in Tokyo at 2.19%, as described in figure 2.

Prohibited substances or methods associated with TUEs: Olympics

The percentage of prohibited substances or methods, across two Summer and two Winter Olympic games, ranged from 0% to 0.5%. In Rio, 150 prohibited substances or methods were identified in granted TUEs, with 106 in Tokyo, 35 in Pyeongchang, and 37 in Beijing, for a total of 328 (among 258 athletes) across the Olympic games were observed. At the Summer games, stimulants (S6) were the most frequently encountered substances in Tokyo at 0.39%, while glucocorticoids (S9) had the highest prevalence in Rio at 0.50%.

In the Winter games, stimulants (S6) and hormone and metabolic modulators (S4) emerged as the most prevalent class of prohibited substances in the granted TUEs in Pyeongchang and Beijing, respectively. However, some TUEs were granted for multiple prohibited substances to treat the same medical condition. If, for example, an athlete had one TUEs for three substances, these would be counted three times in table 1 (percentage of prohibited substances and methods) but only once in figure 2 (TUE prevalence).

Table 1

Percentage of prohibited substances or methods associated with TUEs among all athletes competing at the 2016–2022 Olympic games

Prohibited substances or methods associated with TUEs: Paralympics

The data in table 2 illustrate the percentage of prohibited substances or methods associated with TUEs across two Summer and two Winter Paralympic games. The percentages ranged from 0% to 1.60%. In Rio, 173 substances were identified, while in Tokyo, Pyeongchang and Beijing, 131, 31 and 29 substances were identified, respectively, resulting in 364 substances (among 272 athletes) approved across all Paralympic games. During the Summer games in Rio, the highest percentage of prohibited substances was observed in hormone and metabolic modulators (S4; 0.67%) and diuretics (S5; 0.79%), whereas in Tokyo, stimulants (S6; 0.75%) were most predominant.

Table 2

Percentage of prohibited substances or methods associated with therapeutic use exemptions among all athletes competing at the 2016–2022 Paralympic games

In the Pyeongchang and Beijing Winter games, narcotics (S7) were the most common, with percentages of 1.41%–1.60% respectively. As indicated above, TUEs may be granted for more than one prohibited substance.

Medical conditions associated with TUEs

Various medical conditions were commonly associated with substances approved for TUEs. During the Olympic and Paralympic games, over 95.0% of narcotics (S7) were prescribed for analgesic purposes, while more than 90.0% of hormone and metabolic modulators (S4) were specifically employed in the treatment of diabetes; approximately 68.0% of stimulants (S6) were prescribed for attention-deficit hyperactivity disorder (ADHD) and 15.0% for anaphylaxis. Additionally, diuretics and masking agents (S5) were associated with a multitude of conditions such as cardiovascular and renal disease, spinal cord injury, ophthalmic conditions and acne (spironolactone). Glucocorticoids (S9) were primarily authorised for musculoskeletal conditions, autoimmune diseases, asthma, allergies and skin diseases.

Discussion

Assessing the prevalence of TUEs presents a formidable challenge due to the variability and number of athletes, potentially tens of millions, subject to antidoping rules. All new TUEs granted are entered in ADAMS by ADOs. This number averages between 3500 and 4000 per year, with a dip in 2021 and 2022 attributed to the COVID-19 pandemic. Each country, through its NADO, defines the scope of athletes subject to antidoping regulations including their need for TUE approval in advance of testing. In addition, international sports federations may specify athletes subject to doping control regulations. Consequently, the global athlete population remains extensive and constantly varying, making the accurate determination of TUE prevalence difficult at any given time. The defined dataset of athletes competing at Olympic and Paralympic games provides a unique opportunity to evaluate TUE prevalence in elite sport.

Prevalence of TUEs at Olympic and Paralympic games

The results indicate an average TUE prevalence at the last four Olympic games of 0.90%. These findings align with a 2020 study examining TUE prevalence in individual athlete competitions.14 Further, substances with high ergogenic potential, such as testosterone and erythropoietin (EPO), were not present in the TUEs approved for the games surveyed. This adds strength to the argument that the TUE process is not used to circumvent antidoping regulations.

At the last four Paralympic games, the TUE prevalence was 2.76%. A higher percentage among Paralympic athletes is expected, given the higher prevalence of complex medical conditions necessitating treatment with prohibited substances.17 These findings align with recent reports by WADA Independent Observers, suggesting a TUE prevalence between 2.20% and 4.10%.18–20

A notable decline in TUE prevalence was observed between the Rio and Tokyo Olympic and Paralympic games (1.06% to 0.74%; 3.03% to 2.19%, respectively). The reduction may be attributed to several factors such as increased education and awareness of changing List and TUE requirements, including the new article (4.1e) in the revised (2021) ISTUE.16 There may have been disparities in the medical prescribing practices of local physicians who treated visiting athletes at games venues, between Rio and Tokyo. Furthermore, there may have been an influence due to the COVID-19 pandemic and the stringent safety measures implemented.21 At the Tokyo games, athletes were asked to arrive shortly before and depart shortly after their events concluded, significantly limiting their days of attendance compared with previous Olympics.22 23 Consequently, this may have impacted the frequency and duration of illness and injury during the games, thereby diminishing the need for treatment and potential TUE application.

Prohibited substance evaluation

Differences were observed in prohibited substances and methods by class, associated with TUEs in subsequent games, which may have varied due to List changes, country-specific restrictions and the COVID-19 pandemic.

Olympic games

Analyses of the TUE substance classes identified several variations between the Rio and Tokyo Summer Olympic games. Stimulants (S6) increased from 0.28% to 0.39%, reflecting a global trend of increased diagnosis of attention-deficit hyperactivity disorder, demanding treatment with stimulants.24

In contrast, a decrease in TUEs for glucocorticoids (S9) was observed, with a reduction from 0.50% in Rio to 0.17% in Tokyo. This drop was the largest noted across all the games evaluated. It could be attributed to the introduction of ISTUE Article 4.1(e) which allows athletes the right to apply retroactively for a TUE for the use of a substance only prohibited in-competition but used out of competition. This reduced the burden on ADOs to assess unnecessary TUE applications prior to competition. Leading up to the games, WADA provided educational events for ADOs, athletes, physicians and other athlete support personnel and resources such as guidelines for the ISTUE and webinars.25 It should be noted that since 2022, the prohibition of glucocorticoids was expanded to include all injectable routes of administration. This may impact the number of glucocorticoid TUEs for future games. Additionally, a decrease in TUEs for narcotics (S7) was observed, with a reduction from 8 (0.07%) in Rio to none in Tokyo. Strict Japanese regulations regarding narcotics may have impacted their availability and use in Tokyo 2020.26

Paralympic games

An analysis of the TUE substances identified several variations between the Summer Paralympic games. There were notable reductions in TUEs for hormone and metabolic modulators (S4) 0.67% to 0.25%, diuretics (S5) 0.79% to 0.34% and narcotics (S7) 0.62% to 0.23%. One could hypothesise that the reduction in narcotics observed occurred for reasons previously discussed. In contrast, an increase in cannabinoids (S8) was observed (0.02% to 0.18%). This coincides with several countries across the globe relaxing laws regarding the use of medical cannabis.27 28

This study presents several methodological strengths. First, the adoption of a cross-sectional study design enabled the comprehensive evaluation of ADAMS TUE data during four Olympic and four Paralympic games. This design facilitated the assessment of period prevalence of TUEs during each games, involving athletes with TUEs relative to the total number of competing athletes.

Strengths and limitations

It is a mandatory requirement for ADOs to upload all granted TUEs into ADAMS. WADA works closely with, and monitors ADOs to ensure compliance with these regulations. Thus, it is extremely unlikely that a TUE was not recorded for these events.

In general, the assessment of a proportion of athletes with medical conditions necessitating a TUE is difficult to evaluate due to the large number of athletes competing globally. Therefore, another strength is the utilisation of data from high-profile competitions, involving diverse sports, nationalities, age and gender, within a singular study framework.

However, it is important to note the small cohort sizes at the Winter games in this study, which ranged from 22 to 29 athletes with TUEs. Due to the small sizes of these cohorts, results were described but difficult to interpret.

This study has acknowledged further limitations including the potential overestimation of TUE prevalence. Data on athletes’ event dates were not available for this study; thus, TUEs granted at the games by the IOC or IPC may have been prior or post their competition yet counted as a TUE during the games. In addition, a limitation may be due to disparities in the data verification process. The data extracted from ADAMS were validated by comparing publicly accessible results from the IOC and IPC websites. Athletes without Olympic or Paralympic results were excluded from the study. Thus, inaccurate data entry may have resulted in the misidentification and omission of athletes with TUEs.

Conclusion

The results of this study are consistent with previous findings, showing that TUE prevalence among Olympic athletes at the games remains below 1.0%. For Paralympic athletes, the TUE prevalence was just below 3.0%, which was not unexpected due to the complex medical conditions common to these athletes.

Continued monitoring of TUEs at Olympic and Paralympic games is essential to ensure transparency and to instil confidence in the sporting community. Outcomes from analyses of future monitoring data may help inform policy and education initiatives in sport and antidoping.

Data availability statement

No data are available. We are not able to share the data publicly as Therapeutic Use Exemptions data in ADAMS contain sensitive medical information and are subject to WADA’s International Standard for Protection of Privacy and Personal Information.

Ethics statements

Patient consent for publication

Ethics approval

This research falls within the scope of Article 2.5 of the Canadian Tri-Council Policy Statement on the Ethical Conduct for Research Involving Humans and is considered a quality assurance study, and hence exempt from an ethical review board.

References

Footnotes

  • Contributors AV and DH: study conception and design. DH and TB: data analysis. All authors: interpretation of results, draft manuscript preparation. AV and AP: draft review and revision and critical feedback on manuscript. AV is the guarantor of this study.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Provenance and peer review Not commissioned; externally peer reviewed.