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To screen or not to screen for sickle cell trait in American football?
  1. Kimberly G Harmon1,
  2. Jonathan A Drezner2,
  3. Douglas J Casa3
  1. 1Department of Family Medicine and Sports Medicine and Orthopaedics, Hall Health Sports Medicine Clinic, University of Washington, Seattle, Washington, USA
  2. 2Department of Family Medicine, Hall Health Sports Medicine Clinic, University of Washington, Seattle, Washington, USA
  3. 3Department of Kinesiology, Neag School of Education, University of Connecticut, Connecticut, USA
  1. Correspondence to Kimberly G Harmon, Departments of Family Medicine and Sports Medicine and Orthopaedics, 4060 East Stevens Circle, Hall Health Sports Medicine Clinic, University of Washington, Seattle, WA 98195, USA; kharmon{at}

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Sickle cell trait (SCT) in America football athletes has been a topic of recent media attention. The deaths of college football athletes Ereck Plancher, Aaron O’Neil, Dale Lloyd and others as well as the recent decision of Pittsburgh Steelers safety Ryan Clark to forego a play-off game at altitude in Denver have contributed to the characterisation in the lay press of SCT as a dangerous condition. In fact, deaths in National Collegiate Athletic Association (NCAA) football players and concern from NCAA member institutions for the health and safety of student athletes led to legislation mandating all Division I athletes be screened or know their SCT status since August of 2010. On 26th January 2012, the American Society for Haematology (ASH) denounced the NCAA position. The disparity between these two positions is striking and deserves comment.

The relevant facts

SCT is common, with 1 in 14 (7%) of blacks having SCT and up to 1 in 625 Caucasians carrying the gene. SCT is generally considered benign and provides a survival advantage in areas endemic with malaria. In military recruits, the risk of exertional death is 28–30 times higher in those with SCT compared with those without SCT.1 In Division I football players, the risk of exertional death in those with SCT is 1:827 versus 1:30 578 in those without (a 37-fold greater risk in athletes with SCT).2 Exertional deaths have been reported in other athletes (basketball, track) but the vast majority of exertional deaths in those with SCT have occurred in African–American athletes playing Division I football. Although there is a clear association of exertional death with SCT, the precise pathophysiology of death is unknown.3

Concerns abound

ASH expressed many concerns in their statement including the disclosure of protected health information and mandatory (vs voluntary) screening. However, some of these concerns may not apply to the college athletic setting. The transmission of medical information in an elite team setting is very different than informing an employer regarding personal medical information. Coaches are necessarily informed of not just SCT status, but of any medical condition a player has which may affect ability to perform or compromise their safety. Informing a coach of a player's SCT status is not much different than discussing an athlete with diabetes or asthma and precautions that should be undertaken.

ASH also recommends using universal preventive interventions for all athletes/recruits undergoing training. They recommend monitoring heat acclimatisation and work–rest cycles adjusted for the environment, implementing guidelines for hydration, and maintaining staff preparedness for early and rapid detection and treatment of heat illness. This approach has been used in the US Army although other branches of the military still opt to screen. Although these hydration and acclimation measures are advocated by the NCAA, deaths have occurred.

As the NCAA looks for additional strategies, it is unclear whether knowing an athlete's SCT status will prevent exertional death. Proponents of screening support directed education of athletes with SCT, and increased awareness and emergency planning for coaches and medical staff responsible for players with SCT. The last decade saw at least nine exertional deaths in NCAA athletes with SCT – three of these individuals were known to have SCT. Screening low-risk groups is likely to be ineffective. Perhaps the NCAA should focus screening on groups such as football athletes with demonstrated excessive risk.

On one hand, the NCAA has the duty to protect the health and safety of its athletes and a known high-risk group. NCAA policy provides all athletes with education on SCT as well as the option to opt out of screening without penalty to participation. On the other hand, ASH expresses concern that ‘the NCAA policy attributes risk imprecisely, obscures consideration of other relevant risk factors, fails to incorporate appropriate counselling’ and has the potential to harm the student athlete and the larger community. Caught in the middle is the sports physician.

Clearly, this debate is just maturing with major issues obscured by legal, societal and ethical concerns. In the meantime, clinical judgment and experience suggest the following:

  • targeted screening of high-risk groups;

  • aggressive educational intervention for athletes with SCT and those who supervise them (sports coaches, strength and conditioning coaches and medical staff);

  • allowing appropriate time and access for hydration of athletes;

  • gradual acclimation to novel activity and the heat;

  • modification of activity in the heat and at altitude;

  • appropriate strength and conditioning programmes developed by qualified strength and conditioning coaches;

  • punitive exercise and conditioning sessions be prohibited;

  • early recognition of athletes who are struggling, so they can immediately be allowed to rest and not pushed past their physiologic limit;

  • adequate emergency planning for all individuals responsible for athletes during training and conditioning.


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  • Competing interests None.

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