Implementation of transcranial Doppler ultrasonography screening and primary stroke prevention in urban and rural sickle cell disease populations

Impact of telehealth visits on hydroxyurea response in sickle cell anemia

BACKGROUND

It is important to ensure access to hydroxyurea (HU) for patients with sickle cell anemia (SCA) living in rural areas. The University of Alabama at Birmingham (UAB) Pediatric Sickle Cell program's satellite clinics reduce the barrier of transportation to the university-based clinic. However, as compared with the university clinic, these satellite clinics do not offer immediate access to HU dosing laboratory results and a nurse clinician calls families with HU dose adjustments after the clinic visit. This study evaluated the impact of telehealth dosing adjustments on HU laboratory and clinical response as compared with university-based patients.

METHODS

A one-year retrospective chart review was performed to evaluate HU laboratory and clinical response based on clinic location and socioeconomic status for patients with SCA. We identified the number of clinic and acute care visits for one year and calculated the mean complete blood count and fetal hemoglobin (HbF) values for each patient.

RESULTS

We identified 107 academic center participants with SCA-prescribed HU and 65 satellite clinic participants. The mean age of participants was 11 ± 5 years. We identified no difference in HbF (13.3 ± 0.7 vs 11.7 ± 0.8, P = 0.13), Hb (8.46 ± 1.1 vs 8.55 ± 1.1, P = 0.59), mean corpuscular volume (91.0 ± 10.6 vs 91.7 ± 9.5, P = 0.67), or absolute neutrophil count (4.85 ± 2.3 vs 4.87 ± 2.3, P = 0.95) when comparing Birmingham versus satellite clinics. We also identified no difference in hospital admissions (0.99 ± 0.1 versus 0.85 ± 0.2, P = 0.49), based on clinic location.

CONCLUSIONS

The use of telehealth did not negatively impact laboratory response to HU. Future studies should identify novel approaches to improve access to HU among patients with SCA living in rural areas.

Evidence-based interventions implemented in low-and middle-income countries for sickle cell disease management: A systematic review of randomized controlled trials

BACKGROUND

Despite ~90% of sickle cell disease (SCD) occurring in low-and middle-income countries (LMICs), the vast majority of people are not receiving evidence-based interventions (EBIs) to reduce SCD-related adverse outcomes and mortality, and data on implementation research outcomes (IROs) and SCD is limited. This study aims to synthesize available data on EBIs for SCD and assess IROs.

METHODS

We conducted a systematic review of RCTs reporting on EBIs for SCD management implemented in LMICs. We identified articles from PubMed/Medline, Global Health, PubMed Central, Embase, Web of Science medical subject heading (MeSH and Emtree) and keywords, published from inception through February 23, 2020, and conducted an updated search through December 24, 2020. We provide intervention characteristics for each study, EBI impact on SCD, and evidence of reporting on IROs.

MAIN RESULTS

29 RCTs were analyzed. EBIs identified included disease modifying agents, supportive care agents/analgesics, anti-malarials, systemic treatments, patient/ provider education, and nutritional supplements. Studies using disease modifying agents, nutritional supplements, and anti-malarials reported improvements in pain crisis, hospitalization, children's growth and reduction in severity and prevalence of malaria. Two studies reported on the sustainability of supplementary arginine, citrulline, and daily chloroquine and hydroxyurea for SCD patients. Only 13 studies (44.8%) provided descriptions that captured at least three of the eight IROs. There was limited reporting of acceptability, feasibility, fidelity, cost and sustainability.

CONCLUSION

EBIs are effective for SCD management in LMICs; however, measurement of IROs is scarce. Future research should focus on penetration of EBIs to inform evidence-based practice and sustainability in the context of LMICs.

CLINICAL TRIAL REGISTRATION

This review is registered in PROSPERO #CRD42020167289.

Maintaining High Level of Care at Satellite Sickle Cell Clinics

Traveling to and from university-based clinics is a major health care barrier for children with sickle cell disease in Alabama. To reduce this barrier, the University of Alabama at Birmingham (UAB) developed satellite clinics. This study seeks to determine if these satellite clinics provide a similar level of comprehensive care when compared with the university-based clinic using four surrogate markers: 1) attendance rates, 2) percentage of patients on hydroxyurea, 3) percentage of screening MRIs obtained, and 4) percentage of transcranial dopplers (TCD) completed. A retrospective review of sickle cell visits from June 1, 2012 to May 31, 2013 demonstrated that satellite clinics can provide levels of medical care for children with sickle cell disease similar to those provided by university-based clinics.

Sickle cell disease and implementation science: A partnership to accelerate advances

Sickle cell disease (SCD) results in end organ damage and a shortened lifespan. Both the pathophysiology of the disease and the social determinants of health affect patient outcomes. Randomized controlled trials have been completed among this population and resulted in medical advances; however, the gestation of these advances and the lack of penetrance into clinical practice have limited advancements in clinical improvements for many people with SCD. We discuss the role of implementation science in SCD and highlight the need for this science to shorten the length of time to implement evidence-based care for more people with SCD.

Transcranial Doppler screening for stroke risk in children with sickle cell disease: a systematic review

Background Sickle cell disease (SCD) is one of the most common causes of stroke in children worldwide. Based on the results of the Stroke Prevention Trial in Sickle Cell Anemia (STOP), annual transcranial Doppler ultrasound (TCD) screening for affected children is standard practice. However, the need for TCD surveillance programs could override the accuracy of the screening, affecting the correct stratification of stroke risk and subsequent clinical management of the target population. Aims To shed light on this issue, a systematic review of the literature on TCD screening for children and adolescents with SCD was carried out (CRD42016050549), according to a list of clinically relevant questions, with a particular focus on screening practices in European countries. Quality of the evidence was rated using the grading of recommendations assessment, development and evaluation. Summary of review Thirty-three studies published in English or French were included (5 randomized controlled trials, 8 experimental non-randomized, and 20 observational studies). The quality of the retrieved evidence ranged between low and high, but was rated as moderate or high most of the times. TCD is effective as a screening tool for the primary prevention of stroke in SCD children. There is no high-quality evidence on the effectiveness of alternative screening methods, such as imaging-TCD with or without angle correction or magnetic resonance angiography. No evidence was found on effectiveness of the screening on children on hydroxyurea and with genotypes other than HbSS and HbS/β0. No European data were found on screening rates or adherence of screening practices to the STOP protocol. Conclusions High-quality studies on alternative screening methods that are currently used in real-world practice, and on screening applicability to specific subgroups of patients are urgently needed. Considering the low awareness of the disease in European countries and the lack of data on screening practices and adherence, clinicians need up-to-date guidelines for more uniform and evidence-based surveillance of children with SCD.

Determining Adherence to Quality Indicators in Sickle Cell Anemia Using Multiple Data Sources

INTRODUCTION

Advances in primary prophylaxis have resulted in improved outcomes for patients with sickle cell anemia (SCA; i.e., hemoglobin SS- and Sβ(0)-thalassemia). Standard prophylactic measures include a first pneumococcal polysaccharide vaccine (PPV) and transcranial Doppler ultrasound (TCD) at age 2 years. Though efficacious, evidence suggests that delivery of these interventions is suboptimal. This study reports adherence to these measures and examines concordance across various data sources, using Registry and Surveillance for Hemoglobinopathies project data.

METHODS

Retrospective database and SCA center chart review identified children with SCA aged 24-36 months between January 1, 2004, and December 31, 2008. PPV and TCD administration were determined through Medicaid and Children's Health Insurance Program administrative claims data, medical record review, and Georgia Registry of Immunization Transaction and Services. Analysis was conducted in 2015.

RESULTS

A total of 125 children met inclusion criteria. Forty-five (36.0%) children had documentation of both interventions, whereas 19 (15.2%) had no documentation of either intervention. Sixty-one (48.8%) children obtained only one intervention. Of these, more were likely to have had PPV than TCD (77.0% vs 23.0%, respectively, p<0.001). Agreement between claims data and medical record review was moderate for PPV (κ=0.55) and substantial for TCD (κ=0.74).

CONCLUSIONS

No single, reliable data source for tracking standard of care for children with SCA statewide was found. According to study data, prophylaxis measures were not universally implemented during the surveillance period. Further research is needed to adequately track changes over time, determine risk groups, and develop methods of evaluating important metrics.

Prevention of conversion to abnormal transcranial Doppler with hydroxyurea in sickle cell anemia: A Phase III international randomized clinical trial

Children with sickle cell anemia (SCA) and conditional transcranial Doppler (TCD) ultrasound velocities (170-199 cm/sec) may develop stroke. However, with limited available clinical data, the current standard of care for conditional TCD velocities is observation. The efficacy of hydroxyurea in preventing conversion from conditional to abnormal TCD (≥200 cm/sec), which confers a higher stroke risk, has not been studied prospectively in a randomized trial. Sparing Conversion to Abnormal TCD Elevation (SCATE #NCT01531387) was a National Heart, Lung, and Blood Institute-funded Phase III multicenter international clinical trial comparing alternative therapy (hydroxyurea) to standard care (observation) to prevent conversion from conditional to abnormal TCD velocity in children with SCA. SCATE enrolled 38 children from the United States, Jamaica, and Brazil [HbSS (36), HbSβ(0) -thalassemia (1), and HbSD (1), median age = 5.4 years (range, 2.7-9.8)]. Because of the slow patient accrual and administrative delays, SCATE was terminated early. In an intention-to-treat analysis, the cumulative incidence of abnormal conversion was 9% (95% CI = 0-35%) in the hydroxyurea arm and 47% (95% CI = 6-81%) in observation arm at 15 months (P = 0.16). In post hoc analysis according to treatment received, significantly fewer children on hydroxyurea converted to abnormal TCD velocities when compared with observation (0% vs. 50%, P = 0.02). After a mean of 10.1 months, a significant change in mean TCD velocity was observed with hydroxyurea treatment (-15.5 vs. +10.2 cm/sec, P = 0.02). No stroke events occurred in either arm. Hydroxyurea reduces TCD velocities in children with SCA and conditional velocities.