Association of social-environmental factors with cognitive function in children with sickle cell disease

Comorbid ADHD and Pediatric Sickle Cell Disease: Prevalence and Risk Factors

Sickle cell disease (SCD) is a genetic blood condition that places youth at increased risk for deficits in complex attention suggestive of increased risk for Attention-Deficit/Hyperactivity Disorder (ADHD). We used systematic screening to assess the prevalence of ADHD in a clinic-based sample of youth with SCD and explored factors related to ADHD. Caregivers of 107 children with SCD (ages 7-11 years) completed routine psychosocial screening which included inattentive symptoms of ADHD. Follow-up diagnostic procedures were completed for patients with elevated inattentive symptoms to assess for ADHD diagnoses. Biomedical and social-environmental variables were examined from the screening and medical records. Twenty-six percent of patients showed elevated inattentive symptoms with 13% meeting diagnostic criteria for ADHD diagnoses. Most children (75%) who met criteria for ADHD had not been previously diagnosed. Disease severity did not predict inattentive symptoms or ADHD diagnoses, though a measure of chronic inflammation was associated with ADHD. Family functioning was related to elevated inattentive symptoms but not ADHD diagnoses. Children with SCD show relatively high rates of ADHD with many cases not detected through routine care. Screening for ADHD as part of hematology care may be a feasible strategy to improve identification and access to intervention.

Academic performance in Jamaican children with sickle cell disease

OBJECTIVE

Children with sickle cell disease (SCD) are at risk for neurocognitive deficits that can affect school performance, and psychosocial functioning. The aim of this study was to assess the academic performance of school-aged children with SCD in Jamaica compared to their school peers.

METHOD

A cross-sectional survey of academic performance was done in a group of children 11 to 13 years of age, using a standardized state administered examination, the Grade Six Achievement Test (GSAT), covering 5 subjects. Scores were obtained from the Ministry of Education (MOE) for eligible children with SCD, as well as mean scores with standard deviation for unaffected classmates by gender. Socio-demographic and clinical data were obtained from our sickle cell clinic database and an interview administered questionnaire.

RESULTS

Sixty-four children satisfied eligibility criteria. Children with SCD had lower percentage scores and significantly lower mean z-scores for 4 of 5 subjects (p < 0.05). Males had significantly lower mean z-scores compared with females. Thirty-seven children (57.8%) were classified as underperformers. Haemoglobin level was a significant predictor of subject score rank.

CONCLUSION

Children with SCD in Jamaica perform worse in standardized school examinations than their class peers with boys being particularly vulnerable.

Executive Function and Processing Speed in Children Living with Sickle Cell Anemia

Executive function and processing speed difficulties are observed in children living with sickle cell anemia (SCA). The influence of processing speed on executive function is not well understood. We recruited 59 children living with SCA and 24 matched controls aged 8-18 years between 2010 and 2016 from clinics in the UK. Children completed tests in processing speed and cognitive flexibility, subdomains of executive function. MRI scans were conducted within one year of testing; oxygen saturation was obtained on the day of testing. Hemoglobin levels were obtained from medical records. Caregivers completed the executive function questionnaire. Hierarchical linear regressions found that hemoglobin, oxygen saturation, age, infarct status, and processing speed were not independent predictors for any model. However, for all cognitive flexibility tests, there was a significant interaction between infarct status and processing speed; children without silent cerebral infarction (SCI) with faster processing speed had better cognitive flexibility. Our findings indicate that, when interpreting executive function difficulties, it is important to account for the relationship between SCI status and processing speed. More research is needed to elucidate the mechanisms, but clinically, including executive function testing as part of clinic visits by embedding psychologists within the healthcare team would appear to be a critical step.

Health literacy correlates with abbreviated full-scale IQ in adolescent and young adults with sickle cell disease

INTRODUCTION

Sickle cell disease (SCD) is a chronic condition with progressive neurocognitive deficits. Health literacy (HL) is essential during adolescence and young adulthood, as the transition to adult care requires healthcare decisions. HL is known to be low in SCD; however, relation between general cognitive ability and HL has not been investigated.

METHODS

This cross-sectional study included adolescent and yound adults (AYAs) with SCD from two institutions. Logistic regression measured the association between HL, measured by the Newest Vital Sign tool, and general cognitive ability, measured with abbreviated full-scale intelligence quotient (FSIQ) on the Wechsler Abbreviated Scale of Intelligence.

RESULTS

Our cohort contained 93 participants at two sites: 47 (51%) at Memphis, TN and 46 (49%) at St. Louis, MO, ranging from ages 15-45 years (mean = 21 years) and with a majority (70%) possessing a high school education or greater. Only 40/93 participants (43%) had adequate HL. Lower abbreviated FSIQ (p < .0001) and younger age at assessment (p = .0003) were associated with inadequate HL. For every standard score point increase in abbreviated FSIQ, the odds of having adequate HL compared to limited or possibly limited HL increase by 1.142 (95% confidence interval [CI]: 1.019-1.322) and 1.116 (95% CI: 1.045-1.209), respectively, after adjusting for age, institution, income, and educational attainment.

CONCLUSIONS

Understanding and addressing HL is imperative in improving self-management and health outcomes. Among AYA with SCD, low HL was prevalent and influenced by abbreviated FSIQ. Routine screening for neurocognitive deficits and HL should be performed to guide development of interventions to adapt to the HL of AYA with SCD.

Mental and Emotional Health of Caregivers of Youth with Sickle Cell Disease: A Systematic Review

People of African descent and those identifying as Black and/or Latino experience a disproportionate burden of sickle cell disease (SCD), a chronic, serious blood condition. Caregivers of children with chronic medical conditions report worse mental health than others. Disease-associated stressors can affect caregivers of children with SCD. We conducted a systematic review to summarize the prevalence of mental health symptoms in caregivers of children with SCD and to see if symptoms were associated with the child's SCD. This review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We searched PubMed, PsycINFO, and Embase, identifying 1,322 records of which 40 met criteria for inclusion in this review. Findings suggest caregivers experience mental health problems, and poorer mental health was associated with worse child SCD-related outcomes and treatment adherence. Efforts should be made to routinely screen SCD caregiver mental health and to refer accordingly.

Neurodevelopmental Outcomes in Preterm Children with Sickle Cell Disease

OBJECTIVES

To explore the combined effect of pediatric sickle cell disease (SCD) and preterm birth on cognitive functioning.

METHODS

Cognitive functioning was examined in children ages 6-8 with high risk SCD genotypes born preterm (n = 20) and full-term (n = 59) and lower risk SCD genotypes/no SCD born preterm (n = 11) and full-term (n = 99) using tests previously shown to be sensitive to SCD-related neurocognitive deficits. Factorial ANOVAs and log linear analyses were conducted to examine the relationship between SCD risk, preterm birth status, and cognitive outcomes. Continuous scores were examined for specific tests. Children were categorized as having an abnormal screening outcome if at least one cognitive score was ≥1.5 standard deviations below the population mean.

RESULTS

Children with elevated risk due to high risk SCD and preterm birth performed worse than other groups on a test of expressive language but not on tests that emphasize processing speed and working memory. There was a three-way interaction between preterm status, SCD risk, and abnormal screening outcome, which was largely driven by the increased likelihood of abnormal cognitive scores for children with high risk SCD born preterm.

CONCLUSIONS

The combination of SCD and preterm birth may confer increased risk for language deficits and elevated rates of abnormal cognitive screenings. This suggests that neurodevelopmental risk imparted by comorbid SCD and preterm birth may manifest as heterogenous, rather than specific, patterns of cognitive deficits. Future studies are needed to clarify the domains of cognitive functioning most susceptible to disease-related effects of comorbid SCD and preterm birth.

Mental health assessment of youth with sickle cell disease and their primary caregivers during the COVID-19 pandemic

Youth with sickle cell disease (SCD) and their caregivers are susceptible to stress and depression, perhaps exacerbated by pandemic-associated health and economic concerns. Most of the 50 youth-caregiver dyads enrolled in the multisite trial, Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment (HABIT), took an online survey of self-reported mental health symptoms and food insecurity during the 2020 COVID-19 pandemic. Compared to largely pre-pandemic results, prevalence of mental health symptoms in dyad members appeared to have shifted: fewer youth and more caregivers were affected during the pandemic; many of both groups lacked optimism. Pandemic/post-pandemic screening of youth with SCD for mental health symptoms and food insecurity appears warranted.

A case-control and seven-year longitudinal neurocognitive study of adults with sickle cell disease in Ghana

Ageing in sickle cell disease (SCD) is associated with a myriad of end-organ complications, including cerebrovascular damage and cognitive impairment (CI). Although CI is very common in SCD, little is known about cognitive functioning and how it changes with age. This study examines cognitive patterns of 63 adults with SCD and 60 non-SCD, age- and education-matched controls in Ghana. Of those adults with SCD, 34 completed the neuropsychological battery at baseline and again seven years later. In cross-sectional data, adults with SCD performed worse than controls in all cognitive test domains (p < 0.01 for all). The seven-year follow-up data showed that the group exhibited a significant decline in visuospatial abilities (ranging from Cohen's d = 1.40 to 2.38), and to a lesser extent, in processing speed and executive functioning. Exploratory analyses showed a significant time-by-education interaction, indicating that education may be protective from decline in cognitive performance. These findings have implications for clinical practice. Early neuropsychological surveillance coupled with early assessment and remedial programmes will provide avenues for enhancing the quality of life of adults living with SCD in Ghana.

Sluggish Cognitive Tempo in Pediatric Sickle Cell Disease

Background

Sickle cell disease (SCD) imparts risk for a range of neurodevelopmental and neurocognitive disorders. Sluggish cognitive tempo (SCT) is a distinct syndrome that often co-occurs with attention-deficit/hyperactivity disorder (ADHD) but has not been described in SCD. We investigated the reliability and validity of a SCT measure in SCD and examined associations with biopsychosocial risk factors and functional outcomes.

Materials and Methods

Caregivers (n = 85) of children with SCD ages 7-16 reported on socio-demographics and the Kiddie-Sluggish Cognitive Tempo (K-SCT) measure, Behavior Rating Inventory of Executive Function, and Conners 3. Disease-related characteristics were extracted from health records.

Results

The K-SCT demonstrated excellent internal consistency (α = 0.92) and test-retest reliability (r = 0.82, p < 0.001). K-SCT scores were correlated with ADHD-Inattention (r = 0.64, p < 0.001) and ADHD-Hyperactive/Impulsive (r = 0.46, p < 0.001) scores, as well as functional outcomes, including learning problems (r = 0.69, p < 0.001). In multivariate analyses controlling for ADHD symptoms, SCT accounted for unique variance in learning (b = 9.67, p < 0.01) and executive functioning (b = 5.93, p < 0.01). Nearly all participants (93%) with elevated levels of co-occurring SCT and ADHD-Inattention symptoms had significant learning problems.

Conclusion

The K-SCT is a reliable and valid measure of SCT in SCD. SCT symptoms are associated with learning difficulties even after controlling for ADHD symptoms. Further research is needed to understand the biopsychosocial factors that lead to SCT symptoms in SCD and examine long-term implications of SCT.

The influence of perceived racial bias and health-related stigma on quality of life among children with sickle cell disease

Objectives: Individuals with sickle cell disease (SCD) experience significant health problems that may result in unpredictable pain episodes and frequent healthcare utilization. Disparities in clinical care may contribute to health-related stigma and racial bias for this majority African-American/Black population. There is less known about the influence of health-related stigma and racial bias on the health-related quality of life (HRQOL) of children with SCD. In the present study, we assessed these relationships and identified differences across demographic factors (i.e. age, gender).Design: Data was collected from African American children with SCD aged 8-16 years (57% male, 63% HbSS). Children completed the Childhood Stigma Scale (adapted for SCD), the Child Perceptions of Racism in Children and Youth scale, and the Pediatric Quality of Life Inventory Sickle Cell Disease Module. Caregivers provided demographic information.Results: In the first regression model, health-related stigma (p = .007) predicted HRQOL, but neither age nor gender were significant predictors. In the second regression model, age (p = .03) predicted HRQOL, but neither gender nor racial bias were significant predictors. Of interest, there was a significant interaction between age, gender, and racial bias (p = .02). Specifically, older girls who reported high levels of perceived racial bias had poorer HRQOL.Conclusions: Our study highlights the need for increased awareness about the effects of health-related stigma and racial bias on HRQOL for children with SCD, particularly for older girls who endorse racial bias. Our findings will guide future stigma and bias reduction interventions that may meet the needs of older girls with SCD.

The Role of Sleep-Disordered Breathing Symptoms in Neurocognitive Function Among Youth With Sickle Cell Disease1

OBJECTIVE

To examine associations between sleep-disordered breathing (SDB) and executive/attentional function in pediatric sickle cell disease (SCD).

METHODS

Sixty youth with SCD ages 8-18 years and caregivers completed the Pediatric Sleep Questionnaire (PSQ), Delis Kaplan Executive Function System Trail Making Test (DKEFS TMT), Psychomotor Vigilance Test (PVT), and the Behavior Rating Inventory Of Executive Function, Second Edition (BRIEF-2) Parent Report.

RESULTS

The PSQ significantly predicted the BRIEF-2 Parent Report, F(1, 58) = 44.64, p < .001, R² = 0.44, f² = 0.77.

CONCLUSIONS

Sleep-disordered breathing symptoms may predict informant-rated executive dysfunction in pediatric SCD, but not performance-based executive function.

Developmental delay in infants and toddlers with sickle cell disease: a systematic review

AIM

To summarize developmental delay among infants and toddlers with sickle cell disease (SCD).

METHOD

This systematic review included studies that reported developmental outcomes of children with SCD between 0 months and 48 months of age and followed standards set forth by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Ten studies were included, describing 596 unique developmental assessments. The rate of developmental delay ranged from 17.5% to 50% and increased with age. Cognition was the only domain included in all studies and the most frequently identified delay. One study reported that more severe SCD genotypes predicted worse development, while five studies reported no difference in rates of developmental delay across genotypes.

INTERPRETATION

These findings emphasize the need for standardized screening to identify children with SCD at risk of delay at a young age to facilitate appropriate referrals for therapeutic intervention. Frequent and comprehensive developmental screening is necessary among all SCD genotypes.

Academic Performance of Children With Sickle Cell Disease in the United States: A Meta-Analysis

Background: Students with sickle cell disease are at risk for poor academic performance due to the combined and/or interactive effects of environmental, psychosocial, and disease-specific factors. Poor academic performance has significant social and health consequences. Objective: To study academic achievement and attainment in children with sickle cell disease in the United States. Design: Medline, Embase, SCOPUS, CINAHL, ERIC, and PsycINFO were searched for peer-reviewed articles. Studies of children (ages 5-18) diagnosed with sickle cell disease of any genotype reporting academic achievement (standardized tests of reading, math, and spelling) or attainment (grade retention or special education) outcomes were included. Outcomes were analyzed using a random effects model. Achievement scores were compared to within study controls or normative expectations. Prevalence of grade retention and special education services were compared to national (United States) estimates for Black students. Age at assessment and overall IQ were evaluated separately for association with reading and mathematics scores. Subgroup analyses of reading and math scores were analyzed by cerebral infarct status (no cerebrovascular accident, silent infarct, stroke). Results: There were 44 eligible studies. Students with sickle cell disease scored 0.70, 0.87, and 0.80 (p < 0.001) SD below normative expectations on measures of reading, mathematics, and spelling, respectively. Compared to unaffected sibling and/or healthy controls (k = 8, n = 508), reading and math scores were 0.40 (p = 0.017) and 0.36 (p = 0.033) SD below expectations. Grade retention was approximately 10 times higher in students with sickle cell disease than Black students nationally. Intellectual functioning explained 97.3 and 85.8% of the variance in reading and mathematics performance, respectively (p < 0.001). Subgroup analyses revealed significant differences in reading (p = 0.034) and mathematics (p < 0.001) based on infarct status, with lower performance associated with presence of a silent infarct or stroke. Conclusion: Students with sickle cell disease demonstrate notable academic difficulties and are at high risk for grade retainment. Development of academic interventions and increased access to school support services are needed for this vulnerable population. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020179062.

Prevalence and risk factors of cognitive impairment in children with sickle cell disease in Egypt

Little is known about cognitive impairment in patients with sickle cell disease in Africa. This study aimed to assess cognitive impairment and identify possible risk factors in patients with sickle cell disease in Egypt. This study was conducted at Cairo University Children Hospital. Patients with sickle cell disease, between ages of 6-20 years were enrolled. Cognitive ability was tested using the Stanford Binet intelligence quotient (IQ) test, fourth edition. Transcranial Doppler, magnetic resonance imaging and magnetic resonance angiography of the brain were performed within a week of the IQ test. Among the 40 enrolled patients, 55% had a Full Scale IQ at least 1 standard deviation below the mean, and 27.5% had an IQ 2 standard deviations below the mean. High lactate dehydrogenase was significantly associated with low IQ (p = 0.004). In univariate analyses, IQ was significantly correlated with older age (p = 0.025), high lactate dehydrogenase (p = 0.008) and older age at the start of hydroxyurea (p = 0.025). Impaired cognition is prevalent among sickle cell disease patients. Early initiation of hydroxyurea therapy, which should also reduce hemolysis and lactate dehydrogenase, may be a simple measure to preserve mental abilities in these patients.

Developmental screening of three-year-old children with sickle cell disease compared to controls

We previously found that neurodevelopmental deficits commonly occurred in three-year-olds with sickle cell disease (SCD), but clinical significance was uncertain because a comparison group was lacking. Our objective in the current study was to prospectively compare neurodevelopment in three-year-old children with SCD to an age-appropriate control group. The Brigance Preschool Screen II is a neurodevelopmental screening examination which can be administered in 15-20 min. SCD patients (Group 1) were compared with community controls of similar age and ethnicity enrolled in daycare/preschool (Group 2). SCD patients who were receiving hydroxycarbamide treatment were also compared (Group 3). Two hundred forty-five three-year-olds were evaluated: Group 1, 111; Group 2, 114; and Group 3, 20. The below cut-off rate on the Brigance test was higher in Group 1 (73%) than in Group 2 (61%; P = 0·04). In multivariate analysis of Group 1 patients, only lower household income and more persons living in the home were independent predictors of this. Patients with SCD and matched controls had high rates of 'failing' the Brigance test. The below cut-off rate in untreated children with SCD was associated with low household income and increased number of persons living in the home.

Hydroxyurea Use Associated with Nonverbal and Executive Skills in Sickle Cell Anemia

OBJECTIVE

Hydroxyurea (HU) is used in children with sickle cell disease (SCD) to increase fetal hemoglobin (HF), contributing to a decrease in physical symptoms and potential protection against cerebral microvasculopathy. There has been minimal investigation into the association between HU use and cognition in this population. This study examined the relationship between HU status and cognition in children with SCD.

METHODS

Thirty-seven children with SCD HbSS or HbS/β0 thalassaemia (sickle cell anemia; SCA) ages 4:0-11 years with no history of overt stroke or chronic transfusion completed a neuropsychological test battery. Other medical, laboratory, and demographic data were obtained. Neuropsychological function across 3 domains (verbal, nonverbal, and attention/executive) was compared for children on HU (n = 9) to those not taking HU (n = 28).

RESULTS

Children on HU performed significantly better than children not taking HU on standardized measures of attention/executive functioning and nonverbal skills. Performance on verbal measures was similar between groups.

CONCLUSIONS

These results suggest that treatment with HU may not only reduce physical symptoms, but may also provide potential benefit to cognition in children with SCA, particularly in regard to attention/executive functioning and nonverbal skills. Replication with larger samples and longitudinal studies are warranted.

Neurologic and Cognitive Outcomes in Sickle Cell Disease from Infancy through Adolescence

Children with sickle cell disease (SCD) are at risk for neurologic and cognitive complications beginning in early childhood. Current treatment for SCD focuses on primary prevention of complications, such as hydroxyurea for prevention of pain and acute chest syndrome, and chronic transfusion therapy for children who are at high risk for strokes. In this article, the prevalence, pathophysiology, and available interventions to prevent and treat neurologic and cognitive complications of SCD will be reviewed.

Cognitive Correlates of Math Performance in School-Aged Children with Sickle Cell Disease and Silent Cerebral Infarcts

OBJECTIVE

Attention, processing speed, executive functioning, and math difficulties are common in youth with sickle cell disease (SCD) with silent cerebral infarcts (SCI). This study investigated the cognitive underpinnings of math difficulties in children with SCD and SCI.

METHOD

Youth (n = 68) with SCD and SCI completed measures of attention [Digit Span forward (DSF); Conners Continuous Performance Test-Third Edition/Kiddie Conners Continuous Performance Test-Second Edition (CPT-3/KCPT-2)]; working memory [Wechsler Intelligence Scales (WPPSI-IV, WISC-IV, WISC-V, WAIS-IV), Working Memory Index (WMI), Digit Span backwards (DSB)]; processing speed [WPPSI-IV, WISC-IV, WISC-V, WAIS-IV Processing Speed Index (PSI)]; math reasoning [Wechsler Individual Achievement Test-Third Edition (WIAT-III) Mathematics composite (MC)]; and math fluency [WIAT-III Math Fluency composite (MF)] as part of a clinical neuropsychological evaluation. Parent ratings of attention and executive functioning were obtained [Behavior Assessment System for Children-Third Edition (BASC-3), Behavior Rating Inventory of Executive Function (BRIEF)].

RESULTS

MC was positively correlated with WMI (r = 0.59, p = 0.00), PSI (r = 0.40, p < 0.001), DSF (r = 0.29, p = 0.03), DSB (r = 0.47, p < 0.001), and MF (r = 0.71, p < 0.001). Correlations between MC, sustained attention, and parent ratings were nonsignificant. The linear regression model using correlated variables was significant [F(4,51) = 8.29, R2 = 0.39, p < 0.001]. WMI was the only significant variable within the model (p = 0.02).

CONCLUSIONS

Working memory deficits account for significant variance in untimed mathematical performance in this population-consistent with other populations with white matter dysfunction. Interventions targeting both mathematics and working memory may be beneficial.

The Impact of Environmental Factors on Monogenic Mendelian Diseases

Environmental factors and gene-environment interactions modify the variable expressivity, progression, severity, and onset of some classic (monogenic) Mendelian-inherited genetic diseases. Cystic fibrosis, Huntington disease, Parkinson's disease, and sickle cell disease are examples of well-known Mendelian disorders that are influenced by exogenous exposures. Environmental factors may act by direct or indirect mechanisms to modify disease severity, timing, and presentation, including through epigenomic influences, protein misfolding, miRNA alterations, transporter activity, and mitochondrial effects. Because pathological features of early-onset Mendelian diseases can mimic later onset complex diseases, we propose that studies of environmental exposure vulnerabilities using monogenic model systems of rare Mendelian diseases have high potential to provide insight into complex disease phenotypes arising from multi-genetic/multi-toxicant interactions. Mendelian disorders can be modeled by homologous mutations in animal model systems with strong recapitulation of human disease etiology and natural history, providing an important advantage for study of these diseases. Monogenic high penetrant mutations are ideal for toxicant challenge studies with a wide variety of environmental stressors, because background genetic variability may be less able to alter the relatively strong phenotype driving disease-causing mutations. These models promote mechanistic understandings of gene-environment interactions and biological pathways relevant to both Mendelian and related sporadic complex disease outcomes by creating a sensitized background for relevant environmental risk factors. Additionally, rare disease communities are motivated research participants, creating the potential of strong research allies among rare Mendelian disease advocacy groups and disease registries and providing a variety of translational opportunities that are under-utilized in genetic or environmental health science.

Pediatric Neurodevelopmental Delays in Children 0 to 5 Years of Age With Sickle Cell Disease: A Systematic Literature Review

INTRODUCTION

Sickle cell disease (SCD) is the most common abnormal genetic blood disease that affects ∼100,000 Americans. Approximately 20% to 37% of children with sickle cell anemia have silent cerebral infarcts by the age of 14 years old. Neurocognitive deficits are identified in infants and preschool children with SCD. The purpose of this systematic literature review is to provide a comprehensive understanding of the prevalence, severity, and the associated risk factors for neurodevelopmental delays (NDDs) in children with SCD 5 years of age and younger.

METHODS

Systematic search of 6 databases identified 2467 potentially relevant publications and 8 were identified through a manual search. Only 24 articles met the inclusion criteria.

RESULTS

We identified an increased prevalence of NDDs (cognitive, motor, or both). Children experienced deficits with language, attention and behavior, executive functioning, school readiness and/or academic performance, and motor skills (fine and gross motor functioning). Risk factors include silent cerebral infarcts and strokes, SCD genotype (HbSS>HbSC), other biologic, and social factors.

CONCLUSION

NDDs are common in children ages 0 to 5 years old with SCD. There is an opportunity to improve adherence to national guideline recommendations and early detection practices by pediatricians, hematologists, and other health care providers.

Cognitive performance as a predictor of healthcare transition in sickle cell disease

Neurocognitive deficits in sickle cell disease (SCD) may impair adult care engagement. We investigated the relationship between neurocognitive functioning and socio-environmental factors with healthcare transition outcomes. Adolescents aged 15-18 years who had neurocognitive testing and completed a visit with an adult provider were included. Transition outcomes included transfer interval from paediatric to adult care and retention in adult care at 12 and 24 months. Eighty adolescents (59% male, 64% HbSS/HbSβ⁰ -thalassaemia) were included. Mean age at adult care transfer was 18·0 (±0·3) years and transfer interval was 2·0 (±2·3) months. Higher IQ (P = 0·02; P_FDR  = 0·05) and higher verbal comprehension (P = 0·008; P_FDR  = 0·024) were associated with <2 and <6 month transfer intervals respectively. Better performance on measures of attention was associated with higher adult care retention at 12 and 24 months (P = 0·009; P_FDR  = 0·05 and P = 0·04; P_FDR  = 0·12 respectively). Transfer intervals <6 months were associated with smaller households (P = 0·02; P_FDR  = 0·06) and households with fewer children (P = 0·02; P_FDR  = 0·06). Having a working parent was associated with less retention in adult care at 12 and 24 months (P = 0·01; P = 0·02 respectively). Lower IQ, verbal comprehension, attention difficulties and environmental factors may negatively impact transition outcomes. Neurocognitive function should be considered in transition planning for youth with SCD.

The relationship between household chaos and child, parent, and family outcomes: a systematic scoping review

BACKGROUND

Household chaos, represented by the level of disorganisation or environmental confusion in the home, has been associated with a range of adverse child and family outcomes. This review aims to (1) identify how household chaos is measured, (2) chart study details of household chaos literature, and (3) map the existing literature with respect to the relationship between household chaos and child, parent, and family outcomes. We expect that this review will highlight the need to consider the importance of household chaos in child well-being research, particularly in those families where children may be more vulnerable to the adverse effects of household chaos.

METHODS

We searched five electronic databases (last updated September 1st 2018) in addition to Google Scholar, and identified publications via a 3-stage screening process, which was conducted by two researchers. Published studies were included if they investigated the association between household chaos and child, parent, or family outcomes. Research that investigated household chaos as a mediator or moderator, or that investigated how the relationship between household chaos and the outcome of interest was mediated or moderated, were also included.

RESULTS

One hundred twelve studies in 111 publications were included. The majority were conducted in the United States (n = 71), and used either cross-sectional (n = 60) or longitudinal (n = 49) study designs. Outcomes of interest were categorised into seven categories: (1) cognitive and academic (n = 16), (2) socio-emotional and behavioural (n = 60), (3) communication (n = 6), (4) parenting, family, and household functioning (n = 21), (5) parent outcomes (n = 6), (6) hormone (n = 8), and (7) physical health and health behaviours (n = 19). There was consistent evidence for significant correlations between household chaos and adverse outcomes across all seven categories in diverse populations with respect to age, disease status, and socio-economic status (SES).

CONCLUSION

There is consistent evidence for associations between household chaos and a number of adverse child, parent, and family-level outcomes. Household chaos may also help describe variations in outcomes between low SES and child development.

Correlates of Cognitive Function in Sickle Cell Disease: A Meta-Analysis

OBJECTIVE

To provide a comprehensive quantitative review of biological, environmental, and behavioral correlates across domains of cognitive function in sickle cell disease (SCD).

METHODS

Forty-seven studies were identified in PubMed, MedLine, and PsycINFO involving 2573 participants with SCD.

RESULTS

Meta-analytic findings across all identified samples indicate that hemoglobin and hematocrit were positively correlated with Full Scale IQ [FSIQ; r = .15, 95% confidence interval (CI) = .10 to .21], language and verbal reasoning (r = .18, 95% CI = .11 to .24), and executive function (r = .10, 95% CI = .01 to .19) with small effects and significant heterogeneity. Transcranial Doppler velocity was negatively associated with visual spatial and perceptual reasoning (r = -.18, 95% CI = -.31 to -.05). Socioeconomic status was positively associated with FSIQ (r = .23, 95% CI = .17 to .28), language and verbal reasoning (r = .28, 95% CI = .09 to .45), visual spatial and perceptual reasoning (r = .26, 95% CI = .09 to .41), and executive function (r = .18, 95% CI = .07 to .28) with small to medium effects. Finally, total behavioral problems were negatively associated with FSIQ (r = -.12, 95% CI = -.21 to -.02) such that participants with lower FSIQ exhibited greater behavioral and emotional problems.

CONCLUSIONS

Findings provide evidence for biological, environmental, and psychosocial corelates across multiple domains of cognitive function in SCD. More research on more specific cognitive domains and psychosocial correlates is needed in addition to assessments of interactional models among risk factors.

Laboratory Biomarkers, Cerebral Blood Flow Velocity, and Intellectual Function in Children with Sickle Cell Disease

Objective

The aim of this preliminary study was to describe putative markers of cerebral vasculopathy and investigate relationships among these markers, demographic factors, and cognitive function in a young sample of neurologically normal children with SCD. Study Design. Thirty-eight children with homozygous HbS, aged 4-11 years, were included. Estimated IQ and markers of coagulation and endothelial activation, hemolysis, and inflammation, as well as transcranial Doppler velocities, hydroxyurea use, and demographic information were obtained.

Results

Using multiple regression analyses, there were few significant independent associations between biomarkers or blood flow velocity and estimated IQ. Lactic dehydrogenase (LDH) independently predicted cognitive function, but blood flow velocity did not mediate this relationship. Maternal education, patient age, and hydroxyurea status were independent predictors of cognition. Given the small sample size, a LASSO statistical model was employed to further identify potential predictors of IQ, which identified LDH, absolute neutrophil count (ANC), platelet count, thrombin-antithrombin (TAT), tissue factor (TF), maternal education, age, and hydroxyurea as potential predictors of cognition.

Conclusions

In addition to effects of age and maternal education, some vasculopathic markers are associated with cognitive function in young children with SCD, and these relationships do not appear to be mediated through blood flow velocity. Although the lack of association among certain variables was not as predicted, results provide support for further research regarding the influence of vasculopathic markers on cognitive function in children with SCD without stroke, especially intravascular hemolysis and coagulation/endothelial activation, and a possible role for HU treatment in preventing or reversing cognitive decline.

Association between hydroxycarbamide exposure and neurocognitive function in adolescents with sickle cell disease

Patients with sickle cell disease (SCD) are at increased risk for neurocognitive impairments. While disease-modifying treatment, such as hydroxycarbamide (hydroxyurea), may decrease this risk, it has not been systematically investigated in children with SCD. We screened neurocognitive functioning in 103 adolescents with SCD (16-17 years, 50% female) and compared outcomes between patients with a history of exposure to hydroxycarbamide (n = 12 HbSC/HbSβ⁺ thalassaemia; n = 52 HbSS/HbSβ⁰ thalassaemia) and those never treated with hydroxycarbamide (n = 31 HbSC/HbSβ⁺ thalassaemia; n = 8 HbSS/HbSβ⁰ thalassaemia). Demographic distributions were similar between the groups. After adjusting for socioeconomic status, the hydroxycarbamide group had significantly higher scores on nonverbal IQ (HbSC/HbSβ thalassaemia: P = 0·036, effect size [d] = 0·65), reaction speed (HbSS/HbSβ⁰ thalassaemia: P = 0·002, d = 1·70), sustained attention (HbSS/HbSβ⁰ thalassaemia: P = 0·014, d = 1·30), working memory (HbSC/HbSβ⁺ thalassaemia: P = 0·034, d = 0·71) and verbal memory (HbSC/HbSβ⁺ thalassaemia: P = 0·038, d = 0·84) when compared to those who did not receive hydroxycarbamide. In patients with HbSS/HbSβ⁰ thalassaemia, longer treatment duration with hydroxycarbamide was associated with better verbal memory (P = 0·009) and reading (P = 0·002). Markers of hydroxycarbamide effect, including higher fetal haemoglobin (HbF), higher mean corpuscular volume (MCV) and lower white blood cell count (WBC), were associated with better verbal fluency (HbF: P = 0·014, MCV: P = 0·006, WBC: P = 0·047) and reading (MCV: P = 0·021, WBC: P = 0·037). Cognitive impairment may be mitigated by exposure to hydroxycarbamide in adolescents with SCD.

Responsive Parenting Behaviors and Cognitive Function in Children With Sickle Cell Disease

OBJECTIVE

Children with sickle cell disease (SCD) are at increased risk for cognitive impairment as a result in part from biological characteristics of the disease; however, limited research has explored possible social and contextual factors associated with risk for cognitive problems. The primary aim of the present study was to examine the relation between children's cognitive functioning and responsive parenting, a potentially important contextual factor in children with SCD, accounting for family socioeconomic disadvantage, child disease severity, and caregivers' perceived stress.

METHODS

Forty-eight children completed standardized cognitive assessments and caregivers provided self-reports of general and disease-related stress. Parent-child dyads completed a video recorded puzzle-solving task and observed parenting was quantified using two coding systems. Bivariate Pearson correlations were used to assess preliminary hypotheses, and linear multiple regression analyses were used to assess the primary hypothesis.

RESULTS

Results suggested that increased levels of parental stress were related to fewer observations of responsive parenting and provided evidence of an association between children's cognitive function and responsive parenting. Specifically, increased disease-related parent stress and reduced parental use of expansive language were associated with significantly lower cognitive functioning in children with SCD.

CONCLUSIONS

Findings suggest that social environmental factors along with disease characteristics are sources of risk for cognitive problems with children with SCD. Further, these findings highlight the need to develop targeted interventions for parents of children with SCD to decrease levels of stress and enhance parenting skills, with the aim improving cognitive functioning in youth.

Cognitive Function in Sickle Cell Disease Across Domains, Cerebral Infarct Status, and the Lifespan: A Meta-Analysis

OBJECTIVE

To provide a comprehensive quantitative review of neurocognitive function in sickle cell disease (SCD) across multiple domains, cerebral infarct status, and the lifespan.

METHODS

One hundred and ten studies were identified in PubMed, MedLine, and PsycINFO involving 110 studies of 3,600 participants with SCD and 1,127 sibling or health controls.

RESULTS

Meta-analytic findings indicate significant deficits across all neurocognitive domains, age groups, and infarct status. Significant deficits relative to the normative mean ranged from Hedges' g = -.39 to g = -.63 in preschool children, g = -.83 to g = -1.18 in school-aged children and adolescents, and g = -.46 to g = -.86 in adults. Deficits in full scale IQ (FSIQ), verbal reasoning, perceptual reasoning, and executive function increased from preschool to school-aged samples. However, findings also showed that deficits were smaller in adult samples relative to school-aged samples, likely due to sampling bias in adult studies. Findings across infarct status in sickle cell anemia showed that deficits ranged from g = -.54 to g = -.65 in samples without infarcts, g = -.52 to g = -1.03 in samples with silent cerebral infarct, and g = -1.35 to g = -1.82 in samples with stroke. Deficits in each domain increased in magnitude from no infarct or stroke, to silent cerebral infarct, to overt stroke.

CONCLUSION

Individuals with SCD are at risk for cognitive deficits across domains, infarct status, and the lifespan. More research is necessary to determine unbiased effects for cognitive function in adults with SCD.

Integrated psychology support and comprehensive cognitive evaluation improves access to special education services for children with sickle cell disease

BACKGROUND

Children with sickle cell disease (SCD) are at risk for cognitive deficits. Limited data describe whether comprehensive cognitive evaluation improves education resources and whether caregivers perceive the assessment as beneficial. We tested our two hypotheses: (a) an integrated comprehensive cognitive evaluation program in children with SCD results in increased special education services allocation; and (b) caregivers will value comprehensive cognitive evaluation services provided.

PROCEDURE

In a tertiary care medical facility, as part of quality improvement project, in a before-and-after evaluation between March 2011 and July 2014, we examined the impact of targeted comprehensive cognitive evaluation on change in special education services. We also evaluated the caregiver's perception regarding the utility of the provided services.

RESULTS

A total of 21% (42 of 196) students (median age 11 years, range 3-18) with SCD were referred for cognitive assessment due to overt stroke (n = 11), silent stroke (n = 14), or concerns about cognitive or academic functioning without evidence of strokes (n = 17). At baseline, 45.2% received special education services and after the comprehensive cognitive evaluation 86.7% received special education services (P < 0.001). Among 33 caregivers who completed the survey, 97% reported that the assessment was helpful and 60% indicated that assessment led to beneficial changes for their children at school.

CONCLUSION

Education advocacy coupled with comprehensive cognitive assessment in students with SCD improved access to special education services, and caregivers uniformly endorse this service as having added value.

Greater number of perceived barriers to hydroxyurea associated with poorer health-related quality of life in youth with sickle cell disease

BACKGROUND

Despite medical benefits, hydroxyurea adherence in adolescents is often poor. As part of a baseline assessment of 28 youth (10-18 years) parent dyads who participated in a 6-month feasibility trial to improve hydroxyurea adherence, we measured the relationship between greater barriers to adherence and health-related quality of life (HRQL) from youth and parent perspectives.

PROCEDURE

Barriers were measured using the Adolescent and Parent Medication Barriers Scales with nine hydroxyurea items added. Barriers reported by ≥25% of the sample were considered common. Generic and disease-specific HRQL were measured by PedsQL and PedsQL Sickle Cell Disease modules. Data were analyzed using descriptive statistics, Cronbach alpha, Spearman correlation coefficients, and paired t tests.

RESULTS

Fifty-six subjects (28 dyads) participated. Youth reported greater barriers compared with parents (5.0 ± 3.9 and 3.5 ± 3.2; P = 0.03), with >80% of respondents reporting ≥1 barriers. Twelve barriers were reported by ≥25% of adolescents, whereas six were reported by ≥25% of parents. Of these, only two were common to both dyad members. Approximately one-third of youth had generic and disease-specific HRQL scores that fell at or below cutoff scores, suggesting being at risk for impaired HRQL. Greater barriers were inversely associated with poorer generic (parent r = -0.43, P = 0.03; youth r = -0.44, P < 0.001) and disease-specific HRQL (parent r = -0.53, P = 0.005; youth r = -0.53, P < 0.001).

CONCLUSIONS

Hydroxyurea barriers were frequently reported but differed by dyad members' perspective. Greater barriers were associated with poorer generic and disease-specific HRQL. To reduce barriers to hydroxyurea in youth with sickle cell disease, perspectives of both dyad members should be addressed.

Social-environmental factors and cognitive and behavioral functioning in pediatric sickle cell disease

Sickle cell disease (SCD), an inherited blood disorder that primarily affects individuals of African descent, is associated with serious medical complications as well as numerous social-environmental risk factors. These social-environmental factors are linked to long-standing social inequities, such as financial hardship and racial discrimination, both of which impact cognitive and behavioral functioning in youth. Previous research on the relationship between social-environmental risk and psychological functioning has primarily relied on non-modifiable, unidimensional measures of socioeconomic status (SES), such as income and parental education, as a proxy for social-environmental risk. The current study aimed to address the limitations associated with typical SES-type measures by comparing the unique and shared association of SES and more targeted and modifiable social-environmental factors (e.g., parent and family functioning) with specific areas of cognitive and behavioral adjustment in pediatric SCD. Seventy children ages 4-8 years old and their parents completed measures of social-environmental risk and psychological adjustment. Exploratory factor analysis indicated parent and family functioning measures were largely independent of SES. Parent and family functioning predicted phonological processing and ADHD symptoms above and beyond SES alone. In addition, the predictive ability of social-environmental risk factors appears to vary by genotype severity for measures of social functioning and math problem-solving ability. Future studies are needed to explore more specific and well-supported models of modifiable social-environmental risk and the relative impact of social-environmental risk on cognitive and behavioral functioning.

Executive Functioning Mediates the Relationship Between Pain Coping and Quality of Life in Youth With Sickle Cell Disease

Objective

Sickle cell disease (SCD) is a lifelong condition characterized by pain, which is associated with reduced health-related quality of life (HRQL). Data suggest that patients with SCD vary in how they cope and their neurocognitive abilities. This study aimed to characterize executive functioning and pain coping styles in children with SCD experiencing a range of pain frequency (i.e., chronic, episodic, and asymptomatic) and to examine whether executive functioning mediates the relationship between pain coping and HRQL.

Method

Participants included 100 children and adolescents with SCD between the ages of 8 and 18 years (M = 13.53, SD = 2.8) and their parents who were recruited during outpatient SCD clinic visits in a children's hospital. Children completed questionnaires related to pain experience and pain coping. Parents completed questionnaires about demographic information, their child's executive functioning, and HRQL.

Results

Pain intensity, executive dysfunction, and engagement in emotion-focused coping (i.e., internalizing/catastrophizing and externalizing) predicted poor HRQL. In addition, engagement in emotion-focused coping predicted executive dysfunction. Multivariate analysis of covariance revealed executive functioning did not differ based on pain frequency; however, executive functioning was a significant mediator that helped explain the relationships between distraction and emotion-focused coping techniques on HRQL.

Conclusion

Findings support that executive functioning is an important factor in understanding the relationship between pain coping and HRQL in youth with SCD. Future research is warranted to examine the potential impact of executive functioning on the utility of interventions targeting adaptive pain coping in youth with SCD.

Assessment of Executive Functions in Preschool Children With Sickle Cell Anemia

OBJECTIVES

Children with sickle cell anemia (SCA) are commonly reported to experience executive dysfunction. However, the development of executive function (EF) in preschool-age children without stroke in this patient population has not been investigated so it is unclear when and how these deficits emerge.

METHODS

This case-control study examines the feasibility of assessing the early development of executive functioning in 22 preschool children years with SCA in the domains of processing speed, working memory, attention, inhibitory control, and cognitive flexibility, as well as everyday function, in comparison to matched control children.

RESULTS

A pattern of potential deficits in early emerging executive skills was observed in the domains of inhibitory control and cognitive flexibility. Parents reported no differences for everyday EF and no significant differences were observed for working memory and processing speed.

CONCLUSIONS

Results suggest that deficits in everyday executive difficulties, working memory, and processing speed, as commonly reported for older children with SCA, may not yet have emerged at this early developmental stage, despite specific deficits in cognitive flexibility and inhibitory control on behavioral measures. The feasibility of using available executive measures with preschool age children to characterize the development of early EF skills is discussed. (JINS, 2018, 24, 949-954).

Cognitive Function, Coping, and Depressive Symptoms in Children and Adolescents with Sickle Cell Disease

Objective

The objective of this study was to investigate the association between cognitive functioning, coping, and depressive symptoms in children and adolescents with sickle cell disease (SCD).

Method

Forty-four children (M age = 9.30, SD = 3.08; 56.8% male) with SCD completed cognitive assessments measuring working memory (Wechsler Intelligence Scale for Children-Fourth Edition) and verbal comprehension (Wechsler Abbreviated Scale of Intelligence-Second Edition). Participants' primary caregivers completed questionnaires assessing their child's coping and depressive symptoms.

Results

Verbal comprehension was significantly positively associated with secondary control coping (cognitive reappraisal, acceptance, distraction), and both working memory and secondary control coping were negatively associated with depressive symptoms. In partial support of the primary study hypothesis, verbal comprehension had an indirect association with depressive symptoms through secondary control coping, whereas working memory had a direct association with depressive symptoms.

Conclusions

The results provide new evidence for the associations between cognitive function and coping, and the association of both of these processes with depressive symptoms in children with SCD. Findings provide potential implications for clinical practice, including interventions to improve children's cognitive functioning to attenuate depressive symptoms.

Executive Function Deficits in Seriously Ill Children-Emerging Challenges and Possibilities for Clinical Care

The past years have seen an incredible increase in the quality and success rates of treatments in pediatric medicine. One of the resulting major challenges refers to the management of primary or secondary residual executive function deficits in affected children. These deficits lead to problems in the ability to acquire, understand, and apply abstract and complex knowledge and to plan, direct, and control actions. Executive functions deficits are important to consider because they are highly predictive of functioning in social and academic aspects of daily life. We argue that current clinical practice does not sufficiently account for the complex cognitive processes in this population. This is because widely applied pharmacological interventions only rarely account for the complexity of the underlying neuronal mechanisms and do not fit well into possibly powerful "individualized medicine" approaches. Novel treatment approaches targeting deficits in executive functions in seriously ill children could focus on neuronal oscillations, as these have some specific relations to different aspects of executive function. Importantly, such treatment approaches can be individually tailored to the individuals' deficits and can be transferred into home-treatment or e-health solutions. These approaches are easy-to-use, can be easily integrated into daily life, and are becoming increasingly cost-effective.

A pilot study of parent education intervention improves early childhood development among toddlers with sickle cell disease

BACKGROUND

Young children with sickle cell disease (SCD) are at risk for cognitive delay. In addition to biologic risk factors associated with SCD, environmental factors contribute to cognitive dysfunction within this cohort.

METHODS

We completed a single-arm, prospective cohort study. Children with SCD between the ages of 3 and 36 months and their caregivers were followed between October 2010 and December 2013. The aim was to describe the role of a home visitation model, the home environment, and socioeconomic status in the development of young children with SCD. Primary outcome measures were the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) and the Home Observation for Measurement of the Environment (HOME). We hypothesized that the home visitation model, Parents as Teachers^® (PAT), would encourage positive parent-child interactions and improve cognitive outcomes.

RESULTS

Thirty-five participants had at least two PAT visits and BSID-III assessments. Mean scores within all five subtests of the BSID-III improved between enrollment and exit, with significant changes within cognitive (P = 0.016) and expressive language (EL) domains (P = 0.002). Multivariate modeling found the HOME score associated with the exit results of the cognitive domain.

CONCLUSION

We report longitudinal results of the first home visitation program within the early childhood SCD population and show significant improvement in cognitive and EL development. Additionally, home environment was a significant predictor of cognitive development. Randomized controlled trials to test the impact of interventions targeting the home environment are warranted for this vulnerable population.