Limited responsiveness related to the minimal important difference of patient-reported outcomes in rare diseases

QALYs and rare diseases: exploring the responsiveness of SF-6D, EQ-5D-5L and AQoL-8D following genomic testing for childhood and adult-onset rare genetic conditions in Australia

BACKGROUND

Genomic testing transforms the diagnosis and management of rare conditions. However, uncertainty exists on how to best measure genomic outcomes for informing healthcare priorities. Using the HTA-preferred method should be the starting point to improve the evidence-base. This study explores the responsiveness of SF-6D, EQ-5D-5L and AQoL-8D following genomic testing across childhood and adult-onset genetic conditions.

METHOD

Self-reported patient-reported outcomes (PRO) were obtained from: primary caregivers of children with suspected neurodevelopmental disorders (NDs) or genetic kidney diseases (GKDs) (carers' own PRO), adults with suspected GKDs using SF-12v2; adults with suspected complex neurological disorders (CNDs) using EQ-5D-5L; and adults with dilated cardiomyopathy (DCM) using AQol-8D. Responsiveness was assessed using the standardised response mean effect-size based on diagnostic (having a confirmed genomic diagnosis), personal (usefulness of genomic information to individuals or families), and clinical (clinical usefulness of genomic information) utility anchors.

RESULTS

In total, 254 people completed PRO measures before genomic testing and after receiving results. For diagnostic utility, a nearly moderate positive effect size was identified by the AQoL-8D in adult DCM patients. Declines in physical health domains masked any improvements in mental or psychosocial domains in parents of children affected by NDs and adult CNDs and DCM patients with confirmed diagnosis. However, the magnitude of the changes was small and we did not find statistically significant evidence of these changes. No other responsiveness evidence related to diagnostic, clinical, and personal utility of genomic testing was identified.

CONCLUSION

Generic PRO measures may lack responsiveness to the diagnostic, clinical and personal outcomes of genomics, but further research is needed to establish their measurement properties and relevant evaluative space in the context of rare conditions. Expected declines in the physical health of people experiencing rare conditions may further challenge the conventional application of quality of life assessments.

Saturated fat, the estimated absolute risk and certainty of risk for mortality and major cancer and cardiometabolic outcomes: an overview of systematic reviews

OBJECTIVE

To assess the impact of reducing saturated fat or fatty foods, or replacing saturated fat with unsaturated fat, carbohydrate or protein, on the risk of mortality and major cancer and cardiometabolic outcomes in adults.

METHODS

We searched MEDLINE, EMBASE, CINAHL, and references of included studies for systematic reviews and meta-analyses (SRMAs) of randomized controlled trials (RCTs) and observational studies in adults published in the past 10 years. Eligible reviews investigated reducing saturated fat or fatty foods or replacing saturated fat with unsaturated fat, carbohydrate or protein, on the risk of cancer and cardiometabolic outcomes and assessed the certainty of evidence for each outcome using, for example, the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach. We assessed the quality of SRMAs using a modified version of AMSTAR-2. Results were summarized as absolute estimates of effect together with the certainty of effects using a narrative synthesis approach.

RESULTS

We included 17 SRMAs (13 reviews of observational studies with follow-up 1 to 34 years; 4 reviews of RCTs with follow-up 1 to 17 years). The quality of two-thirds of the SRMAs was critically low to moderate; the main limitations included deficient reporting of study selection, absolute effect estimates, sources of funding, and a priori subgroups to explore heterogeneity. Our included reviews reported > 100 estimates of effect across 11 critically important cancer and cardiometabolic outcomes. High quality SRMAs consistently and predominantly reported low to very low certainty evidence that reducing or replacing saturated fat was associated with a very small risk reduction in cancer and cardiometabolic endpoints. The risk reductions where approximately divided, some being statistically significant and some being not statistically significant. However, based on 2 moderate to high quality reviews, we found moderate certainty evidence for a small but important effect that was statistically significant for two outcomes (total mortality events [20 fewer events per 1000 followed] and combined cardiovascular events [16 fewer per 1000 followed]). Conversely, 4 moderate to high quality reviews showed very small effects on total mortality, with 3 of these reviews showing non-statistically significant mortality effects.

CONCLUSION

Systematic reviews investigating the impact of SFA on mortality and major cancer and cardiometabolic outcomes almost universally suggest very small absolute changes in risk, and the data is based primarily on low and very low certainty evidence.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020172141.

Key patient-reported outcomes in children and adolescents with intoxication-type inborn errors of metabolism: an international Delphi-based consensus

Background

Acute intoxication-type inborn errors of metabolism (IT-IEM) such as urea cycle disorders and non-acute IT-IEM such as phenylketonuria (PKU) and their treatment have a major impact on the life of affected children and families. Yet patients’ and parents’ perspectives on the burdens of IT-IEM and its effects on everyday functioning and well-being have rarely been addressed. Patient- and observer-reported outcomes (PROs/ObsROs) are critically important to evaluate and target health care and treatment efficacy. Therefore, it is mandatory to define PROs/ObsROs relevant to patients with IT-IEM, their families, and health care professionals and to provide valid, standardised and reliable measuring instruments. To achieve consensus we performed a two-round, electronic-based modification of a Delphi survey including 27 parents of affected children, nine teenage patients and 35 health professionals (physicians, nutritionists, psychologists). The final set of PROs/ObsROs was discussed and defined in an online consensus meeting with a subsample of three health professionals, three parents and two patients. For this final set, appropriate measures (PROMs/ObsROMs) were assembled.

Results

Seventeen PROs/ObsROs constitute the final core set for paediatric IT-IEM. They cover social (e.g. social participation), emotional (e.g. positive affect), and disease-related aspects (e.g. attitude towards treatment) of patients’ lives as well as the experience of parents (e.g. parental stress).

Conclusion

To promote a holistic treatment approach, this consensus-driven set of relevant PROs/ObsROs should be incorporated into daily IT-IEM care and considered as the key psychological outcomes in clinical trials. We have identified existing—psychometrically and contextual—appropriate PROMs/ObsROMs with open access to facilitate this process.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02183-2.

Experienced fatigue in people with rare disorders: a scoping review on characteristics of existing research

BACKGROUND

Experienced fatigue is an under-recognized and under-researched feature in persons with many different rare diseases. A better overview of the characteristics of existing research on experienced fatigue in children and adults with rare diseases is needed. The purpose of this review was to map and describe characteristics of existing research on experienced fatigue in a selection of rare diseases in rare developmental defects or anomalies during embryogenesis and rare genetic diseases. Furthermore, to identify research gaps and point to research agendas.

METHODS

We applied a scoping review methodology, and performed a systematic search in March 2020 in bibliographic databases. References were sorted and evaluated for inclusion using EndNote and Rayyan. Data were extracted on the main research questions concerning characteristics of research on experienced fatigue (definition and focus on fatigue, study populations, research questions investigated and methods used).

RESULTS

This review included 215 articles on ten different rare developmental defects/anomalies during embryogenesis and 35 rare genetic diseases. Of the 215 articles, 82 had investigation of experienced fatigue as primary aim or outcome. Included were 9 secondary research articles (reviews) and 206 primary research articles. A minority of articles included children. There were large differences in the number of studies in different diseases. Only 29 of 215 articles gave a description of how they defined the concept of experienced fatigue. The most common research-question reported on was prevalence and/ -or associations to fatigue. The least common was diagnostics (development or validation of fatigue assessment methods for a specific patient group). A large variety of methods were used to investigate experienced fatigue, impeding comparisons both within and across diagnoses.

CONCLUSION

This scoping review on the characteristics of fatigue research in rare diseases found a large variety of research on experienced fatigue. However, the minority of studies had investigation of experienced fatigue as a primary aim. There was large variation in how experienced fatigue was defined and also in how it was measured, both within and across diagnoses. More research on experienced fatigue is needed, both in children and adults with rare diseases. This review offers a basis for further research.

Accuracy of chitotriosidase activity and CCL18 concentration in assessing type I Gaucher disease severity. A systematic review with meta-analysis of individual participant data

Chitotriosidase activity and CCL18 concentration are interchangeably used for monitoring Gaucher disease (GD) activity, together with clinical assessment. However, comparative studies of these two biomarkers are scarce and of limited sample size. The aim of this systematic review with meta-analysis of individual participant data (IPD) was to compare the accuracy of chitotriosidase activity and CCL18 concentration for assessing type I GD severity. We identified cross-sectional and prospective cohort studies by searching Medline, EMBASE, and CENTRAL from 1995 to June 2017, and by contacting research groups. The primary outcome was a composite of liver volume >1.25 multiple of normal (MN), spleen volume >5 MN, hemoglobin concentration <11 g/dL, and platelet count <100x109/L. Overall, IPD included 1109 observations from 334 patients enrolled in nine primary studies, after excluding 111 patients with undocumented values and 18 patients with deficient chitotriosidase activity. IPD were unavailable for 14 eligible primary studies. The primary outcome was associated with a 5.3-fold (95% confidence interval [CI], 4.2 to 6.6) and 3.0-fold (95% CI, 2.6 to 3.6) increase of the geometric mean for chitotriosidase activity and CCL18 concentration, respectively. The corresponding areas under the receiver operating characteristics curves were 0.82 and 0.84 (summary difference, 0.02, 95% CI, -0.02 to 0.05). The addition of chitotriosidase activity did not improve the accuracy of CCL18 concentration. Estimates remained robust in the sensitivity analysis and consistent across subgroups. Neither chitotriosidase activity nor CCL18 concentration varied significantly according to a recent history of bone events among 97 patients. In conclusion, CCL18 concentration is as accurate as chitotriosidase activity in assessing hematological and visceral parameters of GD severity and can be measured in all GD patients. This meta-analysis supports the use of CCL18 rather than chitotriosidase activity for monitoring GD activity in routine practice.

The Use of Patient-Reported Outcome Measures in Rare Diseases and Implications for Health Technology Assessment

Background

Patient-reported outcome measures (PROMs) are used in health technology assessment (HTA) to measure patient experiences with disease and treatment, allowing a deeper understanding of treatment impact beyond clinical endpoints. Developing and administering PROMs for rare diseases poses unique challenges because of small patient populations, disease heterogeneity, lack of natural history knowledge, and short-term studies.

Objective

This research aims to identify key factors to consider when using different types of PROMs in HTA for rare disease treatments (RDTs).

Methods

A scoping review of scientific and grey literature was conducted, with no date or publication type restrictions. Information on the advantages of and the challenges and potential solutions when using different types of PROMs for RDTs, including psychometric properties, was extracted and synthesized.

Results

Of 79 records from PubMed, 32 were included, plus 12 records from the grey literature. PROMs for rare diseases face potential data collection and psychometric challenges resulting from small patient populations and disease heterogeneity. Generic PROMs are comparable across diseases but not sensitive to disease specificities. Disease-specific instruments are sensitive but do not exist for many rare diseases and rarely provide the utility values required by some HTA bodies. Creating new PROMs is time and resource intensive. Potential solutions include pooling data (multi-site/international data collection), using computer-assisted technology, or using generic and disease-specific PROMs in a complementary way.

Conclusions

PROMs are relevant in HTA for RDTs but pose a number of difficulties. A deeper understanding of the potential advantages of and the challenges and potential solutions for each can help manage these difficulties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-020-00493-w.

Patient reported outcome measures in a large cohort of patients with type 1 Gaucher disease

Background

It is now acknowledged that the input of patients in health outcome assessment is vital to understanding the impact of diseases and interventions for those diseases. This study is the first report of patient-reported outcome measures (PROM) in a large cohort of patients with type 1 Gaucher disease (GD1) enabling us to study predictors of the reported outcomes.

Method

The PROM was sent via a mobile phone survey to 405 adult patients with GD1. Demographics, clinical data, and treatment status were extracted from clinic charts. Age, sex, severity score index (SSI) at presentation and treatment status were used as variables to assess outcomes.

Results

A total of 192 patients with GD1 (111 females) responded (47.4% response rate), of whom 124 (64.5%) had received GD1-specific therapy. Around 40% of patients reported that GD had restricted their education/job and fun activities and were concerned about being emotional and financial burdens on others. Concerns regarding the risk of bone disease and Parkinson disease were also high (60%). The severity of GD1 (reflected by the need for GD1-specific therapy and a high SSI) was associated with GD1-related restrictions and concerns, fatigue, physical weakness, bone pain, and worry regarding the future.

Conclusions

The use of GD1 specific PROM highlights personal problems that are not captured by traditional outcome parameters and that need to be addressed to improve health-related quality of life. Validated PROM should be included among the outcome measures in clinical practice and future prospective studies for patients with chronic and rare diseases.

Depression, sleep disturbances, pain, disability and quality of LIFE in Brazilian Fabry disease patients

BACKGROUND

Fabry disease (FD) is a lysosomal disease in which mutations affect the GLA gene located on the X chromosome. The defective product, the enzyme alpha-galactosidase A, causes accumulation of substrate and contributes to the disruption of cell function in several organs, with variable severity and consequent damage of tissue or organ function. Patient reported outcomes (PROs) enable patients to provide information regarding the consequences of their disease and its treatment and are often recognized as the most important outcomes for them.

OBJECTIVES

To evaluate pain, depression, sleep disturbances, disability and disease impact on quality of life in a cohort of Brazilian FD patients and compare between groups stratified by the Mainz Symptom Severity Index (MSSI) Methods: Thirty-seven genotype confirmed classic FD patients - 16 male and 21 female - (mutations: C142R, A156D, L180F, R227X, W262X, G271A, P293S, Y264SX) were evaluated and answered the following questionnaires: Brief Pain Inventory (BPI), Hamilton Depression Rating Scale (HAM-D), Pittsburgh Sleep Quality Index (PSQI), Health Assessment Questionnaire Disability Index (HAQ-DI), Short-Form Health Survey 36 (SF-36).

RESULTS

In FD patients, mean ± SD BPI severity result was 2.78 ± 2.66 for severe; 2.80 ± 2.55 for moderate and 1.55 ± 2.38 for mild severity patients. Mean ± SD BPI interference result was 2.55 ± 2.44 for severe; 2.80 ± 3.18 for moderate and 1.36 ± 2.83 for mild patients. BPI severity and interference values correlated with MSSI scores (r = 0.24; p < .001 / r = 0.25; p < .001). Application of HAM-D indicated depression in 21 patients (56.8%). HAM-D results had positive correlation with MSSI values (r = 0.21; p < .001), with BPI severity (r = 0.54; p < .001) and interference (r = 0.65; p < .001). PSQI depicted sleep disturbances in 22 patients (59.5%). PSQI values correlated with MSSI values (r = 0.25; p < .001), with HAM-D results (r = 0.65; p < .001) and BPI severity (r = 0.47; p < .001) and interference (r = 0.66; p < .001). Mean HAQ-DI result was 0.490 for severe; 0.274 for moderate and 0.157 for mild severity patients.

CONCLUSIONS

Depression, sleep disturbances and disability were under-recognized in FD patients. HAQ-DI revealed worse disability according to MSSI severity status. The lowest raw scores from the SF-36 questionnaire were for the domains general health perception and physical role functioning. Standardized assessments should be routine care and started as early as diagnosis of Fabry disease is made.

Best Practices for Conducting and Interpreting Studies to Validate Self-Report Dietary Assessment Methods

Careful consideration of the validity and reliability of methods intended to assess dietary intake is central to the robustness of nutrition research. A dietary assessment method with high validity is capable of providing useful measurement for a given purpose and context. More specifically, a method with high validity is well grounded in theory; its performance is consistent with that theory; and it is precise, dependable, and accurate within specified performance standards. Assessing the extent to which dietary assessment methods possess these characteristics can be difficult due to the complexity of dietary intake, as well as difficulties capturing true intake. We identified challenges and best practices related to the validation of self-report dietary assessment methods. The term validation is used to encompass various dimensions that must be assessed and considered to determine whether a given method is suitable for a specific purpose. Evidence on the varied concepts of validity and reliability should be interpreted in combination to inform judgments about the suitability of a method for a specified purpose. Self-report methods are the focus because they are used in most studies seeking to measure dietary intake. Biomarkers are important reference measures to validate self-report methods and are also discussed. A checklist is proposed to contribute to strengthening the literature on the validation of dietary assessment methods and ultimately, the nutrition literature more broadly.

Patient and observer reported outcome measures to evaluate health-related quality of life in inherited metabolic diseases: a scoping review

Background

Health-related Quality of Life (HrQoL) is a multidimensional measure, which has gained clinical and social relevance. Implementation of a patient-centred approach to both clinical research and care settings, has increased the recognition of patient and/or observer reported outcome measures (PROMs or ObsROMs) as informative and reliable tools for HrQoL assessment. Inherited Metabolic Diseases (IMDs) are a group of heterogeneous conditions with phenotypes ranging from mild to severe and mostly lacking effective therapies. Consequently, HrQoL evaluation is particularly relevant.

Objectives

We aimed to: (1) identify patient and/or caregiver-reported HrQoL instruments used among IMDs; (2) identify the main results of the application of each HrQoL tool and (3) evaluate the main limitations of HrQoL instruments and study design/methodology in IMDs.

Methods

A scoping review was conducted using methods outlined by Arksey and O’Malley. Additionally, we critically analysed each article to identify the HrQoL study drawbacks.

Results

Of the 1954 studies identified, 131 addressed HrQoL of IMDs patients using PROMs and/or ObsROMs, both in observational or interventional studies. In total, we identified 32 HrQoL instruments destined to self- or proxy-completion; only 2% were disease-specific. Multiple tools (both generic and disease-specific) proved to be responsive to changes in HrQoL; the SF-36 and PedsQL questionnaires were the most frequently used in the adult and pediatric populations, respectively. Furthermore, proxy data often demonstrated to be a reliable approach complementing self-reported HrQoL scores. Nevertheless, numerous limitations were identified especially due to the rarity of these conditions.

Conclusions

HrQoL is still not frequently assessed in IMDs. However, our results show successful examples of the use of patient-reported HrQoL instruments in this field. The importance of HrQoL measurement for clinical research and therapy development, incites to further research in HrQoL PROMs’ and ObsROMs’ creation and validation in IMDs.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0953-9) contains supplementary material, which is available to authorized users.

Piloting and psychometric properties of a patient-reported outcome instrument for young people with achondroplasia based on the International Classification of Functioning Disability and Health: the Achondroplasia Personal Life Experience Scale (APLES)

Background: This study describes the psychometric testing of the Achondroplasia Personal Life Experience Scale (APLES): a new disease- and functioning-specific health-related quality of life instrument for young people with achondroplasia, which was developed based on the International Classification of Functioning-Children and Youth Version. Method: The qualitative analysis of focus group statements from German patients and parents using the International Classification of Functioning-Children and Youth Version yielded 59 items, which after cognitive debriefing were included in a pilot-test. Psychometric performance was cross-culturally examined in a field- and re-test in Germany and Spain. Results: Cognitive debriefing and pilot-test results suggested to reduce the 59-APLES version to a 35-items version. Field-test data showed acceptable reliability and validity, which further improved after the APLES was shortened to 21 items. Conclusion: Developing a disease-specific instrument within the framework of the International Classification of Functioning allows the universal assessment and comparison of perceived health. Psychometric analysis showed that the APLES fulfills psychometric quality standards and provides a way to assess health-related quality of life from self- and observer report in young persons with achondroplasia. Further studies may use the instrument in clinical research and practice to understand perceived burden and to optimize care. Implications for Rehabilitation Health-related quality of life instruments are useful tools to include in clinical research and/or practice to evaluate treatment effects directly from the patient's perspective. Cross-culturally developed health-related quality of life measures that are based on the International Classification of Functioning Disability and Health provide the opportunity to assess the health status in a standardized language and to compare it across countries and health professions. All four components of the International Classification of Functioning Disability and Health - Child and Youth Version ("Body Functions & Structures", "Activities and Participation", "Environmental Factors", and "Personal Factors") have been shown to be relevant in assessing health-related quality of life and functioning in young achondroplasia patients. Results underline the important aspects associated with disproportionate short stature, emphasizing the benefits of a disease-specific instrument.

Children with type 1 Gaucher disease: Changing profiles in the 21st century

Gaucher disease (GD) has phenotypic variability. Increased GD awareness especially among at-risk Ashkenazi Jews (AJ) and availability of non-invasive diagnosis induced trend to prenatal screening. We retrospectively assessed pediatric (<16years) Israeli AJ GD patients to ascertain demographics and phenotype at presentation and over-time because many were identified by large-scale screening. 55/67 patients born since 01/01/2000 are AJ with non-neuronopathic GD: 28 (50.9%) are N370S/N370S; 24 (43.6%) are N370S/other; 3 (3.5%) have no N370S allele. 30 (54.5%) diagnosed by screening; 10 (18.2%) with sibling diagnosed by screening. Of 19 (34.5%) receiving enzyme replacement therapy (ERT), 4/19 (21.1%) were by screening (N370S/N370S; N370S/L444P, N370S/84GG, N370S/IVS2+1); 15/19 (78.9%) diagnosed by symptoms and/or symptomatic sibling. 4/19 (21.1%) began ERT at age <2years; 9/19 (47.4%) at 3-5years; 6/19 (31.6%) at 6-12years. 49% presented with height/weight growth percentiles ≤25%, but group means were comparable up to 12years follow-up including 10 receiving ERT (8 for >5years). 22% presented with anemia, 20% with thrombocytopenia; at last follow-up 4% and 6%, respectively, remained cytopenic. We present a new demographic profile for pediatric GD because many identified by screening had/have few GD signs/symptoms. Nonetheless, early diagnosis is important, especially for non-N370S, non-mild genotypes.

PATIENT-REPORTED OUTCOMES IN RARE LYSOSOMAL STORAGE DISEASES: KEY INFORMANT INTERVIEWS AND A SYSTEMATIC REVIEW PROTOCOL

OBJECTIVES

To investigate the use, challenges and opportunities associated with using patient-reported outcomes (PROs) in studies with patients with rare lysosomal storage diseases (LSDs), we conducted interviews with researchers and health technology assessment (HTA) experts, and developed the methods for a systematic review of the literature. The purpose of the review is to identify the psychometrically sound generic and disease-specific PROs used in studies with patients with five LSDs of interest: Fabry, Gaucher (Type I), Niemann-Pick (Type B) and Pompe diseases, and mucopolysaccharidosis (Types I and II).

METHODS

Researchers and HTA experts who responded to an email invitation participated in a telephone interview. We used qualitative content analysis to analyze the anonymized transcripts. We conducted a comprehensive literature search for studies that used PROs to investigate burden of disease or to assess the impact of interventions across the five LSDs of interest.

RESULTS

Interviews with seven researchers and six HTA experts representing eight countries revealed five themes. These were: (i) the importance of using psychometrically sound PROs in studies with rare diseases, (ii) the paucity of disease-specific PROs, (iii) the importance of having PRO data for economic analyses, (iv) practical and psychometric limitations of existing PROs, and (v) suggestions for new PROs. The systematic review has been completed.

CONCLUSIONS

The interviews highlight current challenges and opportunities experienced by researchers and HTA experts involved in work with rare LSDs. The ongoing systematic review will highlight the experience, opportunities, and limitations of PROs in LSDs and provide suggestions for future research.