Effect of etranacogene dezaparvovec on quality of life for severe and moderately severe haemophilia B participants: Results from the phase III HOPE-B trial 2 years after gene therapy.

INTRODUCTION: For people with haemophilia B (PwHB), bleeding may occur despite prophylaxis, negatively affecting health-related quality of life (HRQoL). The pivotal phase 3 HOPE-B trial investigating the adeno-associated virus gene transfer product, etranacogene dezaparvovec (EDZ), demonstrated sustained factor IX (FIX) activity and bleed protection in PwHB with baseline FIX levels ≤2%. AIM: Assess how EDZ affects HRQoL in HOPE-B trial participants. METHODS: HRQoL was evaluated using generic and disease-specific patient reported outcomes (PROs) including the EQ-5D-5L and the Hem-A-QoL questionnaires. Mean domain and total scores were compared 6 months pre- and the first 2 years post-EDZ administration using repeated measures linear mixed models. The percentage of participants with minimal clinically important improvements in HRQoL was also evaluated. RESULTS: Two years post-EDZ, there were nominally significant increases in the least squares (LS) mean score for the EQ-5D-5L Index Value (.04; p = .0129), reflecting better HRQoL. Nominally significant decreases in the LS mean scores, reflecting better HRQoL, were also found for the Hem-A-QoL total score (-6.0; p < .0001) and the Treatment (-13.94; p < .0001), Feelings (-9.01; p < .0001), Future (-6.45; p = .0004) and Work/School (-5.21; p = .0098) domains. The percentage of participants with ≥15-point improvement ranged from 45.83% (95% CI: 31.37%, 60.83%) for Treatment to 13.89% (95% CI: 4.67%, 29.50%) for Family Planning. Results were similar for Year 1. CONCLUSION: In conclusion, gene therapy with EDZ improved HRQoL in the first and second years in several Hem-A-QoL domains, including Treatment, Feelings, Work/School and Future domains, whereas improvement in other aspects of HRQoL were not demonstrated.

Cross-sectional study evaluating the association of haemophilia-related distress and clinically relevant outcomes.

INTRODUCTION: In chronic diseases, disease-related distress can impact disease outcomes. Distress and haemophilia-related distress has been demonstrated in people with haemophilia (PwH). The association of haemophilia-related distress on disease outcomes among PwH is unknown. AIM: To study the association of haemophilia-related distress with haemophilia specific outcomes, including adherence to prophylactic therapy, the presence of a target joint, healthcare utilization and work-impairment. METHODS: In a cross-sectional study, adults with haemophilia A or B were enrolled in a study to validate the haemophilia-related distress questionnaire (HRDq). In this planned analysis, univariate and multivariate associations between the HRDq total score and disease outcomes were explored. RESULTS: The 114 participants in this analysis were male, mostly with haemophilia A (92%) and severe disease (52%) with a median age of 31.9 years. On univariate analysis, HRDq total score (5-point change) was associated with the presence of a target joint (P = .002), high healthcare utilization (P = .011), poor adherence (P = .033) and work-impairment (P ≤ .001). After adjustment for age, race, severity and other potential confounders, adherence (aß 0.33, 95% CI .17, .49) and work-impairment (aß 4.69, 95% CI 3.27-6.1) remained statistically significantly associated with HRDq total score. CONCLUSION: Haemophilia-related distress is associated with poor adherence to factor prophylaxis and work-impairment. The direction of the association (causation) is yet to be determined and requires future study.

Matching-adjusted indirect comparison of bleeding outcomes in severe haemophilia A: Comparing valoctocogene roxaparvovec gene therapy, emicizumab prophylaxis, and FVIII replacement prophylaxis.

INTRODUCTION: Head-to-head evaluation of valoctocogene roxaparvovec, the first gene therapy approved for haemophilia A, with emicizumab is not available. Therefore, phase 3 trial data were indirectly compared. AIM: To compare bleeding rates in trials evaluating 6 × 1013  vg/kg valoctocogene roxaparvovec (GENEr8-1; NCT03370913), 1.5 mg/kg emicizumab dosed every week (HAVEN 3; NCT02847637), and FVIII prophylaxis (270-902) in participants with severe haemophilia A (FVIII ≤1 IU/dL). METHODS: Valoctocogene roxaparvovec versus emicizumab and FVIII prophylaxis as used in 270-902 versus emicizumab cross-trial comparisons were performed using matching-adjusted indirect comparison (MAIC). Individual participant data from GENEr8-1 and 270-902 were weighted to equalise aggregate participant baseline characteristics from HAVEN 3. After MAIC weighting, annualised bleeding rates (ABR) and proportions of participants without bleeds were compared for treated bleeds, all bleeds, treated joint bleeds, and treated spontaneous bleeds. RESULTS: After MAIC weighting, ABR for all bleeds was statistically significantly lower with valoctocogene roxaparvovec than emicizumab (rate ratio [95% CI], .55 [.33-.93]). Additionally, significantly higher proportions of participants had no treated joint bleeds (odds ratio [95% CI], 2.75 [1.20-6.31]) and no treated bleeds (3.25 [1.53-6.90]) with valoctocogene roxaparvovec versus emicizumab. When compared with the mainly standard half-life FVIII prophylaxis regimens in 270-902, mean ABRs (except for all bleeds) were significantly lower, and significantly higher proportions reported 0 bleeds for all outcomes with emicizumab. CONCLUSION: Valoctocogene roxaparvovec provided generally lower bleeding rates and higher probability of no bleeds, including treated joint bleeds, than emicizumab. Emicizumab was more effective than FVIII prophylaxis regimens used in 270-902.

Physical therapy within US HTCs: A multicentre survey of utilization, practice patterns and pain management approaches.

INTRODUCTION: Practice patterns and utilization of physical therapists (PTs) affiliated with Hemophilia Treatment Centers (HTCs) in the United States (US) are not well known. AIMS: Describe utilization, role responsibilities and practice patterns of US HTC PTs. Identify practice patterns specifically focusing on assessment and treatment of pain. Recognize gaps in utilization and role responsibilities of PTs as part of the multidisciplinary team and suggest guidelines for PT involvement within the HTC. METHODS: Respondents were a subset of a convenience sample of healthcare providers who responded to a non-validated survey developed by a multi-disciplinary panel of haemophilia experts. RESULTS: A 33.0% response-rate (n = 59) representing all regions of US HTCs was achieved. Those working ≥10 hours per week were more likely to provide nutrition education (P = .026) and surgical options education (P < .001). Those who billed insurance for their services during comprehensive visits were more likely to provide education regarding surgical options (P = .046). The majority of PTs (95.0%) evaluated pain regardless of time spent in clinic and felt comfortable treating pain. Fifty-eight percent used a formal pain measurement tool and more likely to use a formal pain measurement tool if billing insurance (P = .004). Top five non-pharmacologic treatments recommended for pain management included splints/braces (84.8%), aquatic therapy (74.6%), orthotics (71.2%), surgical options (47.5%) and yoga (32.2%). CONCLUSIONS: This study demonstrated PT utilization across HTC centres varies widely. Gaps in care may be addressed through salary support, funded education, greater regional/national collaboration of PTs specializing in bleeding disorders and advocacy for insurance coverage for appropriate services.

Outcome measures in Haemophilia: Beyond ABR (Annualized Bleeding Rate).

Options for management of haemophilia are increasing rapidly with completely novel therapeutic approaches that cannot be compared using traditional factor assays. In addition, as prophylaxis regimens have improved, bleeding rates have decreased, and consequently, it is difficult to show an impact of novel therapies on rates of spontaneous bleeding. There is currently an urgent need for a panel of outcome measures to compare therapies that are dissimilar in many essential ways. Conventional objective outcome measures including joint physical examination and joint imaging continue to hold a central importance. Factor assays are essential for evaluation of products derived from native factor genes, but are not applicable to some extended half-life factors or non-factor bypassing agents. Global assays including thrombin generation and chromogenic assays of factor X activation are under investigation for their usefulness in haemophilia assessment. Bleeding rate is a conventional subjective patient-reported outcome that, while decreasing in frequency, is indispensable as an outcome given that the primary manifestation of haemophilia is bleeding. Other patient-reported outcomes such as pain intensity and interference, health-related quality of life and activities and participation are increasingly important to distinguish superior outcomes in comparative trials. This review of outcome measures for haemophilia presents examples of existing outcome measures with an emphasis on their strengths and limitations.

An evaluation of PROMIS health domains in adults with haemophilia: A cross-sectional study.

INTRODUCTION: The Patient-Reported Outcomes Measurement Information System (PROMIS) provides measures of health status that assess physical, mental and social well-being from the patient perspective. PROMIS measures are used in clinical practice and research across various patient populations but are not yet validated among patients with haemophilia. AIM: Evaluate the sensitivity of PROMIS to indicators of haemophilia clinical severity and compare PROMIS measures to those from other PRO instruments. METHODS: Male adults with haemophilia (n = 115) completed the PROMIS-29 short form which includes 4 questions for each of 7 domains: depression, anxiety, ability to participate in social roles and activities, physical function, pain interference, fatigue and sleep disturbance. Participant responses for each domain were scored on a T-score metric with a mean of 50 and a standard deviation of 10 based on the original PROMIS reference sample of US adults. Participants also completed other generic and haemophilia-specific health-related quality of life questionnaires. RESULTS: Participants who experienced higher pain and depression levels reported significantly worse health in every PROMIS domain compared with their peers. Those who had recently needed to use crutches, visit an emergency department or were currently unemployed or disabled also reported poor PROMIS scores on most domains. Construct validity was supported by correlations between PROMIS domain scores and domain scores reported using the EQ-5D-5L and Haem-A-QoL. CONCLUSION: The PROMIS instrument provides a potentially valuable tool to evaluate the impact of haemophilia and suggests usefulness in research and clinical practice.

Shortening the Haemophilia Activities List (HAL) from 42 items to 18 items.

INTRODUCTION: The Haemophilia Activities List (HAL) was developed to measure activities and participation in persons with haemophilia (PWH). Shortening the questionnaire may facilitate use of the HAL. AIM: The aim of this study was to determine which items of the HAL are redundant, to construct a shorter version of the HAL, and to determine the construct validity of the HALshort . METHODS: A secondary analysis was performed on pooled data of two published studies using the HAL (seven domains, 42 items, optimum score: 100) in adults with haemophilia A/B. Data were divided into a derivation (62%) and a validation set (38%). Redundant items were identified by evaluation of: floor and ceiling effects, proportions of missing and 'not applicable' responses, inter-item correlations, component loadings in an exploratory factor analysis, internal consistency, and item-total correlations. Correlations with the SF-36 and EQ-5D-5L were used to determine construct validity of the HALshort . RESULTS: Data on 680 PWH were evaluated. In the derivation dataset (n = 420), median age was 30 years (range 18-80), 43% had severe haemophilia and 61% received prophylaxis. Median (IQR) HAL sum score was 65.0 (55.7-88.8). The stepwise procedure resulted in a HALshort of 18 items with a median sum score of 63.3 (54.4-86.7). Construct validity was similar for the HAL and HALshort in the validation dataset (n = 260). CONCLUSION: This clinimetric study resulted in a >50% shortening of the HAL. The 18-item HALshort reduces patient burden and is expected to capture the information on activities and participation. The HALshort needs further validation.

Women and girls with haemophilia receiving care at specialized haemophilia treatment centres in the United States.

INTRODUCTION: Females may have haemophilia with the same factor VIII (FVIII) or factor IX (FIX) levels as affected males. Characterization of females with haemophilia would be useful for health care planning to meet their unique needs. Federally-funded haemophilia treatment centres (HTCs) in the United States contribute data on all individuals with bleeding disorders receiving care to the Population Profile (HTC PP) component of the Community Counts Public Health Surveillance of Bleeding Disorders project. AIMS: To estimate the number of females with haemophilia receiving care at HTCs in the United States and compare their characteristics with those of males with haemophilia. METHODS: HTC PP data collected on people receiving care at an HTC from January 2012 through September 2020 with haemophilia A and B were evaluated by sex for demographic and clinical characteristics. RESULTS: A factor level < 40% was reported for 23,196 males (97.8%) and 1667 females (47.6%) attending HTCs; 51 (.48%) severe, 79 (1.4%) moderate, and 1537 (17.9%) mild haemophilia patients were female. Females were older, more often White, and less often non-Hispanic than males. Females were less likely to have history of HIV or HCV infection, even among those with severe disease, but twice as likely to have infection status unknown. Females with mild haemophilia were more often uninsured than males. CONCLUSIONS: Females with severe or moderate haemophilia are uncommon, even in specialized care centres; however, almost one in five patients with mild haemophilia was female, indicating needs for specialized care based on factor level and history for affected females.

Evidence of a disability paradox in patient-reported outcomes in haemophilia.

INTRODUCTION: People with inherited and long-term conditions such as haemophilia have been shown to adapt to their levels of disability, often reporting better quality of life (QoL) than expected from the general population (the disability paradox). AIM: To investigate the disability paradox in people with haemophilia in the United States by examining preference differences in health state valuations versus the general population. METHODS: We conducted a discrete choice experiment including duration to capture valuations of health states based on patient-reported preferences. Participants indicated their preferences for hypothetical health states using the EQ-5D-5L, where each participant completed 15 of the 120 choice tasks. Response inconsistencies were evaluated with dominated and repeated scenarios. Conditional-logit regressions with random sampling of the general population responses were used to match the sample of patients with haemophilia. We compared model estimates and derived preferences associated with EQ-5D-5L health states. RESULTS: After removing respondents with response inconsistencies, 1327/2138 (62%) participants remained (177/283 haemophilia; 1150/1900 general population). Patients with haemophilia indicated higher preference value for 99% of EQ-5D-5L health states compared to the general population (when matched on age and gender). The mean health state valuation difference of 0.17 indicated a meaningful difference compared to a minimal clinically important difference threshold of 0.07. Results were consistent by haemophilia type and severity. CONCLUSION: Our findings indicated the presence of a disability paradox among patients with haemophilia, who reported higher health states than the general population, suggesting the impact of haemophilia may be underestimated if general population value sets are used.

Validation of a new instrument to measure disease-related distress among patients with haemophilia.

INTRODUCTION: In patients with haemophilia, general psychological distress as measured by the National Comprehensive Cancer Network (NCCN) distress thermometer has been associated with pain, disability and increased healthcare utilization. AIMS: To develop and validate a measure of haemophilia-related distress. METHODS: After qualitative interviews, the Hemophilia-Related Distress Questionnaire (HRDq) was developed. To validate the HRDq, adults (≥18 years) with haemophilia were enrolled, reported demographic and clinical information, and completed the HRDq and other questionnaires that measured similar constructs. Analysis included factor analysis and assessment of internal consistency using Cronbach's α, convergent validity using Pearson's correlation coefficient, and discriminant validity by comparing subgroups of patients. Test-retest reliability was assessed using an intraclass correlation coefficient (ICC). RESULTS: Among 130 enrolled participants, 126 (median age=32.7 years) completed the 24 item HRDq in a median time of 5.4 minutes with overall HRDq scores ranging from 2 to 83 (median score=31.5; higher scores indicating higher distress). Assessment of convergent validity demonstrated a strong correlation (ρ>.60) of the HRDq total score with the NCCN Distress Thermometer, Haem-A-QoL total Score, and PROMIS-29 Profile social role domain and a mild to moderate correlation with all other questionnaire domains (.3-.59, p < .05). Distress was higher among those who had less education, were not employed, and were disabled and was not significantly different among those with severe compared with non-severe disease. Assessment of test-retest reliability demonstrated an ICC value of .84 (95% CI .71-.91) for the total score. CONCLUSIONS: The HRDq demonstrates good internal consistency, construct and discriminant validity, and retest reliability with a low responder burden.

Patient preferences and priorities for haemophilia gene therapy in the US: A discrete choice experiment.

INTRODUCTION: Gene therapy has shown promise in clinical trials for patients with haemophilia, but patient preference studies have focused on factor replacement treatments. AIM: We conducted a discrete choice experiment (DCE) to investigate the relative importance and differential preferences patients provide for gene therapy attributes. METHODS: We surveyed male adults with haemophilia in the United States recruited from patient panels including the National Hemophilia Foundation Community Voices in Research platform using an online survey over 4 months in 2020/21. Participants indicated preferences for gene therapy attributes including dosing frequency/durability, effect on annual bleeding, uncertainty related to side effects, impact on daily activities, impact on mental health, and post-treatment requirements. The relative importance of each attribute was analysed overall and for subgroups based on haemophilia type and severity. RESULTS: A total of 183 males with haemophilia A (n = 120) or B (n = 63) were included. Half (47%) had severe haemophilia; most (75%) were White. Overall, participants gave effect on bleeding rate the greatest relative importance (31%), followed by dose frequency/durability (26%), uncertainty regarding safety issues (17%), and impact on daily activities (11%). Dose frequency/durability had the greatest importance for those with haemophilia B (35%). CONCLUSION: People with haemophilia prioritised reduced bleeding and treatment burden; the former was more important in haemophilia A and the latter in haemophilia B, followed by safety and impact on daily life in this DCE of gene therapy attributes. These findings and differences can inform clinical and health policy decisions to improve health equity for people with haemophilia.

Improvements in Communication and Coordination of Care in a Hemophilia Treatment Center.

INTRODUCTION: In response to the increasing complexity of care for patients with bleeding disorders, we established new clinical teams for our hemophilia treatment center (HTC). AIMS: We undertook a quality improvement project to improve the coordination and communication with our patients by establishing primary assignments of clinical staff to individual patients (primary teams). METHODS: A quality improvement project group was formed that established the goals and assignment of primary teams. Patients were surveyed for their knowledge of their primary teams as well as their ability to schedule and contact their primary providers. As a measure of the effects on clinical staff, a balancing survey was also conducted among providers impacted by the clinical assignment of teams. RESULTS: Our results demonstrate improvements across both coordination and communication as reported by patients. Additionally, the assignment of primary teams was met with high satisfaction and improvement in coordination and communication as reported by the clinical staff members of the HTC. CONCLUSIONS: Initiation of a quality improvement project and the creation of a primary team system were feasible at a large HTC and resulted in improvements in both patient-reported and staff-reported outcomes of coordination and communication of care.

Nonsevere hemophilia A: often overlooked, but not forgotten.

PURPOSE OF REVIEW: Nonsevere hemophilia A (NSHA) patients have received relatively little clinical and research attention as compared with their severe counterparts. There is increasing recognition that despite their milder bleeding phenotype, the management of NSHA can be a challenge, with most management decisions largely inferred from severe hemophilia A data. This review focuses on some of the more recent developments in the field of NSHA. RECENT FINDINGS: Epidemiologic studies suggest that NSHA remain under-recognized and under-diagnosed globally. As the NSHA population ages, they are susceptible to age-related comorbidities. Large cohort studies of NSHA report that the most common primary cause of death is malignancy. NSHA patients have a lifetime risk of inhibitor development with increasing exposure to factor VIII concentrate. Even so, not all patients with inhibitors will require eradication treatment, irrespective of bleeding phenotype at time of inhibitor development. SUMMARY: As there are currently no evidence-based strategies for inhibitor eradication in NSHA patients, preventive strategies are critical to mitigate inhibitor risk in NSHA. There is a need for active surveillance of NSHA patients by hemophilia treatment centers to address hemophilia-related issues and other age-related comorbidities, in collaboration with primary care physicians and other subspecialists.

Occurrence rates of haemophilia among males in the United States based on surveillance conducted in specialized haemophilia treatment centres.

INTRODUCTION: Estimates of the size and characteristics of the US haemophilia population are needed for healthcare planning and resource needs assessment. A network of comprehensive haemophilia treatment centres (HTCs) located throughout the United States receives federal support for diagnosis and management of haemophilia and other rare bleeding disorders. AIM: Estimate the incidence and prevalence of haemophilia among US males using the HTC network. METHODS: During the period 2012-2018, de-identified surveillance data were collected on all males who visited an HTC that included year of birth, gender, race, Hispanic ethnicity, residence zip code, haemophilia type and severity. Data from all patients were used to calculate period prevalence by haemophilia type, severity and state of residence. Data from a subset of patients born 1995-2014 were used to estimate incidence rates over the 20-year period. RESULTS: During the period, 21 748 males with haemophilia visited the HTCs resulting in an age-adjusted prevalence of 15.7 cases per 100 000 males (12 for haemophilia A and 3.7 for haemophilia B). Prevalence was higher among whites (15.1) than blacks (12.4) or Hispanics of either race (12.4). State-specific prevalence varied from 1.6 to 23.3 cases per 100 000. Based on 9587 males born during the index period, the average haemophilia incidence was 1 case per 4334 live male births. CONCLUSION: Based on these data, we estimate that there are between 29 761 and 32 985 males with haemophilia living in the United States today, the majority of whom receive comprehensive care in specialized clinical centres.

Postoperative hemorrhage secondary to acquired hemophilia A.

Acquired hemophilia A in postoperative patients can cause major bleeding and an accurate diagnosis is required for effective treatment. Standard treatment is costly, difficult to obtain, and takes 4 to 6 weeks to be effective. This article describes a patient successfully treated with recombinant factor VIIa, porcine factor VIII, plasmapheresis, rituximab, and high-dose corticosteroids.

What can we learn from using formal patient-reported outcome instruments to assess pain, functional impairment, anxiety, and depression in US adults with hemophilia?

People with hemophilia frequently suffer from arthropathy that leads to pain and functional impairment, ultimately resulting in reduced quality of life. The impact of pain and functional impairment on the lives of people with hemophilia was explored in the Pain, Functional Impairment, and Quality of Life (P-FiQ) study. Various patient-reported outcome (PRO) instruments were employed to assess the effect of pain and functional impairment on multiple aspects of health in people with hemophilia. The results presented in this supplement include detailed observations from PRO instruments regarding pain, functional impairment, anxiety, and depression, an analysis of the differences in health-related quality of life across subgroups of patients defined by demographic and treatment-related characteristics, and results of a modeling analysis to identify patient factors which influence perceptions of pain and functional impairment, independent of joint status. These data provide insights into how the results from PRO assessments may be used to evaluate outcomes for people with hemophilia in the clinical and research settings.

Factors associated with pain severity, pain interference, and perception of functional abilities independent of joint status in US adults with hemophilia: Multivariable analysis of the Pain, Functional Impairment, and Quality of Life (P-FiQ) study.

INTRODUCTION: Levels of pain and dysfunction appear to differ among people with hemophilia despite similar levels of joint disease. OBJECTIVE: To determine patient characteristics that influence pain and function independent of joint status. METHODS: US adults with hemophilia completed a survey that included information on clinical characteristics, demographics, and patient-reported outcome instruments assessing pain (Brief Pain Inventory v2 Short Form [BPI]), functional impairment (Hemophilia Activities List [HAL]), and health status (EQ-5D-5L). Additionally, physiotherapists optionally completed a clinical joint evaluation (Hemophilia Joint Health Score [HJHS]). Associations were examined using simple and multiple regression models. RESULTS: Of 381 adults enrolled, 240 had complete HJHS scores (median age, 32 years). After controlling for HJHS and opiate use, anxiety/anxiolytic use was significantly associated with worse pain severity and interference scores. After controlling for HJHS, the most significant predictors of functional impairment were older age, unemployment, more severe hemophilia, and greater pain. EQ-5D-5L pain/discomfort was associated with worse outcomes on most HAL scores. CONCLUSION: Unemployment, anxiety, and depression were each associated with both greater pain and functional disability after controlling for joint status. Continued attention to pain and psychosocial issues will be important in improving clinical care and research efforts in the hemophilia population.

Reliability and validity of patient-reported outcome instruments in US adults with hemophilia B and caregivers in the B-HERO-S study.

OBJECTIVE: To assess the reliability and validity of six patient-reported outcomes (PRO) instruments for evaluating health-related quality of life in adults with mild-severe hemophilia B and caregivers of children with hemophilia B, including affected women/girls. METHODS: Adults with hemophilia B and caregivers completed separate online surveys containing several PRO instruments, which were administered to adult participants only (EQ-5D-5L, Brief Pain Inventory v2 Short Form, Hemophilia Activities List, and International Physical Activities Questionnaire), both adults and caregivers (Patient Health Questionnaire [PHQ-9]), or caregivers only (Generalized Anxiety Disorder 7-Item [GAD-7] scale). Construct validity and item-total correlation were assessed using Pearson product-moment correlation, internal consistency was assessed using Cronbach's alpha coefficient, and known-group validity was assessed by comparisons to self-reported characteristics based on the Kruskal-Wallis test. RESULTS: Patient-reported outcomes instruments generally showed satisfactory reliability for adults (n = 299) and caregivers (n = 150). In adults, PRO instruments generally showed high construct validity. Most PRO instruments showed expected significant differences among known groups for adults and caregivers. PHQ-9 and GAD-7 did not show significant differences among caregiver age groups. CONCLUSIONS: Patient-reported outcomes instruments administered in B-HERO-S demonstrated reliability and validity in the broader population of adults with hemophilia B and caregivers when including all severities and genders.