Greater number of perceived barriers to hydroxyurea associated with poorer health-related quality of life in youth with sickle cell disease

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.

Study protocol for ADHERE (Applying Directly observed therapy to HydroxyurEa to Realize Effectiveness): Using small business partnerships to deliver a scalable and novel hydroxyurea adherence solution to youth with sickle cell disease

Sickle cell disease (SCD) is an inherited blood disorder that affects approximately 100,000 Americans, primarily from underrepresented racial minority populations, and results in costly, multi-organ complications. Hydroxyurea, the primary disease-modifying therapy for SCD, is effective at reducing most complications; however, adherence to hydroxyurea remains suboptimal and is the primary barrier to clinical effectiveness. Video directly observed therapy (VDOT) has shown promise as an adherence-promoting intervention for hydroxyurea, yet previous VDOT trials were limited by high attrition from gaps in technology access, use of unvalidated adherence measures, and healthcare system limitations of delivering VDOT to patients. As such, we fostered a small business partnership to compare VDOT for hydroxyurea to attention control to address previous shortcomings, promote equitable trial participation, and maximize scalability. VDOT will be administered by Scene Health (formerly emocha Health) and adherence monitoring will be performed using a novel electronic adherence monitor developed to meet the unique needs of the target population. Adolescent and young adult patients as well as caregivers of younger patients (<11 years of age) will be recruited. In addition to visit incentives, all participants will be offered a smartphone with a data plan to ensure all participants have equal opportunity to complete study activities. The primary objectives of this pilot, multi-center, randomized controlled trial (RCT) are to assess retention and sustained engagement and to explore needs and preferences for longer-term adherence monitoring and interventions. This RCT is registered with the National Institutes of Health (NCT06264700). Findings will inform a future efficacy RCT applying VDOT to hydroxyurea to address adherence gaps and improve outcomes within this vulnerable population.

Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment (HABIT) efficacy trial: Community health worker support may increase hydroxyurea adherence of youth with sickle cell disease

Despite disease-modifying effects of hydroxyurea on sickle cell disease (SCD), poor adherence among affected youth commonly impedes treatment impact. Following our prior feasibility trial, the "Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment (HABIT)" multi-site randomized controlled efficacy trial aimed to increase hydroxyurea adherence for youth with SCD ages 10-18 years. Impaired adherence was identified primarily through flagging hydroxyurea-induced fetal hemoglobin (HbF) levels compared to prior highest treatment-related HbF. Eligible youth were enrolled as dyads with their primary caregivers for the 1-year trial. This novel semi-structured supportive, multidimensional dyad intervention led by community health workers (CHW), was augmented by daily tailored text message reminders, compared to standard care during a 6-month intervention phase, followed by a 6-month sustainability phase. Primary outcomes from the intervention phase were improved Month 6 HbF levels compared to enrollment and proportion of days covered (PDC) for hydroxyurea versus pre-trial year. The secondary outcome was sustainability of changes up to Month 12. The 2020-2021 peak coronavirus disease 2019 (COVID-19) pandemic disrupted enrollment and clinic-based procedures; CHW in-person visits shifted to virtual scheduled interactions. We enrolled 50 dyads, missing target enrollment. Compared to enrollment levels, both HbF level and PDC significantly - but not sustainably - improved within the intervention group (p = .03 and .01, respectively) with parallel increased mean corpuscular volume (MCV) (p = .05), but not within controls. No significant between-group differences were found at Months 6 or 12. These findings suggest that our community-based, multimodal support for youth-caregiver dyads had temporarily improved hydroxyurea usage. Durability of impact should be tested in a trial with longer duration of CHW-led and mobile health support.

Understanding multi-level barriers to medication adherence among adults living with sickle cell disease

There is limited research that identifies and examines multi-level barriers to medication adherence among adults with Sickle Cell Disease (SCD); Identify multi-level barriers to medication adherence among adults with SCD; and Examine the relationship between multi-level barriers and medication adherence levels. A cross-sectional study included 130 adults (ages ≥ 18 years old) living with SCD who receive treatment/care from one of the 10 adult SCD clinics within the Networking California for sickle cell care initiative. Study measures included the medication adherence report scale (Professor Rob Horne), Beliefs about Medicine Questionnaire (Professor Rob Horne), and patient reported outcomes measurement information system. Participants reported barriers to medication adherence across 3 levels: Community-level barriers (e.g., COVID-19 pandemic); Institutional-level barriers (e.g., bad experiences with the health care system); and Individual-level barriers (e.g., beliefs and depression severity). Depression severity and patient concerns about SCD medication were inversely correlated with medication adherence (rs = -0.302, P < .001; rs = -0.341, P < .001 respectively). Patient beliefs about the necessity of SCD medication were insignificantly correlated with medication adherence (rs = 0.065, P = .464). Medication adherence was higher among patients who had fewer adherence barriers than multiple adherence barriers (Median medication adherence: fewer barriers = 22 vs multiple barrier = 20.50, P = .085), suggesting clinical significance although statistically insignificant. Identifying multi-level adherence barriers and examining their relationship with medication adherence will help develop targeted public health strategies to promote improved medication adherence and wellness among adults with SCD.

Health-Related Quality of Life and Adherence to Hydroxyurea and Other Disease-Modifying Therapies among Individuals with Sickle Cell Disease: A Systematic Review

Background

Sickle cell disease (SCD) is a hemoglobinopathy with increasing global prevalence resulting in pain episodes and multiorgan complications. Complications of SCD have been shown to adversely impact health-related quality of life (HRQOL) comprised of physical, social, and emotional domains; hence, HRQOL measures can serve as an effective evaluator of disease burden. Hydroxyurea (HU) and other disease-modifying therapies have demonstrated to significantly improve clinical outcomes in patients with SCD. Medication adherence is an essential mediator of the clinical benefits of these therapies; low adherence has been shown to increase disease burden and healthcare utilization. This systematic literature review intends to determine the association between adherence to disease-modifying therapies and HRQOL in patients with SCD.

Methods

We found a total of 12 articles involving 788 participants, which included both patients with SCD and caregivers/parents. Adherence was measured using self-report instruments, laboratory markers, such as fetal hemoglobin and mean corpuscular volume, and mHealth medication trackers. HRQOL was measured using self-report instruments.

Results

All studies demonstrated a correlation between higher HU adherence and better HRQOL scores. Higher HU adherence was associated with lower pain impact, less frequent pain episodes, less fatigue, and improved physical function and mobility, reflecting better physical HRQOL outcomes. Higher adherence was also associated with improved emotional response, decreased anxiety and depressive symptoms, and better social functioning and peer relationships. In addition, our findings indicated that having less frequent barriers to HU adherence was associated with better HRQOL scores. No studies evaluated HRQOL outcomes in relation to adherence to l-glutamine, voxelotor, or crizanlizumab.

Conclusions

Optimizing HU adherence has the potential to improve HRQOL in patients with SCD in addition to reducing healthcare utilization and improving treatment satisfaction. Addressing barriers to HU adherence can positively strengthen the relationship between adherence and HRQOL to potentially improve patient outcomes.

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.

Patient-reported Outcome Measures in Pediatric Non-Malignant Hematology: A Systematic Review

Patient-reported outcome measures (PROMs) are questionnaires completed by patients or caregivers without influence by health care professionals. As such, PROMs show subjective health experiences, enhance the clinical information available to providers, and inform clinical action. The objective of this systematic review is to identify and list which validated PROMs have been used to monitor health-related quality of life in pediatric patients with nonmalignant hematology (hemophilia, immune thrombocytopenia, sickle cell disease, and thalassemia). Databases (MEDLINE, Embase, HaPI, CINAHL, and PsycTESTS) were searched to identify publications that validated or used PROMs as an outcome measure in the 4 disease groups. Overall, 209 articles met the inclusion criteria, identifying 113 PROMs. Of the 113 identified PROMs, 95 are generic and can be used in multiple disease groups. The Pediatric Quality of Life Generic Core Scales was the most frequently used generic PROM (68 studies). The 18 remaining PROMs were disease specific. The results of this review, together with the COSMIN tool for selecting outcome measures, will allow clinicians to evaluate the PROMs that are best suited to their patient population. In addition, the focus groups are currently being conducted with patients, parents, and clinicians to determine the optimal use of PROMs in the clinical environment.

A Systematic Review of Medication Adherence Interventions in Pediatric Sickle Cell Disease

Objective

Adherence to medication regimens is of critical importance in sickle cell disease (SCD). Most notably, data indicate that hydroxyurea, penicillin, and iron chelators increase life expectancy and decrease comorbid medical problems (e.g., strokes). However, average pediatric SCD adherence rates are only 55–74%. Studies have introduced interventions for pediatric SCD adherence, but no review has synthesized these data.

Methods

We conducted a systematic review of interventions for enhancing medication adherence in pediatric SCD. There were 9 studies that met inclusion and exclusion criteria. The Pediatric Self-Management Model provided a framework for organizing the modifiable factors targeted by existing interventions.

Results

The 9 studies had high risk of bias levels and most targeted hydroxyurea. All studies used multiple measures of adherence, the interventions were multicomponent, and most included behavioral or technological interventions. There was variability in terms of whether the intervention targeted the individual, family, community, or healthcare system.

Conclusions

Consistent with the broader adherence literature, targeting knowledge alone was insufficient in increasing adherence. Findings suggest that reminders and targeting self-efficacy were key to success. In addition, addressing multiple domains in an intervention yielded larger effects on adherence. Although these results are promising, this review highlights several limitations of the extant literature, including a paucity of intervention studies and several methodological weaknesses, such as small sample sizes, few randomized controlled trials, and variable measures of adherence. Recommendations for advancing scientific understanding of adherence promoting interventions in pediatric SCD are provided.

Applying the COM-B model to patient-reported barriers to medication adherence in pediatric acute lymphoblastic leukemia

BACKGROUND

Adherence to oral chemotherapy, including 6-mercaptopurine (6-MP), is suboptimal in pediatric acute lymphoblastic leukemia (ALL), which is associated with increased risk of relapse. Study objectives were to examine self-reported adherence to 6-MP and related barriers to adherence, mapped to the capability, opportunity, motivation, and behavior (COM-B) model for behavior change.

PROCEDURE

Forty-nine parents (median, 39 years old; 76% females) and 15 patients (median, 17 years old, 20% females) completed the study survey.

RESULTS

Suboptimal adherence was reported in 43% of parents and 73% of patients. Most parents and patients (80% and 90%, respectively) reported ≥1 adherence barrier. Parents reported difficulty helping their child meet others with ALL (43%), contacting community organizations (39%), and meeting other parents (37%). Patients reported difficulty finding out what their medications are (40%), finding out what 6-MP does (47%), and meeting other patients (40%). Using the COM-B, we found that parents and patients endorsed barriers in multiple components, especially physical (55%, 67%) and social opportunity (56%, 47%), highlighting that barriers to adherence may be multifaceted.

CONCLUSIONS

Our results suggest that parents and patients with ALL face various prevalent barriers to medication adherence and provide insight into the development of behavioral interventions focused on promoting adherence, which is essential to prevent relapse and optimize health outcomes in ALL.

Quality of Life of Latino and Non-Latino Youth With Sickle Cell Disease as Reported by Parents and Youth

INTRODUCTION

Approximately 10% to 15% of people affected by sickle cell disease (SCD) in the United States are Latino, many of whom are primary Spanish speakers. A key tool for self-reported outcome measures, the Pediatric QOL Inventory (PedsQL) SCD module, was not available in Spanish. Here, we assess the linguistic validity of a Spanish translation and compare perception of disease-specific and generic quality of life (QOL) in a sample of Latino and non-Latino children with SCD and their parents.

METHOD

Following forward and backward translation, Spanish-speaking child-parent dyads linguistically validated the translated instruments. Disease-specific and generic QOL perception of 28 child-parent dyads who participated in a clinical feasibility trial, HABIT (Hydroxyurea Adherence for Personal Best in Sickle Cell Disease), were compared by ethnicity. Data were analyzed by descriptive statistics, Mann-Whitney U test, absolute score differences, and minimal clinically important differences (MCID).

RESULTS

The translated questionnaire required no further language changes. QOL scores were higher for Latino children and parents compared with non-Latinos, with score differences exceeding MCIDs for total scores and the majority of subscale scores.

CONCLUSION

Spanish language PedsQL SCD instruments allow measurement of QOL in Spanish-speaking Latino children with SCD and their parents. Score differences for Latinos mostly exceeded MCIDs, suggesting that these differences are clinically meaningful. Confirmation of these findings is warranted.

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.