Prenusinersen economic and health-related quality of life burden of spinal muscular atrophy

Healthcare resource utilisation and direct medical cost for individuals with 5q spinal muscular atrophy in Sweden

BACKGROUND

Spinal muscular atrophy (SMA) is a rare, progressive, neuromuscular disorder. Recent advances in treatment require an updated assessment of burden to inform reimbursement decisions.

OBJECTIVES

To quantify healthcare resource utilisation (HCRU) and cost of care for patients with SMA.

METHODS

Cohort study of patients with SMA identified in the Swedish National Patient Registry (2007-2018), matched to a reference cohort grouped into four SMA types (1, 2, 3, unspecified adult onset [UAO]). HCRU included inpatient admissions, outpatient visits, procedures, and dispensed medications. Direct medical costs were estimated by multiplying HCRU by respective unit costs. Average annual HCRU and medical costs were modelled for SMA versus reference cohorts to estimate differences attributable to the disease (i.e., average treatment effect estimand). The trajectory of direct costs over time were assessed using synthetic cohorts.

RESULTS

We identified 290 SMA patients. Annualised HCRU was higher in SMA patients compared with reference cohorts. Highest risk ratios were observed for inpatient overnight stays for type 1 (risk ratio [RR]: 29.2; 95% confidence interval [CI]: 16.0, 53.5) and type 2 (RR: 23.3; 95% CI: 16.4,33.1). Mean annual direct medical costs per patient for each year since first diagnosis were greatest for type 1 (€114,185 and SMA-attributable: €113,380), type 2 (€61,876 and SMA-attributable: €61,237), type 3 (€45,518 and SMA-attributable: €44,556), and UAO (€4046 and SMA-attributable: €2098). Costs were greatest in the 2-3 years after the first diagnosis for all types.

DISCUSSION AND CONCLUSION

The economic burden attributable to SMA is significant. Further research is needed to understand the burden in other European countries and the impact of new treatments.

Methods used to account for caregivers' sex and gender within studies examining the financial burden of caregivers of children and adolescents : Results from a scoping review

Background

Interest in the financial burden of informal caregivers has been growing. Unfortunately, it remains unclear which method(s) should be used when quantifying this burden.

Purpose

We conducted a scoping review aimed at identifying which methods have been used to conduct such work and quantified their performance. We were also interested in examining how sex and gender considerations were considered within selected studies.

Data Sources

Using a standardized approach, we identified studies published between 2012 and 2022 that aimed to document the financial burden of caregivers to child and adolescent patients. Our search strategy was applied to the MEDLINE, Embase, CINHAL, and Academic Search Premier databases.

Study Selection

Manuscript selection was performed by pairs of reviewers.

Data Extraction

Data extraction was performed by one reviewer with a second reviewer performing quality control. Results were reported using a narrative approach.

Data Synthesis

We identified 9801 unique citations, of which 200 were included in our review. Selected studies covered various disease area (eg, infection/parasitic diseases [n = 31, 16%]) and included quantitative (n = 180, 90%), qualitative (n = 4, 2%) and mixed study designs (n = 16, 8%). Most studies (n = 182, 91%) used questionnaires/surveys, either alone or in combination with other methods, to assess caregivers' financial burden. Less than half (n = 93, 47%) of studies reported on caregivers' sex and none reported on their gender.

Conclusion

We conducted an unrestricted review of published studies examining caregiver's financial burden which allowed us to identify general methodological trends observed in this literature. We believe this work may help improve future studies focusing on this important issue.

Self-Reported Health-Related Quality of Life of Children with Spinal Muscular Atrophy: Preliminary Insights from a Nationwide Patient Registry in Germany

BACKGROUND

Spinal muscular atrophy (SMA) is a rare, severely debilitating neuromuscular disease characterized by a wide spectrum of progressive muscular atrophy and weakness.

OBJECTIVES

The objective of this pilot study was to estimate self-assessed health-related quality of life (HRQoL) of children with SMA.

METHODS

Children with SMA were recruited via the German national TREAT-NMD SMA patient registry and asked to self-complete the following rating-scales: KIDSCREEN-27, KINDL, the PedsQL 3.0 Neuromuscular Module (PedsQL 3.0 NMM), EQ-5D-5L, and the Health Utilities Index (HUI). Estimates were stratified by current best motor function of the lower limb and trunk (i.e., non-sitter, sitter, and walker) and SMA type (i.e., type I, II, and III).

RESULTS

In total, 17 children with SMA (mean age: 9.88 years, SD: 4.33 years, range: 5-16 years; 59% female) participated in the study. Across examined strata, the mean KIDSCREEN-27 total score was estimated at between 48.24 and 83.81; the mean KINDL total score at between 60.42 and 76.73; the mean PedsQL 3.0 NMM total score at between 58.00 and 83.83; the mean EQ-5D-5L utility at between 0.31 and 0.99; and the mean HUI-derived utility at between -0.02 and 0.96.

CONCLUSIONS

The results from this pilot study show that German children with SMA, despite significant physical disability, have surprisingly good HRQoL as assessed using KIDSCREEN-27. Yet, many reside in health states associated with low utility. The disease burden was generally higher among non-sitters compared with walkers, and SMA type I compared with type III, but more research is needed to further delineate this variability. Our preliminary findings contribute to the understanding of HRQoL in pediatric patients with SMA and should be helpful to inform the design of future studies of this patient population.

Are We Capturing the Socioeconomic Burden of Rare Genetic Disease? A Scoping Review of Economic Evaluations and Cost-of-Illness Studies

BACKGROUND AND OBJECTIVES

Rare diseases have a significant impact on patients, families, the health system, and society. Measuring the socioeconomic burden is crucial to valuing interventions for rare diseases. Healthcare system costs are significant, but so are costs to other government sectors, patients, families, and society. To understand the breadth of costs captured in rare disease studies, we examined the cost categories and elements of socioeconomic burden captured in published studies.

METHODS

A scoping review was conducted using five electronic databases to identify English language economic evaluations and cost-of-illness studies of interventions for rare diseases (2011-21). We mapped costs using a previously developed evidence-informed framework of socioeconomic burden costs for rare disease.

RESULTS

Of 4890 studies identified, 48 economic evaluations and 22 cost-of-illness studies were included. While 18/22 cost-of-illness studies utilized a societal perspective, only 7/48 economic evaluations incorporated societal costs. Most reported cost categories related to medical costs, with medication and hospitalizations being the most common elements for both study designs. Costs borne by patients, families, and society were reported less among economic evaluations than cost-of-illness studies. These included: productivity (10% vs 77%), travel/accommodation (6% vs 68%), government benefits (4% vs 18%), and family impacts (0% vs 50%).

CONCLUSIONS

Contrary to cost-of-illness analyses, most of the included economic evaluations did not account for the hidden burden of rare diseases, that is, costs borne by patients, families, and societies. Including these types of costs in future studies would provide a more comprehensive picture of the burden of disease, providing empirical data to inform how we value and make decisions regarding rare disease interventions, health policy, and resource allocation.

Patient and Caregiver Outcomes After Onasemnogene Abeparvovec Treatment: Findings from the Cure SMA 2021 Membership Survey

INTRODUCTION

Onasemnogene abeparvovec (OA) is the only gene replacement therapy currently approved for spinal muscular atrophy (SMA) treatment. We sought to assess real-world patient and caregiver outcomes after OA treatment for SMA.

METHODS

Patients who received OA were identified from the 2021 Cure SMA Membership Survey. Those treated at 6-23 months of age were matched to non-patients treated with OA on the basis of age at the time of survey and survival motor neuron 2 gene copy number. Patient characteristics, motor milestones, and resource and supportive care use, as well as caregiver proxy-reported health-related quality of life (HRQOL), were described. Caregiver unmet needs and HRQOL were also assessed.

RESULTS

Of the 614 patients in the survey, 64 received OA, and 17 were matched with 28 non-OA-treated patients. In general, a greater percentage of OA-treated patients achieved various motor milestones, including 100% sitting without support and 58.8% walking with assistance. OA-treated patients also had numerically lower rates of hospitalization and surgery. None required tracheostomy with a ventilator. The rate of using oxygen or a breathing machine for more than 16 h was also lower for OA-treated patients. OA-treated patients had less frequent trouble swallowing. HRQOL was reported to be similar to non-OA-treated patients. Caregivers of OA-treated patients reported better patient mobility scores and less work impairment.

CONCLUSIONS

The study suggests that treatment with OA is associated with greater rates of motor milestone achievements and less resource and supportive care use for patients with SMA treated at 6-23 months of age in the real world. For caregivers, it may also potentially reduce unmet needs, improve HRQOL, and reduce work impairment.

EQ-5D and SF-6D health utility scores in patients with spinal and bulbar muscular atrophy

OBJECTIVE

This study assessed patient-reported health-related quality of life (HRQoL) using two generic preference-based measures in Chinese patients with spinal and bulbar muscular atrophy (SBMA) and identified demographic and clinical determinants of health utility scores in this population.

METHODS

This study used cross-sectional data of 212 Chinese patients with SBMA who completed both the EQ-5D and SF-6D. Association between response to EQ-5D and SF-6D dimensions was examined using Spearman's correlation coefficient, and the association between the two utility scores was assessed using Pearson's correlation coefficient. The variations in utility scores across patients in different subgroups were compared using one-way ANOVA. Bland-Altman (B-A) plot was used to assess the agreement of utility scores between EQ-5D and SF-6D. A multivariate Tobit regression model was employed to estimate the association between utility scores and the presence of symptoms and chronic conditions.

RESULTS

The mean utility scores for the EQ-5D and SF-6D were 0.54 and 0.56, respectively. The hypothesized correlation between the EQ-5D and SF-6D dimensions ranged from 0.31 to 0.58, and the correlation between their utility scores was 0.64. An acceptable agreement between EQ-5D and SF-6D utility scores was identified by B-A plot. Patients with chronic diseases, misdiagnosis, high financial burden, and several clinical symptoms were highly likely to report a low health utility score.

CONCLUSIONS

This study is the first to investigate the HRQoL of patients with SBMA worldwide. The estimated health utility scores for EQ-5D and SF-6D can be utilized as baseline data for future cost-utility analyses of SBMA-related interventions.

Significant healthcare burden and life cost of spinal muscular atrophy: real-world data

OBJECTIVES

The aim of this study is to quantify the mortality rate, direct healthcare costs, and cumulative life costs of pediatric patients with spinal muscular atrophy (SMA) type 1, type 2, and type 3 born in Hong Kong.

METHODS

Data were collected from genetically confirmed SMA patients born in or after 2000 from the Hospital Authority medical database. Patients were followed up from birth until they died, left Hong Kong, reached 18 years, or initiated disease-modifying treatment. Study outcomes included incidence risks of mortality, cumulative direct medical costs-attendances of special outpatient clinics, emergency department, allied health services, and mean length of stay in hospitals over time. Total direct medical costs were calculated as unit costs multiplied by utilization frequencies of corresponding healthcare services at each age.

RESULTS

Seventy-one patients with SMA were included. Over a median follow-up period of 6 years, the overall incidence rate of death was 5.422/100 person-years (95%CI 3.542-7.945/100 person-years). 67.7% and 11% of deaths occurred in SMA1 and SMA2 groups, respectively. The median age of death was 0.8 years in SMA1 and 10.9 years in SMA2. The mean cumulative direct medical costs in overall SMA, SMA1, SMA2 and SMA3 groups per patient were US$935,570, US$2,393,250, US$413,165, and US$40,735, respectively.

INTERPRETATION

Our results confirmed a significantly raised mortality and extremely high healthcare burden for patients with SMA especially SMA type 1 and 2 without disease-modifying treatment. Study evaluating health and economic impact of newborn screening and early treatment is needed.

Impact of nusinersen on the health-related quality of life and caregiver burden of patients with spinal muscular atrophy with symptom onset after age 6 months

INTRODUCTION/AIMS

Novel disease-modifying approaches for spinal muscular atrophy (SMA) have highlighted the patient's perspective on functional changes over time. In this study, we evaluated the impact of nusinersen on the health-related quality of life (HRQoL) of patients with later-onset SMA and the caregiver burden.

METHODS

We assessed the changes in HRQoL using the Pediatric Quality of Life Inventory 4.0 Generic Core Scale (PedsQL GCS) and the Pediatric Quality of Life Inventory 3.0 Neuromuscular Module (PedsQL NMM) during 26 months of treatment. Caregiver burden was assessed using the Assessment of Caregiver Experience with Neuromuscular Disease. We also assessed motor function using the Hammersmith Functional Motor Scale-Expanded (HFMSE) and the Revised Upper Limb Module score.

RESULTS

Twenty-four patients and their caregivers were included. The median age of patients at treatment onset was 148.8 (6.8 to 269.4) months. A significant improvement was observed in psychosocial health in proxy-reported PedsQL (P = .023). However, the physical health scores of the PedsQL GCS and About my neuromuscular disorder subscores of the PedsQL NMM did not change, although there was a significant increase in HFMSE scores. Regarding the caregiver burden, the financial burden was reduced, whereas time burden increased. A higher HFMSE score was associated with better self-reported PedsQL GCS total scores (P < .001).

DISCUSSION

Our results provide insights into the multifaceted implications of disease-modifying therapies for SMA through patient-reported outcome measures (PROMs). PROMs should be taken into consideration to assess the clinical significance of the functional changes identified by clinician-reported scales.

The estimation of health state utility values in rare diseases: do the approaches in submissions for NICE technology appraisals reflect the existing literature? A scoping review

BACKGROUND

Rare diseases negatively impact patients' quality of life, but the estimation of health state utility values (HSUVs) in research studies and cost-utility models for health technology assessment is challenging.

OBJECTIVES

This study compared the methods for estimating the HSUVs included in manufacturers' submissions of orphan drugs to the National Institute for Health and Care Excellence (NICE) with those of published studies addressing the same rare diseases to understand whether manufacturers fully exploited the existing literature in developing their economic models.

METHODS

All NICE Technology Appraisal (TA) and Highly Specialized Technologies (HST) guidance documents of non-cancer European Medicines Agency (EMA) orphan medicinal products were reviewed and compared with any published primary studies, retrieved via PubMed until November 2020, and estimating HSUVs for the same conditions addressed in manufacturers' submissions.

RESULTS

We identified 22 NICE TA/HST appraisal reports addressing 19 different rare diseases. Sixteen reports presented original HSUVs estimated using EQ-5D or Health Utility Index (n = 12), direct methods (n = 2) or mapping (n = 2), while the other six included values obtained from the literature only. In parallel, we identified 111 published studies: 86.6% used preference-based measures (mainly EQ-5D, 60.7%), 12.5% direct techniques, and 2.7% mapping. The collection of values from non-patient populations (using 'vignettes') was more frequent in manufacturers' submissions than in the literature (22.7% vs. 8.0%).

CONCLUSIONS

The agreement on methodological choices between manufacturers' submissions and published literature was only partial. More efforts should be made by manufacturers to accurately reflect the academic literature and its methodological recommendations in orphan drugs submissions.

Caregiver Burden of Spinal Muscular Atrophy: A Systematic Review

OBJECTIVE

The objective of our study was to review, synthesize, and grade published evidence of caregiver burden of spinal muscular atrophy (SMA), a rare autosomal-recessive neuromuscular disease.

METHODS

We searched Embase and PubMed for full-text articles published from inception up until 28 February, 2022, reporting results from studies of caregiver burden (i.e., negative aspects of providing informal care) in SMA. Two investigators independently screened article titles and abstracts for eligibility, reviewed full-text versions of selected records, extracted the data, and assessed risk of bias using the Newcastle-Ottawa Scale. The evidence was synthesized to answer the following questions: (1) In which geographical settings have the caregiver burden of SMA been studied? (2) What aspects of the caregiver burden of SMA have been investigated? (3) What instruments have been used to measure the caregiver burden of SMA? (4) What is known of the caregiver burden of SMA? (5) How is the caregiver burden of SMA impacted by available disease-modifying drugs?

RESULTS

We identified 15 publications, covering samples from a total of ten countries (i.e., Australia, Canada, China, France, Germany, Romania, Spain, Turkey, the UK, and the USA), reporting estimates of caregiver burden derived using data recorded via surveys or interviews. The most common instruments used to measure caregiver burden were the Zarit Caregiver Burden Interview, the EQ-5D-5L, and the PedsQL Family Impact Model. Caregiving in SMA was found to be associated with reduced health-related quality of life, impaired family function, depression and anxiety, strain, and stress, as well as a substantial impact on work life and productivity. Evidence of the impact of disease-modifying drugs on caregiver burden in SMA was scarce.

CONCLUSIONS

Caregivers to patients with SMA were found to be subject to a significant burden, including impaired health-related quality of life, reduced work ability and productivity, and financial stress, and many devote a substantial proportion of their time to provide informal care. Yet, the current body of literature is relatively scarce and more research is needed to better understand the clinical implications of informal caregiving in SMA and the relationship between caregiver burden and SMA types, as well as the impact of new disease-modifying treatments. Our synthesis will be helpful in informing clinical and social support programs (e.g., the routine screening of depression among caregivers, as well as financial support schemes to help manage the long-term day-to-day care) directed towards families caring for patients with SMA.

Multidisciplinary perspectives and practices of wheelchair prescription for children with neuromuscular conditions

PURPOSE

Clinical practice guidelines for paediatric neuromuscular disorders (NMDs) recommend timely provision of wheelchair equipment. The aim of this qualitative study was to understand healthcare professionals' clinical perspectives and practices when recommending wheelchair equipment for the first time, as well as perceived barriers and enablers to timely wheelchair provision.

METHODS

Twenty-one healthcare professionals (HCPs) from Australia and the United States participated in an interview (response rate: 88%, 16/21 women). Participants were from diverse disciplines, based in hospital or community health settings, and had at least one year of experience working in paediatric neuromuscular care.

RESULTS

Child fatigue, falls and engagement in age-appropriate activity were common reasons for HCP's wheelchair recommendation. HCPs were acutely aware of parents' experiences of grief and loss throughout the wheelchair prescription process, and over half acknowledged the lack of psychological care available to families affected by NMDs. Multi-disciplinary collaboration, psychologically-informed care, and shared decision-making with stakeholders were perceived enablers of wheelchair transition. Barriers included limited access to equipment, lengthy funding processes and lack of funding for home and vehicle modifications.

CONCLUSIONS

Integrated psychosocial care is needed to support families throughout their child's disease progression, including wheelchair transition. Implementation of readiness for change tools, and development of tailored informational resources is recommended. Improved access to equipment options and trials, and more efficient funding processes are highly likely to improve parental engagement throughout the wheelchair prescription process.Implications for rehabilitationHealthcare professionals express a strong demand for integrated psychosocial care within paediatric neuromuscular clinics to support families throughout transitions, including wheelchair introduction.Identifying parents' readiness for change can inform their information and support needs, strengthen their decision-making capacity and facilitate timely wheelchair introduction.Stronger collaboration between hospital- and community-based health professionals working in paediatric neuromuscular care is recommended to facilitate knowledge exchange and support families' transition to wheelchair use.Access to equipment options for extended loan or trial in the community can support timely wheelchair introduction.

Health-Related Quality of Life in Spinal Muscular Atrophy Patients and Their Caregivers-A Prospective, Cross-Sectional, Multi-Center Analysis

Spinal muscular atrophy (SMA) is a disabling disease that affects not only the patient’s health-related quality of life (HRQoL), but also causes a high caregiver burden (CGB). The aim of this study was to evaluate HRQoL, CGB, and their predictors in SMA. In two prospective, cross-sectional, and multi-center studies, SMA patients (n = 39) and SMA patient/caregiver couples (n = 49) filled in the EuroQoL Five Dimension Five Level Scale (EQ-5D-5L) and the Short Form Health Survey 36 (SF-36). Caregivers (CGs) additionally answered the Zarit Burden Interview (ZBI) and the Hospital Anxiety and Depression Scale (HADS). Patients were clustered into two groups with either low or high HRQoL (EQ-5D-5L index value <0.259 or >0.679). The latter group was mostly composed of ambulatory type III patients with higher motor/functional scores. More severely affected patients reported low physical functioning but good mental health and vitality. The CGB (mean ZBI = 22/88) correlated negatively with patients’ motor/functional scores and age. Higher CGB was associated with a lower HRQoL, higher depression and anxiety, and more health impairments of the CGs. We conclude that patient and CG well-being levels interact closely, which highlights the need to consider the health of both parties while evaluating novel treatments.

Utility estimations of different health states of patients with type I, II, and III spinal muscular atrophy in China: A mixed approach study with patient and proxy-reported data

Introduction

Spinal muscular atrophy (SMA) is a rare autosomal-recessive neuromuscular disease. Health state utility values (HSUV) are used in health economic evaluation regarding the desirability of health outcomes such as a certain health state or change in health states over time. There is no utility data of Chinese patients with SMA.

Materials and methods

Vignettes were developed for 10 pediatric neurologists to value the utility of Chinese patients with Type I SMA. A mixed patient/proxy derived approach using EQ-5D-Y-3L, EQ-5D-3L, and CHU9D was adopted to estimate the HSUV data of patients with Type II and III SMA, including 112 patients and 301 caregivers.

Result

The utility of Type I SMA patients ranged from 0.19 to 0.72 with the health state improved from "permanent ventilation" to "walking". The utility of children patients with Type II and III SMA derived from EQ-5D-Y-3L ranged from 0.33 to 0.82 while that derived from CHU9D ranged from 0.46 to 0.75. The utility of adult patients with Type II and III SMA measured by EQ-5D-3L ranged from 0.30 to 0.83.

Conclusion

The better health states the patients with SMA were in, the higher were the HSUV. The utilities derived from population with different age and disease subtypes were not statistically different when patients with SMA were in the same health states. We recommend further studies on the Chinese specific value set for EQ-5D-Y-3L and other PBMs for children to derive more robust utility data.

Assessment of health-related quality of life in patients with spina muscular atrophy in China

Spinal muscular atrophy (SMA) is a rare disease that has attracted considerable interest in China due to its severity and hefty treatment costs. Few studies have been conducted on Chinese patients. The objective of this study was to assess the quality of life of SMA patients in China and to investigate the real impact of new treatments. We used the Pediatric Quality of Life Inventory (PedsQL) to analyze the Health-related quality of life (HRQoL) of patients with SMA in China. Information on demographics, disease-specific characteristics, and treatment were collected using a child-reported or proxy-reported questionnaire. The mean scores of HRQoL for the Nusinersen treatment group and conventional treatment groups are 55.6 and 48.4, respectively. Patients with SMA type I have the lowest scores, while those with type III have the highest scores. A higher proportion of the medication group showed improvement in the condition in the past six months (56.9% vs. 17.1%). Our results show that the clinical type, motor function and treatment strategy have a significant influence on HRQoL. The findings imply that Nusinersen benefits patients by slowing the progression of the disease and increasing their quality of life in the real world.

Cost-effectiveness analysis of gene-based therapies for patients with spinal muscular atrophy type I in Australia

Introduction

Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder and regarded as one of the most frequent genetic causes of infant mortality. The aim of this study is to develop a cost-effectiveness analysis of AVXS-101 (Onasemnogene Abeparvovec/Zolgensma^®) and nusinersen (Spinraza^®) for SMA to inform decision-making on reimbursement policies in Australia.

Methods

A Markov model was developed with five health states to evaluate the costs and effects for patients with SMA Type I from a healthcare system perspective over a time-horizon of 100 years. The model parameters were based on clinical trials, parametric distributions, published literature, and Australian registries. One-way and probabilistic sensitivity analysis were performed to appraise the uncertainties of the parameters in the model. A threshold analysis was conducted to estimate the cost of AVXS-101 of being cost-effective.

Results

The incremental cost-effectiveness ratio (ICER) of AVXS-101 was $1,808,471 per quality-adjusted life year (QALY) and that of nusinersen was $2,772,798 per QALY, compared to standard of care, respectively. The ICER of AVXS-101 was $1,238,288 per QALY compared to nusinersen. The key drivers influencing on ICERs were costs of using treatments and utility values of sitting and walking independently.

Conclusion

Both nusinersen and AVXS-101 resulted in health benefits, but they were not cost-effective with a commonly used willingness-to-pay (WTP) threshold of $50,000 per QALY. Developing high-quality clinical data and exploring appropriate WTP thresholds are critical for decision-making on reimbursement policies in the treatment of rare diseases.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-11319-0.

Modelling the Cost-Effectiveness and Budget Impact of a Newborn Screening Program for Spinal Muscular Atrophy and Severe Combined Immunodeficiency

Spinal muscular atrophy (SMA) and severe combined immunodeficiency (SCID) are rare, inherited genetic disorders with severe mortality and morbidity. The benefits of early diagnosis and initiation of treatment are now increasingly recognized, with the most benefits in patients treated prior to symptom onset. The aim of the economic evaluation was to investigate the costs and outcomes associated with the introduction of universal newborn screening (NBS) for SCID and SMA, by generating measures of cost-effectiveness and budget impact. A stepwise approach to the cost-effectiveness analyses by decision analytical models nested with Markov simulations for SMA and SCID were conducted from the government perspective. Over a 60-year time horizon, screening every newborn in the population and treating diagnosed SCID by early hematopoietic stem cell transplantation and SMA by gene therapy, would result in 95 QALYs gained per 100,000 newborns, and result in cost savings of USD 8.6 million. Sensitivity analysis indicates 97% of simulated results are considered cost-effective against commonly used willingness-to-pay thresholds. The introduction of combined NBS for SCID and SMA is good value for money from the long-term clinical and economic perspectives, representing a cost saving to governments in the long-term, as well as improving and saving lives.

Parents as informal caregivers of children and adolescents with spinal muscular atrophy: a systematic review of quantitative and qualitative data on the psychosocial situation, caregiver burden, and family needs

BACKGROUND

Spinal muscular atrophy (SMA) is a rare degenerative neuromuscular disease, mostly occurring in infants and children, leading to muscle wasting and weakness, and premature death. Due to new developments of multiple disease-modifying treatments within the last years, the interest of research in patients affected by SMA increased steadily. However, the psychosocial situation of parents as informal caregivers is still rarely addressed.

OBJECTIVES

This review aims to highlight quantitative and qualitative data about the psychosocial situation, caregiver burden, and needs of parents as informal caregivers for children and adolescents with SMA.

METHODS

A systematic literature review was performed including quantitative and qualitative original studies focusing on different psychosocial aspects and outcomes for parents of children and adolescents < 21 years of age with SMA type I-IV (PROSPERO; registration number CRD42020219020). We searched the following databases in November 2020 with a research update in August 2021: MEDLINE, CINAHL, PsycINFO and Web of Science.

RESULTS

In total, 24 articles from 23 studies were selected for inclusion (15 quantitative studies, 7 articles from 6 qualitative studies, 2 mixed methods studies). The synthesis of included studies shows multiple sources of psychosocial burden for parents of children and adolescents affected by SMA: Most studies found reduced levels of quality of life, moderate to high levels of caregiver burden and distress, as well as physical and mental health symptoms. Further, findings indicate several unmet family needs regarding information, care coordination, treatment decisions, financial support, and adequate supportive care services.

CONCLUSION

Parents of children and adolescents with SMA face multiple sources of psychosocial stressors, caregiver burden and various unmet family needs. To unburden families, the needs of parents as caregivers should be included in integrated care paths for SMA to improve their psychosocial situation and thus their ability to care for their children and to treat or prevent physical and mental health problems due to overburdening. Future research should focus not only on quality of life and on caregiving-related burden but should also examine the clinical relevance of reported symptoms to support the implementation of adequate support services for families affected by SMA.

Systematic Literature Review of Clinical and Economic Evidence for Spinal Muscular Atrophy

INTRODUCTION

The recent advent of disease-modifying therapies (DMTs) has dramatically changed the treatment landscape of spinal muscular atrophy (SMA), and the multifaceted impact of this advancement has not been assessed thoroughly in the growing body of literature. We sought to summarize the literature on the natural history of SMA and the impact of SMA DMTs, including health-related quality of life (HRQOL) and utilities, clinical efficacy and safety, and economic impact.

METHODS

Systematic literature reviews were conducted following PRISMA guidelines with no inclusive dates. Relevant studies were identified by searching full-text databases on November 12-13, 2020, including MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and EconLit, conference proceedings, health technology assessment databases, and clinical trial registries. All searches used a combination of MeSH and key terms. Studies were screened according to criteria based upon population, intervention, outcomes, and study design structure.

RESULTS

Findings from 17, 23, 32, and 42 studies were included for the evaluation of natural history of SMA, HRQOL and utilities, clinical efficacy and safety, and economic impact of DMTs, respectively. Currently available data indicate that untreated SMA is associated with considerable humanistic and economic burden, with estimates of costs varying by treatment. While a variety of interventions have been evaluated in SMA clinical trials, quantitative synthesis of safety and efficacy findings was not feasible because of inconsistencies in reported outcomes. Data assessing impacts of DMTs on HRQOL were also lacking.

CONCLUSIONS

Overall, this systematic literature review highlights a clear need for up-to-date and methodologically rigorous clinical, HRQOL, and economic data to support unbiased assessments of the relative clinical and economic effectiveness of SMA treatments. More research is required to extend our understanding of the burden of SMA on HRQOL utility assessments and the impact of new DMTs on HRQOL and utilities for patients with SMA.

Systematic Literature Review to Assess the Cost and Resource Use Associated with Spinal Muscular Atrophy Management

BACKGROUND

Spinal muscular atrophy (SMA) is a severe neuromuscular disease that is inherited in an autosomal recessive manner with an estimated incidence of 1 in 10,000 live births. The traditional classification of SMA includes five types (Types 0-4 SMA) based on patient age at disease onset and the highest motor milestone achieved. Spinal muscular atrophy leads to progressive muscle denervation, skeletal muscle atrophy and loss of motor function and ambulation, though phenotypes vary along a disease continuum. Regardless of disease severity, or access to treatment, a multidisciplinary approach to care is required to ease the burden of disease. To date, limited global data exist regarding the cost and resource use associated with SMA management.

OBJECTIVE

We planned to perform a systematic literature review to identify studies on cost and healthcare resource use associated with SMA.

METHODS

A comprehensive search was conducted in 2019 using several electronic databases in addition to supplementary sources and updated in 2021 in order to capture recently published studies. Electronic searches performed in Embase, MEDLINE, Evidence-Based Medicine Reviews and EconLit via the Ovid platform were supplemented by searches of the grey literature (reference lists, conference proceedings, global Health Technology Assessment body websites and other relevant sources). Study eligibility criteria were based on the population, interventions, comparators and outcomes (PICO) framework. Quality assessment of full-text publications was evaluated with reference to a published checklist. To accommodate heterogeneity across studies including countries, currencies, populations, time units and methods of reporting used, costs were reported in Euros in 2019.

RESULTS

A total of 51 publications, comprising 49 unique studies of patients with SMA that met all eligibility criteria were included in the final selection. The publications comprised data from 14 countries and seven additional studies that reported multi-national data. Because of the heterogeneity between the different types of SMA, data were frequently reported separately for individuals with Type 1 or early-onset SMA and for Types 2, 3, and 4 SMA or later-onset SMA. Generally, direct medical costs and resource use were reported to be highest for patients with Type 1 SMA, decreasing incrementally for patients with Type 2 and Type 3 disease. Where cost categories were similar, direct costs were much lower in Europe than in the USA. Indirect costs were primarily associated with informal care, which was a substantial burden on patients and families in terms of both cost and time. Cost drivers were generally found to be dependent on SMA type.

CONCLUSIONS

Long-term robust studies are required to fully elucidate the economic burden of SMA. Considering that motor function can vary broadly, especially in Type 2 SMA, it would be beneficial to understand how costs and resource use are affected by different degrees of ambulation. Reporting data in terms of achieved motor function could also mitigate the challenges of comparing global data studies of small populations. Global, regional, and/or local data collection platforms and disease registry networks could play an important role in helping to address current data gaps.

Systematic Literature Review to Identify Utility Values in Patients with Spinal Muscular Atrophy (SMA) and Their Caregivers

BACKGROUND

Spinal muscular atrophy (SMA) is a progressive neuromuscular disorder that has a substantial impact on health-related quality of life for patients with SMA and their caregivers. Utility values ('utilities') are used in health economic analyses to incorporate individual or societal perspectives regarding the desirability of health outcomes such as a certain health state or change in health states over time.

OBJECTIVES

The primary objective of this systematic literature review (SLR) was to identify published utilities associated with patients with SMA and their caregivers and to determine the extent to which Health Technology Assessment (HTA) requirements of methods used to generate utilities are met. A secondary objective was to broaden the scope to identify utilities associated with other (non-SMA) neuromuscular disorders.

METHODS

A comprehensive search to capture published utilities associated with patients with SMA and their caregivers was performed in 2019 and updated in 2021 using several electronic databases in addition to supplementary sources. As we anticipated that few published utilities associated with SMA would be identified, the search also captured utilities for other (non-SMA) neuromuscular disorders that may serve as useful surrogate values for studies of SMA and other rare diseases. Electronic searches were performed in Embase, MEDLINE, Evidence-Based Medicine Reviews, and EconLit via the Ovid platform and were supplemented by searches of the grey literature (reference lists, conference proceedings, global HTA body websites, and other relevant sources). Study eligibility criteria were based on the population, interventions, comparators, and outcomes (PICO) framework. The quality of the full-text publications was assessed using a checklist based on UK National Institute for Health and Care Excellence technical support documents.

RESULTS

In total, 14 publications that reported SMA-related patient or caregiver utilities or disutilities met the eligibility criteria to be included in the SLR; the included studies demonstrate the substantial health-related quality-of-life burden of SMA on both patients with SMA and their caregivers. A variety of preference-based measures were used to derive utilities for patients with SMA and their caregivers. Different methods for collecting utility data included patient and proxy assessment of health states using questionnaires, vignette methodologies, structured forms of expert elicitation, and mapped data from results of clinical trials. A range of utilities was reported from both patient- and proxy-reported data, which reflects the degree of disability associated with early- and later-onset SMA. Methods for deriving utilities were assessed with respect to three reference cases from HTA bodies in the UK, the USA, and Canada. None of the 14 publications met the requirements of all three HTA bodies because of differing tariff requirements between countries; one study met the requirements of HTA bodies in Canada and the UK. Also, six studies did not report the method of valuation, which precluded analysis with respect to the HTA reference cases.

CONCLUSIONS

This SLR provides a comprehensive repository of the currently available utilities relevant to patients with SMA and their caregivers. This SLR provides recommendations for establishing consensus on the approach to generating utility values for the SMA patient population and their caregivers for health economic decisions.

Eliciting health state utilities for Aromatic L-amino Acid Decarboxylase (AADC) deficiency: a UK vignette study

Purpose

The aim of this study was to generate health state utilities for aromatic L-amino acid decarboxylase (AADC) deficiency, a rare genetic, lifelong neurogenerative condition predominantly manifesting in young infants.

Methods

Participants were presented with health state vignettes. These had been previously developed based on published literature, clinician input, interviews with parents of AADC deficiency patients and expert opinion. A total of 5 health state vignettes were presented: bedridden, head control, sitting unsupported, standing with assistance and walking with assistance. Health state utilities (HSU) were elicited using time-trade off (TTO; 10-year time horizon) and the standard gamble (SG). The vignettes were completed online by panel participants drawn from a representative sample of the United Kingdom residential population.

Results

A total of 1598 participants completed the vignettes. Around 21% had incongruent responses (higher utilities for the bedridden compared to walking health states). Incongruent responses were associated with shorter task completion times, gender and parental status. These responses were removed from the analysis. Health state utilities (HSU) increased correspondingly as health states improved for both the TTO and SG. The mean HSU (standard deviation) for the TTO task were: bedridden state 0.49 (0.34); head control 0.54 (0.33), sitting unsupported 0.63 (0.31); standing with assistance 0.68 (0.31); and walking with assistance 0.73 (0.31). For the SG, mean health state utilities were: 0.56 (0.28), 0.57 (0.27), 0.67 (0.24), 0.70 (0.24), and 0.75 (0.25), respectively.

Conclusion

Health state utilities were derived for AADC deficiency through a vignette study. These will be used for a cost-effectiveness model of an AADC deficiency treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-021-00403-0.

Newborn screening for spinal muscular atrophy with disease-modifying therapies: a cost-effectiveness analysis

OBJECTIVE

To assess cost-effectiveness of newborn screening (NBS) for spinal muscular atrophy (SMA) and early treatment with nusinersen or onasemnogene abeparvovec (gene therapy), compared with nusinersen without SMA screening.

METHODS

Informed by an Australian state-wide SMA NBS programme, a decision analytical model nested with Markov models was constructed to evaluate costs and quality-adjusted life-years (QALYs) from a societal perspective with sensitivity analyses.

RESULTS

By treating one presymptomatic SMA infant with nusinersen or gene therapy, an additional 9.93 QALYs were gained over 60 years compared with late treatment in clinically diagnosed SMA. The societal cost was $9.8 million for early nusinersen treatment, $4.4 million for early gene therapy and $4.8 million for late nusinersen treatment. Compared with late nusinersen treatment, early gene therapy would be dominant, gaining 9.93 QALYs while saving $360 000; whereas early nusinersen treatment would result in a discounted incremental cost-effectiveness ratio (ICER) of $507 000/QALY.At a population level, compared with no screening and late treatment with nusinersen, NBS and early gene therapy resulted in 0.00085 QALY gained over 60 years and saving $24 per infant screened (85 QALYs gained and $2.4 million saving per 100 000 infants screened). More than three quarters of simulated ICERs by probability sensitivity analyses showed NBS and gene therapy would be dominant or less than $50 000/QALY, compared with no screening and late nusinersen treatment.

CONCLUSION

NBS coupled with gene therapy improves the quality and length of life for infants with SMA and would be considered value-for-money from an Australian clinical and policy context.

Epidemiology, healthcare resource utilization and healthcare costs for spinal muscular atrophy in Alberta, Canada

AIMS

Spinal muscular atrophy (SMA) is a progressive neuromuscular disease associated with the degeneration of motor neurons in the brainstem and spinal cord. Studies examining the epidemiology and economic impact of SMA are limited in Canada. This study aimed to estimate the epidemiology as well as healthcare resource utilization (HRU) and healthcare costs for children with SMA in Alberta, Canada.

MATERIALS AND METHODS

We conducted a retrospective study using anonymized data from administrative healthcare databases provided by Alberta Health. Data from 1 April 2010 to 31 March 2018, were extracted for patients <18 years of age identified with SMA. Five-year incidence and prevalence were calculated for cases identified between 1 April 2012 and 31 March 2017. HRU and healthcare costs were assessed one year after SMA diagnosis, including hospitalizations, physician visits, ambulatory care visits and long-term care admissions.

RESULTS

The five-year incidence and prevalence of pediatric onset SMA were 1.03 per 100,000 person-years and 9.97 per 100,000 persons, respectively. General practitioner, specialist, and ambulatory care visits were common among children with SMA in the first-year post-diagnosis. The mean (SD) total annual direct cost per patient in the first-year post-diagnosis was $29,774 ($38,407); hospitalizations accounted for 41.7% of these costs ($12,412 [$21,170]), followed by practitioner visits at 32.3% ($9,615 [$13,054]), and ambulatory care visits at 26.0% ($7,746 [$9,988]).

CONCLUSIONS

Children with SMA experience substantial HRU, particularly for hospitalizations and practitioner visits, following diagnosis. Given the high costs of SMA, timely access to effective treatment strategies, such as the novel survival motor neuron (SMN)-restoring treatments recently approved for use, are needed to improve health outcomes and HRU.

Real-world respiratory and bulbar comorbidities of SMA type 1 children treated with nusinersen: 2-Year single centre Australian experience

AIM

To describe the respiratory and nutritional supportive care and hospitalisations required in the real-world scenario in children with SMA type 1 treated with nusinersen.

METHODS

Single-centre observational cohort study of children with SMA1 commencing nusinersen from November 2016 to September 2018. Motor, respiratory and nutritional clinical characteristics and management are described from initiation of nusinersen for a minimum of two years.

RESULTS

Nine children (5 females, 4 males), median age 10.7 months (range 2.7-181.2) commenced treatment with nusinersen and outcomes were assessed over a total of 270.5 patient months and 209 hospital admissions. Supportive care in newly-diagnosed patients (n = 7) included gastrostomy insertion (n = 4) and commencement of noninvasive ventilation (n = 4) at an average of 8.3 and 4.5 months after diagnosis, respectively. The annualised hospitalisation rate was 9.3/patient/year, average length of stay (LOS) of 3.3 days (SD = 5.6). Children with two SMN2 copies required more gastrostomies (p < 0.05) and had more frequent admissions (p < 0.05). Number of total admissions halved from the first to the second year of treatment in all patients (p < 0.005).

INTERPRETATION

Children with treated SMA1 experienced considerable respiratory and bulbar comorbidities, necessitating substantial respiratory and nutritional supportive care. Proactive respiratory and nutritional surveillance and management is essential in SMA1 patients treated with nusinersen.

Costs of Illness of Spinal Muscular Atrophy: A Systematic Review

OBJECTIVES

The objective of our study was to conduct a systematic literature review of estimates of costs of illness of spinal muscular atrophy (SMA).

METHODS

We searched MEDLINE (through PubMed), CINAHL, Embase, Web of Science, National Health Service Economic Evaluation Database, and the National Health Service Health Technology Assessment Database for studies published from inception up until 31 August, 2020, reporting direct medical, direct non-medical, and/or indirect costs of any phenotype of SMA. Two reviewers independently screened records for eligibility, extracted the data, and assessed studies for risk of bias using the Newcastle-Ottawa Scale. Costs were adjusted and converted to 2018 US dollars.

RESULTS

The search identified 14 studies from eight countries (Australia, France, Germany, Italy, Spain, Sweden, the UK, and the USA). The mean per-patient annual direct medical cost of illness was estimated at between $3320 (SMA type III, Italy) and $324,410 (SMA type I, USA), mean per-patient annual direct non-medical cost between $25,880 (SMA types I-III, Spain) and $136,800 (SMA type I, Sweden), and mean per-patient annual indirect cost between $9440 (SMA type I, Germany) and $74,910 (SMA type II, Australia). Most studies exhibited a risk of bias.

CONCLUSIONS

The current body of evidence of costs of illness of SMA is relatively scarce and characterized by considerable variability across geographical settings and disease phenotypes. Our review provides data pertaining to the economic impact of SMA, which is of particular relevance in light of emerging treatments and ongoing research in this field, and underscores the substantial unmet medical need in this patient population.

Systematic literature review of the economic burden of spinal muscular atrophy and economic evaluations of treatments

Background

Spinal muscular atrophy (SMA) is a rare and devastating condition for which new disease-modifying treatments have recently been approved. Given the increasing importance of economic considerations in healthcare decision-making, this review summarizes the studies assessing the cost of SMA and economic evaluations of treatments. A systematic review of the literature in PubMed and Scopus up to 15 September 2020 was conducted according to PRISMA guidelines.

Results

Nine studies reporting the annual cost of care of patients with SMA and six evaluations of the cost-effectiveness of SMA treatments were identified. The average annual cost of SMA1, the most frequent and severe form in which symptoms appear before the age of 6 months were similar according to the different studies, ranged from $75,047 to $196,429 per year. The yearly costs for the forms of the later-onset form, called SMA2, SMA3, and SMA4, which were usually pooled in estimates of healthcare costs, were more variable, ranging from $27,157 to $82,474. The evaluations of cost-effectiveness of treatment compared nusinersen treatment against standard of care (n = 3), two treatments (nusinersen and onasemnogene abeparvovec) against each other and no drug treatment (n = 1), nusinersen versus onasemnogene abeparvovec (n = 1), and standard of care versus nusinersen with and without newborn screening (n = 1). The incremental cost-effectiveness ratio (ICER) of nusinersen compared to standard of care in SMA1 ranged from $210,095 to $1,150,455 per quality-adjusted life years (QALY) gained and that for onasemnogene abeparvovec ranged from $32,464 to $251,403. For pre-symptomatic patients, the ICER value ranged from $206,409 to $735,519. The ICERs for later-onset forms of SMA (2, 3 and 4) were more diverse ranging from $275,943 to $8,438,049.

Conclusion

This review confirms the substantial cost burden of standard of care for SMA patients and the high cost-effectiveness ratios of the approved drugs at the current price when delivered in post-symptomatic patients. Since few studies have been conducted so far, there is a need for further prospective and independent economic studies in pre- and post-symptomatic patients.