Abstract
Sickle cell disease is a debilitating chronic illness characterized by persistent anemia and increased risk for stroke and cognitive impairment. The current study presents findings on the cognitive and functional task performance deficits of adults with sickle cell disease. An opportunity exists for OTs to improve the long-term outcomes of this population by providing appropriate evaluation and cognitive intervention.
Primary Author and Speaker: Taniya Varughese
Additional Authors and Speakers: Mallory Varnum, Erica Hull
Contributing Authors: Regina Abel, Allison King
Sickle cell disease (SCD) is the most common genetic hematologic disorder in the United States, affecting about 100,000 people. The incidence of overt stroke in children with sickle cell anemia, the most severe form of SCD, is ∼300-fold higher than the general population making SCA the most common cause of childhood stroke. By 20 years of age, 11% of children with SCA will have an overt clinical stroke and an additional 17-22% will have a silent infarct. Consequently, 50-70% of children with SCA have cognitive deficits that are academically significant when entering school: 17.5% fail a grade and 18.3% require special education services. In addition, chronic anemia, decreased oxygen saturation, and lower socioeconomic status are common in individuals with SCD and are associated with cognitive challenges. Although cognitive impairment is well documented in children with SCD and is reported to increase over time, few studies have evaluated cognition or functional task performance in individuals with SCD as they age into adulthood. Advances in preventative medical care and disease management has led to an increased lifespan for patients with SCD; the majority of individuals are now living well into their forties. Therefore, it is imperative to identify the prevalence of cognitive dysfunction in adults with SCD and understand the implications for occupational performance.
The current study uses a longitudinal, prospective design to determine:
1.) If adults with SCD have greater cognitive and task impairment as measured by decreased performance on neuropsychological and performance-based assessments when compared to a normative sample
2.) If cognitive function and task performance declines over time in adults with SCD
Patients, ≥ 18 years of age, with SCD were recruited from the SCD clinics at Washington University. Participants completed the Weschler Abbreviated Scale of Intelligence (WASI-II), National Institutes of Health Toolbox Cognition Battery (NIHTBCB), and two-subtests of the Executive Function Performance Test (EFPT) at baseline. The WASI-II and NIHTBCB will be repeated annually for a minimum of 3 years, and an alternate version of the EFPT (aEFPT) will be delivered prior to study exit. T-tests were conducted to compare baseline individual measure and composite scores from the WASI-II and NIHTBCB to normative data. Baseline results on subtests of the EFPT were compared to previously tested Control and Stroke groups. Repeated annual and exit scores will be compared with participants' baseline results to assess for longitudinal changes in cognition and task performance.
These findings indicate that adults with SCD have marked deficits in executive function, attention, working memory, and self-awareness--skills critical for chronic disease self-management and productive daily functioning. Occupational therapists have a unique opportunity to improve the long-term outcomes of individuals with SCD by regularly assessing cognition and task performance and designing interventions to improve self-awareness, compensate for impairments, and increase independence.
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