Social-environmental factors and cognitive and behavioral functioning in pediatric 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.

Impact of Race, Socioeconomic Status, and Geography on Healthcare Outcomes for Children With Sickle Cell Disease in the United States: A Scoping Review

A large proportion of patients with sickle cell disease (SCD) identify as Black or African American (AA). Social bias and stigma in healthcare outcomes for children with SCD are impossible to explore without considering the impact of racial/cultural identity, socioeconomic status (SES), and geography. It is important to understand the current influences of social movements, expanded health insurance coverage, and telehealth on these variables when considering healthcare outcomes for patients with SCD. The objective of this study was to determine the roles of racial identity, SES, and geography in healthcare outcomes for the pediatric population of children with SCD in the United States (US). This study is a scoping review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The databases utilized included Cochrane, CINHAL, Medline, and Nursing and Allied Health Collection, all accessed through the EBSCO Information Services. Studies met the following inclusion criteria: published in English, pediatric patients residing in the US, and published between 2017 and 2022. Search terms included "sickle cell" AND "pediatric", which were then combined with "minority" OR "racial" OR "rural" OR "urban" OR "poverty" OR "income" OR "socioeconomic status". The initial search yielded 635 unique articles, with 17 articles meeting full inclusion criteria. Overall, it was clear that there are examples of positive effects of race, low SES, and rural geographic location on positive health outcomes, though a large number of studies oscillated between showing negative associations or no association at all. Barriers to care for patients with SCD are multifaceted, making it difficult to isolate and analyze the impact of individual variables. Many studies demonstrated the significance of family, community, and institutional relationships as positive support for patients with SCD. This review highlights the need for additional research on the healthcare outcome benefits of patient/familial support groups aiming to bring together patients who share racial experience and SCD diagnosis regardless of SES and geography.

The Bias of Medicine in Sickle Cell Disease

Sickle cell disease (SCD) is the most common monogenetic condition in the United States (US) and one that has been subjected to a history of negative bias. Since SCD was first described approximately 120 years ago, the medical establishment has, directly and indirectly, harmed patients by reinforcing biases and assumptions about the disease. Furthermore, negative biases and stigmas have been levied upon patients with SCD by healthcare providers and society, researchers, and legislators. This article will explore the historical context of SCD in the US; discuss specific issues in care that lead to biases, social and self-stigma, inequities in access to care, and research funding; and highlight interventions over recent years that address racial biases and stigma.

Sickle cell disease and social determinants of health: A scoping review

Social determinants of health (SDoH) may impact outcomes in sickle cell disease (SCD). We conducted a comprehensive literature review of five electronic databases to elucidate the relationship between SDoH and SCD, and identify gaps in the literature. Our search yielded 59 articles, which we organized into five SDoH areas: Neighborhood and Built Environment, Health and Healthcare, Social and Community Context, Education, and Economic Stability. We found that social determinants, such as access to healthcare, were inconsistently evaluated. Improved recognition and understanding of SDoH should enhance the development of programs that directly address its detrimental effects on patients with SCD.

Demand-only patient-controlled analgesia for treatment of acute vaso-occlusive pain in sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a chronic illness that is associated with frequent admissions for vaso-occlusive episodes (VOE). Opioids are frequently utilized in pain management, but dosing is often provider dependent. Opioids cause both short-term and long-term side effects, so the minimal effective dose is desired. This study examined demand-only patient-controlled analgesia (PCA) in pediatric patients.

METHODS

A new clinical practice guideline (CPG) for a single institution was implemented, which eliminated basal infusion dosing for PCAs on hospital admission. The primary aim of this retrospective study was to evaluate length of stay (LOS) before and after implementation of a CPG of demand-only PCA and, in a selected subpopulation, addition of short-term methadone. Secondary aims included opioid utilization, acute chest syndrome (ACS), and hypoxia. Inclusion criteria included SCD, ≤21 years of age, uncomplicated VOE admission, and ≥ 3 and ≤ 8 hospital admissions for SCD pain control within one calendar year.

RESULTS

LOS decreased postintervention (7.2 ± 5.1 vs 4.5 ± 3.8 days, P < 0.001). Mean total opioid utilization in morphine equivalents mg/kg markedly decreased between the cohorts (13.3 ± 33.8 vs 3.6 ± 3.0, P < 0.001). ACS (21.9% vs 2.8%, P = 0.004) and hypoxia (28% vs 6.9%, P< 0.001) decreased significantly as well.

CONCLUSION

Bolus PCA dosing of opioids resulted in decreased LOS and reductions in opioid utilization, hypoxia, and ACS.

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.

Reading intervention targeting phonemic awareness and symbol imagery in children with sickle cell disease

Children with sickle cell disease (SCD) frequently have diminished academic attainment and are particularly vulnerable to reading dysfunction. We explored the effectiveness of a multisensory reading intervention offered during the summer to children with SCD at our institution. Subjects with reading deficits were identified through parent report, clinical findings, or school meetings. Summer reading programs utilizing Phonemic Awareness and Symbol Imagery were provided. The Lindamood-Bell Auditory Conceptualization/Phonemic Awareness Test, Third Edition (LAC-3), and the Symbol Imagery Test were used as pre- and postintervention examinations to measure progress. Fifteen students (median age 9.4 years, range 6-14 years, eight females, all African American) received the Phonemic Awareness intervention, two times a week for 6 weeks. The subjects showed statistically significant gains in standard scores derived from the LAC-3 (mean change 7.9 points, p < .001), with associated improvements in age equivalency (AE) and grade equivalency (GE). Twenty-nine students (median age 9 years, range 6-17 years, 13 females, all African American) participated in the Symbol Imagery reading program, also two times a week for 6 weeks. These students showed significant gains in overall standard scores (mean change 9.8 points, p < .001). Although results should be interpreted with caution due to small sample sizes, we found that summer reading clinics for children with SCD improved phonological processing and symbol imagery skills, potentially leading to substantial gains in reading capability.

Neurocognitive functioning in preschool children with sickle cell disease

BACKGROUND

Children with sickle cell disease (SCD) experience neurodevelopmental delays; however, there is limited research with preschool-age children. This study examined neurocognitive risk and protective factors in preschoolers with SCD.

PROCEDURE

Sixty-two patients with SCD (60% HbSS/HbSβ⁰ -thalassemia; 40% HbSC/HbSβ⁺ -thalassemia) between the ages of 3 and 6 years (mean = 4.77 years) received a neuropsychological evaluation as routine systematic surveillance. Patients were not selected for disease severity, prior central nervous system findings, or existing cognitive concerns. Thirty-four patients (82% HbSS/HbSβ⁰ -thalassemia) were prescribed hydroxyurea (HU) at the time of their neuropsychological evaluation. On average, these patients had been prescribed HU at 2.15 (standard deviation = 1.45) years of age. The average dose was 28.8 mg/kg/day. Besides genotype, there were no group differences in medical or demographic factors based on HU treatment status.

RESULTS

Patients with HbSS/HbSβ⁰ -thalassemia scored below normative expectations on measures of intelligence, verbal comprehension, and school readiness (false discovery rate-adjusted p-value [p_FDR ] < .05). Age, sickle genotype, and HU treatment exposure were not associated with measured neurocognitive outcomes (p_FDR  > .05). Greater social vulnerability at the community level was associated with poorer performance on measures of intellectual functioning, verbal comprehension, visuomotor control, and school readiness, as well as parent report of executive dysfunction (p_FDR  < .05). Greater household socioeconomic status was positively associated with academic readiness.

CONCLUSIONS

Preschoolers with severe SCD (HbSS/HbSβ⁰ -thalassemia) perform below age expectations on measures of intelligence and academic readiness. Sociodemographic factors were stronger drivers of neurocognitive performance than disease severity or disease-modifying treatment. Neurodevelopmental interventions targeting the home and broader community environment are needed.

Co-Occurrence of Neurodevelopmental Disorders in Pediatric Sickle Cell Disease

OBJECTIVE

The objective of this study is to retrospectively determine the co-occurrence, associated characteristics, and risk factors for neurodevelopmental disorders (NDD) in a pediatric sickle cell disease (SCD) clinic population.

METHOD

We investigated the co-occurrence and features of NDD in pediatric SCD through a retrospective cohort study conducted between July 2017 and January 2019. The participants were patients with SCD younger than 18 years of age identified from our institutions' clinic rosters and medical records databases.

RESULTS

A total of 276 participants were eligible for study inclusion, and 65 participants were found to have various NDD. Children with SCD and NDD were more likely to have a history of multiple SCD-related complications in comparison to children with SCD without NDD. Children with SCD and NDD were more likely to use disease-modifying therapies in comparison to children with SCD without NDD (χ2 27.2, p < 0.001).

CONCLUSION

Children with SCD and NDD have higher odds of having certain disease-related complications and higher use of disease-modifying treatments than children with SCD who do not have NDD. Screening and diagnoses of NDD may be relevant to clinical management of pediatric SCD.

Cognitive Functioning and Educational Support Plans in Youth With Sickle Cell Disease

Children with sickle cell disease (SCD) face academic challenges because of direct and indirect disease-related events. This study examined the proportion of youth with SCD with educational plans and whether cognitive functioning is associated with educational support. Ninety-one youth (7 to 16 y) with SCD completed the WISC-V; caregivers reported educational support (504 Plan/Individualized Education Program) and completed the Behavior Rating Inventory of Executive Function. χ2 square and t test analyses explored whether overall intelligence (full-scale intelligence quotient [FSIQ]), relative weaknesses in processing speed and working memory (> 1SD below FSIQ), and parent-reported executive functioning were associated with educational plans. Participants with a FSIQ<90 were more likely to have support (74%) compared with youth with a FSIQ≥90 (47%; P=0.012). Those with FSIQ≥90 and FSIQ=80 to 89 were less likely to have support (47%, 58%, respectively) compared with those with FSIQ≤79 (89%; P=0.004). Relative weaknesses in processing speed were associated with educational support (83% vs. 52%, P=0.018) as well as behavioral aspects of executive functioning (Ps<0.05). Despite universal eligibility for a 504 Plan, 42% of youth with SCD in our sample did not have educational support. Significant deficits in intellectual functioning, processing speed, and parent-observed executive functioning are associated with having a plan, but children with subtle deficits seem less likely to be identified for educational support.

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.

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.

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.

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.

The Role of Family Functioning in the Development of Executive Functions in Preschool Children with Sickle Cell Anemia

Executive functions are compromised in children with sickle cell anemia. There is limited research on the development of executive functions in preschool children with sickle cell anemia and the factors that contribute to executive dysfunction. We looked at the relation between biomedical and environmental factors, including family functioning and socioeconomic status, and executive functions in 22 preschool children with sickle cell anemia. We found that family functioning was the strongest predictor of executive outcomes in young children with sickle cell anemia with no evidence for an influence of disease severity at this early stage.