Psychometric properties of the Patient Reported Outcomes, Burdens and Experiences (PROBE) questionnaire

Outcome measures in hemophilia: current and future perspectives

INTRODUCTION

Hemophilia can detrimentally affect patients' quality of life and likelihood of survival. In the evolving landscape of therapies, the therapeutic gain of each treatment must be understood to accurately position it in the therapeutic armamentarium. Accordingly, appropriate outcomes must be measured with appropriate tools.

AREAS COVERED

Our narrative review (PubMed search for 'hemophilia AND outcome' until June 2023), provides a compendium of outcome measures used in hemophilia clinical research. To define each outcome measure's relative value and applicability, several characteristics are critically discussed.

EXPERT OPINION

Bleeding assessment, first annual/annualized bleeding rate, remains central in evaluating the efficacy and safety of hemophilia treatments. As modern therapies improve clinical outcomes toward zero bleeding events, this endpoint may become less sensitive to detect differences between therapeutic approaches. Technological advancements necessitate the adaptation of outcome measures to address infrequent bleeding events, age-related comorbidities, and laboratory parameters with limited comparability after different treatments. Considerable effort has been dedicated to the development of tools that comprehensively assess coagulation, such as thrombin generation assays. Patient-reported outcome measures are gaining importance although limited by their subjectivity. A definitive set of research outcome measures remains elusive. Outcomes may need to be tailored to different therapeutic interventions.

Canadian clinical experience on switching from standard half-life recombinant factor VIII (rFVIII), octocog alfa, to extended half-life rFVIII, damoctocog alfa pegol, in persons with haemophilia A ≥ 12 years followed in a Comprehensive Hemophilia Care Program in Canada

INTRODUCTION

Damoctocog alfa pegol (BAY 94-9027, Jivi®) is an extended half-life recombinant factor (F)VIII replacement, indicated for the treatment of haemophilia A in patients aged ≥12 years. Following introduction of damoctocog alfa pegol in Canada in 2020, there have been no reports on routine clinical effectiveness and satisfaction, when switching from a previous FVIII product in Canada.

AIM

To report changes in pharmacokinetics, effectiveness, utilization and patient satisfaction when switching to damoctocog alfa pegol prophylaxis from previous standard half-life octocog alfa (BAY 81-8973, Kovaltry®) treatment.

METHODS

A single-centre, intra-patient comparison of pharmacokinetics and clinical outcomes was performed. Blood samples drawn once pre-dose and ≥2 times post-dose were measured by a one-stage assay to assess pharmacokinetic parameters including area under the curve (AUC, primary endpoint). Patient-reported outcomes data were collected using the Patient-Reported Outcomes, Burdens and Experiences questionnaire (PROBE). Clinical outcomes included annualized bleeding rate (ABR) and factor utilization.

RESULTS

Dose-normalized AUC was significantly increased after switch to damoctocog alfa pegol from octocog alfa. Median (quartile [Q]1; Q3) annualized bleeding rates were 0.67 (0.00; 1.33) with damoctocog alfa pegol and 1.33 (0.00; 2.67) with octocog alfa. Half of the patients receiving damoctocog alfa pegol prophylaxis experienced zero bleeds (n = 9, 50.0%) versus 38.9% (n = 7) of patients treated with octocog alfa. Patients' good quality of life was maintained.

CONCLUSION

This study provides routine clinical evidence supporting the benefits of switching from octocog alfa to damoctocog alfa pegol for patients with severe haemophilia A.

Gene Therapy in Hemophilia: A Transformational Patient Experience

Hemophilia is a bleeding disorder caused by a single absent/defective gene and characterized by a lack of functional clotting factors. People with hemophilia may experience joint damage, pain, and psychological impairments, all of which could contribute to reduced health-related quality of life (HRQoL). The current standard of care is clotting factor replacement, which is associated with regular infusions; therefore, alternative treatments such as gene therapy (GT) are in development. GT involves the delivery of a functional copy of the clotting factor 8/9 gene by a single infusion into the patient's cells, enabling them to produce their own clotting factor VIII/IX. The impact of treatment on patients' HRQoL can be assessed using hemophilia-specific patient-reported outcome (PRO) measures. Since these measures were designed before the advent of GT, there is a need for updated individualized PRO measures. Patient groups and regulatory authorities emphasize the need for increased patient engagement when considering clinical trial design. Here, we provide patients' perspective on undergoing GT and discuss how to capture the patient voice when measuring the therapy's transformative impact.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research priorities in health services; diversity, equity, and inclusion; and implementation science

BACKGROUND

The National Hemophilia Foundation (NHF) conducted extensive all-stakeholder inherited bleeding disorder (BD) community consultations to inform a blueprint for future research. Sustaining and expanding the specialized and comprehensive Hemophilia Treatment Center care model, to better serve all people with inherited BDs (PWIBD), and increasing equitable access to optimal health emerged as top priorities.

RESEARCH DESIGN AND METHODS

NHF, with the American Thrombosis and Hemostasis Network (ATHN), convened multidisciplinary expert working groups (WG) to distill priority research initiatives from consultation findings. WG5 was charged with prioritizing health services research (HSR); diversity, equity, and inclusion (DEI); and implementation science (IS) research initiatives to advance community-identified priorities.

RESULTS

WG5 identified multiple priority research themes and initiatives essential to capitalizing on this potential. Formative studies using qualitative and mixed methods approaches should be conducted to characterize issues and meaningfully investigate interventions. Investment in HSR, DEI and IS education, training, and workforce development are vital.

CONCLUSIONS

An enormous amount of work is required in the areas of HSR, DEI, and IS, which have received inadequate attention in inherited BDs. This research has great potential to evolve the experiences of PWIBD, deliver transformational community-based care, and advance health equity.

Long-term prophylaxis: what are our options and how to define success?

Currently, we are at an enviable place in hemophilia treatment. Although full prophylaxis with standard half-life recombinant or plasma-derived factor concentrates has been definitively shown to be inadequate for full protection against bleeding and arthropathy, a number of novel therapies with improved hemostatic enhancement are clinically available or in promising clinical trials. In order to compare outcomes among a number of very efficacious therapies, it is necessary to have sensitive tools employed in long-term follow-up for several years for participants with no or minimal joint disease. The tool kit must be comprehensive, with outcomes of bleeding, factor level restoration or hemostatic capacity, joint structure, joint function, pain, quality of life, and patient satisfaction. This article reviews the history of prophylaxis, the promise of emerging therapies, and the sensitive tools used to assess long-term efficacy for joint structure and function.

Pain and functional disability amongst adults with moderate and severe haemophilia from the Irish personalised approach to the treatment of haemophilia (iPATH) study

Objectives

To establish the prevalence of pain and functional disability in Irish adults with moderate and severe haemophilia, and to examine demographic and lifestyle influences.

Methods

Males ≥18 years with moderate or severe haemophilia participated. Pain and function were examined using the PROBE questionnaire.

Results

Of 49 participants [median age 44 (IQR 32, 52) years], most had severe haemophilia (Factor VIII = 30; Factor IX = 13) and were on regular prophylaxis (88%). Those with moderate haemophilia (Factor VIII = 5; Factor IX = 1) treated on demand (12%). Acute (72%) and chronic pain (71%), functional difficulties (58%), and analgesic requirements (92%) were prevalent. Age was significantly associated with more advanced haemophilic arthropathy (p = .002), chronic pain (p = .029) and functional difficulties (p = .036). Adults who reported chronic pain commenced prophylaxis significantly later in life [32 (20, 51) vs. 8 (1, 23) years; p = .004]. Physical activity was significantly lower in those with functional difficulties (p < .05). A disparity between self‐perceived ‘target joints’ and clinically defined target joints was also identified (76% vs. 23%).

Conclusion

Haemophilic arthropathy, pain and functional disability were prevalent amongst Irish adults with moderate and severe haemophilia. Age‐dependent lifestyle, analgesic and treatment influences on pain and function warrant further investigation.

User-Centered Development and Testing of the Online Patient-Reported Outcomes, Burdens, and Experiences (PROBE) Survey and the myPROBE App and Integration With the Canadian Bleeding Disorder Registry: Mixed Methods Study

Background

The Patient-Reported Outcomes, Burdens, and Experiences (PROBE) questionnaire is a tool for assessing the quality of life and disease burden in people living with hemophilia.

Objective

The objectives of our study were (1) to assess the needs of relevant stakeholders involved in the use of PROBE, (2) to develop the software infrastructure needed to meet these needs, and (3) to test the usability of the final product.

Methods

We conducted a series of semistructured interviews of relevant stakeholders, including PROBE investigators, people with hemophilia, and representatives of the sponsor. Based on these, we developed an online survey and a mobile app for iOS and Android. A user group evaluated the final product using the System Usability Scale (SUS) and an open feedback framework.

Results

The online survey was updated, and the myPROBE app for mobile devices and a new application programming interface were developed. The app was tested and modified according to user feedback over multiple cycles. The final version of the app was released in July 2019. Seventeen users aged 23 to 67 years evaluated the final version of the app using the SUS. The median (first, third quartile) SUS score for the app was 85 (68, 88) out of 100. The newly introduced functionalities were as follows: (1) capability to longitudinally track repeated fillings of the questionnaire at different time points by the same participant (as opposed to anonymous completion); (2) linking of the questionnaire with hemophilia registries, starting with the Canadian Bleeding Disorders Registry as a proof of concept; (3) removing or adding questions as needed; and (4) sending notifications to the users (eg, reminders). A new secure database was built for securely storing personal information separately from the questionnaire data. The PROBE online survey is currently available in 96 countries and 34 languages.

Conclusions

The online survey was updated successfully, and the myPROBE app was developed, with a SUS score of 85 (out of 100). The app has been released in 81 countries and 34 languages. This will facilitate data collection for research and advocacy purposes, and the use of this tool in everyday clinical practice.

Recombinant factor IX-Fc fusion protein in severe hemophilia B: Patient-reported outcomes and health-related quality of life

INTRODUCTION

In 2017, all people with severe hemophilia B in Ireland switched to recombinant factor IX Fc fusion protein concentrate (rFIXFc) prophylaxis. Patient-reported outcomes (PROs) and health-related quality of life (HRQoL) are important to evaluate with new treatments.

AIMS

To assess HRQoL in people with severe hemophilia B and their experience after switching to rFIXFc prophylaxis.

METHODS

Participants completed a Patient Reported Outcomes Burden and Experience (PROBE) questionnaire on initiation and following two years of rFIXFc prophylaxis. The PROBE questionnaire has four domains: demographics, general health, haemophilia-specific, and European Quality of Life 5-Dimensions (EQ-5D-5L) questionnaire.

RESULTS

Twenty-three participants completed the questionnaire at both time points. The number of activities where chronic pain occurred and interfered with the activity was reduced by 25% and 33%, respectively (P < .001), following two years of rFIXFc prophylaxis. There was a 9% decrease in chronic pain during the second year of rFIXFc prophylaxis compared to baseline, but the rate remained high, at 74%. A 25% reduction in the number of affected activities of daily living (ADLs) was reported following 2 years of rFIXFc prophylaxis (P = .007). The most common health problems were arthritis, hypertension, anxiety/depression, and gingivitis. The median EQ-5D-5L score was similar following two years of rFIXFc prophylaxis, 0.76 (range, -0.01 to 0.95), compared to 0.77 (range, 0.36-1) at baseline.

CONCLUSION

This study of real-world patient experience using PROs demonstrates a reduction in chronic pain and improvement in ADLs in participants after switching to rFIXFc prophylaxis. It provides important insights into patient-identified health care needs and living with severe hemophilia B.

Patient-relevant health outcomes for hemophilia care: Development of an international standard outcomes set

BACKGROUND

Patient-relevant health outcomes for persons with hemophilia should be identified and prioritized to optimize and individualize care for persons with hemophilia. Therefore, an international group of persons with hemophilia and multidisciplinary health care providers set out to identify a globally applicable standard set of health outcomes relevant to all individuals with hemophilia.

METHODS

A systematic literature search was performed to identify possible health outcomes and risk adjustment variables. Persons with hemophilia and multidisciplinary health care providers were involved in an iterative nominal consensus process to select the most important health outcomes and risk adjustment variables for persons with hemophilia. Recommendations were made for outcome measurement instruments.

RESULTS

Persons with hemophilia were defined as all men and women with an X-linked inherited bleeding disorder caused by a deficiency of coagulation factor VIII or IX with plasma activity levels <40 IU/dL. We recommend collecting the following 10 health outcomes at least annually, if applicable: (i) cure, (ii) impact of disease on life expectancy, (iii) ability to engage in normal daily activities, (iv) severe bleeding episodes, (v) number of days lost from school or work, (vi) chronic pain, (vii) disease and treatment complications, (viii) sustainability of physical functioning, (ix) social functioning, and (x) mental health. Validated clinical as well as patient-reported outcome measurement instruments were endorsed. Demographic factors, baseline clinical factors, and treatment factors were identified as risk-adjustment variables.

CONCLUSION

A consensus-based international set of health outcomes relevant to all persons with hemophilia, and corresponding measurement instruments, was identified for use in clinical care to facilitate harmonized longitudinal monitoring and comparison of outcomes.

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.

Non-severe haemophilia: Is it benign? - Insights from the PROBE study

INTRODUCTION

There are limited data on the impact of haemophilia on health status and health-related quality of life (HRQL) in people with non-severe (mild and moderate) haemophilia.

AIM

To evaluate the health status of people living with mild or moderate haemophilia.

METHODS

Data on respondents with no bleeding disorder (NoBD), mild and moderate haemophilia patients were drawn from the PROBE study. Respondents were enrolled using network patient organizations. This analysis was performed as a cross-sectional study. Primary outcomes were reported bleeding, acute and chronic pain, activities of daily living and HRQL.

RESULTS

A total of 862 respondents with NoBD (n = 173), mild (n = 102) and moderate (n = 134) haemophilia were eligible, with a median age of 33, 42 and 43, respectively. In relation to haemophilia-related sequalae, 53% of male and 29% of female patients with mild and 83% of males with moderate haemophilia had more than 2-3 bleeds in the last 12 months. Reporting of acute and chronic pain is less in those with NoBD compared to the mild and moderate cohorts for both genders. Multivariate analysis demonstrates significant reductions in quality of life using VAS, EQ-5D-5L and PROBE for males with mild and moderate haemophilia (P ≤ .001) with only PROBE indicating a significant reduction for females with mild (P = .002).

CONCLUSION

People affected by mild or moderate haemophilia report a significant HRQL impact due to haemophilia-related bleeding. Future research is needed to identify the optimal care management of patients with mild and moderate haemophilia.

How to discuss gene therapy for haemophilia? A patient and physician perspective

Gene therapy has the potential to revolutionise treatment for patients with haemophilia and is close to entering clinical practice. While factor concentrates have improved outcomes, individuals still face a lifetime of injections, pain, progressive joint damage, the potential for inhibitor development and impaired quality of life. Recently published studies in adeno‐associated viral (AAV) vector‐mediated gene therapy have demonstrated improvement in endogenous factor levels over sustained periods, significant reduction in annualised bleed rates, lower exogenous factor usage and thus far a positive safety profile. In making the shared decision to proceed with gene therapy for haemophilia, physicians should make it clear that research is ongoing and that there are remaining evidence gaps, such as long‐term safety profiles and duration of treatment effect. The eligibility criteria for gene therapy trials mean that key patient groups may be excluded, eg children/adolescents, those with liver or kidney dysfunction and those with a prior history of factor inhibitors or pre‐existing neutralising AAV antibodies. Gene therapy offers a life‐changing opportunity for patients to reduce their bleeding risk while also reducing or abrogating the need for exogenous factor administration. Given the expanding evidence base, both physicians and patients will need sources of clear and reliable information to be able to discuss and judge the risks and benefits of treatment.

Hemophilia trials in the twenty-first century: Defining patient important outcomes

Treatment for hemophilia has advanced dramatically over the past 5 decades. Success of prophylactic therapy in preventing bleeding and decreasing associated complications has established a new standard of care. However, with the advent of gene therapy and treatments that effectively mimic sustained coagulation factor replacement, outcome measures that worked well for assessing factor replacement therapies in past clinical trials need to be reassessed. In addition, while therapies have advanced, so has the science of outcome assessment, including recognition of the importance of patient important and patient reported outcomes. This manuscript reviews strengths and limitations of outcome measures used in hemophilia from both a provider and patient perspective.

Exploring regional variations in the cross-cultural, international implementation of the Patient Reported Outcomes Burdens and Experience (PROBE) study

BACKGROUND

The Patient Reported Outcomes Burdens and Experience (PROBE) study has developed and validated the PROBE questionnaire for assessing patient-reported outcomes in people with haemophilia and participants without bleeding disorders.

OBJECTIVE

To explore the regional variations in the international implementation of the PROBE questionnaire.

METHODS

Data were collected from participants in four regions (Western Pacific, South America, North America and Europe). Participants were able to choose English or translated versions of the PROBE questionnaire into their first language. We used analysis of variance methods and multivariable regression to determine the relative contribution of the variance explained by region controlling for haemophilia diagnosis, age group and levels of educations. We also explored interactions between region and the other components.

RESULTS

We used 862 questionnaires from 14 countries. Mean age of participants was 40.03 years (standard deviation 13.89), and 73.67% were male. After adjusting, region contributed 0.44%-7.98% of the variance component in subitem scores and 0.26% in the PROBE score. Years of education contributed 0.34% in the PROBE score. Age and haemophilia diagnosis contributed 3.42% and 22.42% of the PROBE score.

CONCLUSIONS

The results demonstrate that the PROBE questionnaire is valid to implement for assessing health status among patients with haemophilia and participants without bleeding disorders across regions.