Hydroxyurea Use in Young Children With Sickle Cell Anemia in New York State

Assessing multilevel barriers to hydroxyurea adherence in youth with sickle cell disease using pharmacy-based refill records

BACKGROUND

Suboptimal medication adherence is common across youth with chronic health conditions and may contribute to health disparities and adverse health outcomes, especially in underserved communities.

METHODS

Using pharmacy prescription records and guided by the World Health Organization Multidimensional Adherence Model, we examined patient-, treatment-, and health system-related factors that may affect hydroxyurea adherence in 72 youth with sickle cell disease (SCD), 10-18 years who had participated in the multisite "Hydroxyurea Adherence for Personal Best in SCD" (HABIT) feasibility (6 months) and efficacy (12 months) trials. Pharmacy data were collected from the year prior to study entry through the duration of each trial. We also examined hydroxyurea dose at baseline, prescribing patterns (hydroxyurea formulation and dose prescribed), quantity of hydroxyurea dispensed, and number of daily capsules/tablets prescribed. Data were analyzed using descriptive statistics.

RESULTS

On average, youth were prescribed 1095 ± 402 mg hydroxyurea per day, requiring ingestion of 3 or more capsules for 39.4% of youth. Frequently identified potential barriers were complex medication regimens in which dose of hydroxyurea differed by day of week (47.2%); receipt of an inadequate (< 30 days) supply of hydroxyurea from the pharmacy ≥ 3 times during record collection period (29.2%); and prescription of hydroxyurea suspension suggesting problems swallowing capsules (22.2%). In this sample, most youth were exclusively prescribed 500 mg capsules (62.5%), which was associated with complex medication regimens (RR 3.0, 95% CI 1.4-6.7). Potential barriers were common, occurred at all levels and are potentially modifiable with targeted interventions at the treatment- and health system-related levels.

Hydroxyurea to prevent brain injury in children with sickle cell disease (HU Prevent)-A randomized, placebo-controlled phase II feasibility/pilot study

Central nervous system (CNS) injury is common in sickle cell disease (SCD) and occurs early in life. Hydroxyurea is safe and efficacious for treatment of SCD, but high-quality evidence from randomized trials to estimate its neuroprotective effect is scant. HU Prevent was a randomized (1:1), double-blind, phase II feasibility/pilot trial of dose-escalated hydroxyurea vs. placebo for the primary prevention of CNS injury in children with HbSS or HbS-β0-thalassemia subtypes of SCD age 12-48 months with normal neurological examination, MRI of the brain, and cerebral blood flow velocity. We hypothesized that hydroxyurea would reduce by 50% the incidence of CNS injury. Two outcomes were compared: primary-a composite of silent cerebral infarction, elevated cerebral blood flow velocity, transient ischemic attack, or stroke; secondary-a weighted score estimating the risk of suffering the consequences of stroke (the Stroke Consequences Risk Score-SCRS), based on the same outcome events. Six participants were randomized to each group. One participant in the hydroxyurea group had a primary outcome vs. four in the placebo group (incidence rate ratio [90% CI] 0.216 [0.009, 1.66], p = .2914) (~80% reduction in the hydroxyurea group). The mean SCRS score was 0.078 (SD 0.174) in the hydroxyurea group, 0.312 (SD 0.174) in the placebo group, p = .072, below the p-value of .10 often used to justify subsequent phase III investigations. Serious adverse events related to study procedures occurred in 3/41 MRIs performed, all related to sedation. These results suggest that hydroxyurea may have profound neuroprotective effect in children with SCD and support a definitive phase III study to encourage the early use of hydroxyurea in all infants with SCD.

Case Ascertainment of Sickle Cell Disease Using Surveillance or Single Administrative Database Case Definitions

OBJECTIVE

In the absence of access to surveillance system data, single-source administrative databases are often used to study health care utilization and health outcomes among people with sickle cell disease (SCD). We compared the case definitions from single-source administrative databases with a surveillance case definition to identify people with SCD.

MATERIALS AND METHODS

We used data from Sickle Cell Data Collection programs in California and Georgia (2016-2018). The surveillance case definition for SCD developed for the Sickle Cell Data Collection programs uses multiple databases, including newborn screening, discharge databases, state Medicaid programs, vital records, and clinic data. Case definitions for SCD in single-source administrative databases varied by database (Medicaid and discharge) and years of data (1, 2, and 3 years). We calculated the proportion of people meeting the surveillance case definition for SCD that was captured by each single administrative database case definition for SCD, by birth cohort, sex, and Medicaid enrollment.

RESULTS

In California, 7117 people met the surveillance case definition of SCD from 2016 through 2018; 48% of this group was captured by the Medicaid case definition and 41% by the discharge case definition. In Georgia, 10 448 people met the surveillance case definition of SCD from 2016 through 2018; 45% of this group was captured by the Medicaid case definition and 51% by the discharge case definition. These proportions differed by years of data, birth cohort, and length of Medicaid enrollment.

PRACTICE IMPLICATIONS

The surveillance case definition identified twice as many people with SCD as the single-source administrative database definitions during the same period, but trade-offs exist in using single administrative databases for decisions on policy and program expansion for SCD.

High hydroxyurea usage in sickle cell anemia regardless of patient demographics

Hydroxyurea is highly effective in sickle cell disease, but it is still underutilized. Reports of hydroxyurea utilization largely use Medicaid data, and socioeconomics is often cited as a barrier. To address whether patient demographics influenced the high hydroxyurea usage rate recently reported for the pediatric sickle cell program of Northern Virginia, analysis of data from 2011 to 2021 revealed no statistical difference in hydroxyurea usage rate between Medicaid and non-Medicaid, African American and African, or age less than 13 and age greater than or equal to 13 years cohorts, demonstrating that hydroxyurea can be successfully implemented across demographic groups.

Adherence to hydroxyurea and clinical outcomes among children with sickle cell anemia

OBJECTIVE

Hydroxyurea lowers the incidence of vaso-occlusive pain crises (VOC) and acute chest syndrome (ACS) among children with sickle cell anemia (SCA). Our objective was to assess the relationship between levels of adherence to hydroxyurea and clinical outcomes among children and adolescents with SCA.

METHODS

This retrospective cohort study included Medicaid data (2005-2012) from Florida, Illinois, Louisiana, Michigan, South Carolina, and Texas. The study population consisted of children 1-17 years old with SCA enrolled in Medicaid for 3 years. Among children that initiated hydroxyurea, the medication possession ratio (MPR) was calculated as the proportion of days covered by hydroxyurea. Six months after initiation of hydroxyurea, clinical outcomes were assessed through the end of the study period: numbers of VOC-related inpatient admissions and emergency department visits, and encounters for ACS. Multivariable Poisson models were used to predict outcomes by MPR quartile adjusting for previous healthcare utilization, state, and age.

RESULTS

Hydroxyurea was initiated by 515 children. The median MPR was 0.53 (interquartile range = 0.3-0.8). The annual median number of visits was 0.0 for ACS, 1.3 for VOC-related emergency department, and 1.4 for VOC-related inpatient admissions. For each outcome, the highest quartile of MPR had the lowest predicted count; this difference was significant for ACS visits when compared with the lowest quartile of MPR.

CONCLUSION

This study demonstrated a high level of adherence (>75%) was essential to achieve a lower incidence of common negative clinical outcomes. Further, moderate and severe hydroxyurea nonadherence may be more common than previously appreciated among children, emphasizing the importance of developing and testing innovative strategies to increase adherence.

Impact of adherence to hydroxyurea on health outcomes among patients with sickle cell disease

Although new pharmaceutical therapy options have recently become available, hydroxyurea is still the most commonly used and affordable treatment option for sickle cell disease (SCD). This study aimed to update the evidence on hydroxyurea adherence and its association with clinical and economic outcomes among individuals with SCD. This retrospective study used Texas Medicaid claims data from 09/2011-08/2016. Individuals were included if they had ≥1 inpatient or ≥2 outpatient SCD diagnoses, had ≥1 hydroxyurea prescription, were 2-63 years of age, and were continuously enrolled in Texas Medicaid between 6 months before and 1 year after the first hydroxyurea prescription fill date (index date). Hydroxyurea adherence (Medication Possession Ratio; MPR), vaso-occlusive crisis (VOC)-related outcomes, healthcare utilization and expenditures (SCD-related and all-cause) during the 1 year following the index date were measured. Bivariate and multivariable analyses were used to address the study objectives. Among 1035 included individuals (age: 18.8 ± 12.5 years, female: 52.1%), 20.9% were adherent to hydroxyurea (defined as MPR≥0.8). After adjustment for demographic and clinical characteristics, compared to being non-adherent, adhering to hydroxyurea was significantly associated with: a lower risk (Odds Ratio [OR] = 0.480, p = .0007) and hazard rate (Hazard Ratio [HR] = 0.748, p = .0005) of a VOC event, fewer VOC events (Incidence Rate Ratio [IRR] = 0.767, p = .0009), fewer VOC-related hospital days (IRR = 0.593, p = .0003), fewer all-cause and SCD-related hospitalizations (IRR = 0.712, p = .0008; IRR = 0.707, p = .0008, respectively) and emergency department visits (IRR = 0.768, p = .0037; IRR = 0.746, p = .0041, respectively), and lower SCD-related total healthcare expenditures (IRR = 0.796, p = .0266). Efforts to increase adherence to hydroxyurea could improve clinical and economic outcomes among individuals with SCD.

Higher hydroxyurea adherence among young adults with sickle cell disease compared to children and adolescents

BACKGROUND

Sickle cell disease (SCD) results in severe complications, such as anaemia and pain episodes. Hydroxyurea (HU) is efficacious in SCD, yet adherence remains low.

OBJECTIVE

To assess the relationship of HU adherence to health care utilization and patients' characteristics.

METHODS

This is a 5-year retrospective chart review. Patients' demographics and medical history were collected from the electronic medical record (EMR). HU adherence was evaluated using foetal haemoglobin "HbF%", mean corpuscular volume "MCV", and absolute neutrophil count "ANC". Age groups included children (<12 years), adolescents (12-17 years), and young adults (≥18 years).

RESULTS

A total of 113 SCD patients on HU were included (median age 14 years, IQR 10-20; 50% female; 88% HbSS). Young adults had significantly higher HU adherence compared to adolescents and children, including higher median HbF% (24.2 vs. 12.4 vs. 8.6, p = .003), MCV (fl) (106.4 vs. 96.2 vs. 95.4, p = .01) and lower ANC (10³/ml) (3.25 vs. 4.9 vs. 4.2, p = .01), respectively. Patients with chronic pain had lower HU adherence (HbF% 15.3 vs. 10.7, p = .04; ANC 3.6 vs. 6.3, p = .002; MCV 102.3 vs. 93.1, p = .1). Patients with higher HbF or MCV and lower ANC had significantly less frequent emergency room visits (r_s=-0.26, p = .01; r_s=-0.23, p = .01; r_s=0.24, p = .01) and hospitalizations (r_s=-0.27, p = .01; r_s=-0.31, p = .01; r_s=0.21, p = .02) as well as shorter length of stays (r_s=-0.27, p = .0045; r_s=-.34, p = 0.004; r_s=0.23, p = .02), respectively. Similar trends in HU adherence and health care utilization were seen in subgroup analysis of only HbSS patients. There was no significant association of HU adherence to patients' sex, socio-economic status, distance from hospital, and HU duration.

CONCLUSIONS

Young adults with SCD had significantly higher HU adherence compared to children and adolescents. Patients with lower HU adherence and/or chronic pain had increased health care utilization. Future studies examining barriers to adherence and evaluating interventions to optimize HU adherence in SCD are warranted.KEY MESSAGESYoung adults with SCD had significantly higher HU adherence, as reflected in their laboratory markers, compared to children and adolescents.Patients with higher HU adherence and/or those without chronic pain had lower or less frequent health care utilization.No significant association of HU adherence to patients' sex, socio-economic status and distance from hospital.

Ten-year Longitudinal Analysis of Hydroxyurea Implementation in a Pediatric Sickle Cell Program

Hydroxyurea (HU) has proven benefit in sickle cell anemia (SCA), but HU is still underutilized. The Pediatric Sickle Cell Program of Northern Virginia prescribes HU regardless of symptoms to all SCA patients age ≥ 9 months and prospectively tracks outcomes. HU is dosed to maximum tolerated dosing (MTD), targeting 30% Hgb F. Longitudinal data from 2009-2019 encompassing 1222 HU-eligible and 950 HU-exposure patient-years were analyzed in 2-year intervals for hemoglobin (Hgb), fetal hemoglobin (Hgb F), hospitalizations, transfusions, and treat-and-release ED visits. Comparing HU-eligible patients in the interval prior to HU implementation (2009-2011) to the last interval analyzed after HU implementation (2017-2019), HU usage increased from 33% to 93%, average Hgb increased from 8.3±0.98 to 9.8±1.3 g/dL (p<0.0001), average Hgb F rose from 13±8.7% to 26±9.9% (p<0.0001), hospitalizations decreased from 0.71 (95% CI 0.54-0.91) to 0.2 (95% CI 0.13-0.28) admissions/person-year, sporadic transfusions decreased from 0.4 (95% CI 0.27-0.55) to 0.05 (95% CI 0.02-0.12) transfusions/person-year. Treat-and-release ED visit rates remained unchanged, varying between 0.49 (95% CI 0.36-0.64) and 0.64 (95% CI 0.48-0.83) visits/person-year. By the last interval, 72% of patients had Hgb ≥ 9g/dL, 42% had Hgb F ≥ 30%, 79% experienced no hospitalizations, and 94% received no transfusions. Uniform HU prescription for SCA patients with close monitoring to achieve high Hgb F resulted in significant improvements in laboratory and clinical outcomes within 2 years, which continued to improve over the next 6 years. Rigorous HU implementation in a pediatric sickle cell population is feasible, effective, and sustainable. This article is protected by copyright. All rights reserved.

Impact of hydroxyurea dose and adherence on hematologic outcomes for children with sickle cell anemia

BACKGROUND

Hydroxyurea is the primary treatment for sickle cell anemia (SCA), yet real-world implementation in high-income settings is suboptimal. Variation in prescribed hydroxyurea dose and patient adherence in these settings can both affect actual exposure to hydroxyurea. Quantifying the contributions of hydroxyurea dose and medication adherence to the relationship between hydroxyurea exposure and hematologic parameters could inform strategies to optimize exposure and improve outcomes.

PROCEDURE

We evaluated the relationship between hydroxyurea exposure, defined by average prescribed dose and adherence, and hematologic parameters using data from children with SCA who were enrolled in two prospective hydroxyurea adherence studies. Hydroxyurea adherence was assessed by video directly observed therapy or electronic pill bottle and medication administration record. Average prescribed dose was abstracted from prescriptions in patients' electronic medical record. Participants with a hydroxyurea exposure >20 mg/kg/day and ≤20 mg/kg/day were included in the higher and lower exposure groups, respectively.

RESULTS

Forty-five participants were included in the analysis (56% male; median age 12 years [range 2-19]; 98% Black). Higher exposed participants (n = 23) were prescribed a higher dose (27.2 vs. 24.4 mg/kg/day, p = .002) and had better adherence (0.92 vs. 0.71, p ≤ .001) compared to lower exposed participants (n = 22). Higher exposure was associated with higher fetal hemoglobin (p = .04) and mean corpuscular volume (p = .02).

CONCLUSIONS

Higher hydroxyurea exposure is associated with improved hematologic parameters in the high-income setting and is affected by both prescribed dose and adherence. Future studies are needed to optimize both adherence and hydroxyurea prescribing and confirm that increasing exposure improves clinical outcomes in this setting.

Age-related healthcare services utilization for the management of sickle cell disease among treated Texas Medicaid patients

Objectives

To determine if there are age-related differences in sickle cell disease (SCD)-related healthcare utilization and to describe temporal healthcare utilization following an emergency department (ED) visit or hospitalization in treated SCD patient population.

Methods

Texas Medicaid prescription and medical claims from 1 September 2011 to 31 August 2016 were used. Patients aged 2–63 years with at least one inpatient or outpatient SCD medical claim and receiving one or more SCD-related medications (hydroxyurea, opioid or non-opioid analgesics) were included. The primary outcomes were utilization of SCD-related ED, inpatient and outpatient visits, all-cause prescription medications and type of SCD-related service at index and subsequent healthcare services. Age group was the primary independent variable.

Key findings

Overall (N = 2339), healthcare service utilization was relatively higher among age groups 2–12, 18–25 and 26–40. Proportions of patients having ≥1 ED and ≥1 inpatient visits, respectively, were significantly higher among age groups 2–12 (33.2%; 23.0%), 18–25 (29.3%; 25.1%) and 26–40 (32.3%; 22.4%) as compared with age group 13–17 (21.3%; 12.9%). The number of outpatient visits was highest among children aged 2–12 (4.5 ± 7.6, P &lt; 0.0001), while mean number of all-cause medications was the highest for older adults aged 41–63 (22.4 ± 16.3; P &lt; 0.0001). After an index ED visit (N = 598), outpatient visits were the most prevalent healthcare services. After an index hospitalization (N = 203), a subsequent hospitalization was the most prevalent healthcare service.

Conclusions

Texas Medicaid SCD patients receiving treatment have a high use of healthcare services, especially among children and young adults who are transitioning from childhood to adulthood. Age-specific interventions should be developed to promote optimal care transitions among young adults.

Administrative data identify sickle cell disease: A critical review of approaches in U.S. health services research

To identify people living with sickle cell disease (SCD) and study their healthcare utilization, researchers can either use clinical records linked to administrative data or use billing diagnosis codes in stand-alone administrative databases. Correct identification of individuals clinically managed for SCD using diagnosis codes in claims databases is limited by the accuracy of billing codes in outpatient encounters. In this critical review, we assess the strengths and limitations of claims-based SCD case-finding algorithms in stand-alone administrative databases that contain both inpatient and outpatient records. Validation studies conducted using clinical records and newborn screening for confirmation of SCD case status have found that algorithms that require three or more nonpharmacy claims or one inpatient claim plus two or more outpatient claims with SCD codes show acceptable accuracy (positive predictive value and sensitivity) in children and adolescents. Future studies might seek to assess the accuracy of case-finding algorithms over the lifespan.

The association between hydroxyurea adherence and opioid utilization among Texas Medicaid enrollees with sickle cell disease

BACKGROUND: Individuals with sickle cell disease (SCD) suffer from recurrent catastrophic pain crises that are often managed by opioid analgesics. Being adherent to hydroxyurea has been associated with decreased health care resource use for pain; however, evidence of its association with opioid use is limited. OBJECTIVE: To determine if adherence to hydroxyurea is associated with opioid use among patients with SCD. METHODS: This retrospective study used Texas Medicaid data from September 1, 2011, to August 31, 2016 (study period). The index date was the date of hydroxyurea initiation. Patients who were aged 2-63 years at the index date, had ≥ 1 inpatient or ≥ 2 outpatient SCD diagnoses during the study period, had ≥ 1 hydroxyurea prescription during the identification period (September 1, 2011-August 31, 2015), had no diagnosis of other indications for hydroxyurea during the study period, and were continuously enrolled for at least 12 months after the index date were included. Hydroxyurea adherence was measured using medication possession ratio (MPR). The study outcomes (measured 1-year post-index) were (a) opioid use; (b) number of opioid prescriptions; (c) strong opioid use (morphine, hydromorphone, fentanyl, and methadone); (d) number of strong opioid prescriptions; (e) high-dose opioid use (≥ 50 mg morphine milligram equivalent [MME]); and (f) days supply for opioid prescriptions. Covariates included demographic (age and gender) and clinical (vaso-occlusive crisis [VOC], avascular necrosis, iron overload, acute chest syndrome, and blood transfusion) characteristics. Descriptive, bivariate (chi-square and Wilcoxon-Mann-Whitney tests), multiple logistic regression, and negative binomial regression analyses were performed. RESULTS: 1,146 patients (18.3 [12.3] years) met the inclusion criteria. Of these, 19.6% were adherent to hydroxyurea (defined as MPR ≥ 80%) and mean (SD) MPR was 48.3% (29.7%). In the 1 year following hydroxyurea initiation, 923 (80.5%) patients had ≥ 1 opioid prescription with 7.6 (9.4) opioid prescriptions per patient, while 259 (22.6%) patients had ≥ 1 strong opioid prescription with 1.5 (4.4) strong opioid prescriptions per patient. Average (SD) opioid dose was 41.7 (74.3) mg MME, and 27.1% had high daily MME doses (≥ 50 mg MME). Average (SD) opioid days supply was 83.1 (112.2) days. After adjusting for covariates, compared with being nonadherent, being adherent to hydroxyurea was associated with a 50.5% decreased risk of having strong opioids (OR = 0.495, 95% CI = 0.278-0.879, P = 0.0165). Additionally, SCD-related complications (VOC, avascular necrosis, and iron overload) and older age were significant factors associated with opioid use and higher MME. Post hoc analyses showed that being adherent to hydroxyurea was significantly associated with lower probabilities of experiencing SCD-related complications. CONCLUSIONS: Results showed that patients with SCD are moderately adherent to hydroxyurea. Being adherent to hydroxyurea was found to be associated with a lower risk of receiving a prescription for strong opioids. Findings suggest that close monitoring and interventions to improve adherence may help mitigate strong opioid use among these patients. DISCLOSURES: This research did not receive any specific funding. Barner and Kang report grants from Novartis Pharmaceuticals, unrelated to this work. A part of this study was presented as a poster at the American Pharmacists Association (APhA) 2019 Annual Meeting and Exposition (March 22-25, 2019, Seattle, WA) and received the 2019 APhA-APRS Presentation Award in the APhA-APRS Contributed Research Paper, Graduate Student/Fellow/Postdoctoral Scholar category.

Association between clinical outcomes and metformin use in adults with sickle cell disease and diabetes mellitus

Metformin was recently found to increase fetal hemoglobin, which is protective in sickle cell disease (SCD). We tested the hypothesis that, among adults with SCD and diabetes mellitus (DM), metformin use is associated with fewer adverse SCD clinical outcomes and lower health care utilization. This is a retrospective cohort study using the MarketScan Medicaid claims database for 2006 to 2016, comparing metformin users and nonusers. Patients on hydroxyurea, insulin, or iron chelation were excluded. Main outcomes included annual rates of all-cause inpatient encounters, all-cause emergency department (ED) encounters, inpatient and ED encounters with SCD codes, vaso-occlusive episodes (VOEs), strokes, acute chest syndrome (ACS), avascular necrosis (AVN), and gallstones. Of 457 adults (median age [interquartile range], 43 years [33-52 years]; 72% female), 142 (31%) were treated with metformin. Adjusted for age, sex, and Charlson Comorbidity Index, metformin users had significantly lower rate ratios of all-cause inpatient encounters (0.68; 95% confidence interval [CI], 0.52-0.88; P < .01), inpatient encounters with SCD codes (0.45; 95% CI, 0.30-0.66; P < .01), ED encounters with SCD codes (0.34; 95% CI, 0.21-0.54; P < .01), VOE (0.22; 95% CI, 0.12-0.41; P < .01), ACS (0.17; 95% CI, 0.05-0.60; P = .01), and AVN (0.30; 95% CI, 0.11-0.87; P = .03). A subgroup analysis of 54 enrollees preinitiation and postinitiation of metformin did not indicate significant changes in rates of clinical events. Metformin was associated with significantly fewer inpatient and ED SCD encounters in adults with SCD and DM; however, confounding of underlying SCD severity cannot be excluded.

Performance of ICD-10-CM diagnosis codes for identifying children with Sickle Cell Anemia

OBJECTIVE

To develop, test, and validate the performance of ICD-10-CM claims-based case definitions for identifying children with sickle cell anemia (SCA).

DATA SOURCES

Medicaid administrative claims (2016) for children <18 years with potential SCA (any D57x diagnosis code) and newborn screening records from Michigan and New York State.

STUDY DESIGN

This study is a secondary data analysis.

DATA COLLECTION/EXTRACTION METHODS

Using specific SCA-related (D5700, D5701, and D5702) and nonspecific (D571) diagnosis codes, 23 SCA case definitions were applied to Michigan Medicaid claims (2016) to identify children with SCA. Measures of performance (sensitivity, specificity, area under the ROC curve) were calculated using newborn screening results as the gold standard. A parallel analysis was conducted using New York State Medicaid claims and newborn screening data.

PRINCIPAL FINDINGS

In Michigan Medicaid, 1597 children had ≥1 D57x claim; 280 (18 percent) were diagnosed with SCA. Measures of performance varied, with sensitivities from 0.02 to 0.97 and specificities from 0.88 to 1.0. The case definition of ≥1 outpatient visit with a SCA-related or D571 code had the highest area under the ROC curve, with a sensitivity of 95 percent and specificity of 92 percent. The same definition also had the highest performance in New York Medicaid (n = 2454), with a sensitivity of 94 percent and specificity of 86 percent.

CONCLUSIONS

Children with SCA can be accurately identified in administrative claims using this straightforward case definition. This methodology can be used to monitor trends and use of health services after transition to ICD-10-CM.

Hydroxyurea Initiation Among Children With Sickle Cell Anemia

This study assesses characteristics of children with sickle cell anemia associated with hydroxyurea initiation. Medicaid administrative claims from 6 states (2005-2012) were used to identify children with sickle cell anemia enrolled in Medicaid for ≥2 years. Hydroxyurea use was defined as >30 days' supply of filled prescriptions. Children were classified as initiators (no use in year 1; use in year 2) or nonusers (no use in either year). Logistic regression was used to estimate associations between initiation, health care encounters, and demographics. A total of 4435 children were enrolled for 2 years during the study period; 885 (20.0%) initiators and 3080 (69.4%) nonusers. Children had an annual mean of 2.0 sickle cell disease-related inpatient admissions (SD = 2.2), 8.2 sickle cell disease-related outpatient visits (SD = 7.2), and 3.6 emergency department visits (SD = 3.5). The odds of initiating hydroxyurea increased with increasing health care utilization, age, and calendar year (all P values <.05).

HABIT efficacy and sustainability trial, a multi-center randomized controlled trial to improve hydroxyurea adherence in youth with sickle cell disease: a study protocol

Background

Hydroxyurea (HU) is recommended as standard practice for youth with sickle cell disease (SCD). Yet, despite its efficacy, HU adherence in adolescents and young adults is often poor. Poor medication adherence increases disease burden, healthcare cost and widens health disparities. Adolescence is a critical time to improve adherence through improved chronic disease self-management. This study aims to test the efficacy of an intervention delivered to youth/parent dyads by community health workers (CHWs), augmented by tailored text messages on HU adherence (primary outcome). Secondary outcomes are intervention sustainability, youth health-related quality of life, self-management responsibility concordance, acute hospital use and self-reported disease symptoms.

Methods

Hydroxyurea Adherence for Personal Best in Sickle Cell Disease, “HABIT,” is a 12 month multi-center randomized controlled trial. One hundred four youth, 10 to 18 years of age prescribed HU who meet eligibility criteria, enrolled with their parent as dyads, will be randomized 1:1 to either the HABIT intervention or to usual clinical care plus education handouts. All subjects will complete clinic visits at months 0, 2, 4, 6 (efficacy component), 9 and 12 (sustainability component) for assessment of HbF biomarker, other hematologic parameters, and to complete questionnaires. In addition, dyads assigned to the HABIT intervention will work with CHWs to identify a daily habit (e.g., brushing teeth) on which to build a HU adherence habit. Tailored daily text message reminders to support the habit will be developed by the dyad in collaboration with the CHWs and sent to parent and youth. At the 6 month visit, the intervention will end and the sustainability portion of the trial will begin. All data analyses will be based on intention to treat with all randomized subjects included in the analyses.

Discussion

Prior retrospective studies demonstrate that a majority of adolescents are poorly adherent to HU. If efficacious, the HABIT intervention has the potential to improve the lives of youth with SCD.

Trial registration

Clinicaltrials.gov NCT03462511. Registered March 6, 2018, last updated July 26, 2019.

Hydroxyurea use in young infants with sickle cell disease

BACKGROUND

Hydroxyurea (HU) reduces complications and improves quality and duration of life in sickle cell disease. Evidence supports the use of HU starting after nine months of age.

PROCEDURES

We performed a retrospective study of patients starting HU at less than five years of age between January 1, 2008, and December 31, 2016. We evaluated clinical events, laboratory data, and toxicity between three different age groups: cohort 1 (0-1 year), cohort 2 (1-2 years), and cohort 3 (2-5 years).

RESULTS

Sixty-five patients were included in the analysis. The mean age was 7.2 months (n = 35), 19.5 months (n = 13), and 35.5 months (n = 17) for cohorts 1, 2, and 3, respectively. Cohort 1 had higher hemoglobin (P = 0.0003) and MCV (P = 0.0199) and lower absolute reticulocyte count (P = 0.0304) at 24 months of age compared with cohort 3. The absolute neutrophil count (ANC) was lower compared with both older cohorts (P = 0.0364, 0.0025). The mean baseline hemoglobin F in cohort 1 was 31.5% compared with 19.7% and 16.5% in cohorts 2 and 3, respectively (P = 0.002, P < 0.0001). The mean duration of therapy was 31.3 months, 57.6 months (P = 0.018), and 29.1 months (P = 0.401), respectively. Mean Hb F levels remained higher in cohort 1 (29.9%) compared with cohorts 2 and 3 (20.4%, P = 0.007; 20.6%, P = 0.003). Cohort 1 experienced fewer hospitalizations (P = 0.0025), pain crises (P = 0.0618), and transfusions (P = 0.0426). There was no difference in toxicity between groups.

CONCLUSION

HU is safe and effective in patients 5 to 12 months of age and generated a more robust response compared with initiation in older patients.

Advances in the Treatment of Sickle Cell Disease

Sickle cell disease (SCD) is a monogenic disorder that afflicts approximately 100,000 Americans and millions of people worldwide. It is characterized by hemolytic anemia, vaso-occlusive crises, relentless end-organ injury, and premature death. Currently, red blood cell transfusion and hydroxyurea are the major disease-modifying therapies available for SCD. Hematopoetic stem cell transplant is curative, but barriers to treatment are substantial and include a lack of suitable donors, immunologic transplant rejection, long-term adverse effects, prognostic uncertainty, and poor end-organ function, which is especially problematic for older patients. Gene therapy to correct the β^s point mutation is under investigation as another curative modality. Deeper insights into the pathophysiology of SCD have led to the development of novel agents that target cellular adhesion, inflammation, oxidant injury, platelets and/or coagulation, vascular tone, and hemoglobin polymerization. These agents are in preclinical and clinical trials. One such agent, L-glutamine, decreases red blood cell oxidant injury and is recently US Food and Drug Administration approved to prevent acute pain episodes of SCD in patients 5 years of age or older. The purpose of this review is to describe the currently established therapies, barriers to curative therapies, and novel therapeutic agents that can target sickle cell hemoglobin polymerization and/or its downstream sequelae. A PubMed search was conducted for articles published up to May 15, 2018, using the search terms sickle cell disease, novel treatments, hematopoietic stem cell transplantation, and gene therapy. Studies cited include case series, retrospective studies, prospective clinical trials, meta-analyses, online abstracts, and original reviews.

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.

HABIT, a Randomized Feasibility Trial to Increase Hydroxyurea Adherence, Suggests Improved Health-Related Quality of Life in Youths with Sickle Cell Disease

OBJECTIVES

To examine the effect of a community health worker (CHW) intervention, augmented by tailored text messages, on adherence to hydroxyurea therapy in youths with sickle cell disease, as well as on generic and disease-specific health-related quality of life (HrQL) and youth-parent self-management responsibility concordance.

STUDY DESIGN

We conducted a 2-site randomized controlled feasibility study (Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment [HABIT]) with 2:1 intervention allocation. Youths and parents participated as dyads. Intervention dyads received CHW visits and text message reminders. Data were analyzed using descriptive statistics, the Wilcoxon signed-rank test, and growth models adjusting for group assignment, time, and multiple comparisons. Changes in outcomes from 0 to 6 months were compared with their respective minimal clinically important differences.

RESULTS

A total of 28 dyads (mean age of youths, 14.3 ± 2.6 years; 50% Hispanic) participated (18 in the intervention group, 10 in the control group), with 10.7% attrition. Accounting for group assignment, time, and multiple comparisons, at 6 months intervention youths reported improved generic HrQL total score (9.8 points; 95% CI, 0.4-19.2) and Emotions subscale score (15.0 points; 95% CI, 1.6-28.4); improved disease-specific subscale scores for Worry I (30.0 points; 95% CI, 8.5-51.5), Emotions (37.0 points, 95% CI, 9.4-64.5), and Communication I (17.8 points; 95% CI, 0.5-35.1); and 3-month dyad self-management responsibility concordance (3.5 points; 95% CI, -0.2 to 7.1). There were no differences in parent proxy-reported HrQL measures at 6 months.

CONCLUSIONS

These findings add to research examining effects of behavioral interventions on HrQL outcomes in youths with sickle cell disease.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02029742.

Predictive validity of developmental screening in young children with sickle cell disease: a longitudinal follow-up study

AIM

To assess the predictive validity of developmental screenings in children with sickle cell disease (SCD) for academic outcomes and stroke risk.

METHOD

Parent questionnaires and medical record data were collected for a cohort receiving developmental screenings between September 2004 and May 2008 as toddlers or early school age. Screening outcomes were dichotomized (positive, negative) by a priori criteria. Questionnaires assessed school and social functioning, services received, and quality of life. Medical record data assessed general SCD morbidity and stroke risk.

RESULTS

Forty-one toddlers (mean age 2y 5mo; 25 males, 16 females) and 49 early school-age children (mean age 6y 5mo; 26 males, 23 females) completed follow-up. The mean follow-up period was 8 years 6 months (range 6.1-10.8y). For toddlers, positive screenings for language delays predicted lower academic performance (p=0.023). For older children, positive screenings for cognitive delays predicted more frequent academic/attentional problems at school (p<0.001), grade retention (p=0.007), and lower academic performance (p=0.001). Positive screenings were associated with an earlier onset of school problems and lower quality of life. Positive screenings for language/cognitive delays predicted increased stroke risk (both p<0.05).

INTERPRETATION

Screening for language or cognitive development in young children with SCD predicts academic outcomes and stroke risk.

WHAT THIS PAPER ADDS

Developmental screening predicts academic outcomes in sickle cell disease. Children with concerning language/cognitive screenings have early-onset school difficulties. Developmental screenings may help predict cerebrovascular complications.

Antibiotic Prophylaxis for Children With Sickle Cell Anemia

BACKGROUND

Children with sickle cell anemia (SCA) are at increased risk for invasive pneumococcal disease; antibiotic prophylaxis significantly reduces this risk. We calculated the proportion of children with SCA who received ≥300 days of antibiotic prophylaxis and identified predictors of such receipt.

METHODS

Children aged 3 months to 5 years with SCA were identified by the presence of 3 or more Medicaid claims with a diagnosis of SCA within a calendar year (2005-2012) in Florida, Illinois, Louisiana, Michigan, South Carolina, and Texas. Receipt of antibiotics was identified through claims for filled prescriptions. The outcome, receipt of ≥300 days of antibiotics, was assessed annually by using varying classifications of antibiotics. By using logistic regression with generalized estimating equations, we estimated the odds of receiving ≥300 days of antibiotics, with potential predictors of age, sex, year, state, and health services use.

RESULTS

A total of 2821 children contributed 5014 person-years. Overall, only 18% of children received ≥300 days of antibiotics. Each additional sickle cell disease-related outpatient visit (odds ratio = 1.01, 95% confidence interval: 1.01-1.02) and well-child visit (odds ratio = 1.08, 95% confidence interval: 1.02-1.13) was associated with incrementally increased odds of receiving ≥300 days of antibiotics.

CONCLUSIONS

Despite national recommendations and proven lifesaving benefit, antibiotic prophylaxis rates are low among children with SCA. Numerous health care encounters may offer an opportunity for intervention; in addition, such interventions likely need to include social factors that may affect the ability for a child to receive and adhere to antibiotic prophylaxis.

Sickle cell disease: a malady beyond a hemoglobin defect in cerebrovascular disease

INTRODUCTION

Sickle cell disease (SCD) is a devastating monogenic disorder that presents as a multisystem illness and affects approximately 100,000 individuals in the United States alone. SCD management largely focuses on primary prevention, symptomatic treatment and targeting of hemoglobin polymerization and red blood cell sickling. Areas covered: This review will discuss the progress of SCD over the last few decades, highlighting some of the clinical (mainly cerebrovascular) and psychosocial challenges of SCD in the United States. In addition, focus will also be made on the evolving science and management of this inherited disease. Expert commentary: Until recently hydroxyurea (HU) has been the only FDA approved therapy for SCD. However, advancing understanding of SCD pathophysiology has led to multiple clinical trials targeting SCD related thrombo-inflammation, abnormal endothelial biology, increased oxidant stress and sickle cell mutation. Yet, despite advancing understanding, available therapies are limited. SCD also imposes great psychosocial challenges for the individual and the affected community, which has previously been under-recognized. This has created a pressing need for complementary adjuvant therapies with repurposed and novel drugs, in addition to the establishment of comprehensive clinics focusing on both the medical treatment and the psychosocial issues associated with SCD.

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

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

A Retrospective Review to Determine If Children with Sickle Cell Disease Receive Hydroxyurea Monitoring

Introduction:

Sickle cell disease guidelines recommend that patients on hydroxyurea receive monitoring at least every 2–3 months, but it is unknown if this occurs in clinical practice. This study aimed to determine if patients with sickle cell disease at Nationwide Children’s Hospital had at least 4, in-person monitoring visits during a 12-month period and if frequent monitoring was associated with hydroxyurea adherence and clinical outcomes.

Methods:

We performed a retrospective analysis of children on hydroxyurea for at least 12 months during 2010–2015. Patients’ demographics, laboratory studies, prescriptions, and number of hydroxyurea and acute visits were recorded from their 12-month period that met eligibility criteria. Patients were considered frequently monitored if they had ≥ 4 hydroxyurea visits and adherent if they had prescriptions for hydroxyurea for ≥ 80% of the days in their 12-month period.

Results:

Seventy-four children met the eligibility criteria and 57 (77%) had frequent monitoring. The most common reason for not obtaining frequent monitoring was missing a scheduled appointment. A greater proportion of frequently monitored patients were adherent to hydroxyurea (66.7% versus 17.7%; P < 0.001), and they had significantly fewer acute visits (median 1 versus 2 visits; P = 0.032) compared with infrequently monitored patients.

Conclusions:

Our study shows that most children on hydroxyurea at Nationwide Children’s Hospital received frequent monitoring and that it was associated with improved adherence and outcomes. Our results suggest that frequent in-person monitoring could be an opportunity to identify poorly adherent patients. These data inform our next quality improvement initiative that will maximize adherence to these monitoring guidelines.

Study protocol for a randomized controlled trial to assess the feasibility of an open label intervention to improve hydroxyurea adherence in youth with sickle cell disease

BACKGROUND

Community health workers (CHW) are increasingly recognized as a strategy to improve health outcomes for the underserved with chronic diseases but has not been formally explored in adolescents with sickle cell disease (SCD). SCD primarily affects African American, Hispanic and other traditionally underserved populations. Hydroxyurea (HU), an oral, once-daily medication, is the only approved therapeutic drug for sickle cell disease and markedly reduces symptoms, morbidity and mortality and improves quality of life largely by increasing hemoglobin F blood levels. This paper presents the rationale, study design and protocol for an open label randomized controlled trial to improve parent-youth partnerships in self-management and medication adherence to HU in adolescents with SCD.

METHODS/DESIGN

A CHW intervention augmented by text messaging was designed for adolescents with SCD ages 10-18years and their parents to improve daily HU adherence. Thirty adolescent parent dyads will be randomized with 2:1 intervention group allocation. Intervention dyads will establish a relationship with a culturally aligned CHW to identify barriers to HU use, identify cues to build a habit, and develop a dyad partnership to improve daily HU adherence and achieve their individualized "personal best" hemoglobin F target. Intervention feasibility, acceptability and efficacy will be assessed via a 2-site trial. Outcomes of interest are HU adherence, dyad self-management communication, quality of life, and resource use.

DISCUSSION

Despite known benefits, poor HU adherence is common. If feasible and acceptable, the proposed intervention may improve health of underserved adolescents with SCD by enhancing long-term HU adherence.

TRIAL REGISTRATION

NCT02029742.