Cost-effectiveness of hydroxyurea in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia

Cost-Effectiveness of Hydroxyurea for Sickle Cell Anemia in a Low-Income African Setting: A Model-Based Evaluation of Two Dosing Regimens

BACKGROUND AND OBJECTIVE

The disease burden of sickle cell anemia (SCA) in sub-Saharan African (SSA) countries is substantial, with many children dying without an established diagnosis or proper treatment. The global burden of SCA is increasing each year, making therapeutic intervention a high priority. Hydroxyurea is the only disease-modifying therapy with proven feasibility and efficacy suitable for SSA; however, no one has quantified the health economic implications of its use. Therefore, from the perspective of the health care provider, we estimated the incremental cost-effectiveness of hydroxyurea as a fixed-dose regimen or maximum tolerated dose (MTD) regimen, versus SCA care without hydroxyurea.

METHODS

We estimated the cost of providing outpatient treatment at a pediatric sickle cell clinic in Kampala, Uganda. These estimates were used in a discrete-event simulation model to project mean costs (2021 US$), disability-adjusted life years (DALYs), and consumption of blood products per patient (450 mL units), for patients between 9 months and 18 years of age. We calculated cost-effectiveness as the ratio of incremental costs over incremental DALYs averted, discounted at 3% annually. To test the robustness of our findings, and the impact of uncertainty, we conducted probabilistic and one-way sensitivity analyses, scenario analysis, and price threshold analyses.

RESULTS

Hydroxyurea treatment averted an expected 1.37 DALYs and saved US$ 191 per patient if administered at the MTD, compared with SCA care without hydroxyurea. In comparison, hydroxyurea at a fixed dose averted 0.80 DALYs per patient at an incremental cost of US$ 2. The MTD strategy saved 11.2 (95% CI 11.1-11.4) units of blood per patient, compared with 9.1 (95% CI 9.0-9.2) units of blood per patient at the fixed-dose alternative.

CONCLUSIONS

Hydroxyurea at MTD is likely to improve quality of life and reduce the consumption of blood products for children with SCA living in Uganda. Compared with a fixed dose regimen, treatment dosing at MTD is likely to be a cost-effective treatment for SCA, using realistic ranges of hydroxyurea costs that are relevant across SSA. Compared with no use of the drug, hydroxyurea could lead to substantial net savings per patient, while reducing the disease morbidity and mortality and increasing quality of life.

Efficacy of Hydroxyurea in Transfusion-Dependent Major β-Thalassemia Patients: A Meta-Analysis

The present meta-analysis was conducted to determine the efficacy of hydroxyurea in patients with transfusion dependent major β-thalassemia. The present meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines. A systematic search was carried out to evaluate the efficacy of hydroxyurea in patients with transfusion-dependent B-thalassaemia using electronic databases, including MEDLINE, Cochrane Central Register of Controlled Trials, and EMBASE. The keywords used to search for relevant studies included "hydroxyurea", "thalassemia", "transfusion-dependent", and "efficacy". Outcomes assessed in the present meta-analysis included transfusion in one year and intervals between transfusions (in days). Other outcomes assessed in the present meta-analysis were fetal hemoglobin (%), hemoglobin (%), and ferritin levels (ng/dl). Total of five studies were included in the analysis enrolling 294 patients with major B-thalassemia. The pooled analysis reported that the mean interval between transfusions was significantly higher in patients receiving hydroxyurea compared to those not receiving hydroxyurea (mean deviation {MD}: 10.07, 95% CI: 2.16, 17.99). Hemoglobin was significantly higher in patients receiving hydroxyurea compared to its counterparts (MD: 1.71, 95% CI: 0.84, 2.57). Patients receiving hydroxyurea had significantly lower ferritin levels compared to those not receiving hydroxyurea (MD: -299.65, 95% CI: -518.35, -80.96). These findings suggest that hydroxyurea may be a promising and cost-effective alternative to blood transfusions and iron chelation therapies for beta-thalassemia patients. However, the authors noted that further randomized controlled trials are needed to validate these findings and to determine the optimal dosages and treatment regimens for hydroxyurea in this patient population.

Determinants of hydroxyurea use among doctors, nurses and sickle cell disease patients in Nigeria

Background

Hydroxyurea (HU) is an evidence-based therapy that is currently the most effective drug for sickle cell disease (SCD). HU is widely used in high-income countries with consequent reduction of morbidity and mortality. In Nigeria, HU is prescribed by physicians while nurses are mainly involved in counseling the patients to ensure adherence. The extent of utilization and the determinant factors have not been sufficiently evaluated in Nigeria.

Objective

To assess the frequency of use of HU and factors affecting utilization among healthcare providers, patients, and caregivers for SCD.

Methods

A questionnaire was administered online and in- person to assess the frequency of HU use and the factors that promote and limit its use. The data were analyzed by descriptive statistics using IBM SPSS software version 23 and the result was presented in frequency tables and percentages.

Result

A total of 137 physicians, 137 nurses, and 237 patients/caregivers responded to the survey. The rate of prescription of HU by doctors in the past 6 months was 64 (46.7%), 43 (31.4%) nurses provided counseling and 36 (15.6%) patients were on HU. Among doctors, adequate knowledge (91.3%), clinical benefits and safety (94.8%), and inclusion of HU in management guidelines (86.9%) were motivators for prescribing it while inadequate knowledge (60.9%) and unawareness of treatment guidelines (68.6%) constituted barriers. Among nurses, reduction of crisis (91.6%) and safety (64.8%) were the major motivators while barriers were high cost (79.1%) and intensive monitoring (63.1%) of HU treatment. Among the patients, the major motivator was the reduction of crises (80.3%) while poor knowledge (93.2%), high cost of the drug (92.2%) while monitoring (91.2%), non-availability (87.7%) and side effects (83.9%) were the major barriers for the utilization of HU.

Conclusion

HU prescription and utilization are still poor among healthcare providers and patients. Inadequate knowledge, non-availability and high cost of HU as well as unawareness of treatment guidelines constitute major barriers to prescription and utilization.

Hydroxyurea (hydroxycarbamide) for sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is one of the most common inherited diseases worldwide. It is associated with lifelong morbidity and a reduced life expectancy. Hydroxyurea (hydroxycarbamide), an oral chemotherapeutic drug, ameliorates some of the clinical problems of SCD, in particular that of pain, by raising foetal haemoglobin (HbF). This is an update of a previously published Cochrane Review.

OBJECTIVES

The aims of this review are to determine through a review of randomised or quasi-randomised studies whether the use of hydroxyurea in people with SCD alters the pattern of acute events, including pain; prevents, delays or reverses organ dysfunction; alters mortality and quality of life; or is associated with adverse effects. In addition, we hoped to assess whether the response to hydroxyurea in SCD varies with the type of SCD, age of the individual, duration and dose of treatment, and healthcare setting.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Haemoglobinopathies Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries. The date of the most recent search was 17 February 2022.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials (RCTs and quasi-RCTs), of one month or longer, comparing hydroxyurea with placebo or standard therapy in people  with SCD.

DATA COLLECTION AND ANALYSIS

Authors independently assessed studies for inclusion, carried out data extraction, assessed the risk of bias and assessed the quality of the evidence using GRADE.

MAIN RESULTS

We included nine RCTs recruiting 1104 adults and children with SCD (haemoglobin SS (HbSS), haemoglobin SC (HbSC) or haemoglobin Sβºthalassaemia (HbSβºthal) genotypes). Studies lasted from six to 30 months. We judged the quality of the evidence for the first two comparisons below as moderate to low as the studies contributing to these comparisons were mostly large and well-designed (and at low risk of bias); however, the evidence was limited and imprecise for some outcomes such as quality of life, deaths during the studies and adverse events, and the results are applicable only to individuals with HbSS and HbSβºthal genotypes. We judged the quality of the evidence for the third and fourth comparisons to be very low due to the limited number of participants, the lack of statistical power (both studies were terminated early with approximately only 20% of their target sample size recruited) and the lack of applicability to all age groups and genotypes. Hydroxyurea versus placebo Five studies (784 adults and children with HbSS or HbSβºthal) compared hydroxyurea to placebo; four recruited individuals with only severe disease and one recruited individuals with all disease severities. Hydroxyurea probably improves pain alteration (using measures such as pain crisis frequency, duration, intensity, hospital admissions and opoid use) and life-threatening illness, but we found no difference in death rates (10 deaths occurred during the studies, but the rates did not differ by treatment group) (all moderate-quality evidence). Hydroxyurea may improve measures of HbF (low-quality evidence) and probably decreases neutrophil counts (moderate-quality evidence). There were no consistent differences in terms of quality of life and adverse events (including serious or life-threatening events) (low-quality evidence). There were fewer occurrences of acute chest syndrome and blood transfusions in the hydroxyurea groups.  Hydroxyurea and phlebotomy versus transfusion and chelation Two studies (254 children with HbSS or HbSβºthal also with risk of primary or secondary stroke) contributed to this comparison. There were no consistent differences in terms of pain alteration, death or adverse events (low-quality evidence) or life-threatening illness (moderate-quality evidence). Hydroxyurea with phlebotomy probably increased HbF and decreased neutrophil counts (moderate-quality evidence), but there were more occurrences of acute chest syndrome and infections. Quality of life was not reported. In the primary prevention study, no strokes occurred in either treatment group but in the secondary prevention study, seven strokes occurred in the hydroxyurea and phlebotomy group (none in the transfusion and chelation group) and the study was terminated early.  Hydroxyurea versus observation One study (22 children with HbSS or HbSβºthal also at risk of stoke) compared hydroxyurea to observation. Pain alteration and quality of life were not reported. There were no differences in life-threatening illness, death (no deaths reported in either group) or adverse events (very low-quality evidence). We are uncertain if hydroxyurea improves HbF or decreases neutrophil counts (very low-quality evidence). Treatment regimens with and without hydroxyurea One study (44 adults and children with HbSC) compared treatment regimens with and without hydroxyurea. Pain alteration, life-threatening illness and quality of life were not reported. There were no differences in death rates (no deaths reported in either group), adverse events or neutrophil levels (very low-quality evidence). We are uncertain if hydroxyurea improves HbF (very low-quality evidence).

AUTHORS' CONCLUSIONS

There is evidence to suggest that hydroxyurea may be effective in decreasing the frequency of pain episodes and other acute complications in adults and children with sickle cell anaemia of HbSS or HbSβºthal genotypes and in preventing life-threatening neurological events in those with sickle cell anaemia at risk of primary stroke by maintaining transcranial Doppler velocities. However, there is still insufficient evidence on the long-term benefits of hydroxyurea, particularly with regard to preventing chronic complications of SCD, or recommending a standard dose or dose escalation to maximum tolerated dose. There is also insufficient evidence about the long-term risks of hydroxyurea, including its effects on fertility and reproduction. Evidence is also limited on the effects of hydroxyurea on individuals with the HbSC genotype. Future studies should be designed to address such uncertainties.

A randomised controlled provider-blinded trial of community health workers in sickle cell anaemia: effects on haematologic variables and hydroxyurea adherence

Hydroxyurea (hydroxycarbamide) (HU) for sickle cell anaemia (SCA) is underutilised. Case management is an evidence-based health management strategy and in this regard patient navigators (PNs) may provide case management for SCA. We hypothesised that HU-eligible patients exposed to PNs would have improved indicators of starting HU and HU adherence. We randomised 224 HU-eligible SCA adults into the Start Healing in Patients with Hydroxyurea (SHIP-HU) Trial. All patients received care from trained physicians using standardised HU prescribing protocols. Patients in the Experimental arm received case management and education from PNs through multiple contacts. All other patients were regarded as the Control arm and received specialty care alone. Study physicians were blinded to the study arms and did not interact with PNs. At baseline, 6 and 12 months we assessed and compared laboratory parameters and HU adherence indicators. Experimental patients had higher 6-month mean fetal haemoglobin (HbF) levels than controls. But at 12 months, mean HbF was similar, as were white blood cell count, absolute neutrophil count, total haemoglobin, platelet count and mean corpuscular volume. At 12 months there were fewer experimental patients missing HU doses than controls (mean 1·8 vs. 4·5, P = 0·0098), and more recent HU prescriptions filled than for controls (mean 53·8 vs. 92 days, median 27·5 vs. 62 days, P = 0·0082). Mean HU doses were largely similar. We detected behavioural improvements in HU adherence but no haematological improvements by adding PNs to specialty care.

Total Annual Economic Burden of Patients with Sickle Cell Disease in Steady State in Greece

Sickle cell disease includes a group of congenital hemolytic anemias, all characterized by the predominance of Hb S (HBB: c.20A>T). The population movement due to economic migration or escape from conflict zones will further affect the health systems of countries by either increasing the number of patients or forcing countries to create care units for sickle cell disease patients. This will probably also increase the incidence of the disease in areas where their incidence and prevalence were previously low. In the present study, an attempt has been made to estimate the total annual cost of the treatment of sickle cell disease in Greece. This was the first attempt to calculate the total annual cost of treating sickle cell disease patients in a steady state. The annual cost of sickle cell disease was estimated to be €21,152,340.00 (US$25,219,300.41), without calculating the cost of hospitalization for severe complications. Since 2013, in Greece, a pharmaceutical expenditure limit (decreasing with the years) has been budgeted at €1,945,000,000.00 (US$2,318,965,150.00), annually. It is therefore calculated that approximately 1.0% of the budget allocated to pharmaceutical spending is used to treat patients with sickle cell disease.

Implementation of the therapeutic use of hydroxyurea for sickle cell disease management in resource-constrained settings: a systematic review of adoption, cost and acceptability

OBJECTIVES

Mortality associated with sickle cell disease (SCD) is high in many low- and middle-income countries (LMICs). Hydroxyurea, a medicine to effectively manage SCD, is not widely available in resource-constrained settings. We identified and synthesised the reported implementation outcomes for the therapeutic use of hydroxyurea for SCD in these settings.

DESIGN

Systematic review.

DATA SOURCES

PubMed, Embase, Cochrane, Web of Science Plus, Global Health, CINAHL, and PsycINFO were searched February through May 2019 without any restrictions on publication date.

ELIGIBILITY CRITERIA

We included empirical studies of hydroxyurea for management of SCD that were carried out in LMICs and reported on implementation outcomes.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently assessed studies for inclusion, carried out data extraction using Proctor et al.'s implementation and health service outcomes, and assessed the risk of bias using ROBINS-I (Risk Of Bias In Non-randomised Studies - of Interventions).

RESULTS

Two cross-sectional surveys (n=2) and one cohort study (n=1) reported implementation of hydroxyurea for SCD management, namely regarding outcomes of adoption (n=3), cost (n=3) and acceptability (n=1). These studies were conducted exclusively among paediatric and adults populations in clinical settings in Nigeria (n=2) or Jamaica (n=1). Adoption is low, as observed through reported provider practices and patient adherence, in part shaped by misinformation and fear of side effects among patients, provider beliefs regarding affordability and organisational challenges with procuring the medicine. There was no difference in the cost of hydroxyurea therapy compared with blood transfusion in the paediatric population in urban Jamaica. Risk of bias was low or moderate across the included studies.

CONCLUSIONS

This review rigorously and systematically assessed the evidence on implementation of hydroxyurea in resource-constrained settings such as LMICs. Findings suggest that knowledge regarding implementation is low. To address the know-do gap and guide clinical practice, implementation research is needed. Integrating effective interventions into existing health systems to improve hydroxyurea uptake is essential to reducing SCD-associated mortality.

PROSPERO REGISTRATION NUMBER

CRD42020155953.

Patient-reported outcomes in sickle cell disease and association with clinical and psychosocial factors: Report from the sickle cell disease implementation consortium

Understanding patient experiences, quality of life, and treatment needs in individuals with sickle cell disease (SCD) is essential in promoting health and well-being. We used measures from the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me), Patient Reported Outcomes Measurement Information System (PROMIS), and Quality of Life in Neurological Disorders (NeuroQol) to evaluate pain impact, sleep impact, social functioning, depressive symptoms, tiredness, and cognitive function (collectively, patient reported outcomes [PROs]) and to identify associated demographic and clinical characteristics. Participants (n = 2201) between 18 and 45 years were recruited through the eight Sickle Cell Disease Implementation Consortium (SCDIC) sites. In multivariate models, PROs were significantly associated with one another. Pain impact was associated with age, education, employment, time since last pain attack, hydroxyurea use, opioid use, sleep impact, social functioning, and cognitive function (F = 88.74, P < .0001). Sleep impact was associated with household income, opioid use, pain impact, social functioning, depressive symptoms, and tiredness (F = 101.40, P < .0001). Social functioning was associated with employment, pain attacks in the past year, autoimmune/inflammatory comorbidities, pain impact, sleep impact, depressive symptoms, tiredness, and cognitive function (F = 121.73, P < .0001). Depressive symptoms were associated with sex, sleep impact, social functioning, tiredness, and cognitive function (F = 239.51, P < .0001). Tiredness was associated with sex, education, sleep impact, social functioning, depressive symptoms, and cognitive function (F = 129.13, P < .0001). These findings reflect the baseline PRO assessments among SCDIC registry participants. Further research is needed to better understand these outcomes and new targets for interventions to improve quality of life and function in people with SCD.

Development of the InCharge Health Mobile App to Improve Adherence to Hydroxyurea in Patients With Sickle Cell Disease: User-Centered Design Approach

Background

Sickle cell disease (SCD) is an inherited blood disorder causing acute complications and chronic progressive end organ damage. SCD is associated with significant morbidity, early mortality, impaired health-related quality of life, and increased acute health care utilization. Hydroxyurea is a US Food and Drug Administration–approved medication that reduces disease complications, acute health care utilization, and costs. However, adherence to hydroxyurea is suboptimal. Mobile health (mHealth) interventions have the potential to improve hydroxyurea adherence, but few examples exist that are specific to the SCD population.

Objective

This study aimed to design a mHealth intervention for individuals with SCD to improve adherence to hydroxyurea, using a user-centered design that was informed by specific barriers to hydroxyurea adherence and utilization in this population.

Methods

This study consisted of 4 phases. In phase 1, individuals with SCD and health care providers participated in an optimization digital workshop. In phase 2, patients completed surveys pertaining to their interest in mHealth use, barriers and facilitators to hydroxyurea use, and health literacy. Phases 3 and 4 involved semistructured interviews and focus groups, respectively, and used the Health Belief Model (HBM) as the framework to investigate drivers of poor hydroxyurea adherence and to inform the development of an app prototype. In addition, in phase 4, we have incorporated the patients’ feedback on the preliminary app prototype and its features.

Results

Barriers to hydroxyurea adherence were consistent with the literature and included forgetfulness and several specific thoughts and emotions associated with hydroxyurea use (eg, fear of side effects, depression, stigma, and hopelessness). In addition, more than half of the participants reported potentially low health literacy. Preferred patient app features included 7 key components, namely (1) medication reminders and tracker, (2) disease education, (3) communication, (4) personalization, (5) motivation, (6) support during pain episodes, and (7) social support. Utilizing a user-centered design approach, data obtained from patients and providers were translated into features within the app, mapping to components of the HBM and the specific drivers of hydroxyurea adherence and matching the literacy level of the population, resulting in the development of a novel mobile app called InCharge Health.

Conclusions

The InCharge Health app is an mHealth intervention developed with substantial input from users and by mapping the HBM as the framework that guided the choice for its components. InCharge Health is a customized product for the SCD population aimed at optimizing medication adherence, with the end goal of improving quality of life and health outcomes among patients with SCD. The efficacy and implementation of the InCharge Health app as an mHealth intervention to promote hydroxyurea adherence will be tested in a future stepped-wedge multicenter trial for adolescents and adults with SCD.

Improved health care utilization and costs in transplanted versus non-transplanted adults with sickle cell disease

Patients with sickle cell disease (SCD) have access to fewer health care resources and therapies compared to other diseases, which contributes to increased morbidity and health care utilization. We compared health care utilization (inpatient hospital days, emergency care visits) and health care-related costs between SCD adults that underwent hematopoietic stem cell transplantation (HSCT) using a nonmyeloblative conditioning regimen versus those referred for HSCT but did not proceed due to lack of an HLA-matched sibling donor, denial by insurance, red blood cell antibodies to the potential donor, or declining further evaluation. Between 8/2011 and 4/2016, 83 SCD patients were referred for allogeneic HSCT and 16 underwent the procedure. The HSCT and non-HSCT groups were similar by age, sex, prior SCD-related therapy and complications. Compared to pre HSCT, significantly fewer inpatient hospital days (median of 1 versus 22 days, P = 0.003) and emergency care visits (median of 1 versus 4 visits, P = 0.04) were observed by the 2nd year post-HSCT. Similar results were observed in comparison to the standard-of-care group (median of 1 versus 12 hospital days, P = 0.002; median of 1 versus 3 emergency visits, P = 0.03). Lower health care costs were observed by the 2nd year post-HSCT (median of $16,281 versus $64,634 pre-HSCT (P = 0.01) and versus $54,082 in the standard-of-care group (P = 0.05). A median reduction of -$20,833/patient/year (IQR, -$67,078-+$4,442/patient/year) in health care costs compared to pre-HSCT was observed in the 2nd year post-HSCT. In conclusion, allogeneic HSCT leads to improvements in health care utilization and costs compared to standard-of-care therapy in high-risk SCD adults.

The Evolving Pharmacotherapeutic Landscape for the Treatment of Sickle Cell Disease

Sickle cell disease (SCD) is an extremely heterogeneous disease that has been associated with global morbidity and early mortality. More effective and inexpensive therapies are needed. During the last five years, the landscape of the pharmacotherapy of SCD has changed dramatically. Currently, 54 drugs have been used or under consideration to use for the treatment of SCD. These fall into 3 categories: the first category includes the four drugs (Hydroxyurea, L-Glutamine, Crizanlizumab tmca and Voxelotor) that have been approved by the United States Food and Drug Administration (FDA) based on successful clinical trials. The second category includes 22 drugs that failed, discontinued or terminated for now and the third category includes 28 drugs that are actively being considered for the treatment of SCD. Crizanlizumab and Voxelotor are included in the first and third categories because they have been used in more than one trial. New therapies targeting multiple pathways in the complex pathophysiology of SCD have been achieved or are under continued investigation. The emerging trend seems to be the use of multimodal drugs (i.e. drugs that have different mechanisms of action) to treat SCD similar to the use of multiple chemotherapeutic agents to treat cancer.

Low-dose hydroxycarbamide therapy may offer similar benefit as maximum tolerated dose for children and young adults with sickle cell disease in low-middle-income settings

The multiple clinical benefits of hydroxycarbamide in sickle cell disease are supported by a large body of evidence. The maximum tolerated dose (MTD) is the regimen recommended by guidelines from a panel of National Heart, Lung, and Blood Institute (NHLBI) experts, but other dosage regimens have been used in babies (BABY-HUG) 9 to 18 months old (20 mg/kg per day) and developing countries such as India (10 mg/kg per day); however, there has been no direct comparison of the efficacy, effectiveness, or cost-effectiveness of these different regimens. The purpose of this review was to investigate the current situation with various hydroxycarbamide regimens with particular relevance to low-middle-income countries. In regard to methodology, a literature review was undertaken by using multiple databases in PubMed and Google and the search terms included sickle cell disease, hydroxyurea, hydroxycarbamide, sickle cell anaemia, low-middle-income countries, Sub-Saharan Africa, and India. Although MTD regimens have been widely used in research, especially within North America, clinical trials elsewhere tend to use fixed-dose regimens. In a survey of haematologists across Europe and Africa, 60% (75% response rate) did not use the MTD regimen for hydroxycarbamide treatment of sickle cell disease. The recommendations are (1) for practical purposes to commence using fixed-dose hydroxycarbamide in line with BABY-HUG recommendations and then (2) to consider or propose a trial comparing MTD escalation with various fixed doses and to include as end points health-related quality of life, haemoglobin F levels, adherence, and cost-effectiveness.

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.

Beliefs about hydroxyurea in youth with sickle cell disease

BACKGROUND

Hydroxyurea reduces complications and improves health-related quality of life (HRQOL) in sickle cell disease (SCD) patients, however adherence remains suboptimal. Understanding patients' views of hydroxyurea is critical to optimize adherence, particularly in adolescents and young adults (AYA). Study objectives were to assess beliefs about hydroxyurea using the Beliefs about Medicines Questionnaire (BMQ), and to examine the relationship of patients' beliefs to their hydroxyurea adherence and HRQOL.

METHODS

Thirty-four AYA with SCD participated in a cross-sectional study January-December 2015. Study assessments included BMQ to examine beliefs about hydroxyurea; Visual Analogue Scale (VAS) to assess hydroxyurea adherence; and Patient Reported Outcomes Measurement Information System (PROMIS®) to evaluate HRQOL.

RESULTS

Participants (41% female, 91% Black) had median age of 13.5 (IQR 12-18) years. Participants' concerns about overuse of medications correlated with concerns about hydroxyurea (r_s = 0.36, p = 0.04) and overall harm of medications (r_s = 0.5, p = 0.003). Participants' age positively correlated with the necessity of hydroxyurea (r_s = 0.45, p = 0.007). Participants' concerns about hydroxyurea and overuse of medications positively correlated with anxiety (r_s = 0.41, p = 0.02; r_s = 0.44, p = 0.01) and depression (r_s = 0.37, p = 0.04; r_s = 0.54, p = 0.001), but inversely correlated with peer relationships (r_s = -0.45, p = 0.03; r_s = -0.44, p = 0.03), respectively, suggesting better HRQOL with concerns. Fifty percent of participants reported low hydroxyurea adherence (VAS < 80%), which was more seen in patients with higher concerns about hydroxyurea (p = 0.02).

CONCLUSIONS

Beliefs about hydroxyurea correlated with HRQOL scores and adherence levels. Addressing patients' concern about hydroxyurea and medications overall as well as routine assessment of adherence and beliefs could help to overcome adherence barriers.

Blood transfusion versus hydroxyurea in beta-thalassemia in Iran: a cost-effectiveness study

INTRODUCTION

Thalassemia intermedia is a type of anemia which has several treatments modalities. We aimed to study the cost effectiveness of two treatments, including blood transfusion and hydroxyurea, in patients with beta-thalassemia intermedia in south of Iran referred to a referral center affiliated to Iran, Shiraz University of Medical Sciences in 2015.

MATERIALS AND METHODS

This was a cost-effectiveness study which was conducted on 122 patients with beta-thalassemia intermedia. The indicator of effectiveness in this study was the reduction of growth disorder (normal BMI). Data analysis was done using SPSS 21, Excel 2010 and Treeage 2011. Finally, the one-way sensitivity analysis was performed to determine the robustness of the results.

RESULTS

The average annual costs of blood transfusion and the use of hydroxyurea in 2015 were 20733.27 purchasing power parity (PPP)$ and 7040.29 PPP$, respectively. The effectiveness of blood transfusion was57.4% while in hydroxyurea group was 60.7%.

CONCLUSION

The results showed that the cost effectiveness of using hydroxyurea was more than that of blood transfusion. Therefore, it is recommended that the use of hydroxyurea in the treatment of patients with beta-thalassemia intermedia would become the first priority, and more basic and supplementary insurance coverage for treating such patients using hydroxyurea should be considered.

Hydroxyurea for lifelong transfusion-dependent β-thalassemia: A meta-analysis

OBJECTIVE

Chronic blood transfusion remains the most feasible therapeutic option for lifelong transfusion-dependent β-thalassemia (lifelong TDβT). However, it is associated with serious risks and complications. Hydroxyurea (HU), an oral chemotherapeutic drug, is expected to increase hemoglobin levels, thereby minimizing the burden of blood transfusion and its complications. Growing literature over the last twenty years suggests promising results of the use HU in lifelong TDβT; however, its role and safety remain unanswered questions. The objective of this study was to evaluate the clinical efficacy and safety of HU in patients with lifelong TDβT.

METHODS

MEDLINE, EMBASE, Cochrane databases, and major preceding conferences for studies that assessed HU in lifelong TDβT patients were searched. The effect size was estimated as a proportion (responder/sample size).

RESULTS

Eleven observational studies, collectively involving 859 patients, fulfilled eligibility criteria. HU was associated with a significant decrease in transfusion need with complete and overall (≥50%) response rates of 26% [95% confidence interval (CI), 13-41%] and 60% (95% CI, 41-78%), respectively. No serious adverse effects were reported. All of the studies had several limitations, such as lack of a comparison group.

CONCLUSION

HU appears to be effective, well tolerated; however, large randomized clinical trials should be done to confirm such findings.

Hydroxyurea for hemoglobin E/β-thalassemia: a systematic review and meta-analysis

Hemoglobin E-beta thalassemia (Hb E/β-thalassemia) is a distinct, yet common, type of β-thalassemia, in which the patient co-inherits a β-thalassemia allele from one parent, and a structural variant, Hb E, from the other parent. This co-inheritance leads to remarkable clinical heterogeneity, varying degrees of chronic anemia, and a wide spectrum of complications due to ineffective erythropoiesis and iron overload. Hydroxyurea (HU), an oral chemotherapeutic drug, is expected to decrease disease severity. To assess the clinical efficacy and safety of HU in Hb E/β-thalassemia patients. We searched MEDLINE, EMBASE, Cochrane databases, and major preceding conferences for studies that assessed HU in Hb E/β-thalassemias patients. The effect size was estimated as a proportion (responder/sample size). Qualities of eligible studies were assessed using NIH tools. A total of five [one randomized clinical trial (RCT) and four observational] studies involving 106 patients were included. HU was associated with a significant RR of 46% with no statistical heterogeneity. No serious adverse effects were reported. Patients with Hb E/β-thalassemia may benefit from a trial of HU, though large RCTs assessing efficacy should be conducted to confirm the findings of this meta-analysis and to assess long-term toxicity and response sustainability.

Clinic Attendance of Youth With Sickle Cell Disease on Hydroxyurea Treatment

OBJECTIVE

The objective of this study is to describe rates of clinic attendance of youth with sickle cell disease prescribed hydroxyurea and examine potential demographic and medical factors related to consistent clinic attendance.

METHODS

Participants included 148 youth diagnosed with sickle cell disease and prescribed hydroxyurea during a single calendar year. Clinic attendance and potential demographic and medical factors related to attendance were extracted via systematic retrospective medical chart review.

RESULTS

Youth attended 90.3% of scheduled appointments and 85.1% of youth attended at least 80% of scheduled clinic appointments during the study window. Adjusting for other factors, multivariate analysis revealed families with fewer children in the household, families with private insurance, youth experiencing fever, and youth not experiencing pain during the calendar year were more likely to consistently attend clinic visits.

CONCLUSIONS

Adherence to clinic appointments is critical to optimizing health outcomes for youth with sickle cell disease and integral for adequate monitoring of youth prescribed hydroxyurea, in particular. Findings may aid providers in appropriately identifying possible barriers to clinic attendance to develop attendance promotion interventions.

Hydroxyurea (hydroxycarbamide) for sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is one of the most common inherited diseases worldwide. It is associated with lifelong morbidity and a reduced life expectancy. Hydroxyurea (hydroxycarbamide), an oral chemotherapeutic drug, ameliorates some of the clinical problems of SCD, in particular that of pain, by raising fetal haemoglobin. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the effects of hydroxyurea therapy in people with SCD (all genotypes), of any age, regardless of setting.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Register, comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries.Date of the most recent search: 16 January 2017.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials, of one month or longer, comparing hydroxyurea with placebo, standard therapy or other interventions for people with SCD.

DATA COLLECTION AND ANALYSIS

Authors independently assessed studies for inclusion, carried out data extraction and assessed the risk of bias.

MAIN RESULTS

Seventeen studies were identified in the searches; eight randomised controlled trials were included, recruiting 899 adults and children with SCD (haemoglobin SS (HbSS), haemoglobin SC (HbSC) or haemoglobin Sβºthalassaemia (HbSβºthal) genotypes). Studies lasted from six to 30 months.Four studies (577 adults and children with HbSS or HbSβºthal) compared hydroxyurea to placebo; three recruited individuals with only severe disease and one recruited individuals with all disease severities. There were statistically significant improvements in terms of pain alteration (using measures such as pain crisis frequency, duration, intensity, hospital admissions and opoid use), measures of fetal haemoglobin and neutrophil counts and fewer occurrences of acute chest syndrome and blood transfusions in the hydroxyurea groups. There were no consistent statistically significant differences in terms of quality of life and adverse events (including serious or life-threatening events). Seven deaths occurred during the studies, but the rates by treatment group were not statistically significantly different.Two studies (254 children with HbSS or HbSβºthal also with risk of primary or secondary stroke) compared hydroxyurea and phlebotomy to transfusion and chelation; there were statistically significant improvements in terms of measures of fetal haemoglobin and neutrophil counts, but more occurrences of acute chest syndrome and infections in the hydroxyurea and phlebotomy group. There were no consistent statistically significant differences in terms of pain alteration and adverse events (including serious or life-threatening events). Two deaths occurred during the studies (one in a the hydroxyurea treatment arm and one in the control arm), but the rates by treatment group were not statistically significantly different. In the primary prevention study, no strokes occurred in either treatment group but in the secondary prevention study, seven strokes occurred in the hydroxyurea and phlebotomy group (none in the transfusion and chelation group) and the study was terminated early.The quality of the evidence for the above two comparisons was judged as moderate to low as the studies contributing to these comparisons were mostly large and well designed (and at low risk of bias); however evidence was limited and imprecise for some outcomes such as quality of life, deaths during the studies and adverse events and results are applicable only to individuals with HbSS and HbSβºthal genotypes.Of the remaining two studies, one (22 children with HbSS or HbSβºthal also at risk of stoke) compared hydroxyurea to observation; there were statistically significant improvements in terms of measures of fetal haemoglobin and neutrophil counts but no statistically significant differences in terms of adverse events (including serious or life-threatening events).The final study (44 adults and children with HbSC) compared treatment regimens with and without hydroxyurea - there was statistically significant improvement in terms of measures of fetal haemoglobin, but no statistically significant differences in terms of adverse events (including serious or life-threatening events). No participants died in either of these studies and other outcomes relevant to the review were not reported.The quality of the evidence for the above two comparisons was judged to be very low due to the limited number of participants, the lack of statistical power (as both studies were terminated early with approximately only 20% of their target sample size recruited) and the lack of applicability to all age groups and genotypes.

AUTHORS' CONCLUSIONS

There is evidence to suggest that hydroxyurea is effective in decreasing the frequency of pain episodes and other acute complications in adults and children with sickle cell anaemia of HbSS or HbSβºthal genotypes and in preventing life-threatening neurological events in those with sickle cell anaemia at risk of primary stroke by maintaining transcranial doppler velocities. However, there is still insufficient evidence on the long-term benefits of hydroxyurea, particularly in preventing chronic complications of SCD, recommending a standard dose or dose escalation to maximum tolerated dose. There is also insufficient evidence about the long-term risks of hydroxyurea, including its effects on fertility and reproduction. Evidence is also limited on the effects of hydroxyurea on individuals with HbSC genotype. Future studies should be designed to address such uncertainties.

Hydroxycarbamine: from an Old Drug Used in Malignant Hemopathies to a Current Standard in Sickle Cell Disease

While hydroxycarbamide (hydroxyurea, HU) has less and fewer indications in malignant hemopathies, it represents the only widely used drug which modifies sickle cell disease pathogenesis. Clinical experience with HU for patients with sickle cell disease has been accumulated over the past 25 years in Western countries. The review of the literature provides increasing support for safety and efficacy in both children and adults for reducing acute vaso-occlusive events including pain episodes and acute chest syndrome. No increased incidence of leukemia and teratogenicity was demonstrated. HU has become the standard-of-care for sickle cell anemia but remains underused. Barriers to its use should be identified and overcome.

Hematopoietic Stem Cell Transplantation in Adult Sickle Cell Disease: Problems and Solutions

Sickle cell disease-related organ injuries cannot be prevented despite hydroxyurea use, infection prophylaxis, and supportive therapies. As a consequence, disease-related mortality reaches 14% in adolescents and young adults. Hematopoietic stem cell transplantation is a unique curative therapeutic approach for sickle cell disease. Myeloablative allogeneic hematopoietic stem cell transplantation is curative for children with sickle cell disease. Current data indicate that long-term disease-free survival is about 90% and overall survival about 95% after transplantation. However, it is toxic in adults due to organ injuries. In addition, this curative treatment approach has several limitations, such as difficulties to find donors, transplant-related mortality, graft loss, graft-versus-host disease (GVHD), and infertility. Engraftment effectivity and toxicity for transplantations performed with nonmyeloablative reduced-intensity regimens in adults are being investigated in phase 1/2 trials at many centers. Preliminary data indicate that GVHD could be prevented with transplantations performed using reduced-intensity regimens. It is necessary to develop novel regimens to prevent graft loss and reduce the risk of GVHD.

Effects of hydroxyurea treatment for patients with hemoglobin SC disease

Although hemoglobin SC (HbSC) disease is usually considered less severe than sickle cell anemia (SCA), which includes HbSS and HbS/β(0) -thalassemia genotypes, many patients with HbSC experience severe disease complications, including vaso-occlusive pain, acute chest syndrome, avascular necrosis, retinopathy, and poor quality of life. Fully 20 years after the clinical and laboratory efficacy of hydroxyurea was proven in adult SCA patients, the safety and utility of hydroxyurea treatment for HbSC patients remain unclear. Recent NHLBI evidence-based guidelines highlight this as a critical knowledge gap, noting HbSC accounts for ∼30% of sickle cell patients within the United States. To date, only 5 publications have reported short-term, incomplete, or conflicting laboratory and clinical outcomes of hydroxyurea treatment in a total of 71 adults and children with HbSC. We now report on a cohort of 133 adult and pediatric HbSC patients who received hydroxyurea, typically for recurrent vaso-occlusive pain. Hydroxyurea treatment was associated with a stable hemoglobin concentration; increased fetal hemoglobin (HbF) and mean corpuscular volume (MCV); and reduced white blood cell count (WBC), absolute neutrophil count (ANC), and absolute reticulocyte count (ARC). Reversible cytopenias occurred in 22% of patients, primarily neutropenia and thrombocytopenia. Painful events were reduced with hydroxyurea, more in patients >15 years old. These multicenter data support the safety and potentially salutary effects of hydroxyurea treatment for HbSC disease; however, a multicenter, placebo-controlled, Phase 3 clinical trial is needed to determine if hydroxyurea therapy has efficacy for patients with HbSC disease.

Biomarkers and recent advances in the management and therapy of sickle cell disease

Although production of hemoglobin S, the genetic defect that causes sickle cell disease (SCD), directly affects only red blood cells, the manifestations of SCD are pervasive, and almost every cell type and organ system in the body can be involved. Today, the vast majority of patients with SCD who receive modern health care reach adulthood thanks to vaccine prophylaxis and improvements in supportive care, including transfusion. However, once patients reach adulthood, they commonly experience recurrent painful vaso-occlusive crises and frequently have widespread end-organ damage and severely shortened life expectancies. Over the last several decades, research has elucidated many of the mechanisms whereby abnormal red blood cells produce such ubiquitous organ damage. With these discoveries have come new ways to measure disease activity. In addition, new pharmaceutical interventions are now being developed to address what has been learned about disease mechanisms.

Hydroxyurea use in prevention of stroke recurrence in children with sickle cell disease in a developing country: A cost effectiveness analysis

We undertook a cost effectiveness analysis (CEA) of hydroxyurea (HU) in preventing stroke recurrence and/or death. We followed 43 children with sickle cell disease from 2000 to 2009 after having a first clinical stroke, of whom 10 opted for HU therapy. HU use led to decreased stroke recurrence and death without significantly increasing the annual cost of care per patient (J$83,250 vs. J$76,901, P = 0.491). The incremental cost effectiveness ratio (ICER) for prevention of stroke recurrence amounted to J$169,238 (US$1,900), while that for death prevention equalled J$635,843 (US$7,140). HU may be recommended when safe and affordable transfusion therapy is not feasible.

The proportion of potentially preventable emergency department visits by patients with sickle cell disease

BACKGROUND

Emergency department (ED) visits by children with sickle cell disease (SCD) are often classified as urgent based on resource utilization. This classification may not accurately reflect the potentially preventable nature of SCD visits. We sought to determine the proportion of SCD crisis-related pediatric ED visits that are possibly preventable.

PROCEDURE

We reviewed 2 years of ED visits with a diagnosis of SCD with crisis at a hospital with an established sickle cell program. Criteria for preventable visits were predefined by pediatric hematologists. Non-pain-related chief complaints requiring emergent evaluation or painful episodes preceded by 2 opioid doses were considered not preventable; others were potentially preventable.

RESULTS

The study included 603 visits by 187 patients; 33% were potentially preventable. Overall, 29% of visits were emergent based on non-pain-related emergent complaints. Of the remaining pain-related visits, 26% were preceded by 2 or more doses of opioids at home. Visits by children with asthma were 0.58 times as likely to be preventable, due to more non-pain-related emergent chief complaints (32%) and more children (36%) taking 2 or more opioid doses.

CONCLUSIONS

Approximately two thirds of SCD crisis-related pediatric ED visits are not immediately preventable; that percentage is higher in children with asthma.

Emerging drugs for sickle cell anemia

INTRODUCTION

The search for effective therapeutic interventions for sickle cell disease (SCD) has been an ongoing endeavor for over 50 years. During this period, only hydroxyurea (HU), which received US FDA approval in February 1998, was identified as an effective therapeutic agent in preventing or ameliorating the frequency of vaso-occlusive crises, acute chest syndrome and the need for blood transfusion. Approximately 25% of patients with sickle cell anemia (SCA), however, do not respond to HU and some patients experiencing serious side effects of this chemotherapeutic agent. Nevertheless, the success of HU opened the sluice gates to identify other effective drug therapies. The objective of this review is to describe the emerging drug therapies for SCA.

AREAS COVERED

In this review, we describe the pathophysiology of SCD and provide an in-depth analysis of the current and new pharmacologic therapies in the field. Literature searches involved multiple databases including Medline In-Process & Other Non-Indexed Citations, MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Scopus.

EXPERT OPINION

SCA is a heterogeneous disease that has caused tremendous global morbidity and early mortality. More effective, individualized and inexpensive therapies are needed. New therapies targeting multiple pathways in its complex pathophysiology are under investigation.

Economic evaluation of a hypothetical screening assay for alloimmunization risk among transfused patients with sickle cell disease

BACKGROUND

Prophylactic antigen-matching can reduce alloimmunization rates among chronically transfused patients with sickle cell disease (SCD), but this matching increases costs and may only benefit 30% of patients. We assessed the clinical and financial value of a potential assay for alloimmunization risk that would allow for targeted antigen-matching.

STUDY DESIGN AND METHODS

A Markov-based model evaluated direct medical costs and alloimmunization events over 10 to 20 years among transfused (simple or exchange) patients with SCD. Four matching strategies were evaluated: prospective matching (for all patients), history-based matching (only for patients with prior alloimmunization), perfectly informed matching (assay with 100% sensitivity, 100% specificity), and imperfectly informed matching (reduced accuracy). Under all matching protocols, matching included C, E, K, and any additional alloantibodies present. A hospital perspective was adopted, with costs (2012US$) and events discounted (3%).

RESULTS

Perfectly informed antigen-matching using a $1000 assay is expected to save $82,334 per patient over 10 years, compared to prospective matching. Perfectly informed antigen-matching is more costly than history-based matching, but reduces alloimmunization events by 45.6% over 10 years. Averting each alloimmunization event using this strategy would cost an additional $10,934 per patient. Imperfectly informed antigen-matching using an assay with 75% specificity and 75% sensitivity is less costly than prospective matching, but increases alloimmunization events. Compared to history-based matching, imperfectly informed matching would decrease alloimmunization events by 32.61%, at an additional cost of $147,915 per patient over 10 years. Cost-effectiveness of informed antigen-matching is largely driven by assay specificity.

CONCLUSIONS

A sufficiently specific assay to inform antigen-matching may be cost-effective in reducing alloimmunization among transfused patients with SCD.

Hydroxyurea is associated with lower costs of care of young children with sickle cell anemia

BACKGROUND AND OBJECTIVE

In the BABY HUG trial, young children with sickle cell anemia randomized to receive hydroxyurea had fewer episodes of pain, hospitalization, and transfusions. With anticipated broader use of hydroxyurea in this population, we sought to estimate medical costs of care in treated versus untreated children.

METHODS

The BABY HUG database was used to compare inpatient events in subjects receiving hydroxyurea with those receiving placebo. Unit costs were estimated from the 2009 MarketScan Multi-state Medicaid Database for children with sickle cell disease, aged 1 to 3 years. Inpatient costs were based on length of hospital stay, modified by the occurrence of acute chest syndrome, splenic sequestration, or transfusion. Outpatient expenses were based on the schedule required for BABY HUG and a "standard" schedule for 1- to 3-year-olds with sickle cell anemia.

RESULTS

There were 232 hospitalizations in the subjects receiving hydroxyurea and 324 in those on placebo; length of hospital stay was similar in the 2 groups. Estimated outpatient expenses were greater in those receiving hydroxyurea, but these were overshadowed by inpatient costs. The total estimated annual cost for those on hydroxyurea ($11 072) was 21% less than the cost of those on placebo ($13 962; P = .038).

CONCLUSIONS

Savings on inpatient care resulted in a significantly lower overall estimated medical care cost for young children with sickle cell anemia who were receiving hydroxyurea compared with those receiving placebo. Because cost savings are likely to increase with age, these data provide additional support for broad use of hydroxyurea treatment in this population.

Cost-effectiveness of prospective red blood cell antigen matching to prevent alloimmunization among sickle cell patients

BACKGROUND

Sickle cell disease is associated with extensive health care utilization; estimated lifetime costs exceed $460,000 per patient. Approximately 30% of chronically transfused sickle cell patients become alloimmunized to red blood cell antigens, but these patients cannot be identified a priori. Prospective antigen matching can prevent alloimmunization, but is costly and may not benefit most patients.

STUDY DESIGN AND METHODS

A Markov-based model was constructed to compare the health and financial implications of four alternative antigen-matching strategies for chronically transfused sickle cell patients. The strategies varied by the group of patients receiving matched blood (all patients prophylactically or only patients with a history of alloimmunization [history-based]), and by the extent of antigen matching (limited to C, E, and K, or extended to 11 antigens). Direct medical costs and alloimmunization events were assessed over 10- and 20-year periods, for a hypothetical cohort of initially transfusion-naive patients and for a dynamic population.

RESULTS

Within a hypothetical cohort of initially transfusion-naive patients, implementing prophylactic limited matching for all chronically transfused patients instead of history-based limited matching is expected to cost an additional $765.56 million over 10 years, but result in 2072 fewer alloimmunization events. Within the same cohort, implementing prospective extensive matching is expected to cost $1.86 billion more than history-based extensive matching, but result in 2424 fewer alloimmunization events. Averting a single alloimmunization event using prospective matching would cost $369,482 to $769,284. Among a dynamic population over 10 years, prospective limited matching is expected to cost $358.34 million more than history-based limited matching.

CONCLUSIONS

While prospective matching for all transfused patients would reduce alloimmunization, this strategy requires considerable expenditure.

High resource hospitalizations among children with vaso-occlusive crises in sickle cell disease

BACKGROUND

Vaso-occlusive crises (VOCs) contribute to frequent hospitalizations among children with sickle cell disease (SCD). The objective of this study was to identify factors associated with high resource utilization during hospitalizations for VOC.

PROCEDURE

We analyzed pediatric discharges 0-18 years of age with a primary diagnosis of SCD with crisis from the 2006 Kids' Inpatient Database, a nationally representative sample of pediatric hospital discharges. High resource hospitalizations were defined as those in the highest decile for total charges. We conducted sample-weighted regression analyses to determine associations between independent variables (patient demographics, hospital characteristics, illness severity) and high resource use.

RESULTS

There were 9,893 (0.371%) discharges for children with VOCs. Median total hospitalization charges were $10,691. In multivariate analysis, children 15-18 years of age (odds ratio [OR] 3.39, 95% confidence interval [CI] 2.54-4.53), 10-14 years of age (OR 2.72, 95% CI 2.07-3.59), and 5-9 years of age (OR 1.74, 95% CI 1.30-2.34) had higher odds of high resource hospitalizations compared to children 0-4 years of age. Care in a children's hospital had three times the odds of high resource use compared to care in a general hospital. Discharges with secondary diagnoses including pneumonia (OR 2.46, 95% CI 1.96-3.09) and constipation (OR 1.78, 95% CI 1.31-2.40) were also associated with high resource use.

CONCLUSIONS

Older age and secondary diagnoses were associated with high resource use during VOC hospitalizations. These findings suggest the need to improve adherence to comprehensive care among older children to prevent VOCs and standardize protocols to manage VOC complications.

Hydroxyurea adherence and associated outcomes among Medicaid enrollees with sickle cell disease

While laboratory and clinical benefits of hydroxyurea for patients with sickle cell disease (SCD) are well-established, few data describe the extent and implications of non-adherence. We sought to assess adherence to hydroxyurea among patients with SCD and investigate associations between adherence and clinical and economic outcomes. Insurance claims of North Carolina Medicaid enrollees (6/2000-8/2008) with SCD were analyzed. Inclusion criteria included age < 65 years, continuous Medicaid enrollment ≥ 12 months before and following hydroxyurea initiation, and ≥ 2 hydroxyurea prescriptions. Three hundred twelve patients, mean age 21 (± 12.2) years, met inclusion criteria and 35% were adherent, defined as a medication possession ration (MPR) ≥ 0.80; mean MPR was 0.60. In the 12 months following hydroxyurea initiation, adherence was associated with reduced risk of SCD-related hospitalization (hazard ratio [HR] = 0.65, p = .0351), all-cause and SCD-related emergency department visit (HR = 0.72, p = .0388; HR = 0.58, p =.0079, respectively), and vaso-occlusive event (HR = 0.66, p = .0130). Adherence was associated with reductions in health care costs such as all-cause and SCD-related inpatient (-$5,286, p < .0001; -$4,403, p < .0001, respectively), ancillary care (-$1,336, p < .0001; -$836, p < .0001, respectively), vaso-occlusive event-related (-$5,793, p < .0001), and total costs (-$6,529, p < .0001; -$5,329, p <.0001, respectively). Adherence to hydroxyurea among SCD patients appears suboptimal and better adherence is associated with improved clinical and economic outcomes.

Examining the characteristics and beliefs of hydroxyurea users and nonusers among adults with sickle cell disease

The attitudes of patients with sickle cell disease (SCD) toward the use of hydroxyurea (HU) therapy may contribute to the underutilization of HU in the United States, yet our understanding of these attitudes is limited. We examined the attitudes and beliefs of 94 adult SCD patients, comparing those who never used HU (n 5 37), formerly used HU (n 5 23), and were currently using HU (n 5 34). Seventy percent of current HU users reported some level of improvement from the drug ("average" or "very much") and 80% reported little or no trouble from side effects. Fifty-seven percent of former users reported taking HU for less than 6 months, with "doctor"s recommendation," or "not liking the way it made me feel" given as the most commonly reported reasons for stopping HU. Fifty percent of the never users reported receiving no information about HU from any source, and 85% of the never users thought that they would receive no improvement if they were to take HU. A deeper understanding of patient perspectives toward HU utilization is required as part of multipronged efforts to combat its underutilization in the treatment of SCD.

Hydroxyurea and acute painful crises in sickle cell anemia: effects on hospital length of stay and opioid utilization during hospitalization, outpatient acute care contacts, and at home

CONTEXT

Exploratory findings from the randomized, double-blind, placebo-controlled, multicenter study of hydroxyurea (MSH) in sickle cell anemia (SS). Recurrent acute painful crises may be mild, moderate, or severe in nature and often require treatment at home, in acute care facilities as outpatients, and in the hospital with oral and/or parenteral opioids.

OBJECTIVES

The objectives of this study were to determine the effects of hydroxyurea (HU) on length of stay (LOS) in hospital and opioid utilization during hospitalization, outpatient acute care contacts, and at home.

METHODS

Data from patient diaries, follow-up visit forms, and medical contact forms for the 299 patients enrolled in the MSH were analyzed. Types and dosages of at home, acute care, and in-hospital analgesic usage were explored descriptively.

RESULTS

At-home analgesics were used on 40% of diary days and 80% of two-week follow-up periods, with oxycodone and codeine the most frequently used. Responders to HU used analgesics on fewer days. During hospitalization, 96% were treated with parenteral opioids, with meperidine the most frequently used; oxycodone was the most commonly used oral medication. The average LOS for responders to HU was about two days less than for other groups, and their cumulative time hospitalized during the trial was significantly less than for nonresponders or placebo groups (P<0.022). They also had the lowest doses of parenteral opioids during acute care crises (P=0.015).

CONCLUSION

Beneficial effects of HU include shortening the duration of hospitalization because of acute painful episodes and reducing the net amount of opioid utilization.

How I use hydroxyurea to treat young patients with sickle cell anemia

Hydroxyurea has many characteristics of an ideal drug for sickle cell anemia (SCA) and provides therapeutic benefit through multiple mechanisms of action. Over the past 25 years, substantial experience has accumulated regarding its safety and efficacy for patients with SCA. Early proof-of-principle studies were followed by prospective phase 1/2 trials demonstrating efficacy in affected adults, then adolescents and children, and more recently infants and toddlers. The phase 3 National Heart, Lung and Blood Institute-sponsored Multicenter Study of Hydroxyurea trial proved clinical efficacy for preventing acute vaso-occlusive events in severely affected adults. Based on this cumulative experience, hydroxyurea has emerged as an important therapeutic option for children and adolescents with recurrent vaso-occlusive events; recent evidence documents sustained long-term benefits with prevention or reversal of chronic organ damage. Despite abundant evidence for its efficacy, however, hydroxyurea has not yet translated into effective therapy for SCA. Because many healthcare providers have inadequate knowledge about hydroxyurea, patients and families are not offered treatment or decline because of unrealistic fears. Limited support for hydroxyurea by lay organizations and inconsistent medical delivery systems also contribute to underuse. Although questions remain regarding its long-term risks and benefits, current evidence suggests that many young patients with SCA should receive hydroxyurea treatment.

The cost of health care for children and adults with sickle cell disease

Although sickle cell disease (SCD) is marked by high utilization of medical resources, the full cost of care for patients with SCD, including care not directly related to SCD, is unknown. The purpose of this study was to estimate the total cost of medical care for a population of children and adults with SCD. We used data from individuals diagnosed with SCD enrolled in the Florida Medicaid program during 2001-2005 to estimate total, SCD-related, and non-SCD-related cost per patient-month based on patient age at the time of health care use. Across the 4,294 patient samples, total health care costs generally rose with age, from $892 to $2,562 per patient-month in the 0-9- and 50-64-year age groups, respectively. Average cost per patient-month was $1,389. Overall, 51.8% of care was directly related to SCD, the majority of which (80.5%) was associated with inpatient hospitalizations. Notably, non-SCD-related costs were substantially higher than those reported for the general US population. These results suggest a discounted (3% discount rate) lifetime cost of care averaging $460,151 per patient with SCD. Interventions designed to prevent SCD complications and avoid hospitalizations may reduce the significant economic burden of the disease.

Systematic review: Hydroxyurea for the treatment of adults with sickle cell disease

BACKGROUND

Hydroxyurea is the only approved drug for treatment of sickle cell disease.

OBJECTIVE

To synthesize the published literature on the efficacy, effectiveness, and toxicity of hydroxyurea when used in adults with sickle cell disease.

DATA SOURCES

MEDLINE, EMBASE, TOXLine, and CINAHL were searched through 30 June 2007.

STUDY SELECTION

Randomized trials, observational studies, and case reports evaluating efficacy and toxicity of hydroxyurea in adults with sickle cell disease, and toxicity studies of hydroxyurea in other conditions that were published in English.

DATA EXTRACTION

Paired reviewers abstracted data on study design, patient characteristics, and outcomes sequentially and did quality assessments independently.

DATA SYNTHESIS

In the single randomized trial, the hemoglobin level was higher in hydroxyurea recipients than placebo recipients after 2 years (difference, 6 g/L), as was fetal hemoglobin (absolute difference, 3.2%). The median number of painful crises was 44% lower than in the placebo group. The 12 observational studies that enrolled adults reported a relative increase in fetal hemoglobin of 4% to 20% and a relative reduction in crisis rates by 68% to 84%. Hospital admissions declined by 18% to 32%. The evidence suggests that hydroxyurea may impair spermatogenesis. Limited evidence indicates that hydroxyurea treatment in adults with sickle cell disease is not associated with leukemia. Likewise, limited evidence suggests that hydroxyurea and leg ulcers are not associated in patients with sickle cell disease, and evidence is insufficient to estimate the risk for skin neoplasms, although these outcomes can be attributed to hydroxyurea in other conditions.

LIMITATION

Only English-language articles were included, and some studies were of lower quality.

CONCLUSION

Hydroxyurea has demonstrated efficacy in adults with sickle cell disease. The paucity of long-term studies limits conclusions about toxicity.

Systematic review: Hydroxyurea for the treatment of adults with sickle cell disease

BACKGROUND

Hydroxyurea is the only approved drug for treatment of sickle cell disease.

OBJECTIVE

To synthesize the published literature on the efficacy, effectiveness, and toxicity of hydroxyurea when used in adults with sickle cell disease.

DATA SOURCES

MEDLINE, EMBASE, TOXLine, and CINAHL were searched through 30 June 2007.

STUDY SELECTION

Randomized trials, observational studies, and case reports evaluating efficacy and toxicity of hydroxyurea in adults with sickle cell disease, and toxicity studies of hydroxyurea in other conditions that were published in English.

DATA EXTRACTION

Paired reviewers abstracted data on study design, patient characteristics, and outcomes sequentially and did quality assessments independently.

DATA SYNTHESIS

In the single randomized trial, the hemoglobin level was higher in hydroxyurea recipients than placebo recipients after 2 years (difference, 6 g/L), as was fetal hemoglobin (absolute difference, 3.2%). The median number of painful crises was 44% lower than in the placebo group. The 12 observational studies that enrolled adults reported a relative increase in fetal hemoglobin of 4% to 20% and a relative reduction in crisis rates by 68% to 84%. Hospital admissions declined by 18% to 32%. The evidence suggests that hydroxyurea may impair spermatogenesis. Limited evidence indicates that hydroxyurea treatment in adults with sickle cell disease is not associated with leukemia. Likewise, limited evidence suggests that hydroxyurea and leg ulcers are not associated in patients with sickle cell disease, and evidence is insufficient to estimate the risk for skin neoplasms, although these outcomes can be attributed to hydroxyurea in other conditions.

LIMITATION

Only English-language articles were included, and some studies were of lower quality.

CONCLUSION

Hydroxyurea has demonstrated efficacy in adults with sickle cell disease. The paucity of long-term studies limits conclusions about toxicity.

Sickle cell disease vasculopathy: a state of nitric oxide resistance

Sickle cell disease (SCD) is a hereditary hemoglobinopathy characterized by microvascular vaso-occlusion with erythrocytes containing polymerized sickle (S) hemoglobin, erythrocyte hemolysis, vasculopathy, and both acute and chronic multiorgan injury. It is associated with steady state increases in plasma cell-free hemoglobin and overproduction of reactive oxygen species (ROS). Hereditary and acquired hemolytic conditions release into plasma hemoglobin and other erythrocyte components that scavenge endothelium-derived NO and metabolize its precursor arginine, impairing NO homeostasis. Overproduction of ROS, such as superoxide, by enzymatic (xanthine oxidase, NADPH oxidase, uncoupled eNOS) and nonenzymatic pathways (Fenton chemistry), promotes intravascular oxidant stress that can likewise disrupt NO homeostasis. The synergistic bioinactivation of NO by dioxygenation and oxidation reactions with cell-free plasma hemoglobin and ROS, respectively, is discussed as a mechanism for NO resistance in SCD vasculopathy. Human physiological and transgenic animal studies provide experimental evidence of cardiovascular and pulmonary resistance to NO donors and reduced NO bioavailability that is associated with vasoconstriction, decreased blood flow, platelet activation, increased endothelin-1 expression, and end-organ injury. Emerging epidemiological data now suggest that chronic intravascular hemolysis is associated with certain clinical complications: pulmonary hypertension, cutaneous leg ulcerations, priapism, and possibly stroke. New therapeutic strategies to limit intravascular hemolysis and ROS generation and increase NO bioavailability are discussed.

Limitations of clinical trials in sickle cell disease: a case study of the Multi-center Study of Hydroxyurea (MSH) trial and the Stroke Prevention (STOP) trial

In the past two decades, two landmark randomized controlled trials (RCT) have been completed among individuals with sickle cell disease (SCD), the Multi-center Study of Hydroxyurea (MSH) trial and the Stroke Prevention (STOP) trial. The MSH trial tested the hypothesis that hydroxyurea will reduce the frequency of painful episodes for adults with hemoglobin SS who had a history of 3 or more painful episodes per year. The STOP trial tested the hypothesis that among children with hemoglobin SS and an elevated transcranial Doppler (TCD) velocity measurement, blood transfusion therapy would decrease the risk of an initial stroke. After completion, both trials have defined standard care for individuals with hemoglobin SS. The purpose of this review is to examine the limitations of the MSH and STOP trials. In the context of these trials, we will examine the effects of narrow inclusion criteria that primarily include participants with hemoglobin SS and secondary analyses that are prone to false-positive results. In addition, we describe how after publication of these two trials use of hydroxyurea and TCD assessment has drifted towards a standard practice without evidence of therapeutic efficacy among groups that were excluded from the trials. Finally, we suggest that rigorously conducted RCTs or at the minimum multicenter observation studies with strong methodology should be performed in these excluded subgroups to confirm a benefit of hydroxyurea or TCD measurement.

Hospitalization rates and costs of care of patients with sickle-cell anemia in the state of Maryland in the era of hydroxyurea

The multicenter study of hydroxyurea (MSH) in sickle-cell anemia (SCA) demonstrated that patients treated with hydroxyurea (HU) had a 44% decrease in hospitalizations when compared with those taking placebo. A subsequent study looking at the cost-effectiveness of HU showed that decreased hospitalizations for painful crisis accounted for the majority of cost savings in those taking HU. The purpose of this study was to examine whether the expected decrease in hospital utilization occurred after the approval of HU in Maryland. We used data collected by the Maryland Health Services Cost Review Commission to obtain SCA discharge data for Maryland from FY1995 through FY2003. We also reviewed the inpatient and outpatient charts of all adults with SCA admitted to a large university hospital during 2003. Hospitalization rates for adults with SCA in Maryland have increased significantly since approval of HU. While the total costs of inpatient care in Maryland are estimated to have increased by 31% above inflation from 1995 to 2003, the costs of inpatient care for adult SCA patients has increased by almost 60% above inflation. By comparison, there has been no significant increase in the pediatric hospitalization rate. We found that 70% of patients in one hospital who were appropriate candidates for HU were not taking the medication. Hospital utilization among adults with SCA has increased significantly. There are likely many factors that have played a role in this increase. One factor that appears to be involved is the underutilization of HU.

Hydroxyurea therapy for sickle cell disease in community-based practices: a survey of Florida and North Carolina hematologists/oncologists

Little is known about patterns of hydroxyurea (HU) use by community-based hematologist/oncologists (H/Os) for the treatment of sickle cell disease (SCD). Determination of these practice patterns pertaining to adult SCD patients was the focus of this study. A self-administered survey was mailed to H/Os in two southeastern states. Replies were received from 70% of eligible physicians. This study focuses on responses from 184 community H/Os and a comparison group of 30 university-based/affiliated H/Os providing ongoing care for at least 3 SCD patients/month. The majority of community H/O respondents saw less than 3 SCD patients/month. HU was prescribed by more than half (55%) of community H/Os in at least 10% of their patients. The most common reasons cited for prescribing HU include frequent painful crises (76%), chronic pain with frequent narcotic use (58%), and acute chest syndrome (43%). Although the majority of community H/Os care for few patients with SCD, the reported indications for HU were consistent with currently accepted recommendations. However, community H/Os reported acute chest syndrome, stroke, and pulmonary hypertension as indications for HU less often than the academic H/O group. Barriers to wider use of HU include physician concerns about carcinogenic potential, doubts about HU effectiveness, perceived patient apprehension about adverse effects, concern about lack of contraceptive use, and patient compliance. Further resources should focus on updating physicians on recently published material supporting the effectiveness of HU in symptomatic SCD as well as providing management guidelines to optimize the use of HU.

Three decades of innovation in the management of sickle cell disease: the road to understanding the sickle cell disease clinical phenotype

In the United States, sickle cell disease affects approximately 1 in 350 African-American newborn infants each year, and approximately 72,000 individuals total. Sickle cell disease is the most prevalent genetic hematologic disorder in the US. In 1972, the National Sickle Cell Disease Control Act was passed by Congress. This landmark piece of legislation established the National Sickle Cell Disease Program which mandated that scientific research programs should be funded to improve the care and quality of life of patients with sickle cell disease. The National Heart, Lung, and Blood Institute has been responsible for the organization and funding of the extramural research programs in sickle cell disease since establishment of the National Sickle Cell Disease Program. This review will discuss the major prospective epidemiologic cohort study that described the prevalence and incidence of the major syndromes responsible for the morbidity and mortality in sickle cell disease, as well as the major phase II and phase III clinical trials that have lead to the major therapeutic advances in the care of sickle cell disease patients. The clinical research conducted by the National Sickle Cell Disease Program has allowed the description of the major risk factors responsible for morbidity and mortality in sickle cell disease. These clinical studies have paved the way to our understanding the severe phenotype that will ultimately allow aggressive therapies to be targeted to patients at high risk for a morbid outcome.