Hydroxyurea prescription, availability and use for children with sickle cell disease in Italy: Results of a National Multicenter survey

Acute chest syndrome in children with sickle cell disease: Data from a national AIEOP cohort identify priority areas of intervention in a hub-and-spoke system

Acute chest syndrome (ACS) is a frequent cause of hospitalization in sickle cell disease (SCD). Despite advances in acute care, many settings still lack knowledge about ACS best practices. After the AIEOP Guidelines were published in 2012, suggesting standardized management in Italy, a retrospective study was performed to assess the diagnostic and therapeutic pathways of ACS in children. From 2013 to 2018, 208 ACS episodes were presented by 122/583 kids in 11 centres. 73 were male, mean age 10.9 years, 85% African, 92% HbSS or Sβ°. In our hub-and-spoke system, a good adherence to Guidelines was documented, but discrepancies between reference centres and general hospitals were noted. Improvement is needed for timely transfer to reference centres, use of incentive spirometry, oxygen therapy and pain management.

Impact of hydroxyurea on lymphocyte subsets in children with sickle cell anemia

BACKGROUND

Hydroxyurea (HU) has beneficial effects in the management of sickle cell anemia (SCA), but there is a paucity of data on the effect of HU on immune cells in SCA. Herein we aimed to evaluate the effect of HU on immune profiles of Egyptian children with SCA.

METHODS

This was a controlled prospective cohort study conducted in 30 children with SCA and 30 healthy age-matched controls. Flow cytometry was used to evaluate lymphocyte profiles, including CD8+ T, CD19+ B, CD3+, CD4+, natural killer (NK), NK T, T helper 1 (Th1), Th2, T cytotoxic (Tc1), and Tc2 cells, prior to and after 1 year of treatment with HU.

RESULTS

HU treatment led to significant increases in hemoglobin (Hb), red blood cell, and hematocrit counts and a significant decrease in the percentage of sickle Hb, with subsequent improvement in SCA complications. Compared with baseline values, CD3+, CD4+, Th1, and CD8+ T cells were significantly increased, while NK, Th2, and Tc2 cells were significantly decreased, with a resulting increase in the Th1/Th2 and Tc1/Tc2 ratios.

CONCLUSIONS

HU has the beneficial effect of restoring the abnormally elevated immune parameters in children with SCA.

IMPACT

Hydroxyurea treatment restores the abnormal immune parameters in children with sickle cell anemia. HU treatment led to significantly increased CD3+, CD4+, Th1, and CD8+ T cells, while NK, Th2, and Tc2 cells were significantly decreased, with a resulting increase in the Th1/Th2 and Tc1/Tc2 ratios. Our study showed the impact of HU therapy on immune parameters in children with SCA.

Characterisation of medical conditions of children with sickle cell disease in the USA: findings from the 2007-2018 National Health Interview Survey (NHIS)

OBJECTIVES

We used the National Health Interview Survey (NHIS) data set to examine the prevalence of comorbid medical conditions; explore barriers to accessing healthcare and special educational services; and assess the associations between sickle cell disease (SCD) status and demographics/socioeconomic status (SES), and social determinants of health (SDoH) on comorbidities among children in the USA.

DESIGN

Cross-sectional.

SETTING

NHIS Sample Child Core questionnaire 2007-2018 data set.

PARTICIPANTS

133 481 children; presence of SCD was determined by an affirmative response from the adult or guardian of the child.

MAIN OUTCOME MEASURES

Multivariate logistic regression was used to compare the associations between SCD status, SES and SDoH for various medical conditions for all races and separately for black children at p<0.05.

RESULTS

133 481 children (mean age 8.5 years, SD: 0.02), 215 had SCD and ~82% (weighted) of the children with SCD are black. Children with SCD were more likely to suffer from comorbid conditions, that is, anaemia (adjusted OR: 27.1, p<0.001). Furthermore, children with SCD had at least two or more emergency room (ER) visits (p<0.001) and were more likely to have seen a doctor 1-15 times per year (p<0.05) compared with children without SCD. Household income (p<0.001) and maternal education were lower for children with SCD compared with children without SCD (52.4% vs 63.5% (p<0.05)). SCD children with a maternal parent who has < / > High School degree were less likely to have no ER visits or 4-5 ER visits, and more likely to have 2-3 ER visits within 12 months.

CONCLUSION

Children with SCD experienced significant comorbid conditions and have high healthcare usage, with black children being disproportionately affected. Moreover, maternal education status and poverty level illustrates how impactful SES can be on healthcare seeking behaviour for the SCD population. SDoH have significant implications for managing paediatric patients with SCD in clinical settings.

The Burden of Sickle Cell Disease in Saudi Arabia: A Single-Institution Large Retrospective Study

Purpose

Sickle cell disease (SCD) is a significant burden for patients and healthcare systems due to multiple factors, including high readmission rates. This study aimed to determine the general characteristics, etiology of admissions, annual admission rate, length of stay, and readmission rate of patients with SCD.

Patients and Methods

This retrospective observational study included all adult patients with SCD admitted to the General Internal Medicine (GIM) unit between 2016 and 2021.

Results

There were 160 patients (mean age, 31.08 ± 9.06 years; 51.25% female) with SCD included in this study. Most originated from southern Saudi Arabia (45.62%). The average annual number of emergency department (ED) visits was 4, and approximately 19% of patients had ≥3 annual admissions. The mean length of stay was 6 days. The readmission rates at 7, 30, 60, and 90 days were 8%, 24.5%, 13.6%, and 10.8%, respectively.

Conclusion

SCD generates a significant economic burden on the Saudi society and the effects on the healthcare system and patients' quality of life are evident in the high ED visits, readmission rates and prolonged hospitalization. Thereupon we advocate the implementation of sickle cell disease-specialized multidisciplinary clinics.

Consensus definition of essential, optimal, and suggested components of a pediatric sickle cell disease center

Sickle cell disease (SCD) requires coordinated, specialized medical care for optimal outcomes. There are no United States (US) guidelines that define a pediatric comprehensive SCD program. We report a modified Delphi consensus-seeking process to determine essential, optimal, and suggested elements of a comprehensive pediatric SCD center. Nineteen pediatric SCD specialists participated from the US. Consensus was predefined as 2/3 agreement on each element's categorization. Twenty-six elements were considered essential (required for guideline-based SCD care), 10 were optimal (recommended but not required), and five were suggested. This work lays the foundation for a formal recognition process of pediatric comprehensive SCD centers.

Nasopharyngeal Carriage and Antibiogram of Pneumococcal and Other Bacterial Pathogens from Children with Sickle Cell Disease in Tanzania

Background

Bacterial infections contribute significantly to morbidity and mortality in sickle cell disease (SCD) patients, particularly children under five years of age. In Tanzania, prophylaxis against pneumococcal infection among children with SCD advocates the use of both oral penicillin V (PV) and pneumococcal vaccines (PNV). Therefore, this study aimed to investigate nasopharyngeal carriage and antibiogram of Streptococcal pneumoniae (S. pneumoniae) and Staphylococcus aureus (S. aureus) in children with SCD in Tanzania.

Methods

This cross-sectional study was undertaken at the two Sickle Pan-African Research Consortium (SPARCO) study sites in Dar es salaam, Tanzania. The study was conducted for six months and enrolled children with SCD between the ages of 6 to 59-months. A semi-structured questionnaire was used to collect patient data. Nasopharyngeal swabs were collected from all participants and cultured for Streptococcal pneumoniae and other bacterial isolates. Antimicrobial susceptibility tests of the isolates were done using the disc diffusion method.

Results

Out of 204 participants, the overall prevalence of bacterial carriage was 53.4%, with S. aureus (23.5%), coagulase-negative Staphylococci (CoNS) (23%) and S. pneumoniae (7.8%) being commonly isolated. In antibiotic susceptibility testing, S. aureus isolates were most resistant to penicillin (81.8%), whereas 81.3% of S. pneumoniae isolates were resistant to co-trimoxazole. The least antimicrobial resistance was observed for chloramphenicol for both S. aureus and S. pneumoniae isolates (6.3% versus 0%). The proportion of multi-drug resistance (MDR) was 66.7% for S. aureus isolates and 25% for S. pneumoniae isolates.

Conclusion

There are substantially high nasopharyngeal carriage pathogenic bacteria in children with SCD in Dar es Salaam, Tanzania. The presence of MDR strains to the commonly used antibiotics suggests the need to reconsider optimizing antimicrobial prophylaxis in children with SCD and advocacy on pneumococcal vaccines.

Transfusional Approach in Multi-Ethnic Sickle Cell Patients: Real-World Practice Data From a Multicenter Survey in Italy

Sickle cell disease (SCD) is a worldwide distributed hereditary red cell disorder characterized by recurrent acute vaso-occlusive crises (VOCs and anemia). Gold standard treatments are hydroxycarbamide (HC) and/or different red blood cell (RBC) transfusion regimens to limit disease progression. Here, we report a retrospective study on 1,579 SCD patients (median age 23 years; 802 males/777 females), referring to 34 comprehensive Italian centers for hemoglobinopathies. Although we observed a similar proportion of Caucasian (47.9%) and African (48.7%) patients, Italian SCD patients clustered into two distinct overall groups: children of African descent and adults of Caucasian descent. We found a subset of SCD patients requiring more intensive therapy with a combination of HC plus chronic transfusion regimen, due to partial failure of HC treatment alone in preventing or reducing sickle cell-related acute manifestations. Notably, we observed a higher use of acute transfusion approaches for SCD patients of African descent when compared to Caucasian subjects. This might be related to (i) age of starting HC treatment; (ii) patients' low social status; (iii) patients' limited access to family practitioners; or (iv) discrimination. In our cohort, alloimmunization was documented in 135 patients (8.5%) and was more common in Caucasians (10.3%) than in Africans (6.6%). Alloimmunization was similar in male and female and more frequent in adults than in children. Our study reinforces the importance of donor-recipient exact matching for ABO, Rhesus, and Kell antigen systems for RBC compatibility as a winning strategy to avoid or limit alloimmunization events that negatively impact the clinical management of SCD-related severe complications.

Drug Repurposing: Hydroxyurea Therapy Improves the Transfusion-Free Interval in HbE/Beta-Thalassemia-Major Patients with the XmnI Polymorphism

Aims: HbE/β-thalassemia is the most prevalent form of severe β-thalassemia in Asian countries. Hydroxyurea (HU) is the most common drug used for the management of sickle-cell anemia but not thalassemia. In this study, we aimed to assess clinical HU response among the Bengali HbE/β-thalassemia patients with respect to the XmnI γ^Gglobin polymorphism and elucidate the association between this polymorphism and HU response efficacy. Materials and Methods: We enrolled 49 transfusion-dependent patients with HbE/β-thalassemia. Fetal hemoglobin levels were measured using high-performance liquid chromatography and complete blood counts were determined pre- and post-HU therapy. Polymerase chain reaction-restriction fragment length polymorphism analyses were performed for genotyping the XmnI γ^Gglobin polymorphism. Results: A total of 30 (61.22%) patients were found to be responders, whereas the remaining 19 (38.78%) were nonresponders. We found 33 patients with the heterozygous (C/T) and three with the homozygous mutant (T/T) genotype status. We obtained a statistically significant correlation (p < 0.001) between the XmnI polymorphism genotype and transfusion-free interval. Patients with the XmnI polymorphism were found to be good responders for HU therapy and showed increased hemoglobin levels. Conclusions: Our findings indicate that HU is a potential drug candidate for thalassemia management, particularly for HbE/β-thalassemia. These results hold implications in repurposing HU as an effective and efficient therapy for HbE/β-thalassemia.

Disease burden and quality of life of in children with sickle cell disease in Italy: time to be considered a priority

The objective of the present article is to highlight the need for attention to Quality of Life of patients with Sickle Cell Disease living in Italy. The transformation of sickle cell disease from a severe life-threatening disease of childhood into a chronic, lifelong condition due to the significant improvements in care and treatment options, imposes increasing new challenges to health care providers and patients. Patients now face physical, psychosocial and emotional challenges throughout their lives. They generally have to receive chronic treatments and regular multidisciplinary monitoring which increase social and emotional burden rendering adherence to treatment sometimes complicated. A chronic disease impacts all aspects of patients’ lives, not only the physical one, but also the social and emotional aspects as well as the educational and working life. The entire “Quality of Life” is affected and recent evidence demonstrates the importance quality of life has for patients with chronic illness. The results of this review focus on emerging data regarding quality of life across the lifespan of patients with Sickle Cell Disease, and highlight the need for more action in this field in Italy, where recent immigration and improved care determine an increasing population of children with sickle cell disease being taken into long term care.

A Scoping Review of the Health of African Immigrant and Refugee Children

Migration is a growing phenomenon around the world, including within the African continent. Many migrants, especially African children, face challenges related to health and social inclusion and can face increased health risks. A systematic scoping review of available literature on the health of African migrant children across the globe was conducted to offer insight into these health risks. The review was conducted over a 15-month period from January 2019 to April 2020, yielding 6602 articles once duplicates were removed. This search included electronic databases, reference lists of articles reviewed, and searches of libraries of relevant organisations. A total of 187 studies met the inclusion criteria, of which 159 were quantitative, 22 were qualitative, and 6 used mixed methods. The findings reveal decreased health in this population in areas of nutrition, infectious diseases, mental health, birth outcomes, sexual and reproductive health, physical and developmental health, parasitic infections, oral health, respiratory health, preventative health, endocrine disorders, health care services, and haematological conditions. The findings offer insights into factors influencing the health of African immigrant and refugee children. Further studies, especially qualitative studies, are needed to determine barriers to service access after migration and to investigate other underexplored and overlooked health concerns of African migrant children, including pneumonia and child maltreatment.

Hydroxyurea Use Among Children With Sickle Cell Disease at King Abdulaziz University Hospital in Jeddah City

Background

Sickle cell disease (SCD) is an autosomal recessive hemoglobinopathy that is very common and causes a great burden in Saudi Arabia and worldwide. This study aims to determine the frequency and benefits of using hydroxyurea in treating children with SCD in King Abdulaziz University Hospital (KAUH) in Saudi Arabia.

Method

This retrospective observational study included all SCD patients, males and females, who were following up in KAUH and were less than 18 years old. Patients on chronic transfusion therapy or who had previous stem cell transplantation were excluded from the study. The study was approved by the unit of biomedical ethics in KAUH, Jeddah.

Result

The study included 102 SCD patients; the median age of the sample was 7.5±4.2, with the majority being female (58 patients; 56.9%). Hydroxyurea users among participants in the study were 62 patients (60.8%). Thirty-seven (37) of the patients using hydroxyurea had an increase in the mean corpuscular volume (MCV). There was a decrease in the level of white blood cells (WBCs) and neutrophil count from 15.81±10.24 and 48.31±23.23% to 12.48±5.48 and 40.81±15.78%, respectively. Platelet count showed an increase from 345.4±2.1096 to 359.162±199.87 after starting hydroxyurea. The incidence of vaso-occlusive crisis (VOC) increased after hydroxyurea initiation from 4.555±4.08 to 6.288±9.80. Moreover, the frequency of blood transfusion in patients using hydroxyurea was statistically significant as p-value = 0.048.

Conclusion

In conclusion, our results showed significant clinical and laboratory benefits of hydroxyurea in children with SCD. Hydroxyurea has been shown to reduce the frequency of VOC and blood transfusion in patients with SCD.

Sickle Cell Anemia: Variants in the CYP2D6, CAT, and SLC14A1 Genes Are Associated With Improved Hydroxyurea Response

Differences in hydroxyurea response in sickle cell anemia may arise due to a series of factors with genetic factors appearing to be predominant. This study aims to investigate the effects of single nucleotide polymorphisms in genes encoding drug-metabolizing enzymes and solute carriers on hydroxyurea response, in patients with sickle cell anemia. For that purpose, a total number of 90 patients with sickle cell anemia were recruited, 45 were undergoing hydroxyurea treatment, while 45 were not under the treatment. Association analyses were performed between CYP3A4 (rs2740574), CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and laboratory parameters. According to our findings, patients with hydroxyurea treatment demonstrated higher HbF levels and a significant improvement in hemolytic, hepatic, inflammatory, and lipid parameters in comparison to those without the treatment. We also found significant associations between the CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and an improvement of the therapeutic effects, specifically the hemolytic, hepatic, inflammatory, lipid, and renal parameters. In conclusion, our results highlight the importance of the investigated variants, and their strong association with hydroxyurea efficacy in patients with sickle cell anemia, which may be considered in the future as genetic markers.

An evaluation of ticagrelor for the treatment of sickle cell anemia

INTRODUCTION

Ticagrelor is an antiplatelet agent approved for the treatment of patients with an acute coronary syndrome or a history of myocardial infarction. Considering the evidence demonstrating that ticagrelor-mediated inhibition of platelet activation and aggregation have beneficial effects in the treatment of thrombotic conditions, clinical studies have been conducted to evaluate the use of this drug for the treatment of sickle cell disease (SCD), demonstrating satisfactory tolerability and safety.

AREAS COVERED

Clinical investigation has characterized the pharmacokinetic and pharmacodynamical profile, as well as the efficacy and safety of ticagrelor to prevent painful vaso-occlusive crisis (painful episodes and acute chest syndrome) in SCD patients.

EXPERT OPINION

While phase 1 and 2 clinical trials demonstrated satisfactory tolerability and safety, the conclusion of phase 3 clinical trials is crucial to prove the efficacy of ticagrelor as a therapeutic option for the treatment of SCD. Thus, it is expected that ticagrelor, especially in combination with other drugs, will improve the clinical profile and quality of life of patients with SCD.

Sickle cell disease: a comprehensive program of care from birth

As more children are appropriately being diagnosed, the burden of sickle cell disease is increasing greatly in Africa and in high-resource countries such as the United States and Europe. Early management is mandatory, but newborn screening is not implemented everywhere. Point-of-care testing devices are increasingly being used in low-resource countries, showing good sensitivity and specificity. Because the diagnosis is often traumatic for the families, the announcement should be made by an experienced person. The development of care networks is urgently required to facilitate daily life by defining the respective functions of nearby and highly specialized health care professionals, who should work in close collaboration. Comprehensive programs targeting the prevention of pneumococcal infections, malaria in infested zones, and stroke may substantially improve patient care. Hydroxyurea is increasingly being used, but whether it should be systematically prescribed in all children is debated, and its access is still limited in many African countries. Yearly checkups should be organized early in life in order to screen and then treat any organ impairment. Enhancing parents' and patients' knowledge and skills is mandatory.

HbS/β+ thalassemia: Really a mild disease? A National survey from the AIEOP Sickle Cell Disease Study Group with genotype-phenotype correlation

OBJECTIVES

HbS/β+ patients' presence in Italy increased due to immigration; these patients are clinically heterogeneous, and specific guidelines are lacking. Our aim is to describe a cohort of HbS/β+ patients, with genotype-phenotype correlation, in order to offer guidance for clinical management of such patients.

METHODS

Retrospective cohort study of HbS/β+ patients among 15 AIEOP Centres.

RESULTS

A total of 41 molecularly confirmed S/β+ patients were enrolled (1-55 years, median 10.9) and classified on β+ mutation: IVS-I-110, IVS-I-6, promoter, and "others." Prediagnostic events included VOC 16/41 (39%), ACS 6/41 (14.6%), sepsis 3/41 (3.7%), and avascular necrosis 3/41 (7,3%). Postdiagnostic events were VOC 22/41 (53.6% %), sepsis 4/41 (9.7%), ACS 4/41 (9.7%), avascular necrosis 3/41 (7.3%), aplastic crisis 2/41 (4.8%), stroke 1/41 (2.4%), ACS 1/41 (2.4%), and skin ulcerations 1/41 (2.4%). The IVS-I-110 group presented the lowest median age at first SCD-related event (P = .02 vs promoter group) and the higher median number of severe events/year (0.26 events/patient/year) (P = .01 vs IVS-I-6 and promoter groups). Promoter group presented a specific skeletal phenotype. Treatment regimen applied was variable among the centers.

CONCLUSIONS

HbS/β+ is not always a mild disease. Patients with IVS-I-110 mutation could benefit from a standard of care like SS and S/β° patients. Standardization of treatment is needed.

Selective Difficulties in Lexical Retrieval and Nonverbal Executive Functioning in Children With HbSS Sickle Cell Disease

Language deficits in multilingual children with sickle cell disease (SCD) are poorly understood. We tested the hypothesis that selective language deficits in this population could relate to an impaired frontal lobe functioning often associated with high-risk homozygous HbS disease (HbSS). In all, 32 children from immigrant communities with HbSS SCD aged 6 to 12 years (mean age = 9.03, n = 9 with silent infarcts) and 35 demographically matched healthy controls (mean age = 9.14) were tested on their naming skills, phonological and semantic fluency, attention, and selected executive functions (response inhibition and planning skills). Analyses of variance showed significant differences between patients and controls in inhibition and planning (p = .001 and .001), and phonological fluency (p = .004). The poorer performance in phonological fluency of the children with SCD was not associated with any visible brain damage to language areas. Hierarchical regression analyses showed that, whereas the control children's vocabulary knowledge explained their performance in the phonological fluency tasks, only inhibition skills accounted for variance in the performance of the children with SCD. These results suggest a selective impairment of verbal and nonverbal executive functioning (i.e., planning, inhibition, and phonological fluency) in children with SCD, with deficits possibly owing to frontal area hypoxia.

Hydroxyurea alters hematological, biochemical and inflammatory biomarkers in Brazilian children with SCA: Investigating associations with βS haplotype and α-thalassemia

This study investigated the effects of hydroxyurea (HU) on hematological, biochemical and inflammatory parameters in children with sickle cell anemia (SCA) in association with βS haplotype and α-thalassemia. We included 22 children with SCA who were followed for an average of 14.5 months. Laboratory parameters were assessed by electronic methods, and molecular analysis was investigated by PCR-RFLP and allele-specific PCR. Results showed significant increases in hemoglobin, HbF, hematocrit, MCV, MCH, glucose, HDL-C and albumin levels, as well as significant decreases in MCHC and AST levels, WBC, neutrophils, eosinophils, lymphocytes and reticulocytes, in children during HU therapy. HbF levels were positively correlated with hemoglobin, hematocrit, MCV and total protein, yet negatively correlated with MCHC, RDW, AAT and AST during HU therapy (p<0.05). Children who carried the Central African Republic haplotype, in response to HU therapy, presented significant increases in hemoglobin, hematocrit, triglycerides and uric acid levels, as well as significant decreases in MCHC, AST and direct bilirubin levels, WBC, neutrophils, eosinophils, lymphocytes and reticulocytes. Those with the Benin haplotype presented increases in HbF and albumin levels, and a reduction in platelet counts (p<0.05). Children with α-thalassemia presented decreased ALT during HU use, while those without this deletion presented increases in hemoglobin, hematocrit, MCV, MCH, HDL-C and albumin, as well as decreases in MCHC, neutrophils, lymphocytes, reticulocytes and AST (p<0.05). Hence, regardless of its use in association with βS haplotypes or α-thalassemia, HU seems to be linked to alterations in hemolytic, inflammatory, hepatic, lipid and glycemic profiles.

Current challenges in the management of patients with sickle cell disease - A report of the Italian experience

Sickle cell disease (SCD) is an inherited red blood cell disorder caused by a structural abnormality of hemoglobin called sickle hemoglobin (HbS). Clinical manifestations of SCD are mainly characterized by chronic hemolysis and acute vaso-occlusive crisis, which are responsible for severe acute and chronic organ damage. SCD is widespread in sub-Saharan Africa, in the Middle East, Indian subcontinent, and some Mediterranean regions. With voluntary population migrations, people harboring the HbS gene have spread globally. In 2006, the World Health Organization recognized hemoglobinopathies, including SCD, as a global public health problem and urged national health systems worldwide to design and establish programs for the prevention and management of SCD. Herein we describe the historical experience of the network of hemoglobinopathy centers and their approach to SCD in Italy, a country where hemoglobinopathies have a high prevalence and where SCD, associated with different genotypes including ß-thalassemia, is present in the native population.

Healthcare utilization and hydroxyurea adherence in youth with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) complications lead to poor health-related quality of life (HRQOL) and increased healthcare utilization in this population, which could be mitigated with hydroxyurea therapy; however, adherence is suboptimal. We assessed the relationship of healthcare utilization to hydroxyurea adherence and HRQOL amongst youth with SCD.

METHODS

Thirty-four patients with SCD (median age 14 years, IQR 12-18) on hydroxyurea participated in this cross-sectional study and completed Morisky Adherence Scale 8-items and Patient Reported Outcomes Measurement Information System (PROMIS®) HRQOL measures. A medical chart review was conducted to assess healthcare utilization.

RESULTS

Participants with more frequent hospitalizations and emergency room (ER) visits and longer length of stay (LOS) had significantly lower fetal hemoglobin (r_s=-0.44; r_s=-0.45; r_s=-0.46, p < 0.05) and mean corpuscular volume (r_s=-0.47; r_s=-0.42; r_s=-0.48, p < 0.05), respectively. More frequent hospitalizations and ER visits and longer LOS correlated significantly with worse fatigue (r_s=0.51; r_s=0.41; r_s=0.53, p < 0.05), pain (r_s=0.41; r_s=0.38; r_s=0.47, p < 0.05), physical function mobility (r_s=-0.67; r_s=-0.59; r_s=-0.67, p < 0.05), depression (r_s=0.38; r_s=0.31; r_s=0.42, p < 0.05), and social isolation (r_s=0.76; r_s=0.76; r_s=-0.84, p < 0.05), respectively.

CONCLUSIONS

We conclude that increased healthcare utilization in youth with SCD is associated with low adherence to hydroxyurea and worse HRQOL domain scores. It is important emphasize the clinical benefits of high adherence to hydroxyurea, particularly among youth with SCD. Future longitudinal studies are warranted to assess the directionality of these relationships, and may reveal modifiable behavioral factors associated with early changes in hydroxyurea adherence levels.

Hydroxycarbamide adherence and cumulative dose associated with hospital readmission in sickle cell disease: a 6-year population-based cohort study

Sickle cell disease (SCD) is a congenital haemoglobinopathy that causes frequent acute care/emergency room visits and hospital admissions for affected individuals. Evidence from population-based studies demonstrating the role of hydroxycarbamide (HC, also termed hydroxyurea) in reducing hospital readmission rates is limited. Our objective was to describe the use of HC and its association with acute care utilization and readmission rates using a large, nationally-representative US health insurance claims database over a 6-year period between 2009 and 2014. We identified 20 721 SCD-related inpatient and acute care encounters. Patients had been exposed to HC within 6 months prior to admission in 4263 (21%) of SCD-related admission events. HC use was more common among children aged 10-17 years and young adults aged 18-29 years. HC was associated with lower 30-day all-cause readmission rates in adults treated with average daily doses ≥1 g (odds ratio [OR], 0·72, 95% confidence interval [CI] 0·52-0·99) and doses of 0·5-1 g (OR, 0·73, 95% CI 0·57-0·93), compared to HC treatment with average daily doses of <0·5 g; adherence to HC with proportion of days covered of ≥0·80 was also associated with significantly lower 30-day all-cause readmission risks (OR, 0·59, 95% CI 0·41-0·84). Optimal therapeutic dosing and adherence to HC treatment significantly reduces 30-day readmissions among patients with SCD.