Universal Precautions Help Decrease Rate of Exercise-Related Death in Patient With Sickle Cell Trait

Exercise-induced death has previously been associated with sickle cell trait. Evidence for this association was based initially on case reports from military recruits. Subsequently, a landmark population-based study conducted by the U.S. armed forces and published in 1987 indicated that during basic training, recruits with sickle cell trait had a relative risk of death of 27, when compared to those without sickle cell trait.¹  Recently, multiple Division I football players with sickle cell trait have sustained injuries or died while practicing. On behalf of the surviving families, multiple lawsuits were filed against the National Collegiate Athletic Association (NCAA), the Division I institution, or both. Subsequently, the NCAA implemented a mandatory edict that all student athletes in Divisions I, II, and III receive sickle cell trait testing. Despite the public health premise that screening for a genetic disease should be coupled with genetic counseling for informed reproductive decision, the NCCA’s decree of mandatory screening was not accompanied by compulsory genetic counseling of the athlete, their significant other, or both. However, the NCAA policy did include a provision for the athlete to opt out of the sickle cell trait screening provided that the athlete sign a waiver of liability against the NCAA and their institution.

Noting concerns about the NCAA’s policy requiring mandatory screening for sickle cell trait of all incoming student athletes, ASH convened a 2011 workshop of experts to evaluate the evidence for the association between sickle cell trait and death during rigorous exercise. The experts reviewed all of the available literature, including evidence from branches of the U.S. armed forces that instituted universal precautions to prevent heat-induced and exercise-induced injury and death and noted a significant decline in death for both black recruits and white recruits during basic training. Ultimately, the experts determined that current scientific evidence did not justify this requirement and was not consistent with good medical practice or established principles of public health ethics. Based on the expert review and discussion, ASH released a Statement on Screening for Sickle Cell Trait and Athletic Participation in 2012, which specifically, recommends the implementation of universal interventions to reduce exertion-related injuries and deaths because this approach can be effective for all athletes, irrespective of their sickle cell status. The policy statement notes that the NCAA’s screening policy has unintended consequences, including, but not limited to harming the student athlete and the larger community of individuals with sickle cell trait if other risk factors are not considered and if the application of their mandate resulted in stigmatization and possible discrimination. Finally, the ASH policy statement calls for more biomedical and population-based research on sickle cell trait and adverse health outcomes. The provisions in the ASH policy statement are available on the ASH website.

We now have the strongest possible evidence that implementing universal precautions to prevent dehydration and heat-induced and exercise-induced illness, as outlined by the U.S. armed forces,²  will not result in an increased rate of death in individuals with sickle cell trait, when compared to those without sickle cell trait. In a large retrospective analysis of U.S. armed service recruits, Dr. D. Alan Nelson and colleagues employed Cox proportional-hazards models to test whether death and exertional rhabdomyolysis occurred more frequently in those with sickle cell trait versus those without. Sickle cell trait status was determined in 47,944 black soldiers, of whom 7.4 percent had sickle cell trait. In soldiers with sickle cell trait (vs. those without), the percentage of all cause of death was exactly the same (0.2%), with no statistical difference in the hazard ratio of death observed (hazard ratio, 0.99; 95% confidence interval [CI], 0.46 to 2.13; p=0.97). However, for exertional rhabdomyolysis there was an absolute difference in those with sickle cell trait (vs. those without) of 0.4 percent (1.2% vs. 0.8%), with an increase in the corresponding hazard ratio (1.54 [95% CI, 1.12 to 2.12]; p=0.008).