Debate continues over merits of screening vs. intervention for athletes with sickle cell trait

The NCAA plans to expand testing, while ASH says preventive measures will offer better protection to carriers.

  • HemOnc Today, March 25, 2012

In 1974, Polie Poitier — a 19-year-old freshman football player at the University of Colorado — became the first documented college athlete to die from complications related to sickle cell trait.

Twenty-two other young athletes with sickle cell trait have died in the past 30 years, and complications from the trait were considered the primary cause of death in 15 of those cases, according to the US National Registry of Sudden Death in Athletes.

The deaths have sparked a debate about whether universal screening or universal precautions are more likely to protect student athletes.

The National Collegiate Athletic Association adopted a policy in 2010 that requires incoming student athletes at Division I institutions to undergo screening for sickle cell trait, which — in rare cases — can trigger severe distress during periods of intense physical activity. The schools determined mandatory screening “is the best way to raise awareness among student athletes and coaches and prevent potential serious illness or death in student athletes who may carry the trait,” according to a background statement on the NCAA website.

The screening requirement — which followed recommendations from the National Athletic Trainers Association and the College of American Pathologists — is scheduled to extend to Division II institutions this summer, and Division III membership may vote on a similar proposal in 2013.

The American Society of Hematology, however, issued a policy statement in January opposing mandatory screening of athletes. ASH instead recommended athletic programs implement preventive interventions to reduce the risk of exertion-related injuries or death among all athletes.

Scott Anderson, ATC
Scott Anderson, ATC, head athletic trainer at the University of Oklahoma and former co-chair of the Inter-Association Task Force on Sickle Cell Trait and the Athlete, said screening is an effective weapon against deaths related to sickle cell trait.

Photo courtesy of University of Oklahoma, reprinted with permission

“Current scientific evidence does not justify this [screening] requirement. It is also not consistent with good medical practice or established principles of public health ethics,” the policy statement reads. “Until the NCAA requires universal interventions, student athletes remain at risk for suffering from significant heat stress/exertion-related injury or death.”

A landmark study

The roughly 2 million Americans who have sickle cell trait — an inherited blood disorder — are carriers of one of the two defective globin genes associated with sickle cell disease, which causes production of abnormal hemoglobin. About 8% of African Americans have sickle cell trait; the condition is rare in the Caucasian population.

Sickle cell trait traditionally had been considered a benign condition. However, research eventually showed that under extreme conditions — such as high altitude, dehydration or intense physical activity — it can trigger exertional rhabdomyolysis, splenic ischemia/infarction, other serious health problems or even death.

In 1987, John A. Kark, MD, of the hematology-oncology division at Howard University Hospital in Washington, and colleagues discovered a link between sickle cell trait and exertional heat illness.

The researchers conducted a landmark study that involved 2.1 million US Army recruits who enlisted from 1977 to 1981. Kark and colleagues found the rate of sudden death unexplained by pre-existing disease was 39.8 times higher among all recruits with sickle cell trait. The rate was 27.6 times higher among black recruits.

NCAA requires screening

The findings offered an explanation for why otherwise seemingly healthy young athletes were dying.

After Poitier’s death, NCAA officials thought the best way to protect athletes was to screen all black student athletes for sickle cell trait, Scott Anderson, ATC, head athletic trainer at the University of Oklahoma and former co-chair of the Inter-Association Task Force on Sickle Cell Trait and the Athlete, told HemOnc Today.

Although that recommendation was rescinded in 1992, some schools continued testing, he said. In fact, a 2006 survey by Clarke and colleagues of institutions with Division I football programs revealed that 64% of respondents were screening for sickle cell trait.

The NCAA was forced to revisit screening after Dale Lloyd II, a 19-year-old Rice University freshman, collapsed during practice in 2006 and later died of complications related to previously undiagnosed sickle cell trait.

Lloyd’s parents sued Rice, which was not among the schools that were screening at that time, and the NCAA. As part of a 2009 settlement, the NCAA required all incoming Division I athletes to undergo sickle cell solubility tests as a prerequisite to athletic participation.

The program took effect in fall 2010. Students who provide proof of prior testing are exempt, and students can opt out of screening if they sign a waiver that releases their institution from liability.

The Division II Management Council voted in January to require sickle cell trait screening of its athletes starting this summer.

“The NCAA believes that the knowledge of sickle cell trait status provides the best environment for student-athlete safety through intervention and education as one more layer of protection,” the NCAA said in a statement provided to HemOnc Today. “If sickle cell trait status is not known, NCAA legislation requires testing to be a component of a student-athlete’s medical examination in Division I and Division II, and recommends in Division III that this status be confirmed during the mandatory medical examination.”

The NCAA declined further comment for this story.

ASH issues policy statement

After the NCAA announced its plan to test all incoming Division I athletes, ASH convened a panel of hematologists and other experts from the National Institutes of Health, Department of Health and Human Services, the armed forces, and the Centers for Disease Control and Prevention.

Dale Lloyd II (rear), a Rice University freshman
Dale Lloyd II (rear), a Rice University freshman, died in 2006 of complications related to previously undiagnosed sickle cell trait.

Photo courtesy of Ricefootball.net, reprinted with permission

Attendees, who met in June 2010, reviewed the “science, biology and medicine” available on sickle cell trait, said Janis L. Abkowitz, MD, head of the division of hematology at the University of Washington School of Medicine and president-elect of ASH.

Based on the consensus of those experts, ASH developed the policy statement in which the organization opposed the NCAA’s mandatory screening.

“From our perspective, it’s insufficient and overly broad,” Abkowitz told HemOnc Today. “Screening without intervention — we think — is wrong. Interventions and actions save lives, not screening and labeling. The lack of a mandated action is a problem.”

Screening also should be voluntary and private, said Alexis Thompson, MD, MPH, director of hematology services at Northwestern University Feinberg School of Medicine.

“The recommendations by the NCAA do not provide what we think are really important protections for privacy of this genetic information,” said Thompson, who helped run the ASH workshop.

Further, student athletes who test positive for the trait require comprehensive counseling from a knowledgeable provider.

Alexis Thompson, MD, MPH
Alexis Thompson

“We think screening without counseling is wrong,” Abkowitz said.

Anderson emphasized college athletes are assured of counseling provided by the team physicians. This differs drastically from the public sector, he said.

“There is evidence from the literature that primary [care] doctors are not prepared to counsel and are reticent to refer [patients] to counseling,” Anderson said. “I would counter that with the NCAA screening, that concern becomes negated.”

Stigmatization, discrimination

There is considerable concern that the broadness of the screening policy could lead to stigmatization and racial discrimination, according to the ASH policy statement. Testing is required for athletes of all ethnicities, not just those with a higher risk of sickle cell trait, and for all sports, not just football.

Issues with population screening occurred when newborn screening for sickle cell disease was instituted in the 1970s, said Nigel Key, MB, ChB, FRCP, chief of the section of hematology in the division of hematology/oncology at the University of North Carolina at Chapel Hill.

Children with sickle cell disease were highly susceptible to certain bacterial infections because of their suboptimal spleen function. Research proved that giving antibiotics during the first few years of life could save many children.

“The trick then was to recognize sickle cell disease at birth or early in life,” Key said. “It became a reason for screening newborns for sickle cell disease.”

Unfortunately, the testing was misapplied, he said.

“The counseling was all over the place,” Key said. “There were a lot of concerns about potential discrimination.”

Anderson called this a non-issue.

“The concept of discrimination can easily be debunked,” Anderson said. “There’s no evidence in the following 35, almost 40 years [since Polie Poitier’s death] that any athlete has ever been discriminated against.”

Other conditions overlooked

By screening only for sickle cell trait, the NCAA policy may overlook other causes of heat-related illness, critics say.

Nigel Key, MB, ChB, FRCP
Nigel Key

“The current screening is only for sickle cell trait, while other conditions, including long QT interval and cardiomyopathy, are also associated with exertional-related deaths,” Abkowitz said. “For the student athlete in general, there’s a possibility of a false sense of security if they’re sickle cell trait-negative. They may still have cardiac disease.”

Thompson agreed.

“One of the challenges with these cases is that other potential contributors have not really been seriously considered,” she said. “Most of these individuals have not been evaluated for other things.”

In 2011, Harmon and colleagues showed that cardiovascular-related sudden death was the leading cause of death in 45 of 80 medical cases in the NCAA. Cardiac death represented 75% of sudden deaths during exertion. The overall rate was about 1 in 43,000 students. Despite this, the NCAA has no cardiac screening policy in place. In this same report of nearly 2 million athelete-participant years, five deaths were attributed to sickle cell trait.

The effects of this screening program may trickle into the community, too.

“As a provider, I’m already hearing from parents and primary care providers levels of concern which are way out of proportion for otherwise healthy children and adults who have sickle cell trait,” Thompson said. “They presume that the discussion and the mandate for screening means that all individuals who have sickle cell trait should be concerned, and that’s not the case.”

Screening vs. interventions

Screening is an effective weapon against deaths related to sickle cell trait, Anderson said.

“Screening gives opportunity for knowledge,” he said. “Out of knowledge, one can have some targeted education. Out of that targeted education, one can implement precautions.”

However, there is no data indicating that screening for trait status saves lives.

“In fact, one-third of the deaths that have occurred in the NCAA in the last 10 years have been in individuals whose trait status was known,” Thompson said.

A study published earlier this year suggests screening alone is not enough to save athletes’ lives.

Beth A. Tarini, MD, MS, an assistant professor in the department of pediatrics and communicable diseases at the University of Michigan, and colleagues estimated the potential effect of the NCAA screening policy on the identification of sickle cell trait and prevention of sudden death. The researchers used NCAA reports, population-based sickle cell trait prevalence estimates and published risks for exercise-related sudden death.

Results showed that mandatory screening would identify more than 2,000 NCAA Division I student athletes with sickle cell trait. Without strictly enforced interventions, however, researchers determined approximately seven NCAA Division I athletes would die from sickle cell trait complications over a 10-year period.

“A successful screening program consists of both identification and action — in this case, rigorous compliance with conditioning precautions,” researchers wrote. “Interventions, not screening tests, save lives. For this screening policy to be successful, testing must be only the first step in the NCAA’s overall strategy. However, the question still remains whether [sickle cell trait] screening is a necessary step to prevent exercise-related sudden death in student-athletes.”

The Army way

Kark and colleagues conducted a follow-up prospective, controlled trial in which they tested the effectiveness of the following interventions on US Army recruits with sickle cell trait:

  • Monitoring heat acclimatization;
  • Adjustable work-rest cycles based on the environment;
  • Hydration guidelines;
  • Maintaining staff preparedness for early and rapid detection of heat illness.

Compared with results of their 1987 study, the rate of exertion-related deaths among recruits with sickle cell trait who used the universal precautions decreased 22-fold.

“We had zero deaths in the test group in the second study, and we had 14 deaths previously,” Kark told HemOnc Today.

John A. Kark, MD
John A. Kark

Based on the results, the Army shifted its focus from screening to the application of universal precautions.

“The message is you can restore the risk for unexpected death in exercise to normal in people who have sickle cell trait if you use constant measures to prevent injury from excessive heat accumulation,” Kark said. “We introduced an approach for safety and training, and we took it and applied it to everyone. It seemed to have benefited everybody.”

ASH officials believe following the same course would yield similar results in athletes, and not just those with sickle cell trait.

“We felt there was some relevance in the Army experience,” Abkowitz said. “They found that by instituting universal precautions, everyone benefits — those sickle with cell trait, those with cardiac disease and other conditions. From a health policy standpoint, that’s a much more appropriate approach [than screening for sickle cell trait].”

Equally important, the Army made commanders responsible for implementing the rules, Abkowitz said.

“It wasn’t just a printed policy statement,” she said. “It was concrete and implemented. We’re not trying to imply that the NCAA should be like the Army, but to be effective, the NCAA must mandate specific actions and also assure their implementation.”

Anderson, however, noted several recruits with sickle cell trait have died in recent years. The deaths of two recruits were listed in a 2006 Army textbook and the death of an Army National Guard recruit was reported in the literature.

E. Randy Eichner, MD, Anderson’s colleague at the University of Oklahoma Health Sciences Center, wrote about two other deaths in Military Medicine this year. In addition, two recruits died last fall, one at Ft. Bliss and one at Lackland Air Force Base, according to Eichner.

“Despite the universal precautions without screening, exertional sickling deaths continue to occur in US Army recruits with sickle cell trait,” Anderson said. “Suffice it to say, the Army way isn’t working for the Army.”

The Army is investigating whether certain dietary supplements played a role in two of the soldiers’ deaths.

Significant knowledge gaps

Perhaps the most important part of the ASH policy statement was a call for more biomedical and population-based research on sickle-cell trait and its link to exertion-related illness, as well as other medical conditions.

“We really do need to generate medical policy based on better evidence and understanding,” Key said.

The knowledge gaps were discussed at a June 2010 consensus conference hosted by the National Heart, Lung and Blood Institute at the National Institutes of Health. After reviewing the existing data, attendees developed lists of what they called “research opportunities,” which have now been published in the American Journal of Hematology.

Fast Facts

For instance, they gave top priority to more research on the potential complications of sickle cell trait, such as renal and coagulation issues, as well as access to genetic counseling. Additional research is needed to understand the basic biology and clinical implications of sickle cell.

ASH, meanwhile, reached out to the NCAA prior to releasing its policy statement. The NCAA set up a meeting — scheduled for this month — to discuss its screening policy and its extension to Division II and possibly Division III athletes.

ASH representatives have been invited and plan to attend, Abkowitz said.

Following that discussion, ASH will consider whether an additional meeting open to all interested parties — including trainers, sports medicine physicians, hematology experts, screening experts and health policymakers — is warranted.

The goal is to make sure everyone works together to devise an approach that best protects student athletes without unintended and deleterious consequences, Abkowitz said.

“Everyone wants us to make this a fight,” Abkowitz said. “That’s just plain not the case.” – by Colleen Owens

Disclosure: Drs. Abkowitz, Kark, Key and Thompson, and Mr. Anderson, report no relevant financial disclosures.

PERSPECTIVE

Michael R. DeBaun, MD, MPH
Michael R. DeBaun

To date, no empirical evidence exists demonstrating the benefit of universal screening for sickle cell trait in student athletes. The cornerstone of any screening program is that early detection will decrease morbidity, decrease mortality or improve quality of life for the at-risk individual or community. The implementation of universal screening for the student athlete meets none of these prerequisites. The consequences of the National Collegiate Athletic Association (NCAA) screening recommendations may prove harmful and misleading to student athletes. The NCAA policy is almost exclusively focused on protecting the institution from liability and does not empower student athletes with the utility (pros and cons) of knowing their hemoglobinopathy trait status. Further, once an athlete with sickle cell trait is identified, evidence-based strategies — beyond universal precautions — do not exist to limit the risk of exercise-induced morbidity and mortality. If testing is offered, the testing should be optional, confidential and under the guidance of a health professional with expertise in sickle cell trait counseling. Empiric evidence does support the implementation of universal heat exhaustion precautions for all student athletes. The US Army has implemented a universal heat exhaustion prevention program during basic training, resulting in a statistically significant decrease in all-cause mortality. Universal heat exhaustion requirements should be adopted for all organized sports training activities, starting in youth sports and continuing through professional sports. Research is required to better determine the environmental and genetic risk factors that are associated with heat-related morbidity and mortality for all athletes.

– Michael R. DeBaun, MD, MPH

Professor of pediatrics and medicine

Director, Vanderbilt-Meharry Center for Excellence in Sickle Cell Disease

Vanderbilt University School of Medicine

Nashville, Tenn.

Disclosure: Dr. DeBaun reports no relevant financial disclosures.

PERSPECTIVE

Gregory M. Vercellotti, MD, FACP
Gregory M. Vercellotti

I agree with the American Society of Hematology (ASH) policy that opposes mandatory sickle cell trait screening for athletic participation because there’s really no strong evidence that it would prevent morbidity or even mortality in Division 1 athletes. Screening for trait should be voluntary. It should take place in a private setting and should be performed with an individual who can give comprehensive counseling about what sickle cell trait means for their life and what the potential risks are. There is potential harm for students with this screening policy. It gets into the issue of genetic testing and who is going to use the information. Stereotyping may occur, and inappropriate counseling could stigmatize or discriminate against the athlete. Furthermore, why does the NCAA only test Division I athletes as opposed to Division II or Division III? They do not sweat at Carlton College or Jackson State? It makes no sense. There are ways to prevent exertion-related deaths. The most important thing is to pay attention to hydration and overexertion, but that should be for all athletes, not just African-American or sickle cell trait athletes. Every athletic program in the country should have universal mandates for conditioning programs, training programs and appropriate hydration, so that no athlete will die of exertion-related hyperthermia or rhabdomyolysis. The US Army has implemented these universal interventions, as has the Brazilian army. I would like to see the NCAA require those universal interventions to prevent heat stress or exertion-related death or injury. In that case, testing for sickle cell trait is unnecessary.

– Gregory M. Vercellotti, MD, FACP

HemOnc Today Editorial Board member

Disclosure: Dr. Vercellotti reports no relevant financial disclosures.

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