Genesis of the Current SCD/SCT Policy Review

1
Genesis of the Current SCD/SCT Policy Review

• Terrence Lee, MPH
• U.S. Army Center for Health Promotion and
  Preventive Medicine, DCPM, Disease and Injury
  Control Program, Aberdeen Proving Grounds, MD
• Armed Forces Epidemiological Board, 22 May 2002,
  Gaithersburg, MD

2
Initial Fatality August 1999

• Case 1 (B.T.), 31 Aug 1999, Fort Jackson
• Assigned to fitness training unit for BCT
• 535 am, temperature 72F
• after .8 miles, stopped, began to walk, ran a bit
  more then sat down at 610 am
• Arrived at Fort Jackson hospital at 630 temp
  107.6 then transferred to hospital at Fort
  Gordon.
• Died from rhabdomyolysis and impaired renal
  function
• Sickle solubility test was positive
• Association between sudden exertional death and
  SCT found in medical literature (Kark et. al.)
• Case was reported to Safety Center Commander, but
  no immediate action taken at this point this was
  considered an isolated case

3
More Sudden Deaths

• Case 2 (S.M.), 5 Jan 00, Ft. Jackson, SCT unk
• Case 3 (A.B.), 31 Jan 00, Ft. Jackson, SCT unk
• Case 4 (T.W.), 28 Feb 00, Ft. Jackson, SCT-
• Case 5 (A.A.), 30 May 00, Ft. Jackson, SCT-
• Case 6 (C.G.), 1 Aug 00, Ft. Jackson, SCT
• Case 7 (S.B.), 3 Aug 00, Ft. Jackson, SCT(not a
  trainee)
• Case 8 (J.D.), 17 Aug 00, Ft. Knox, SCT

4
Deaths Reported to Chief of Staff of the Army at
3rd Quarter In Progress Review 28 Sep 00

• Six Sudden Exertion Syndrome Deaths
• Four SCT
• Two SCT-
• Two Untested
• Safety Center asks if it may be advisable for the
  Army to routinely screen recruits
• Chief of Staff of the Army tasks CHPPM to
  research the issue
• There have been additional deaths since this

5
How many Army and Military Accession are
Estimated to have SCT ?
Based on 8 African Americans SCT, 0.08
non-African Americans SCT Data from FY 1998,
Population Representation in the US Military
http//dticaw.dtic.mil/prhome/poprep98/ Army
population Includes Active Duty, National Guard
and Reserve DoD includes Army, Navy, Air Force
and Marines, Active Duty, National Guard and
Reserve
6
(No Transcript)
7
Backup Slides Details on Sudden Exertional
Deaths (Jan 00- Aug 00) - will not be presented
unless asked

• SM, 5 Jan 00, Ft. Jackson, SCT unk, 20 yo,
  African Am F, acute water intoxication, drank
  lots of water for a drug screen, hyponatrmia, BCT
• AB, 31 Jan 00, Ft. Jackson, SCT unk , 27 yo,
  African Am F, run at Recept Battln., cardiac
  arrhythmia, BCT
• TW, 28 Feb 00, Ft. Jackson, SCT-,29 yo, African
  Am M, unit run, Cardiac Arrhythmia, may have had
  preexisting cardiac condition, family med records
  indicate chest pain and shortness of breath, BCT
• AA, 30 May 00, Ft. Jackson, SCT- ,34 yo, on rifle
  range when collapsed, taken to hosp, GI bleeding,
  autopsy indicated idiopathic myocardial fibrosis,
  BCT
• CG, 1 Aug 00, Ft. Jackson, SCT, 18 yo, African
  Am M, collapsed after 1 mile physical training
  assessment exam, cardiac arrest, BCT
• SB, 3 Aug 00, Ft. Jackson, SCT, 32 yo, African
  Am, PT run, rhabdomyolysis, (reported to have
  been using laxatives and Ephedra prior to arrival
  on post) (not a trainee), E5
• JD, 17 Aug 00, Ft. Knox, SCT, 25 yo, African Am
  M, rhabdomyolysis, HbS 48, BCT

8
Backup Slides Details on More Sudden Exertional
Deaths (Sep 00 May 01) - will not be presented
unless asked

• TB, 7 Sep 00, SCT unk ,22 yo, Caucasian M, Ft.
  Campbell, heat stroke,12 mile road march, not a
  trainee
• DP, 18 Sep 00, Ft. Drum, SCT-, cardiac arrest,
  unit run, not a trainee
• TR, 17 Oct 00, SCT, Ft. LWood, cardiac arrest,
  unit PT test, not a trainee
• PO, 26 Mar 01, 35 HbS, Ft. LWood, thrombus in
  left anterior descending artery, chest pain after
  PT, not a trainee
• MP, 9 May 01, SCT, Ft. Meade, cardiac arrest,
  during PT test (had failed PT test in Apr, not a
  trainee

9
Sickle Cell Trait Screening, A Complex Issue

• Terrence Lee, LTC Mark Lovell, LTC Robert
  Noback
• U.S. Army Center for Health Promotion and
  Preventive Medicine, DCPM, Disease and Injury
  Control Program, Aberdeen Proving Grounds, MD
• U.S. Army Safety Center, Ft. Rucker, AL
• Presented at Recruit Healthcare Symposium April
  2001, San Antonio, TX
• and at Force Health Protection September 2001,
  Albuquerque, NM

10
Revised Abstract
The deaths of three U.S. Army recruits and two
non-recruit soldiers, all who were carriers for
sickle cell trait (SCT), has prompted the Army to
re-examine issues regarding SCT screening. SCT is
a genetic condition seen in 8 of African
Americans and 0.08 of non-African Americans.
The scientific literature indicates that recruits
with SCT have an increased absolute risk of
sudden death during exercise of 32/100,000
compared to 1/100,000 among recruits without SCT.
Adherence to strict heat injury prevention
measures has been shown to be an effective
measure to prevent heat related sudden exertional
deaths for all soldiers the role of SCT
screening in prevention of these deaths is
undetermined. SCT screening raises complex
social, ethical and medical issues. The DoD
services have different policies regarding SCT
screening currently the Army does not have a
universal screening program. These five
deaths, current and past DoD policies and issues
surrounding screening will be presented.
11
Summary 5 Cases
12
Sickle Cell Trait and Sickle Cell Disease

• Hemoglobin (Hb) carries oxygen in the blood HbS
  is an abnormal type of hemoglobin that causes
  sickling in red blood cells. The percentage of
  HbS differentiates disorders
• Sickle Cell Diseases (SCD)
• Sickle Cell Anemia (HbSS) 80 HbS
  complications early in life
• Sickle-ß-Thalassemia 60 HbS less severe than
  (HbSS)
• Sickle-C Disease (HbCS) 50 HbS less severe
  than (HbSS)
• Sickle-Cell Trait (HbAS) 35 HbS normal life
  span
• Hb genotype is inherited from parents.
• Approximately 0.17 of African Americans have
  SCD.1
• 8 African Americans have SCT, 0.08 non-African
  Americans have SCT.2
• For SCD, individuals have symptoms such as
  anemia, jaundice, formation of gallstones,
  blockage in organs and other complications many
  do not live past 50 years old. Mild forms of SCD
  may go unrecognized until adulthood. 3
• For individuals who are sickle cell trait
  positive (SCT) most lead normal lives problems
  may occur under unique or stressful conditions
  associated with severe hypoxia such as flying in
  an un-pressurized airplane at high altitudes.
  Episodic hematuria and splenic infarcts at higher
  altitude have also been reported, but with
  minimal clinical significance.4

13
Normal vs Sickle Cells

• With higher concentration of HbS (eg. SCD) and
  low oxygen levels, HbS forms polymers inside red
  blood cells.
• HbS polymers cause red blood cells to form
  sickle shapes.
• Sickle shaped red blood cells have decreased
  ability to travel through blood vessels which, in
  turn, may clog blood vessels in organs and lead
  to loss of tissue function.

Sickle Cell
Normal Cell
14
Sickle Cell Anemia InheritanceHb genotype is
inherited from parents.
SICKLE CELL TRAIT
NORMAL
2 in 4 or 50
2 in 4 or 50
2 in 4 or 50
1 in 4 or 25
1 in 4 or 25
SICKLE CELL TRAIT
SICKLE CELL TRAIT
SICKLE CELL ANEMIA
NORMAL
NORMAL
15
Sickle Cell Trait and Exercise

• Statistical Associations of Death and Sickle Cell
  Trait
• Military risk, increased absolute risk of sudden
  death for SCT
• 32/100,000 with SCT vs. 1/100,000 without SCT
  (observation of 2 million military recruits 1977-
  1981) Kark et. al. (1987)2
• For SCT recruits, sudden exertional death rate
  dropped to zero and non-SCT death rates
  decreased when heat injury prevention policies
  (hydration, etc.) were rigorously followed at
  selected training sites (unpublished data from
  Kark et.al. (1999)).5
• Kark and Ward (1994) propose the hypothesis
  that excess mortality associated with SCT results
  from exertional heat illness6
• During exercise, greatest risk SCT face are
  damage to the kidney and spleen.
• Kidney fails to conserve water which leads to
  complications of dehydration
• Although there is a higher risk of sudden death
  for SCT, the risk, according to Kark et.al.s
  data and hypothesis, seems to be negated if
  appropriate heat injury countermeasures are
  taken.

16
Common HbS Laboratory Tests

• Screening
• Sickle Solubility Test
• Sickle hemoglobin precipitates when reduced with
  an oxygen depleting reagent.
• Indicates presence of HbS, but not quantity
• Quick, simple to perform, inexpensive
• Confirmatory Test
• Hemoglobin Electrophoresis
• Hemoglobin migration patterns in an electrified
  field
• Differentiates between HbS disorders based on Hb
  percentages

17
Heat Injury Prevention Strategies

• Record wet bulb globe temperature (WBGT), which
  accounts for humidity, at least hourly at the
  training site
• Modify exercise intensity and rest cycles as WBGT
  rises.
• Also modify exercise intensity and rest cycles
  based on prior day WBGT
• Increase water intake and monitor water
  consumption
• In hot weather, exercise wearing light-weight
  clothing.
• Initiate immediate rest with cooling/rehydration
  with early symptoms
• Provide prompt medical evaluation with core
  temperature measurement

18
SCT Screening Policy History

• 1968 Cluster of 4 SCT recruits die during
  training at elevations above 4060 feet.7
• 1969 Navy policy to test all recruits for Hg S 8
• 1970s Occupational restrictions on SCT ,
  aviation, diving, special forces, high altitude
  parachuting 9
• 1981 DoD policy requiring Services to drop their
  restrictions, but to screen for SCT (DODI
  6465.1). Services agree on a temporary cut-off
  of gt41 HgS as a point for restrictions 9
• 1985 DoD policy states all military
  occupational specialty restrictions on SCT
  bearers are to be removed10 This negated the
  41 cutoff.

19
SCT Screening Policy History (continued)

• Mid-1990s after three Air Force recruit deaths,
  Armed Forces Epidemiology Board (AFEB) asked to
  re-evaluate the benefit of SCT screening11
• 1996 AFEB12
• no longer recommend routine screening for
  sickle cell trait (SCT) in the armed forces
• Recommends to continue and improve implementation
  of heat injury preventive measures
• Recommends to conduct further research on adverse
  health outcomes in SCT positive individuals and
  military training

20
Current DoD Screening Policies

• Military Entrance Processing Stations (MEPS)
  screen for Anemia on page 2 of form DD 2807-2
  Medical Prescreen of Medical History. On previous
  form SF-93, identification of disorders was
  indirect through general medical history
  questions. SCD individuals, however, still
  entered as recruits.
• Navy discharges 16-20 SCD recruits per year prior
  to starting basic training13
• Army data is similar approx 10 SCD recruits
  discharged after becoming symptomatic during
  initial training14
• Army screens military occupational specialties
  (MOSs) that include aviation, diving and special
  operations, though being SCT is not
  disqualifying11
• Air Force (AF), Navy and Marine Corps (MC) screen
  accessions.
• To uncover disqualifying hemoglobin disorders
• Screening is required for several MOSs, though
  being SCT is not disqualifying.16
• To inform individuals of SCT status and
  associated military risk
• AF allows SCT to leave service, Navy and MC
  mandate SCT to leave service if HbS gt 45.15
• Navy and MC San Diego identify by medical alert
  tag. Navy Great Lakes basic training also uses
  red waistband (during physical exertion).16,17
• Counseling is done in a group setting for AF,
  Navy and MC.

21
How many Army and Military Accession are
Estimated to have SCT ?
Based on 8 African Americans SCT, 0.08
non-African Americans SCT Data from FY 1998,
Population Representation in the US Military
http//dticaw.dtic.mil/prhome/poprep98/ Army
population Includes Active Duty, National Guard
and Reserve DoD includes Army, Navy, Air Force
and Marines, Active Duty, National Guard and
Reserve
22
Will Screening Prevent Deaths?

• Screening will identify sickle cell disease not
  identified at MEPS. Thus it will avoid sickle
  cell crisis in those with clinically significant
  disqualifying HbS disorders during training and
  possible fatalities.
• Based on data and hypothesis from Kark et. al.,
  screening does not prevent deaths, adherence to
  heat injury prevention policies does.18
• Cases
• Screening would have identified Case 1, thus more
  rapid care may have been administered. This may
  or may not have resulted in a different outcome.
• If Case 4 had known her condition, perhaps she
  would have taken some precautions during PT,
  however, the role of SCT is counfounded by the
  alleged use of non-prescription medications.
• Case 3 may have been eliminated from service
  since his HbS level was 48 (Navy discharges if
  HbS level gt45)

23
Will Screening Prevent Deaths? (continued)

• For individual cases, it is difficult to
  determine role of SCT in the fatality.
• Screening will identify sickle cell disease
  individuals for removal from service, thus
  possibly preventing some deaths. Adherence to
  heat injury prevention policies is an efficacious
  method of preventing heat related injuries and
  deaths for all individuals. However, it is not
  known if the identification of SCT individuals
  will lower the death rate. Identification could
  possibly lead to more rapid health care for SCT
  or alert SCT individuals to follow diligently
  heat injury prevention policies which may lower
  the death rate.19 These are theoretical
  outcomes.

24
Costs and Savings

• Medical Costs
• Annual Lab Costs 541K (Sickle Solubility Test
  and confirmatory electrophoresis)
• 4.00/initial test on 126,690 accessions (FY 98
  Accessions) - 506K
• 16.00/confirmatory test on 2,156 estimated
  positive (1.5 positive in total population) -
  34K
• Counseling Costs 15-25K depending on format
  (Counseling for positives, ½ hour session
  (50.00)/week (50)/training installation (5))
• Total 561 K
• Potential savings
• Army Training Costs savings 200K
• (Based on 20K per recruit x 10 who would
  eventually be discharged due to SCD)
• Medical Cost savings 50K
• (Based on est. average 5K of medical services
  prior to discharge x 10)
• Total 250 K
• Assumes all accessions screened
• Assumes screening program identifies
  disqualifying conditions, does not include
  savings from possible potential lives saved

25
Should Screening be All or only Known High
Prevalence Groups?

• 8 or African Americans have SCT while 0.08
  non-African Americans have SCT.
• Significant number of SCT are non-African
  Americans.
• Based on FY 1998 data and above prevalence rates,
  almost 2,150 Army Enlisted and Officers were
  estimated to be SCT, of which about 4 were
  non-African Americans.
• SCT is also prevalent in people from
  Mediterranean, East Indian and some regions in
  Saudi Arabia 20
• How does one determine if someone has genetic
  roots from Africa or the other high prevalence
  geographic areas? How confidently can one
  determine genotype from phenotype?
• AFEB Meeting, 12 Oct 95 After the Air Force
  changed their policy to allow individuals to
  disenroll if tested SCT, the first person to be
  identified with SCT and accept the option to go
  home was a blond- haired blue-eyed Caucasian.21
• Trying to determine who is in a high prevalence
  group is problematic thus, screening all
  recruits is more feasible.

26
Identify SCT with Tag?

• The Navy and MC San Diego identify SCT with a
  medical alert tag. The Navy Great Lakes also
  identifies recruits with a red waistband/flag
  during training that involves physical exertion.
• May increase likelihood of earlier intervention
  or provision of medical services
• Will SCT recruits be treated differently by
  peers?
• What is effect of labeling someone as different
  during training? Will individual have lower
  self-esteeem? Will individual overexert to
  prove he/she is the same?
• Outwardly visible tag (eg. waistband/flag) or
  not as visible (eg. medical alert tag)?
• Will medical treatment for people with SCT be
  different?
• Genetic privacy issues

27
Mandatory Screen vs. Voluntary Screen?

• Knowledge of SCT status has important
  marriage/reproductive implications
• Brings up genetic privacy issues.
• An individual may not want to know this
  information at this time
• Mandatory screening will help ensure that all
  abnormal hemogobinopathies are identified.
• If screening is voluntary, someone who knew of
  their own disqualifying sickle cell disease
  status would possibly refuse the test (since this
  information was not divulged at MEPS).
• Voluntary screening may negate a major purpose
  for screening (detection of at risk individuals).

28
Allow identified SCT to leave service ?

• About 10 of newly identified SCT individuals
  elect to separate from AF. The same rate for the
  Army would result in 215 leaving the service
  annually.
• SCT individuals may not want the increased
  relative risk of death (albeit small absolute
  risk) due to physical demands of initial entrance
  training.
• If mandated to stay in service, SCT individuals
  who fear their increased relative risk of death
  may not push themselves as hard, and
  theoretically may not reach full potential.
• Individuals may not believe the theory that
  most SCT sudden exertional deaths are heat
  related or they may fear that heat injury
  prevention policies are not adequate protection.

29
How to Counsel?Pre-Screening and Post-Screening
Individual vs. Group

• Due to the personal/sensitive information that
  will be revealed, Pre- as well as Post-screening
  counseling is indicated.
• Pre-screening needs to convey all implications of
  being SCT.
• Post-screening test SCT may need individual
  private counseling to address all personal
  factors.

30
Options

• No Screen
• Implement and enforce aggressive heat injury
  prevention policies
• Expect 10 SCD crises during Initial Entry
  Training.
• SCT individuals may not know of their status
• There is no opportunity to stress the importance
  for SCT to follow heat injury prevention
  policies
• Screen
• Implement and enforce aggressive heat injury
  prevention policies
• Expect 10 SCD removed per year from Initial
  Entry Training due to preexisting SCD.
• SCT individuals are identified of their status
• Opportunity to stress the importance for SCT to
  follow heat injury prevention policies
• Opportunity to counsel on reproductive issues for
  SCT

31

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Personal observation with Ms. Beiley, Great Lakes
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Transcript p.40-45 screening does not prevent
deaths, adherence to heat policy prevents
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Longino. AFEB meeting, 12 Oct 95. Transcript p 28