Prevalence of Duffy null and its impact on hydroxyurea in young children with sickle cell disease in the United States

Consistent with studies showing a high prevalence of the Duffy null phenotype among healthy Black Americans, this retrospective study found that Duffy null was present in >75% of a young and contemporary cohort of children with sickle cell disease (SCD) in the United States. Despite the potential for this phenotype to impact absolute neutrophil counts, hydroxyurea (HU) dosing, and outcomes, it was not associated with being prescribed a lower HU dose or having increased acute SCD visits early in the HU treatment course. Future studies are needed to confirm these findings in older children with SCD.

Using the consolidated framework for implementation research to identify challenges and opportunities for implementing a reproductive health education program into sickle cell disease care

BACKGROUND

As survival rates for individuals with sickle cell disease (SCD) increase, calls have been made to improve their reproductive healthcare and outcomes. The research team created a web-based program entitled Fertility edUcaTion to Understand ReproductivE health in Sickle cell disease (FUTURES). The study aim was to use the Consolidated Framework for Implementation Research (CFIR) during pre-implementation to identify challenges and opportunities from the individual to systems level of implementation to ultimately optimize the integration of FUTURES into clinical practice.

METHODS

Semi-structured interviews were conducted with clinicians, research team members, and adolescent and young adult (AYA) males with SCD and their caregivers who participated in pilot testing. Interviews (N = 31) were coded inductively and then mapped onto CFIR domains (i.e., outer setting, inner setting, characteristics of individuals, and intervention characteristics).

RESULTS

Research team interviews indicated the lack of universal guidelines for reproductive care in this population and gaps in reproductive health knowledge as key reasons for developing FUTURES, also highlighting the importance of collaboration with community members during development. Clinicians reported intraorganizational communication as essential to implementing FUTURES and discussed challenges in addressing reproductive health due to competing priorities. Clinicians, AYAs, and caregivers reported positive views of FUTURES regarding length, engagement, accessibility, and content. Suggestions for the best setting and timing for implementation varied.

CONCLUSIONS

Using CFIR during the pre-implementation phase highlighted challenges and opportunities regarding integrating this program into SCD care. These findings will inform adaptation and further testing of FUTURES to ensure effective implementation of this novel education program.

Experiences and outcomes of fertility testing in male adolescents with sickle cell disease

Adult males with sickle cell disease (SCD) may have abnormal semen parameters, raising the concern that SCD and/or treatments may impact fertility. Yet, studies that include adolescents are lacking. To determine if fertility testing is feasible in male adolescents with SCD, and to explore their experiences and outcomes of fertility testing, 33 adolescents who completed a web-based SCD reproductive health education program were offered a free semen analysis. Five (15%) obtained testing and each had abnormalities. Barriers to testing included lack of time and transportation and discomfort. Findings highlight the need for larger, longitudinal studies using innovative testing approaches.

Comparing super-utilizers and lower-utilizers among commercial- and Medicare-insured adults with sickle cell disease

ABSTRACT

Sickle cell disease (SCD) is a rare but costly condition in the United States. Super-utilizers have been defined as a subset of the population with high health care encounters or expenditures. Although super-utilizers have been described in other disease states, little is known about super-utilizers among adults with SCD. This study aimed to characterize the differences in expenditures, overall health care encounters, and pain episode encounters between super-utilizers (top 10% expenditures) and lower-utilizers with SCD (high, top 10%-24.9%; moderate, 25%-49.9%; and low, bottom 50% expenditures). A retrospective longitudinal cohort of adults with SCD were identified using validated algorithms in MarketScan and Medicare claim databases from 2016 to 2020. Encounters and expenditures were analyzed from inpatient, outpatient, and emergency department settings. Differences in encounters and expenditures between lower-utilizers and super-utilizers were compared using logistic regression. Among super-utilizers, differences in encounters and expenditures were compared according to incidences of pain episode encounters. The study population included 5666 patients with commercial insurance and 8600 with Medicare. Adjusted total annual health care expenditure was 43.46 times higher for super-utilizers than for low-utilizers among commercial-insured and 13.37 times higher in Medicare-insured patients. Among super-utilizers, there were patients with few pain episode encounters who had higher outpatient expenditures than patients with a high number of pain episode encounters. Our findings demonstrate the contribution of expensive outpatient care among SCD super-utilizers, in which analyses of high expenditure have largely focused on short-term care. Future studies are needed to better understand super-utilizers in the SCD population to inform the effective use of preventive interventions and/or curative therapies.

Measuring hydroxyurea adherence by pharmacy and laboratory data compared with video observation in children with sickle cell disease

BACKGROUND

Hydroxyurea nonadherence is common among children with sickle cell disease (SCD), but it is unclear if current adherence measures are valid compared with video directly observed therapy (VDOT), a reference method. The objectives were to evaluate if hydroxyurea adherence by pharmacy records, urine assay, mean corpuscular volume (MCV), and/or fetal hemoglobin (HbF) correlated with and was sensitive and specific compared with VDOT.

METHODS

This was a cross-sectional analysis of adherence data from 34 children with SCD on a single-arm, six-month hydroxyurea adherence study. Spearman correlation coefficient compared participants' adherence by pharmacy records, MCV, and HbF to adherence by VDOT. The sensitivity and specificity of ≥80% adherence by pharmacy records, two urine samples with hydroxyurea, MCV ≥100 fl/L, and HbF ≥20% compared with ≥80% VDOT adherence were also calculated.

RESULTS

Median pharmacy and VDOT adherence rates were similar (87.8% vs 88.1%, P = 0.75) and mildly correlated (r_s  = 0.45; P = 0.008) but the sensitivity of ≥80% adherence by pharmacy records was 72.7% and specificity was 45.5%. MCV (r_s  = -0.02, P = 0.92) and HbF (r_s  = -0.2, P = 0.33) did not significantly correlate with VDOT adherence. Sensitivity and specificity were 83.3% and 33.3% for having two urine samples with hydroxyurea, 35% and 71.4% for MCV ≥100 fl/L, and 75% and 0% for HbF ≥20%, respectively.

CONCLUSIONS

Commonly used tools to measure hydroxyurea adherence may not correlate with or be valid compared with video adherence. Future studies to refine these measures are needed to effectively target adherence interventions to children with SCD who have the potential to benefit. (ClinicalTrials.gov NCT02578017).

A Multidimensional Electronic Hydroxyurea Adherence Intervention for Children With Sickle Cell Disease: Single-Arm Before-After Study

Background

Hydroxyurea is a disease-modifying medication for patients with sickle cell disease (SCD). Despite demonstrated efficacy, hydroxyurea nonadherence in clinical practice is common and results in worse health outcomes for nonadherent patients. Mobile Directly Observed Therapy (Mobile DOT) is a pilot-tested, electronic, multidimensional hydroxyurea adherence intervention for children with SCD. Mobile DOT includes sending daily text message reminders to patients to take hydroxyurea, patients recording and sending daily videos that capture their hydroxyurea administrations for the research team to review and track adherence, providing personalized feedback to patients about their adherence, and providing small monetary incentives to patients if they achieve high hydroxyurea adherence.

Objective

This study aimed to determine if Mobile DOT increases hydroxyurea adherence in children with SCD and to explore its impact on hematologic and clinical outcomes.

Methods

This was a single-arm, 6-month intervention study of patients with SCD on hydroxyurea who were aged ≤19 years and reported having access to an electronic device. Participants’ hydroxyurea adherence when they received Mobile DOT was compared with their adherence 6 months before and after receiving Mobile DOT. Participants’ medication possession ratio (MPR) was calculated from their pharmacy dispensing records and was used to measure adherence. Laboratory and clinical outcomes were abstracted from participants’ electronic medical records. Infrequently hospitalized patients who received at least 160 days of the intervention were considered to be engaged participants.

Results

Of 91 patients who were approached, 55 enrolled and 34 engaged with Mobile DOT. The median age of the engaged participants was 10 years (range 2-18.8 years), and 21 (62%, 21/34) participants were male, 28 (82%, 21/34) had hemoglobin SS SCD, and 19 (56%, 19/34) were prescribed hydroxyurea for at least a year before enrollment. With Mobile DOT, engaged participants’ median MPR increased from 61.7% to 84.4% (P<.001) and significantly more (67% vs 30%; P=.002) achieved ≥80% hydroxyurea adherence compared with baseline values. Engaged participants’ mean fetal hemoglobin (HgbF) levels and mean corpuscular volumes (MCV) improved significantly after 6 months of Mobile DOT (P=.04 and P=.001, respectively), but their adherence, HgbF levels, and MCV returned to baseline values during the 6 months after the intervention. Hospitalizations and the clinical outcomes that were measured occurred infrequently during the study. Nonengagement was associated with being female and having a recent SCD complication. In addition, having insufficient electronic data, being unable to quickly complete Mobile DOT each day, and not perceiving that Mobile DOT was beneficial may have further decreased engagement.

Conclusions

Mobile DOT shows promise as an effective intervention for some children with SCD. Modifications that may improve recruitment, reduce attrition, and increase engagement were identified and could increase the impact that Mobile DOT has on children with SCD.

Trial Registration

ClinicalTrials.gov NCT02578017; https://clinicaltrials.gov/ct2/show/NCT02578017

Impact of erythrocytapheresis on natural anticoagulant levels in children with sickle cell disease: A pilot study

Venous thromboembolism (VTE) is being increasingly recognized in children with sickle cell disease (SCD). In a retrospective cohort study, we identified bilateral central venous catheter (CVC) placement as an independent risk factor for VTE. At our institution, the only indication for bilateral CVC placement in children with SCD is erythrocytapheresis. To investigate the impact of erythrocytapheresis on coagulation, we measured levels of natural anticoagulants in 11 patients with SCD on chronic erythrocytapheresis, immediately before and after apheresis. We demonstrated a statistically significant reduction in most parameters. Additional studies are needed to further investigate the exact etiology and clinical impact of this acute decrease.

Diverse manifestations of acute sickle cell hepatopathy in pediatric patients with sickle cell disease: A case series

The hepatic complications of sickle cell disease (SCD) are associated with increased morbidity and mortality in adults; children usually survive but may suffer significant sequelae. Few diagnostic tools differentiate the various hepatic manifestations of SCD. Why patients exhibit one hepatic pathology versus another is unclear. We report four pediatric patients with hemoglobin SS disease with diverse manifestations of acute hepatic involvement including acute sickle hepatic crisis, hepatic sequestration, sickle cell intrahepatic cholestasis, and a non-SCD cause of hepatopathy in a patient with viral hepatitis. These complications require a systematic approach to extensive evaluation and coordinated multidisciplinary care.

Venous Thromboembolism in Children with Sickle Cell Disease: A Retrospective Cohort Study

OBJECTIVES

To describe the cumulative incidence of venous thromboembolism (VTE) in children with sickle cell disease (SCD) followed at a single institution and report on the risk factors associated with VTE development.

STUDY DESIGN

Charts for all patients with SCD, aged 0-21 years, followed at Nationwide Children's Hospital over a 6-year period (January 1, 2009, to January 31, 2015) were reviewed. Data on VTE diagnosis, sex, body mass index/weight-for-length, SCD genotype, SCD clinical complications, central venous catheter (CVC) placement, and thrombophilia testing were collected.

RESULTS

Cumulative incidence of VTE in children with SCD followed at a single tertiary care institution was found to be 2.9% (12/414). Nine of the 12 VTE were CVC-associated. On univariate analysis, hemoglobin SS genotype (OR 10.7, 95% CI 1.4-83.5), CVC presence (OR 34.4, 95% CI 8.9-134.6), central nervous system vasculopathy (OR 19.4, 95% CI 5.6-63.4), chronic transfusion therapy (OR 30.6, 95% CI 8.9-122.2), and older age (P = .03) were associated with VTE. However, presence of CVC was the only independent risk factor identified on multivariable logistic regression analysis (OR 33.8, 95% CI 8.7-130.9).

CONCLUSION

In our institution, nearly 3% of children with SCD had a history of VTE. CVC is an independent predictor of VTE in children with SCD.

Sickle cell trait knowledge and health literacy in caregivers who receive in-person sickle cell trait education

BACKGROUND

Despite universal screening that detects sickle cell trait (SCT) in infancy, only 16% of Americans with SCT know their status. To increase SCT status awareness, effective education for patients and their families is needed. The objective of this study was to assess caregivers' SCT knowledge before and after an in-person SCT education session.

METHODS

A trained educator provides in-person SCT education to caregivers of referred infants with SCT at Nationwide Children's Hospital. From August 2015 to July 2016, primarily English-speaking caregivers of infants with hemoglobin S-trait were recruited and completed a health literacy assessment and a SCT knowledge assessment (SCTKA) before and after receiving education. Caregivers repeated the SCTKA again after ≥6 months, if they could be contacted.

RESULTS

Thirty-eight (38.1%) percent of 113 caregivers had high SCTKA scores (≥75%) before education but 90.3% achieved high scores after education. Caregivers with low SCTKA scores after education had significantly lower health literacy (P = 0.029) and baseline SCTKA scores (P = 0.003) compared to those with higher scores after education. At ≥6 months, caregivers' scores were significantly higher (P = 0.014) than baseline, but only 73.3% scored ≥75%.

CONCLUSION

Our results suggest that caregivers' baseline SCT knowledge is low, improves with in-person education but may decline with time. Caregivers who do not achieve high SCT knowledge after education had lower health literacy and baseline knowledge. Future studies should determine if adapting in-person education to caregivers' health literacy and knowledge levels results in high and sustained SCT knowledge among all caregivers and more individuals who know their SCT status.

ENHANCE-(Electronic Hydroxyurea Adherence): A Protocol to Increase Hydroxyurea Adherence in Patients with Sickle Cell Disease

Background

Hydroxyurea (HU) is the only disease-modifying medication for patients with sickle cell disease (SCD). HU can reduce SCD-related complications but only 35% to 50% of pediatric patients adhere to HU at the rates achieved in clinical trials and this limits its clinical effectiveness. Mobile Directly Observed Therapy (Mobile DOT) is a pilot-tested, electronic, multidimensional, HU adherence intervention that targets many components of the Health Behavior Model.

Objective

The aim of this study is to evaluate the impact of Mobile DOT on HU adherence in children with SCD. The objective of our study is to inform the development of future adherence interventions and pediatric SCD protocols.

Methods

This is a single-arm crossover study of pediatric patients with SCD. Participants self-record videos of their daily HU administrations and receive text message alerts to take HU, feedback on their HU adherence, and incentives when they achieve adherence goals during the 6-month Mobile DOT phase. Participants’ HU adherence during the Mobile DOT phase is compared with their baseline HU adherence (6 months prior to study entry) and to their HU adherence 6 months after completing the Mobile DOT phase. The primary outcome of this study is HU adherence measured by medication possession ratio.

Results

The trial is ongoing. Preliminary review of participant satisfaction results suggest that most participants can complete Mobile DOT in less than 5 minutes per day and are satisfied with the intervention.

Conclusions

If effective, the Mobile DOT strategy will increase HU adherence and this could improve patients’ clinical outcomes and reduce costs of care.

Hydroxyurea therapy for children with sickle cell disease: describing how caregivers make this decision

Background

Hydroxyurea (HU) is underutilized in children with sickle cell disease (SCD) because caregivers frequently decline HU when it is offered. This study explores what impacts this decision.

Results

Caregivers of children with clinically severe SCD whose children were offered HU previously were interviewed. We used a qualitative analytical approach to analyze their telephone interview transcripts. Caregivers who chose HU (n = 9) reported their children had severe SCD, sought detailed information about HU, and accepted HU as a preventative therapy. In contrast, caregivers who did not choose HU (n = 10) did not perceive their children as having severe SCD and did not question their child’s provider about HU.

Conclusions

This study identifies specific areas that providers should address to when they discuss HU with families so that they can make informed decisions. Our study also uncovered factors that are important to consider when designing future interventions to improve hydroxyurea acceptance and when developing decision-aid tools to assist caregivers of children with SCD who are considering disease modifying therapies.